bio 102 lab manual questions
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Exercise 1: The Microscope
Letter “e” Observation
The letter “e” should appear upside down and backwards. Under high magnification, you will see only part of the“e” and may see dots of ink rather than a continuous flow of ink.
Crossed Threads Observation-Describe your observations
Under low (4x) power: Two of the threads are almost in focus, but it is impossible to get both completely focused at the same time. By focusing first on 1 thread then on the second, it is possible to judge which thread is on top. This is an example of being able to visualize in 3-D.
Under 10x power, you still have some depth perception and can see the threads crossing over each other although you are seeing a smaller area of threads and may need to move the stage to see more of the threads.
Under 40x power, you lose all depth perception and are unable to determine which thread is on top and which is on the bottom. You are seeing smaller areas of the thread because of the higher magnification.
Under which power was it easiest to get the overlapping threads mostly in focus? Low power
1. Summarize the function of the following parts of the microscope:
a. Nosepiece: Holds objective leases
b. Iris diaphragm: Constricts or dilates to allow varying amounts of light to pass through the slide
c. Coarse adjustment: Focusing knob, usually the large one, that allows you to focus your slide more quickly. Use with low power only otherwise you may damage the slide or the lens.
2. What does the term “parfocal” mean?
The microscope is designed so that when you switch to the higher objective lens, the microscope will automatically be partially focused. You will only need minor adjustments of the fine adjustment knob.
3. Why is it important to start with the lowest power objective lens?
This is the magnification under which it is easiest to find your focus quickly using the coarse adjustment knob. At low magnification, your depth of field is best so the precision required for focusing is less.
4. What is the total magnification of your specimen if you are using a 10x ocular and a 45x high-dry objective lens?
10 x 45x = 450x
5. Your lab partner accidently bumps your microscope and you have lost your focus. What should you do in order to find your specimen again?
You should begin again with the low power (4x) objective lens.
6. Why should you center the part of your slide you need to view when switching to a higher power objective lens?
Higher magnification focuses on a smaller area. If the specimen is not centered, you won’t see it in the smaller area of focus available with the higher magnification.
7. Refer back to the crossed threads slide. What have you learned about depth perception and the microscope?
Low magnification gives a greater sense of dimension. You needed to move the slide around under higher magnification in order to see all the threads. It was very difficult to judge which thread was on top in the higher magnifications.
Exercise 2: Cell Anatomy
1. Supply the names of the cell organelles that fit the following descriptions:
a. Control box of the cell; contains DNA and chromosomes: Nucleusb. Cell suicide sacs with enzymes: lysosomesc. Workshop of the cell; they build proteins: ribosomesd. Two short, rodlike structures that compose the centrosome:
centriolese. Outer cell boundary with pores: plasma cell membranef. Tubular network of membranes throughout the cytoplasm:
endoplasmic reticulumg. Potato or peanut shaped powerhouses of the cell: mitochondriah. Stack of flattened membranes nicknamed the cell packaging plant:
2. Name five cell structures that can be observed with your high-dry objective lens:
1. plasma membrane2. nucleus3. nucleolus4. cilia5. flagellum (sperm6. Cytoplasm with unspecified organelle7. chromatin
3. Name five cell organelles that would be visible only with an electron microscope:
1. Golgi apparatus2. mitochondria3. ribosomes4. lysosomes5. centrioles 6. endoplasmic reticulum
4. List 3 statements in the cell theory:
1. The cell is the smallest living system capable of maintaining itself.2. All cells come from pre-existing cells.3. All organisms are composed of cells.
5. What are the functions of cilia and flagella in the human body?Both work to produce motion – either of materials, as in ciliated epithelium, or of the cell as in the sperm’s flagellum.
6. List the 4 cell types you observed and give a brief description of their structure as it relates to their functions:
1. Sperm: small & flagellated for movement2. Ciliated epithelium: larger cell with many cilia for movement of dirt
particles out of the respiratory system.3. Striated muscle: very long, thick cell that can contract & cause movement.4. Motor neuron: very long, slender cell that can carry information over great
7. Name the 3 basic parts of a sperm cell.1. head (consisting of an acrosome & nucleus)2. neck3. flagellum (or tail)
8. How are striated muscle cells different in appearance from typical animal cells?
Striated muscle cells are many times longer than typical animal cells & they are multinucleated.
Exercise 3: Body Terminology, Planes and CavitiesPage 19
1. Supply the proper term to match each definition
a. Lying horizontal on your belly with your dorsal side up proneb. Below or beneath inferiorc. Belly or undersurface ventrald. Having 2 sides alike bilateral symmetrye. Standing erect, face view, with at least one palm forward
anatomical positionf. The front end or an animal anteriorg. The head end of an animal cranialh. Leading to the outside externali. Near or next to proximalj. The rear or tail end of an animal caudal
2. Name these body planes:a. “Cross cut” through a body part transverseb. Longitudinal plane dividing body into anterior and posterior halves
frontalc. Longitudinal plane dividing body into right and left halves sagittal
3. Interpret this lab description: “Make a ventral, superficial, median incision from anterior to posterior through the skin of your fetal pig.”
On the belly side (ventral) make a shallow (superficial) incision cutting the skin along the midline (median) from the front end near the neck (anterior or cephalic end) to the bottom end below the umbilical cord (caudal or tail end). *Note: This description would be slightly different for humans since anterior/posterior means front to back instead of head to tail as it does in the pig.
4. List 5 major organs found within the abdominal cavity:1. Stomach 2. Small intestine3. Large intestine (except the rectum)4. Pancreas5. Spleen6. Liver7. gallbladder8. any abdominal blood vessels
9. kidneys (technically found retroperitoneally)
5. List 3 organs found in the pelvic cavity.1. Urinary bladder2. Urethra3. Rectum4. Uterus
6. Name 5 organs within the thoracic cavity.1. Lungs2. Heart3. Trachea4. Esophagus5. Blood vessels
7. Name the major organ within the:a. Cranial cavity brainb. Spinal cavity spinal cord
8. Where is the gallbladder located in the pig and in humans?a & b. The gallbladder fits into a hollow in the liver which is in the abdominal
cavity of both pigs & humans.
9. Why is it important to know about the various body terms, planes, and cavities, especially at the beginning of your biology course?
You will need to use anatomical terminology in any biology & anatomy courses you take. This terminology is also extensively used in all health and medical professions.
10. Describe a median sagitall incision through an organ:It is a longitudinal cut along the midline of the organ which separates the organ into equal left and right halves.
11. List 4 characteristics unique to mammals:1. warm blooded2. mammary glands3. 4 chambered heart4. body hair
12. Give another name for the mediastinal cavity.Interpleural cavity
13. Name 3 organs within the mediastinal cavity.1. heart2. trachea3. esophagus
Exercise 4: The Tissues
Page 22Name several organs. What are their functions? Discuss with the class what tissues these organs might be composed of. Place your answers below.
Organs Function Tissues1. Heart pump blood cardiac muscle and fibrous
2. Lungs exchange gases simple squamous epithelium and elastic connective tissue
3. Trachea carries air hyaline cartilage and ciliated columnar epithelium
4. Small Intestine digests/absorbs 1. smooth muscle and simple columnar epithelium
5. Pancreas produces energy 2. cuboidal epithelial tissue and loose connective tissue
6. Large intestine absorbs water 3. smooth muscle and columnar epithelial tissue
7. Liver process nutrients and wastes
4. smooth muscle and cuboidal epithelial tissue
8. Stomach Digestion and absorption 5. smooth muscle and simple columnar tissue
Name several organ systems. What organs are part of these systems, and what is the major function of each system?
System Organs Function1. Circulatory Heart, blood vessels Transports chemicals to all
body cells2. Urinary Kidneys, bladder Removes metabolic waste,
regulates fluids and solutes3. Nervous Brain, spinal cord, nerves Controls sensation,
communication, respiration4. Digestive Stomach, small intestine,
large intestineDigests and absorbs nutrients
5. Respiratory Trachea, lungs Exchanges gases
How is simple squamous epithelium adapted to diffusion, filtration and osmosis?
It is a single layer of flat cells so it provides the thinnest possible barrier across which gases, nutrients wastes can easily travel.
How is columnar epithelium adapted to secretion?
1. The volume of cell is large relative to its surface area.
What is the role of cilia in the respiratory system?2. It removes small, unfiltered dust particles from the respiratory tract.
Epithelial Tissue Sketch Function LocationSquamous Diffusion or filtration Lungs, kidneys,
capillariesCuboidal Secretion &
absorptionGlands(salivary), kidney tubules
Columnar Secretion & absorption
Stomach, small intestine
1. What is the arrangement of cells in Hyaline Cartilage?
Cells are spaced apart in small cavities called lacunas.
2. What is the nature of the matrix in this tissue?It is composed of tightly packed collagen fibers that are smooth and solid, but flexible.
1. Describe the arrangement of cells and fibers in areolar tissue.
Fibers are randomly arranged and cells are widely scattered.
2. Do all cells and fibers in this tissue look the same?
Fibers are different-some are thin. reticular fibers & some are thick collagen fibers . Others are wavy elastic fibers.
3. What type of matrix does this tissue form?The matrix is thinner & more fluid than in other tissues. The cells are indistinct & appear as dark dots of varying size.
1. Does this tissue have a matrix? No.
2. This tissue provides a function like one of the other tissues. What function and which tissue?
Adipose tissue provides loose padding similar to areolar connective tissue. The padding & insulation provided by fat in adipose tissue is better than in areolar connective tissue
3. Where is fat stored in this tissue?
The fat is stored in large fat vacuoles within each cell.
Dense White Fibrous Connective Tissue
1. What is the arrangement of fibers in this tissue?
The fibers are parallel to each other.
2. Can you see this tissue’s matrix?
You can see densely packed collagen fibers & an occasional fibroblast.
Page 28 Chart 4.2
Tissue Sketch Function LocationEpithelial Forms linings Inside or outside lining of
all organsHyaline cartilage Protection, flexible
connectionRib cartilage; cartilage at ends of long bones which form a moveable joint
Areolar Loose packaging material
Under skin, around organs
Adipose Insulates, cushions, stores energy
Dense white fibrous Strong connection Tendons
EXERCISE 5- THE INTEGUMENTARY SYSTEM
1. Observe the model of skin and identify all of the structures mentioned in the discussion.
arrector pili musclebasement membraneepidermisdermisfree nerve endinghair folliclehair roothair shaftMeissner's corpusclePacinian corpusclesebaceous (oil) glandstratum corneumstratum lucidumstratum granulosumstratum spinosumstratum basalesudoriferous (sweat) gland
2. Observe the slide of the skin. Identify the structures described in the discussion. Do they differ from the model, photograph and drawing?A slide is typically a random slice through a small piece of skin. It is two-dimensional and shows a view through a structure, rather than from the side of something. It is unlikely to have all of the structures found on the model.
4. Based on the slide, indicate how it differs from the model and Figure 5.1.Answers will vary based upon the specific model you are looking at. However, the model and the slide are different because the model is in three dimensions, and most of the structures in it will appear whole. In the slide, the structures are sectioned.
5. Why do the structures look different from the model?Slides are 2-dimensional, and models are 3-dimensional. The explanations below talk about some specific differences:
a. Consider the sweat gland. As you can see on p. 30, the sweat gland appears as a coiled duct. However, under the microscope it appears as several clusters of cuboidal cells. This is because the slide provides a cross-section, and the coiled duct is cut through in many places. You would see the same thing if you cut across a knot.
b. The direction of the cut (as opposed to the type of cut) may also make a slide look very different from a model, and a hair follicle is a good example of this. Imagine making a vertical (longitudinal) cut through a banana. The section would look like a long white structure surrounded by a thin strip of yellowish peal on the sides. A hair follicle would look like this if cut longitudinally. The hair follicle's cuboidal cells might be found along the sides of a long yellow or brown hair. Now imagine making a transverse (crosswise) cut of the banana. You would see pieces that look circular or oval with a thin strip of yellowish peel all the way around. A hair follicle may look like a circle or an oval of cuboidal cells with a round piece of yellow or brown hair inside if cut through in cross section.
c. Some structures are just too small or indistinct to be able to see them on a slide. While you should be able to see all of the structures identified in this chapter on the model, with the microscopes available in lab, you would only be able to recognize the following on the microscope slide: Hair follicles and sebaceous glands on a scalp slide; the five layers of the epidermis on a Meissner's corpuscle slide; Pacinian corpuscle on a Pacinian corpuscle slide; and sweat glands may be visible as several clumps of small cuboidal cells on any of the slides mentioned. It takes a lot of experience to be able to identify blood vessels, Meissner's corpuscles, and other nerve endings on a slide.
Exercise 6: The Skeletal System
1. Outline the 2 major divisions of the human skeleton.Axial skull, vertebral column, rib cage Appendicular shoulder girdle, arms; pelvic girdle, hips, legs
2. Define the following:a. Diaphysis hollow shaft of long boneb. Epiphysis ends of long bonec. Medullary cavityhollow-area of diaphysis; contains yellow or red bone marrowd. Osteocyte bone cell in mature bone tissue; located in lacuna e. Lacuna small hollow cavity in which osteocytes are found
3. Give at least 2 major differences between the human male and female pelves.
Female: wider; coccyx is straighter; Male: narrower; coccyx is curved inward.
4. What are the 2 major types of bone tissues within a whole bone? What are their functions?
Compact bone is stronger and more dense. It provides support & protection.
Spongy bone is lighter with interwoven threads of bone tissue. It provides the framework for blood forming tissue
5. In which joint type categories do each of the following belong?a. Most vertebrae: slightly moveableb. Sutures: immovablec. Shoulder—humerus: freely movable; synovial type ball & socket jointd. Sacroilliac joint: slightly moveable in late pregnancye. Knee and elbow: moveable; hinge joint; synovial
6. What is a Haversian system?It is a nutrient--waste exchange system in compact bone consisting of rings of osteocytes in lacunas which are joined by canaliculi to Haversian or Central canals which contain the blood vessels.
7. What is unusual about compact bone and cartilage tissue as compared to most body tissues?
They are solid tissues and contain a large proportion of non-living martrix compared to other living cells.
8. Write the anatomical name for the following bones:a. Second cervical vertebrae: axisb. Last 2 pairs of ribs: floatingc. Vestigial tailbone: coccyxd. Shoulder blade: scapulae. Upper jawbone: maxilla
9. Name the 3 ear ossicles (bones).hammer – malleusAnvil – incusStirrup – stapes
10. List at least 4 major functions of the human skeleton:protection of internal organs support mineral storage(calcium) blood cell formationprovides levers for locomotion
Exercise 7: The Muscular SystemPage 50
What are the myofilaments and what is their job in a muscle cell?
The myofilaments are actin & myosin. Myosin uses energy to pull actin protein fibers to the center of the sarcomere in order to shorten & contract the muscle cell.
Match the listed movement with the term that best describes its action.
____1___ A. Extension ___2____ C. Flexion
____4__ B. Rotation ___3____ D. Abduction
1. Starting with your chin on your chest, raise your head to look straight ahead.
2. Cross your arms in front of your chest.
3. Sitting with arms at your side and shoulders facing the table, reach for your textbook on the table.
4. Placing your arm out straight, alternate the “thumbs up, thumbs down” position.
1. Intramuscular injections are typically given in the shoulder and buttocks areas. Which muscles are injected? Deltoid and Gluteus maximus
2. Which muscle is the prime mover for eack of the following movements? Winking: Orbicularis oculiShaking your head “no”: Sternocleidomastoid (SCM)Hugging: Pectoralis majorJumping: Quadriceps femoris and/or gastrocnemius
4. Explain your results.When you are working hard, the muscle depletes its oxygen supply. The blood flow to the muscle increases to replace the lost oxygen. Stressed muscle may force its cells to switch to anaerobic respiration which causes lactic acid formation. Lactic acid dilates blood vessels entering the muscle causing the engorgement of muscle with blood.
Experiment II3. Which average was higher (the first or second)? Why?
The second average should be higher. This is called the “warm up” effect. The enzymes involved in muscle contraction work more effectively at elevated temperatures (sarcoplasmic reticulum calcium levels also tend to be higher)
Part B5. Which average was the lowest? Third
Why? It is demonstrating fatigue. Depleted ATP energy reserves lessen the strength of the contractions regardless of how intensely the nervous system stimulates the muscle to contract.
Muscle Cell Type
Location Voluntary/ Involuntary
Fast or Slow
Skeletal Long, threadlike, multinucleated
Quadriceps Voluntary fast
Smooth Short, unstriated spindle shaped
Cardiac Striated, branched, interconnected
Heart Involuntary Moderately fast, very efficient
2. Name the smallest contractile unit of striated muscle. The sarcomere.
3. Make a sketch of a sarcomere and label at least 5 items.Possible items to label:
4. Briefly explain what happens when a muscle contracts.Myosin uses energy stored in ATP to pull actin fibers closer together. This shortens the length of the sarcomere & in turn shortens (contracts) the whole muscle cell.
5. Define tonus.A mild state of contraction due to alternate contraction of different motor units. Tonus is especially important in maintaining posture.
7. Which type of muscle does not consist of fiberlike cells? Smooth
8. Fill in the term that best fits the description given: a. Moves a joint toward the midline of the body: Adduction
b. Raises a body part: Levatorc. Protein that composes the thick filament: Myosind. Any muscle that bends or decreases the angle of a joint: Flexione. Tension applied without shortening: Isometricf. Muscular stiffness due to death: Rigor mortis g. Mild state of contraction for most muscles: Tonus
9. Name the muscles described below:a. Shoulder muscle that abducts the arm: deltoid b. Large diamond shaped muscle that extends the head: trapeziusc. Two muscles involved in chewing: masseter & temporalisd. Posterior humerus muscle that extends the forearm: tricepse. Large middle back muscle that adducts and extends the arm: latissimus
dorsif. Calf muscle that extends (points) the foot: gastrocnemius
10. Name the 2 muscle groups that move the lower leg and state their main actions: hamstrings flex the lower leg;quadriceps femoris extends the lower leg
Exercise 8: NERVOUS SYSTEM
How might this affect the neuron?
The neuron can’t undergo mitosis. This is part of reason destroyed neurons can’t be replaced.
2. Look at the slide of neurons labeled “ox smear.”
a) Which structures are easily identified? The cell body and the nucleus.
b) Which structures cannot be seen on the slide?
The internal organelles, the Schwann cells and the myelin. The axons and the dendrites are visible but can’t be differentiated from each other.
c) Why can’t you see all of the named structures?
The internal organelles are too small to be seen with a light microscope. (These require an electron microscope.)
3. Look at the demonstration slide of a medullated (myelinated) neuron and explain what you see.
The slide is rarely clear and distinct. You should be able to see axons surrounded by myelin and Schwann cells. (It should look like a beaded necklace)
Page 64Where else is fluid used in a similar manner? (Hint: think pregnancy). Amniotic fluid
Page 66What is the effect of severing the spinal cord?It disrupts communication between the brain and all spinal nerves below the damaged area. The body parts affected display paralysis and a total absence of sensation.
What is the effect of severing the ventral root? Movement and perhaps glandular activity are disrupted. Sensation is still intact.
What is the effect of severing both roots? The same as severing a spinal nerve.
Page 67The ventral root has motor function only. It is composed of axons only. Where
are the cell bodies of these axons? They are inside the gray matter of the spinal cord.
Page 703. Since the subject is a mature adult, what would you expect to occur with an
infant? A positive Babinski demonstrated by a backward fanning of the toes.
What does this tell you about the direction of myelination?
Myelination spreads from the CNS to the periphery of the body.
Can you force an infant to walk at a younger age?
No, they don’t have the rapid nerve impulse transmission and gross motor coordination provided by myelination of motor neurons serving these muscles.
Do all infants develop at the same rate? No
What evidence would you offer for your answer? A range is given for walking and pincer grip. Most babies walk between 10 – 14
Alcoholics with polyneuritis and people with multiple sclerosis exhibit a positive Babinski reflex. What type of damage has occurred to the spinal cord?
There has been damage to the myelin sheath of the nerves.
1. Name and describe the three structural types of neurons. Indicate the major type of function of each type.
Multipolar: an axon with many dendrites attached to the cell body. It’s usually functions as a motor neuron or an interneuron.
Bipolar: has 2 processes which are attached to either side of the cell body. They are sensory and are very rare.
Unipolar: Has one projection which attaches the cell body to the axon. They are usually sensory.
2. Identify the organs forming the central nervous system. The brain and the spinal cord
3. Identify the structures forming the peripheral nervous system.
Ganglia, spinal nerves, cranial nerves. Some texts may also include the receptors as part of the peripheral nervous system.
5. What is a node of Ranvier? It is a small gap of exposed axon between Schwann cells on a myelinated axon.
6. Name the structure essential for axon regeneration. The neurilemma (outermost cell membrane) of the Schwann cell. It produces growth factors and serves as a tunnel or guide for regrowth of a nerve. The neuron cell body must also be alive.
7. Identify the meninges. What are their collective functions?
They are a connective tissue wrapping which encloses the brain & spinal cord. The duramater is the tough outermost layer. The arachnoid mater is the loose middle layer which forms space for the cerebrospinal fluid. The pia mater is the innermost, delicate layer with direct contact with the CNS. These layers protect CNS structures.
8. What is cerebrospinal fluid (CSF)? How is it formed and where is it found? What are its functions? It is a thin liquid formed from the reatively high pressure in the blood vessels called the chorioid plexus. It provides shock absorption and nutrition to all areas which are covered by the liquid.
9. Which spinal root has the cell bodies of the sensory neurons?
The dorsal root.
10. A spinal tap is performed at the level of which vertebrae? Why? (Use your text to find the answer.)
The lower lumbar region since the spinal cord ends at the level of L1 and only the cauda equina is present distal to this level. Since the cauda equina is a collection of nerves rather than a thick, solid cord of tissue, it is less likely that a needle would puncture or damage nerve tissue.
11. Name the three connective tissue wrappings of the nerve and indicate what they wrap.
The endoneurium: wraps directly around the neuron. The perineurium wraps around a bundle of neurons called a fascicle. The epineurium wraps the entire nerve.
12. Name the spinal plexuses and the major nerves emerging from each plexus.Spinal Plexus Nerve
cervical: phrenic nervebrachial radial & ulnar nerveslumbar: femoralsacral: sciatic nerve
13. List the structural components of the reflex arc.
The receptor is the sensory neuron which receives the stimulation. The impulse travels to the spinal cord which is the integration center. In a monosynaptic reflex, the impulse is sent directly to a motor neuron and from there to the effector –the muscle or gland which produces a response. In a polysnaptic reflex, there is an interneuron or association neuron in the spinal cord which routes the impulse to both the brain and the motor neuron to the effector.
EXERCISE 9-NERVOUS SYSTEM II
Was the subject responsive to all of the above tests? If not, indicate which he or she couldn’t carry out and what the implication might be.
A healthy person with no disabilities should be able to perform all of the tests in table 9.1. Inability could be due to either dmage to the nerve or the body part served by the nerve.
Which nerve descends into the abdominopelvic and thoracic cavities?The vagus nerve.
Page 82--Study Questions:
1. List three functions of the cerebrum.Initiation of motor function; receipt of sensory information;processing of information into a response (intelligence)
2. What is the function of the cerebellum? It coordinates motor control.
3. List the functions of the medulla.
It regulates basic life support functions including respiration, cardiac and vasomotor control.
4. List the functions of the hypothalamus. It regulates body temperature and management of the endocrine system.
5. Identify the cranial nerves that are involved in eye movements.
oculomotor (IV); trochlear (IV); and abducens nerves (VI)
6. Identify the cranial nerve which is involved in equilibrium. The vestibulocochlear (also called the auditory) nerve (VIII)
7. This cranial nerve regulates head movement: spinal accessory (XI) nerve
8. Which division of the ANS would be involved in the beating of your heart when you are calm and relaxed?The Parasympathetic Nervous System
9. Identify some sympathetic responses to stress and indicate how they prepare you for coping with the stressful situation. An increased heart rate increases your blood pressure to ensure sufficient blood flow to the brain and muscles. It stimulates the sweat glands (to keep you cool during fight/flight); it dilates bronchial tubes to increase oxygen supply to the blood and it redirects the blood flow to skeletal muscles (rather than the digestive system)
10. Why is exercise beneficial to someone with asthma whose bronchi are constricted?
Sympathetic responses enhanced by exercise tend to constrict systemic blood vessels but dilate bronchial tubes. This reverses the effect of asthma’s constriction.
11. Why might stress raise blood pressure? It activates the sympathetic division which will constrict blood vessels and thus raise
12. Why shouldn’t an athlete eat a large meal prior to participating in an athletic activity?
After a large meal, the Parasympathericl Nervous System stimulates an increase in blood flow directly to the digestive organs which makes it difficult to increase blood pressure and blood flow to muscles. If muscles are deprived of blood flow, cramps or spasm may result. Once the sympathetic nervous system response is activated, it cuts off the blood supply to the digestive structures, thus causing these structures, which are full of food, to cramp which causes pain.
13. Is the stress response appropriate to the type of stressful situations one encounters in modern life? If so, why?
The stress response evolved to help us escape predators and deal with life and death situations. Most stressful situations don’t usually require an active physical response (vs. an emotional response) so the increased blood pressure and other aspects of the stress response may be harmful over time. (Police and firemen, soldiers need an intense sympathetic response due to job requirements.)
EXERCISE 10-THE SENSES
Page 85Which tactile receptors did you learn about when you studied the skin? What were their functions?
Pacinian (pressure) & Meissner’s (light touch) corpuscles
1. Dip a moistened swab into sugar and touch the tip of your tongue with the swab. (Your tongue must be moist – not dry.) Do you taste the sweetness?
Sweet taste receptors generally are found near the tip of your tongue, but you may also find a slight sweet response on the sides of the tongue especially if sugar is placed anteriorly.
3. Repeat the above procedure for salt. Where do you sense the strongest salty taste?
Salt taste receptors are usually found on the sides of the tongue.
4. Use your textbook to look up the location of the various taste receptors of the tongue and list them below.
Bitter receptors are at the back of the tongue; sweet is at the front of the tongue; salty & sour are at sides of the tongue
5. Are taste chemoreceptors specific to categories of chemicals? Explain your answer and your results.
Yes taste chemoreceptors are specific. Since we can’t taste except as indicated above, the receptors must be specific.
6. Propose an explanation for the pattern of tactile receptor density you obtained for the human body.The higher density of tactile receptors would enhance the accuracy of two point discrimination . So, a higher density of receptors would be found in our fingertips and hands. This helps us manipulate materials and tools which require accurate sensory feedback.
3. Explain how the subject’s receptors were working during this experiment?The receptors were detecting minute changes in stress placed on their joints.
Page 88What structures of the eye translate light energy into nervous impulses during the day?
Cones translate light energy into nervous impulses and provide color vision during the day.
At night? Rods are more sensitive at night but do not permit color vision.
What do you think causes color blindness? Loss or malfunction of one or more varieties of cones.
Page 904. What does the term “20/20 vision” really mean?
When standing about 20 feet away from the chart, the person is able to read the last line as accurately as a person with normal vision would be able to read it from 40 feet away.
Why is it more difficult to place the pencil in the tube with one eye closed?You are no longer using binocular vision. (The point of this experiment is that most people should have more success using both eyes since binocular vision enhances the brain’s ability to interpret depth (depth perception).
Observe the color blindness tests on display. Does seeing how these tests are designed to help you answer the earlier question on the cause of color blindness? If so, revise your explanation regarding the cause of color blindness.
Color blindness tests are usually designed such that it would be impossible to see the image provided without the ability to visually separate 2 or more colors. So, color blindness is simply the loss or malfunction of one or more varieties of cones.
Page 91Name, in order, the structures involved in the conduction of sound from the pinna to the brain.
pinna → auditory canal or meatus → tympanic membrane → malleus →incus → stapes → oval window → cochlea → organ of Corti → vestibularcochlear nerve → temporal lobe of the brain
What kind of receptors are used to produce your sense of hearing?hair cells (a kind of mechanoreceptor)
What “organ” in the inner ear translates vibrations into nervous impulses?The Organ of Corti
Page 92Why do you think we have three semicircular canals?
These correspond to the 3 planes of space. Regardless of which direction we move, there is always 1 canal partially oriented to the direction of movement.
2. Repeat placing the tuning fork several times in random order. Where was your partner least able to localize the position of the sound source? _____________________
Propose a reason for this.The only positions where lateralization would be consistently accurate should be laterally. Because they arrive a split second sooner, the brain interprets sound as being louder in the ear that is closer to the source of the sound. This may be why we turn our head to one side when having difficulty localizing a sound.
Bone ConductionYour hearing pathway is designed to magnify sound and bring the sound vibrations directly to the appropriate part of the cochlea. Directly vibrating the skull near the cochlea may be the only way to vibrate the cochlea if there is damage to the conduction pathway. So, when sound decreases in front of the pinna, you should not be able to hear the fork when placed on the mastoid process.
Work in pairs. Have your partner close his or her eyes and place a tuning fork near either ear. Strike a tuning fork of a different frequency near the same ear. Did your partner correctly identify the second tuning fork as making a sound with a higher or lower pitch? ___ Did both sounds stimulate the same hair cells in the cochlea? Explain.
Vibrations of fluid in the vestibular and tympanic canals occurs in the same frequency as the original sound waves. Fibers of the basilar membrane have different lengths at different regions of the cochlea; sound waves convert to vibrations of the basilar membrane in a location specific manner according to tone.
Considering that balancing requires a great deal of motor coordination (recall the role of the cerebellum), what does this experiment prove about the sense of balance?
It reminds you that along with the ears, visual input and the work of cerebellum in motor coordination are also important in helping the brain maintain balance. The cerebellum relies on at least 3 different forms of sensory feedback in order to coordinate movement (including movement important in balance): inner ear balance feedback; proprioceptor feedback and visual feedback. Loss of any one causes difficulty in balance.
Page 931. List four different kinds of receptors and state their basic function.
photoreceptors: retina – vision; chemoreceptors: taste buds; mechanoreceptors/tactile receptors: Meissner’s corpuscles, light touchpain receptors: pain sensation (thought to be a form of chemoreceptor related to tissue damage)
2. How is a receptor different from other neurons studied thus far?They are modified sensory neurons which can trigger an action potential in response to environmental stimuli instead of neurotransmitters. Most neurons can be stimulated only by neurotransmitters under normal circumstances in the body.
3. What structures must light pass through before reaching the retina?
cornea → aqueous humor → pupil → vitreous humor →retina
4. What do the terms “20/60 vision” and “20/15 vision” mean/When standing at 20 feet, the subject reads the last line as correctly as a person with 20/20 vision would be able to read from 60 feet away. 20/15 means that when standing at 20 feet away, the subject reads the last line as correctly as a person with 20/20 vision would be able to read from 15 feet away.
5. What is the transparent portion of the sclera called?The cornea
6. What are the two muscular modifications of the choroid and what are their jobs?They are: iris - modifies size of opening through which light enters pupil
ciliary body - modifies tension on (and therefore) shape of the lens
7. Name four items that protect the eye from damage.The bony socket of skull; tears which contain antibacterial agents; reflexes such as blinking adipose tissue cushion in bony socket.
8. Which light-bending structure can change shape?lens
What happens when this structure loses its elasticity with age?Focusing on either very distant or very near objects becomes increasingly difficult; typically, focusing on near objects becomes more difficult with age.
9. State the basic functions of the inner ear and list the structures involved in each function.The inner ear is important for both hearing and balance. The cochlea is specialized for hearing; the vestibule is specialized for static equilibrium;the semicircular canals are specialized for dynamic equilibrium.
Page 9410. Briefly explain the difference between static equilibrium and dynamic
equilibrium.Static: maintains balance while you are still. Dynamic: maintains balance while you are moving
11.What structures are common to the hearing and equilibrium functions of the inner ear?Hair cell receptors translate vibrations into nervous impulses for hearing and are also pulled by gravity in the vestibule or pushed by moving fluid in the semicircular canals and, thus function in balance.
EXERCISE 11-THE ENDOCRINE SYSTEM
Page 103: Study Questions1. What are the two chemical classes of hormones?
Steroid and amino acid/peptide
2. The hormones released by the posterior pituitary are actually made in the:hypothalamus
Page 1043. What are tropic hormones, and where are they made?
Tropic hormones are hormones that control other endocrine glands. They are made in the anterior pituitary gland
4. Fill in the name for the endocrine portion of each of the following endocrine glands.
Testis interstitutal cellsPancreas Islets of LangerhansOvary follicle & corpus luteum
5. Two endocrine glands discussed in this chapter have both a portion made of glandular (epithelial) tissue, and a portion made of modified nervous tissue. What are they?
The pituitary and adrenal glands
Which portions of each gland are made of epithelial tissue?The anterior pituitary and adrenal cortex
Nervous tissue?The posterior pituitary and the adrenal medulla
6. Match the endocrine gland with its hormone.Pancreas _C a. growth hormoneAnterior pituitary A b. epinephrineOvary D c. insulinAdrenal medulla B d. estrogen
7. Match the hormone with its function.Glucocorticoids d a. Stimulates liver cells to break down glycogen
and release glucoseGlucagon a b. Stimulates smooth muscle contraction in the
uterus during childbirth.ACTH c c. Stimulates the adrenal cortex to produce and
Oxytocin b d. Stimulate cells to produce glucose from other organic molecules.
8. In terms of both identification and function, what is the difference between an ovarian follicle and a corpus luteum?
Follicle produces estrogen & appears as a ball of cells containing the egg cell. Corpus luteum produces progesterone and estrogen and appears as an irregular yellowish mass of cells.
9. Predict what would happen to a person who was unable to produce ADH.The person would be unable to reabsorb water from the kidney tubules. Dehydration would be likely unless the person constantly drank an excessive amount of water.
10.Predict what would happen to a person who was unable to produce sufficient thyroid hormone.Their metabolism would lower decreasing their energy and appetite however the person would gain weight irregularly.
EXERCISE 12: THE BLOOD
Page 108- Observing Erythrocytes3. Describe the appearance of the blood elements you are examining.
Erythrocytes appear as biconcave disks; they are thinner & lighter in the center and thicker at edge. They have no nucleus.
Are the cells the same size or do their sizes differ?Leukocytes are larger than erythrocytes and have a nucleus. Monocytes are lighter in color than the other leukocytes.
Page 110 TABLE
Measurement Normal Value Clinical Significance Of Increased Value
Clinical Significance Of Decreased Value
Total Erythrocyte count(number per mm3)
4.5-5.5 million /mm3
Total leukocyte count(number per mm3)
5,000-10,000 /mm3 Possible infection Increased susceptibility to infection
Allergy or inflammationSpecific immune responseChronic infection
If any of these counts were low, this would indicate a possible bone marrow disorder
Page 112-Study Questions1. Look up and define:
a. Polycythemia high erythrocyte countb. Leukocytosis Abnormally high leukocyte levelsc. Leukopenia low leukocyte countd. Leukemia form of bone marrow cancer where a large number of
non-functional leukocytes are produced2. When en erythrocyte has a shape other than that of a biconcave disk, how
might its function be affected?
There is reduced gas exchange surface, less flexibility with a tendency to clog blood vessels.
Page 1133. Considering its function, why is the biconcave disk shape of the RBC superior
to a simple sphere?Because the disk has more surface area, it is more flexible and allows RBCs to stack when pushed through narrow vessels.
4. How might the lack of a nucleus be an advantage to the red blood corpuscle?The space a nucleus would take provides additional volume for hemoglobin to carry oxygen and makes it easier for the cell to take a biconcave shape.
How might it be a disadvantage?RBC are unable to reproduce or produce materials necessary for their own maintenance. This means that RBC have a limited life span.
5. What is the difference between a total leukocyte count and a differential count?Total count is non-specific with regard to types of leukocytes present and only indicates if levels are high or low. This information can tell us whether or not there is an infection or other disorder A differential gives percentages of each type of leukocyte but not the total leukocyte percentage in whole blood. This provides clues to the kind of infection or disorder that is likely to be causing illness.
6. Where are RBCs produced? They are produced in the red bone marrow.WBCs? Platelets? Both are also produced in the red bone marrow.
7. How is blood viscosity related to blood circulation?Higher viscosity leads to higher resistance. It is difficult to pump thicker blood and this will affect heart function and blood pressure.
8. What is the danger to an individual with a:low total white blood cell count? increased susceptibility to infectionhigh total white blood cell count? possible leukemia or infectionlow number of platelets? impaired blood clottinglow hemoglobin determination? reduced O2 (oxygen) carrying capacitylow red blood corpuscle count? reduced oxygen carrying capacityhigh red blood corpuscle count? This is also called polycythemia and it will lead to increased blood viscosity (thickness)/
9. Why is it dangerous to supply a blood type different than the recipient’s blood type in a transfusion?
The person’s immune system produces antibodies against foreign blood types. Antibodies may agglutinate the foreign blood cells leading to potential damage to cardiovascular system and the kidneys.
EXERCISE 13-THE HEART AND GENERAL CIRCULATION
Page 116How do veins and arteries differ in structure and function?
Arteries are thicker walled (especially the muscular layer) but have a smaller lumen than veins. Semilunar valves are present in veins to facilitate venous return to the heart. Veins have a bigger lumen than arteries.
How does the size and structure of a capillary relate to its function?The small diameter increases surface contact of blood with the body tissues. The single layer of squamous cells provides the thinnest possible barrier for diffusion.
Page 119Why is the heart called a double pump?
Because right and left sides each have separate pumping responsibilities (The left side pumps oxygenated blood to the aorta and thus to the entire body. The right side pumps deoxygenated blood to the lungs where the blood picks up oxygen and is returned to the left side of the heart.
What are the main functions of the valves of the heart?The valves will prevent any backward flow of blood.
Which blood vessels supply the heart muscle with oxygenated blood?The coronary arteries
Page 1203. Have your partner determine your heart rate and record it. Are the rates acquired using the stethoscope and counting the pulse approximately the same?
They should be same
Explain. The pulse corresponds to the beating of heart. You should get identical answers.
6. Compare the results obtained by your classmates. Do you discern any differences between the results of males and females?Males tend to have slower pulse rates than females. Hower, the level of conditioning is a stronger determining factor. Better conditioned people have lower pulse rates regardless of sex.
Page 123After exercise, what changes did you observe in systolic pressure? In diastolic pressure? Are these changes you expected? Explain
Both systolic and diastolic pressures increase during exercise and return to baseline within several minutes.
Diastolic pressure may go down in well conditioned people. The vasodilation of vessels (which tends to lower blood pressure between heart beats) is a normal response to elevated pressure. Additionally, lactic acid accumulates in muscles which dilates blood vessels feeding skeletal muscles. The resulting decrease in diastolic blood pressure is a homeostatic response to the increased blood pressure due to the increased muscle activity.
Define systolic blood pressure:Highest arterial pressure during ventricular systole
Define diastolic blood pressure:lowest arterial pressure during ventricular diastole
Define hypertension: Abnormally elevated blood pressure
Define hypotension: Abnormally low blood pressure
In your own words, describe the effects of hypertension and hypotension.Hypertension can damage structures in many body systems including the cardiovascular and urinary systems and increase the risk of having a stroke. Low blood pressure can cause dizziness and fainting which could lead to shock.
What would you expect to happen to blood pressure and pulse rate during sleep? Explain.Blood pressure should go down due to the lower metabolic demand by most organs. The lower metabolic demand promotes a slower movement of blood around the body. The pulse rate also decreases due to the lower metabolic demands.
EXERCISE 14—THE RESPIRATORY SYSTEMPage 131
4. Notice how your abdomen is pushed outward as the contracted diaphragm flattens. Describe the position of the contracted diaphragm.The diaphragm moves in an inferior direction, toward the abdominopelvic cavity, and flattens as it contracts.
Describe the position of the relaxed diaphragm.It is pushed superiorly, back into the thoracic cavity, and resumes its rounded or dome-shape.
How does the position of the diaphragm affect the size of the thoracic cavity?When the diaphragm is flat (contracted), the volume of the thoracic cavity increases (therefore it has a lower pressure). When the diaphragm is bell-shaped (rounded), the volume of the thoracic cavity decreases and it therefore has higher pressure.
Page 132What could you do to the lung-thorax model to cause the balloons to fill with air?
Pull down on the rubber sheet to increase the volume and lower the pressure inside the jar. Air moves into the balloons to try to equalize pressure.
7. If the integrity of the pleura is disturbed (such as by a puncture into the chest wall), what do you think would happen to the lung?The glass slides represent the pleural membranes. They demonstrate that moist membranes tend to stick together and this is partially why thoracic cavity expansion causes lung expansion. A puncture to this cavity would cause a collapsed lung because it would be impossible for any pressure or volume changes to occur therefore the lungs would be unable to expand.
CHART 14.2Bell Jar Human Body
straight glass tubing
glass wall of jar
Y-shaped glass tube
1. Exhale through your mouth onto a glass plate or mirror. Your results indicate that one component of exhaled air is water vapor .
3. What might you conclude causes the change in temperature?The heavily vascularized respiratory passages.
Page 135 ExperimentsThe breath holding experiments are supposed to illustrate the role of carbon dioxide and increased acidity on stimulating the respiratory rate. By decreasing the carbon dioxide levels (which is what happens when we hyperventilate) we decrease our rate of respiratory stimulation. By rebreathing in a bag, we increase our carbon dioxide levels and thus increase our respiratory stimulation.
Page 136Which activity decreases respiratory rate? Mental acidity decreases the respiratory rate.Which activity increases respiratory rate? Exercise
Can you usually speak aloud and inhale simultaneously? No
Can you swallow and breathe simultaneously? No or else the epiglottis would be open while food or liquids were moving into the pharynx causing airway blockage and choking.
Propose a reason why prolonged sedentary mental activity might produce a yawn. (Boredom is not a valid response.)
Since mental activity decreases the respiratory rate, prolonged mental activity allows CO2 levels to increase. This eventually triggers a deeper inhalation-exhalation cycle and develops into a yawn.
2. Hold your breath until urge to breathe becomes overwhelming. Do not inspire but take a small sip of water. What has happened to your urgent need to breathe?Swallowing seems to suppress your perceived need to inhale.
STUDY QUESTIONS:1. Name the anatomical structure located directly behind the trachea.
2. Name the membrane that covers the lungs. visceral pleura
3. What is the name for the structure that blocks entry into the larynx during swallowing? The epiglottis
4. What is the name given to the groups of air sacs that comprise most of lung tissue? alveoli
5. What is the Adam’s apple? The thyroid cartilage of the larynx
6. Would it be possible for a healthy child to die by holding its breath? Why?No, unconsciousness allows the involuntary respiratory centers of the brain stem to take over and reverses the unconsciousness by causing the child to breathe.
7. Briefly describe the effect of carbon dioxide on breathing.Carbon dioxide is a strong respiratory stimulant. CO2 combines with water forming carbonic acid. Both the increased acidity and increased CO2 affect chemoreceptors which stimulate the brain to increase the respiratory rate.
Page 1378. What effect does exercise have on carbon dioxide production? It increases it.
9. What structures of the respiratory system are involved in the following?
a. Humidifying airb. Warming air c. Filtering air
Contact between air and the warm, moist membranes of the upper respiratory tract facilitate humidifying, warming, and filtering of air. Most of this occurs in the nasal cavity since it contains structures that increase the surface area for contact between air, the nasal membranes and the sinuses. There are also many blood vessels in the nose to help in warming air.
d. Conducting air Air is conducted through the nasal cavity, pharynx, larynx, trachea, primary bronchi, secondary bronchi, tertiary bronchi, bronchioles and alveolar ducts.
e. Producing sound Vocal cords/(folds) in larynx
10. What is the function of the diaphragm?It causes pressure changes in the thoracic cavity by changing the shape and volume of the thoracic cavity.
11. What activities can influence breathing?Conscious control - holding breath or forced breathing; exertion-- increased muscle use can build up CO2 and acidity within the body; miscellaneous items: drinks, stress, disease
12. Differentiate cellular respiration and ventilation. (Use a reference text.)Cellular respiration is a biochemical process converting organic molecular energy into ATP-stored energy. The cellular process also generates CO2 under aerobic
conditions. Ventilation is the respiratory system’s breathing process for exchange of gases.
13. During inhalation is air sucked in or pushed in? Explain:Air is sucked in. The diaphragm flattens and moves in an inferior direction thus increasing the volume of the thoracic cavity. This also causes pressure in the cavity surrounding the lungs to decrease. Air is sucked into the lungs because of the pressure gradient created. Air moves from higher to lower pressure.
14. Does your chest expand because your lungs inflate, or do your lungs inflate because your chest expands? Explain:
Lungs inflate because the chest expands. Thoracic/pulmonary expansion causes the pressure gradient that sucks air in (see above answer.)
15. What structural feature ensures that the trachea will be an open airway?Cartilagenous C-rings are strong and flexible. They are strong enough to keep the trachea open but flexible enough to bend rather than break when exposed to stress.
EXERCISE 15-THE DIGESTIVE SYSTEMPage 140
Give an example of a place in the body where mechanical digestion is performed.Primarily in the mouth by chewing but also in the stomach by its churning action.
Give an example of a place in the body where chemical digestion is performed.Nearly all parts of the digestive tract except the esophagus and the large intestine. The stomach and the small intestine are the main chemical digestion sites.
Consider that the food you eat and the air you filter as you breathe are not sterile. What other benefit might HCl provide in the stomach?
It kills bacteria and any other infectious agents.
Which category of food molecule (protein, starch, or lipid) has not been broken down significantly by enzymes by the time food has left the stomach?
Lipids; lipase is only effective at the pH found in the small intestine.
What two “nonenzymes” are contributed to the duodenum, and what are their jobs?
NaHCO3 (sodium bicarbonate) neutralizes acid. Bile which is important for lipid emulsification.
Would a protease produced by the pancreas or a protease produced by the stomach work best in an acidic environment?
Pepsin produced by the stomach works best in an acidic environment.
In an alkaline environment? Pancreatic protease, delivered to the small intestine, work best in an alkaline environment.
Page 142What parts of the digestive system are not involved with either digestion or absorption of food?
The esophagus and large intestine. (Large intestine absorbs H2O and vitamins.)
What are their functions?Esophagus works to transport food to the stomach. Large intestine absorbs H2O & vitamins made by bacteria.
Compare the approximate length and diameter of the small and large intestine. Which is longer? The small intestine
Which is larger in diameter? The large intestine
Why is the small intestine so named? Because it is smaller in diameter than the large intestine.
Compare the 850-Calorie estimate with your experimental results for a cup of peanuts. Is there any significant difference between the two numbers?
The experimental results should be different.
If so, how much higher or lower? Typically less than half of the 850 Calorie estimate
Page 146Give two reasons for any possible difference between your experimental results and the estimate given by a diet book.
a) The human body is more efficient than fire at extracting chemical energy from a peanut.b) Experimental error; some of the heat is lost to the air so not all of the heat energy is captured by the H2O in the test tube.
Given that 2000 Calories per day is an average energy requirement for a person, how many peanuts per day would be needed to sustain life (if they were the lone food source)?
587. However, peanuts don’t contain all the nutrients, vitamins, & minerals the human body requires for health.
Which test tubes contained sugar at the start of the experiment? #2
Which additional tube(s) tested positive for sugar at the end of the experiment?#5
Where did this sugar in the “new” test tube come from?Sugar comes from starch which was broken down to give up its sugar.
What chemical reaction has occurred in the tube you answered in Question #2?Starch was broken down by the amylase into sugar.
What is the purpose of the other tubes?They are “controls” to prove that starch or amylase will not turn Benedict’s solution orange or yellow. Only sugar can cause this color change.
What is an enzyme?A protein molecule, usually made by cells, that is capable of catalyzing chemical reactions.
Give an example of an enzymatic reaction occurring in humans that relates to this experiment.
Salivary or pancreatic amylase
1. List, in order, the major organs of the digestive tract from beginning to end.mouth → pharynx → esophagus → stomach → small intestine (duodenum, jejunum, ileum) → large intestine---sigmoid colon---rectum
2. Explain the difference between mechanical and chemical digestion.Mechanical digestion causes a physical change (usually breaking of large particles into smaller pieces) – but no chemical change. Chemical digestion breaks food molecules into different smaller molecules (a chemical change).
3. List the three main “macromolecules” described in this exercise and the “building block molecules” each is made of.
Starch/polysaccharide - made of sugar; protein/polypeptides - made of amino acids; lipids are made of glycerol and fatty acids
4. What is peristalsis, and what tissue layer of the digestive tract causes it to occur?
Muscularis (exterma)causes peristalsis, a wavelike motion that pushes food through the digestive tract.
5. In which part of the digestive tract does most digestion occur?The small intestine.
What “accessory glands” assist the digestive process?The liver produces bile. The pancreas produces NaHCO3 (sodium bicarbonate), amylase, lipase & proteases.
6. In which part of the digestive tract does most absorption take place?small intestine
How are the lining cells of this structure modified to facilitate absorption?The microvilli increase the surface area for greater absorption.
7. List the three classes of enzymes and the molecules they help break down.amylase - starch; protease - proteins; lipase - lipids
8. In which part of the digestive system does the most significant amount of fat digestions occur and why?In the small intestine - Pancreatic lipase delivers to the small intestine the main enzyme for lipid digestion. Prior to the small intestine, no active enzyme is available to break down lipids.
9. What is bile?A surfactant or emulsifier that breaks up large fat globules into smaller ones (a physical change) and thus, increases the surface area for lipase attack.
10. In what ways would the anatomy of the human and the fetal pig digestive systems be similar?They have nearly all of the same digestive structures and a gall bladder which is not found in all mammals.
How are they different?The pig has a larger cecum and no appendix. The pig’s large intestine is coiled (spiral colon) but the human large intestine forms a square shape.
SECOND PAGE OF THE ALTERNATE EXPERIMENT
3. Observe the color of the liquid in test tubes 1 & 2. Write your description of the color below:
Test tube #1: orange/dark yellow Test tube #2: dark blue/green
4. Five minutes after the time you recorded in step 2, add 5 drops of IKI solution to test tube #3. Write your description of the color below:
Test tube #3: the liquid should be dark-gray to bluish gray.
Compare test tube #3 with the other test tubes. Describe the color of test tube #3 in comparison to the others:
Similar in color to starch control in test tube #2, but should be lighter shade.
5. Twenty minutes after the time you recorded in step 2, add 5 drops of IKI solution to test tube #4. Write your description of the color below:
Test tube #4: Liquid should be gold or dark amber.
Compare test tube #4 with the other test tubes. Describe the color of test tube #4 in comparison to the others:
Close in color to test tube #1
THIRD PAGE OF THE ALTERNATE EXPERIMENT Using the introduction information on page 1 of this supplement (or that found in your lab book or textbook) explain what happened in test tubes 3 & 4 during this experiment:
Amylase breaks starch molecules into sugar molecules. Because it was closer in color to test tube #2, which had starch, there was plenty of starch left in test tube #3.
Test tube #4 had no starch left, thus the color was similar to test tube #1 (which had no starch). So the enzyme appeared to break down more starch in test tube #4.
If you obtained different colors in tubes 3 & 4 (no matter how slight) propose a reason for this difference:
Test tubes # 3 & 4 had the same ingredients and the only variable was time. Enzymes were present in much smaller amounts than there were starch molecules (similar to the situation in the human body). So the enzymes need more time to react with all the starch molecules. This is why the starch breakdown was incomplete after 5 min.; after 20 min., there were only trace amounts of starch left.
Consider the amount of starch used in test tubes 3 & 4 was less than 1/1000 the amount that would be found in one French fry (or freedom fry if you prefer). What does this suggest to you about the length of the small intestine and the digestive process?
The small intestine needs to be long enough to give the enzymes that break down starch and other molecules enough time to do their work. The length of the small intestine allows the several hours its enzymes may need to break down all starch (and other food) molecules and also leave enough time and distance for absorption of these molecules and thus nutrients.
EXERCISE 16—THE URINARY SYSTEMPage 151
Why do you think drugs must be administered continually during infection?Water soluble drugs will gradually be excreted in the urine as they pass into the nephron and the glomerular filtrate but are not reabsorbed by any tubule.
Page 153What is specific gravity?
It is a relative measurement of buoyancy or solute concentration compared to pure water
What do the differences in specific gravity in the hree urine samples mean?A higher specific gravity infers higher solute concentration and more concentrated urine. A lower specific gravity infers lower solute concentration and a more dilute urine.
For a diabetic, would you expect a high or low specific gravity? Why?Higher →the nephron will be overloaded with excess glucose. Glucose, like any other solute, would increase the buoyancy and specific gravity of the sample.
Page 154Which is the normal urine specimen? Why?
What is considered normal can vary; a normal sample should not have excess protein, sugar, or an extreme pH (outside range 5.5 – 8.0)
Is there a normal urine pH? No, the pH can range from 5.5 – 8.0 and still be considered “normal”.
What could cause glucose to appear in urine?An overload of the nephron’s ability to reabsorb glucose can cause glucose to appear in urine. Diabetes can cause an increase in the blood glucose level which then overloads the nephrons.
What could cause protein to appear in urine?Damage to the glomerulus or some parts of the nephron due to infection or toxins allows proteins to leak into the nephron & could cause protein to appear.
Observe samples of human kidney stones. What might be responsible for kidney stone formation?
Crystalization of various salts in the kidney. Diet and fluid consumption have been linked to kidney stone formation.
Page 1551. What is the first product of filtration in the human nephron called?
What is the final excretory fluid called? urine
2. Define excretion.The movement of materials from the kidney tubules into the filtrate(urine).
3. Name three major processes involved in removing wastes from human blood via the nephrons.
a) filtration b) reabsorption c) tubular excretion or secretion
4. The three major constituents of urine are:a) water b) urea c) electrolytes (salts & other ions)
5. Name at least six components of glomerular filtrate.Waterelectrolytes
vitamins other nutrients
urea glucose6. Name all of the nephron parts in proper order, starting with the glomular
(Bowman’s) capsule and ending with the tubes that empty into the kidney pelvis.glomular (Bowman’s) capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubules, collecting tubule or duct, calyx
7. Starting with the afferent arteriole, name in proper order the flow of blood within the nephron until it re-enters the interlobular vein.afferent arteriole, glomerular, efferent arteriole, peritubular capillaries and vasa recta, interlobular vein
8. Trace the flow of urine from the kidney pelvis to the environment.kidney pelvis → ureter → bladder → uethra → environ
EXERCISE 17-THE MALE REPRODUCTIVE SYSTEM
Page 161-Study Questions1. List the three major accessory glands of the male reproductive system. Give
their functions.a. seminal vesicle: adds nourishing fructose rich fluid to spermb. prostate: adds fluid containing citric acidc. bulbourethral gland: expels a small amount of alkaline lubricating fluid into
urethra which neutralizes urine residue
2. Trace the pathway of a sperm cell from the time it is formed until it leaves the male body. Name all the structures it passes through in proper order.seminiferous tubules of testis, epididymis, ductus (vas) deferens, ejaculatory duct, prostatic urethra, penile urethra
3. What is castration? What are its results in male animals such as altered cats, capons, geldings, and eunuchs?Castration is removal of the testis which prevents both sperm and testosterone production. If performed early in life, feminization is likely. This is desirable in many animals since it reduces aggressive and territorial behaviors that testosterone may cause and it encourages weight gain.
4. What is testosterone? List some of its major functions.Testosterone is male hormone. It causes maturation of male reproductive structures, muscle growth and stimulates the typical male puberty changes (larynx growth and deeper voice, facial hair) May also be linked to behaviors associated with effeminate males and a decrease of these behaviors in females.
5. Sketch a human sperm cell with its three major parts. List the functions and contents of each.Flagellum or tail - movement of sperm head - contains nucleus and acrosomeneck - contains mitochondria for energy production
6. What cell division process is involved in spermatogenesis? Why is this type of cell division essential for sexual reproduction?meiosis: this type of cell division produces cells with ½ the number of chromosomes compared to regular cells. Thus, when sperm and egg nuclei fuse, a normal number of chromosomes will be present in the zygote (fertilized egg).
7. What are the advantages of sexual reproduction?Sexual reproduction produces more variation than asexual reproduction. Variation helps to ensure that some individuals will survive even during times of substantial environmental change.
EXERCISE 18-THE FEMALE REPRODUCTIVE SYSTEM
1. Why is a sterilization operation that involves severing or ligating the tubes more dangerous for a woman than for a man?It Is more dangerous due to the increased risk of infection. Surgery in a body cavity (as is necessary for female tubal ligation) is more risky than surgery of an extension to a body cavity (as happens in a vasectomy).
2. List the female reproductive accessory organs.uterine (fallopian) tubes, uterus, vagina, mammary glands
3. Give two reasons why a woman must urinate more frequently when pregnant.The pelvic cavity is more crowded due to pregnancy and space available for expansion of the uterus. The woman is likely to be producing increased amounts of urine because of filtering and elimination of wastes from the fetus.
4. Trace the pathway of an egg from its origin in the ovary until it is expelled from the body either unfertilized or as a child.
ovary → abdominal cavity (briefly) → fimbriae of uterine tube → uterine tube → body of uterus (if there is a pregnancy, implantation and development of the fertilized egg would occur) →cervix of uterus --- vagina