Chapter 1The Human Body: An

Orientation

Anatomy vs. Physiology

Anatomy- studies the structure of the body parts and their relationships to one another (seen, felt, examined)

• Physiology- concerns the function of the body’s structural machinery (how parts work and carry out life sustaining activities)

Gross Anatomy- study of large body structures visible to the naked eye

• Regional- One region studied in detail

• Systemic- Study system by system

• Surface- How organs relate to the skin

Microscopic Anatomy- parts of the body too small to see with the naked eye (EX: thin slices of tissue)

• Cytology- study of cells

• Histology- study of tissue

Developmental anatomy- changes that occur throughout life

Embryology- changes that occur before birth (look at birth defects)

Tools to Study anatomy Observation

• Manipulation

• Palpation (feeling organ with hands)

• Auscultation- (listening to the organ sounds)

Working Together* What a structure can do

depends on its specific form – Principle of Complementarity of Structure and Function

Levels of Structural Organization

Chemical (atoms form molecules)

Cells (smallest unit of living things)

Tissue (group of cells with common function)

Organ

Organ Systems (organs working together with

common purpose)

Organ Systems 1. Cardiovascular 2. Integumentary 3. Skeletal 4. Muscular 5. Nervous 6. Endocrine

Organ Systems (Cont.) 7. Respiratory 8. Digestive 9. Lymphatic 10. Urinary 11. Reproductive

Maintaining LifeNo organ system works in

isolation they work cooperatively to promote well-being of entire body.

1. Boundaries Single Celled Organisms- outer

membrane to hold in all contents and restrict foreign objects from entering

** All Cells of our body are surrounded by a selectively permeable membrane

Boundaries (Cont) Whole body protected by Integumentary

System or Skin

Protection From: ? Drying out Bacteria Heat Sun Chemicals in the Environment

2. Movement Muscular System allows for the

movements we make while the skeletal system provides the framework for muscles to pull on and create work

• Also have movement of items through internal organs such as food, blood, urine by contracting or shortening of muscle cells

3. Responsiveness

Nervous System – sends electric pulses to stimuli from the environment

4. Digestion Break food into simple molecules that

can be absorbed by blood

Transported through the body cells by the cardiovascular system

5. Metabolism All Chemical Reactions that occur within

the body cells

Systems Working Together: Metabolism depends on Digestive & Respiratory Systems to make nutrients and oxygen available to the blood and Cardiovascular to distribute through the body- regulated largely by hormones secreted by the Endocrine System

6. Excretion Removing Waste from the body

o Digestive System- rids indigestible food

o Urinary- rids of nitrogen containing waste- urine

o Respiratory- rid of Carbon Dioxide

7. Reproduction Can be cellular or organismal level

• Cellular- original cell divides into daughter cells

• Organismal- sperm unites with egg to form an embryo

• Reproductive responsible for offspring but function regulated by Hormones of Endocrine System

8. Growth Increase in size of body part or organism

Can have increase in the number of cells or increase in the individual cell size

Constructive activities must occur faster than destructive activities to have growth

SURVIVAL NEEDS Body Systems goal is to maintain life

but there are other factors that must be present to do so

Including:

NutrientsOxygenWaterAppropriate TemperatureAtmospheric Pressure

1. Nutrients Energy/ Cell Building Carbohydrates- major fuel for cells Proteins- essential for building cell

structures Fats- cushion body organs, insulate,

and provide energy- rich fuel reserve Select Minerals and Vitamins-

chemical reactions that go on in cells for oxygen transport

2. Oxygen Human cells can only survive a few

minutes without oxygen

Approximately 20 % of air we breathe is oxygen

3. Water 60 to 80 % of body weight Single most abundant chemical

substance in the body

• Provides a base for chemical reactions and body secretions and excretions

• Obtain mostly from foods we eat

• Lost by evaporation from lungs, skin, and body excretions

4. Normal Body Temperature Muscular System produces most body heat

As temperature drops below 98 F metabolic reactions become slower until they eventually stop

If temperature is too high chemical reactions occur at a frantic pace and cause proteins to lose their shape and stop functioning

5. Atmospheric Pressure Force air exerts on surface of the body Breathing and gas exchange in the

lungs depends on appropriate atmospheric pressure

High altitudes cause atmospheric pressure to be lower and the air to be thin- gas exchange may be inadequate for cellular metabolism

BALANCE IS IMPORTANT It is very important to have each of

the needs in the appropriate amount Too much oxygen- toxic to body Too much/ little food- obesity/ starvation

Homeostasis The body’s ability to maintain relatively

stable internal conditions even though the outside world changes continuously

* Communication Is KEY- Nervous and Endocrine systems very important for this state of balance

Negative Feedback System shuts off original stimulus or reduces it Change in direction Controls the everyday (moment to moment

changes in Homeostasis of body)

“ Like your Thermostat at Home”

Your thermostat is known as the hypothalamus located in your brain

Positive Feedback Enhances original stimulus

Proceeds in the same direction

Usually control infrequent events such as blood clotting, or enhancing labor contractions during child birth

Homeostatic Imbalance Diseases As we age body is less efficient at

fighting illness

Could also come from negative feedback mechanisms being overwhelmed and destructive positive feedback mechanisms taking over- Example= HEART FAILURE

Language of Anatomy Anatomical Position- standing straight,

feet slightly apart, palms facing forwards “standing at attention”

“right” and “left” on the person not from observers viewpoint

Regional Terms Axial- main axis (head, neck, trunk)

Appendicular- appendages or limbs

Body Planes Sagittal- Vertical/ divided into left and

right

Frontal- Vertical/ Anterior and Posterior

Transverse- Horizontal/ Superior and Inferior “Cross Section”

Organ Systems Do you remember how many organ

systems there were?

11 Organ Systems

Integumentary System Function:

Protects deeper tissue from injury Pain/ Pressure receptors Sweat/ Oil Glands

• Major Organs

• Hair• Skin• Nails

Skeletal System Function:

Protects and Supports body organs Framework for muscles to Pull on Stores Minerals

• Major Organs

• Bones• Joints

Muscular System Function:

Allows manipulation of environment Locomotion, facial expressions, maintain

posture Produce Heat

• Major Organs

• Muscles

Nervous System Function:

Control System Responds by activating appropriate

muscles and glands

• Major Organs

• Brain• Nerves• Spinal Cord

Endocrine System Function:

Glands secrete hormones that regulate growth, reproduction, and nutrient use

• Major Organs

• Thyroid gland• Thymus• Pancreas• ovary

• Testis• Adrenal Gland• Pineal Gland• Pituitary Gland

Cardiovascular System Function:

Blood Vessels transport blood Carries oxygen, Carbon dioxide, nutrients,

and wastes Heart pumps the blood

• Major Organs

• Blood Vessels• Heart

Lymphatic (Immune) Function:

Picks up fluid leaked from the blood vessels and returns it to the blood

Houses White Blood Cells that are involved in immunity (fighting diseases and sickness)

• Major Organs

• Red Bone Marrow• Thymus• Lymphatic Vessels

• Spleen• Thoracic duct• Lymph Nodes

Urinary System Function:

Eliminates nitrogenous waste Regulates Water Electrolyte and acid-base balance of blood

• Major Organs

• Kidney• Ureter• Urinary Bladder• Urethra

Respiratory System Function:

Keeps the blood supplied with oxygen and removes carbon dioxide

Gas exchange for the lungs

• Major Organs• Nasal Cavity• Pharynx• Larynx• Trachea • Lung • Bronchus

Digestive System Function:

Breaks down food into absorbable units Indigestible food is eliminated out of body

• Major Organs• Oral Cavity • Esophagus• Liver• Stomach

• Small Intestine• Rectum• Anus• Large Intestine

Reproductive System Function:

Production of Offspring Testes- Produce sperm and male sex

hormones Ovaries- produce eggs and female sex

hormones

Major Organs – MALE Prostate Gland Penis Testes Scrotum Ductus deferens

Major Organ- Female Mammary Glands Ovary Uterus Vagina Uterine tube

Dorsal Body Cavity Protects the fragile nervous system

organs There are 2 subdivisions

Cranial- encases the brain Vertebral- encloses the spinal cord

Ventral Body Cavity More anterior and larger body cavity

Also has 2 subdivisions Thoracic- (superior) surrounded by ribs

and muscles Abdominopelvic- (inferior)

Thoracic Pleural Cavity- each houses a lung

Mediastinum- contains the pericardial cavity – encloses the heart

and surrounds the thoracic organs such as esophagus, trachea, and others

AbdominopelvicAbdominal Cavity- stomach,

intestines, spleen, liver and other organs

Pelvic Cavity- bladder, some reproductive organs, and rectum