tissues and organ systems

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Tissues and Organ Systems There are between 75 and 100 trillion cells in the body of an adult human They are programmed to form different groups that have specific functions; this occurs due to: The contents of the cell’s cytoplasm --> how organelles are distributed Environmental conditions, such as temperature--> affects the activity of certain molecules in the cell The influence of neighbouring cells--> Surrounding cells can send chemical messages that affect how cells around it will develop

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Tissues and Organ Systems. There are between 75 and 100 trillion cells in the body of an adult human They are programmed to form different groups that have specific functions; this occurs due to: The contents of the cell’s cytoplasm --> how organelles are distributed - PowerPoint PPT Presentation

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Page 1: Tissues and Organ Systems

Tissues and Organ Systems• There are between 75 and 100 trillion cells in

the body of an adult human• They are programmed to form different

groups that have specific functions; this occurs due to:– The contents of the cell’s cytoplasm --> how

organelles are distributed– Environmental conditions, such as temperature-->

affects the activity of certain molecules in the cell– The influence of neighbouring cells--> Surrounding

cells can send chemical messages that affect how cells around it will develop

Page 2: Tissues and Organ Systems

Cell Specialization and Development

• Cells become differentiated because of genes that get turned off.

• They only express a certain set of information.

• Environmental factors (hazardous chemicals, smoking) can affect the expression of these genes leading to abnormalities

Page 3: Tissues and Organ Systems

Types of Tissues• All animals have four main types of tissues• Epithelial: line the surfaces of the body, both

as a body covering and between internal organs; form a barrier

• Muscle: designed to change their shape by shortening or lengthening

• Nervous: neurons receive and transfer signals to coordinate body actions

• Connective: strengthens, supports, protects, binds, or connects cells and tissues.

Page 4: Tissues and Organ Systems

Epithelial tissue• Skin epithelia: made of thin, flat cells that

form sheets and act as a semi-permeable barrier between the inside and outside of a body

• Columnar Epithelia: made of columns of cells that line the small intestine, stomach and glands; may secrete mucus and have finger-like projections, and absorb materials

Page 5: Tissues and Organ Systems

Muscle• Skeletal muscle: cells line up in the

same direction gives it a striped/striated look; attaches to bone making it possible to move

• Smooth muscle: cells are tapered at both ends, found in blood vessels and walls of internal organs, they contract more slowly than skeletal muscle

• Cardiac muscle: found only in the heart, contracts as a unit

Page 6: Tissues and Organ Systems

Nervous Tissue

• Have various actions:– Some relay signals from the brain or spinal

cord to muscles and glands– Others detect information form their

environment and trigger the body’s responses

Page 7: Tissues and Organ Systems

Connective Tissue• Bone: made of cells surrounded by calcium-

hardened tissue through which blood vessels run, needed for movement, support and protection

• Fat (adipose tissue): made of large, tightly packed cells found under the skin and around organs; needed for energy storage, padding and insulation

• Blood: includes red blood cells (RBCs), white blood cells (WBCs) and platelets within a liquid called plasma; used to transport nutrients and oxygen, clots when injury occurs, attacks foreign cells such as bacteria and viruses

Page 8: Tissues and Organ Systems

Stem Cells• Just as plants have meristematic cells that can

give rise to different plant tissues, animals have stem cells that can divide and will eventually will rise to specialized and differentiated tissues.

• A stem cell is an unspecialized cell that can produce various specialized cells

• These stem cells are abundant in an embryo 24 hours after fertilization. They are called totipotent because they can become any kind of cell in the body.

• At 5 days the stem cells are called pluripotent and are capable of producing many but not all kinds of cells

Page 9: Tissues and Organ Systems

Organs and Systems• Specialized tissues formed from stem

cells work together to form organs which work together to perform complementary functions to form organ systems

• Organ systems can be observed using common medical imaging technologies that allow physicians to diagnose disorders

Page 10: Tissues and Organ Systems

Medical Imaging Technologies• X Ray: electromagnetic radiation is transmitted

through the body to expose photographic film on the other side

• CT/CAT scan: reconstruction of X rays of thin slices of a body part using a computer

• Ultrasound sonography: produced by directing high frequency sound waves at a part of the body that shows real-time movement of body parts

• MRI scan (magnetic resonance imaging): produced using radio signals in a magnetic field to create images of body parts

Page 11: Tissues and Organ Systems

Human Organ Systems

Page 12: Tissues and Organ Systems

Hierarchical Organization of the Body

Atom molecules organelles cells tissues organs organ system

organism

* Four main types of tissues: connective, epithelial, nervous & muscle.

Page 13: Tissues and Organ Systems

The Digestive System

Page 14: Tissues and Organ Systems

Digestive System Overview• Known as gastrointestinal (GI) tract or alimentary canal.• Open at both ends to the outside world.• Consists of long convoluted tube with accessory organs.• Components: mouth, pharynx, esophagus, stomach,

small intestine, large intestine & anus.• Accessory organs include: salivary glands, pancreas,

liver & gallbladder.

Page 15: Tissues and Organ Systems

Steps in Digestion

1. Ingestion

2. Digestion

3. Absorption

4. Elimination

Page 16: Tissues and Organ Systems

Types of Digestion

Mechanical• Food mass is shredded, torn & churned.• Occurs in mouth & stomach.

Chemical• Chemicals and enzymes break down food.• Occurs in mouth, stomach & small

intestine.

Page 17: Tissues and Organ Systems

Organs of the Digestive System

• Oral Cavity

• Esophagus

• Stomach

• Small Intestine

• Large Intestine

Page 18: Tissues and Organ Systems

Oral Cavity

• Lips, tongue, teeth & jaw muscles break food down into smaller pieces.

• Food mixes with saliva and amylase, which begins the chemical digestion of carbohydrates.

• A bolus (moistened ball-like mass) forms and is swallowed.

• The bolus passes through the pharynx, past the epiglottis & through the esophagus.

Page 19: Tissues and Organ Systems

Esophagus

• Muscular tube that connects pharynx & stomach.

• The cardiac or lower esophageal sphincter connects the esophagus to the stomach.

• Constriction of this ring of smooth muscle prevents reflux (ensures one-way flow of food).

• Peristalsis is a series of coordinated muscular contractions that propels food along the digestive tract.

Page 20: Tissues and Organ Systems

Stomach

• J-shaped stretchable organ.• Acts as a reservoir for food (1.5 L).

• Two sphincters control the movement of food coming into and out of the stomach. – Cardiac sphincter: Between the stomach & the

esophagus.– Pyloric sphincter: Between the stomach & the

small intestine (the duodenum).

Page 21: Tissues and Organ Systems

Stomach• Smooth muscle forms folds (rugae) that allow the

stomach to expand.• Mechanical digestion: Walls churn & squeeze bolus.• Chemical digestion: Bolus mixes with gastric juices.

– Hydrochloric acid secreted by gastric glands.– Pepsinogen released & converts to pepsin (enzyme that

breaks down proteins).

• Bolus becomes a liquefied paste (chyme).

Page 22: Tissues and Organ Systems

Stomach• Mucus cells secrete mucus to line &

protect stomach from HCl (aq).• Ulcers: HCl (aq) burns a hole through the

mucus, irritating the stomach cells below– Usually the result of a

particular type of bacteria (antibiotics required).

Page 23: Tissues and Organ Systems

Small Intestine

• Major site of digestion & absorption (80% occurs).

• About 6 m long & has a SMALLER diameter than the large intestine.

• Lined with tiny finger-like projections called villi, which project into the lumen.

• Microvilli line the villi.• Villi & microvilli increase the surface area for

absorption.

Page 24: Tissues and Organ Systems
Page 25: Tissues and Organ Systems

Small Intestine• Consists of three sections:

1. Duodenum

2. Jejunum

3. Ileum.

Page 26: Tissues and Organ Systems

Small Intestine

• Mechanical digestion: Alternating contraction & relaxation of the smooth muscle mixes chyme with intestinal juices & secretions from the pancreas & liver.

• Nutrients absorbed into capillaries in the villi.• Nutrients transported to the liver & then to all body cells.• Products from fat digestion are absorbed into lacteals,

which connect to the lymphatic system.

Page 27: Tissues and Organ Systems

Large Intestine• Reabsorbs water, salt & some vitamins.• Holds & compacts unabsorbed material.• About 1.5 m long & has a LARGER diameter than

the small intestine.• Consists of four sections:

1. Caecum2. Colon3. Rectum4. Anus.

Page 28: Tissues and Organ Systems

Large Intestine

• Chyme passes from the small intestine into the caecum, through the ileocaecal valve.

• Waste products accumulate & are compacted into feces (3/4 water, 1/4 solid matter)

• Feces pass through the rectum & exit the body through the anus.

• Appendix attached to caecum, exact function is unknown.

Page 29: Tissues and Organ Systems

Large Intestine

• Defecation controlled by two sphincters:– Rectal sphincter: Between the large

intestine & the rectum.– Anal sphincter: Between the rectum & the

anus.

Page 30: Tissues and Organ Systems

The Circulatory System

• The functions of the circulatory system is to pick up and transport nutrients and oxygen to cells and carries wastes to the organs responsible for eliminating them from the body.

Page 31: Tissues and Organ Systems

Circulation in Various Organisms

• Insects have a circulatory system that is ‘open.’ They have one major vessel that empties oxygenated blood into parts of the body. Cells are literally bathed in blood.

• Mammals and birds have a ‘closed’ circulatory system - the blood stays within tubes or vessels.– Fish have two-chambered hearts, amphibians

have three-chambered hearts.

Page 32: Tissues and Organ Systems

The 3 main parts of TheCirculatory system

• The Heart

• The Blood Vessels

• Blood

Page 33: Tissues and Organ Systems
Page 34: Tissues and Organ Systems

Parts of The Heart

• The Atria

-Receiving Chambers• The Ventricles

-Pumping Chambers• The Valves

-Controls Flow• The Septum

-Divides the Heart

Page 35: Tissues and Organ Systems
Page 36: Tissues and Organ Systems

Types of Blood Vessels• Arteries -Carry blood away from the Heart -The Aorta is the largest artery• Veins -Carry blood away from the Heart -Veins contain valves -The Vena Cava is the largest vein• Capillaries -Known as the “Distribution Pipes”

Page 37: Tissues and Organ Systems

Blood Vessels

Page 38: Tissues and Organ Systems

Passage of Blood Through the Heart• Blood follows this sequence through the heart:

superior and inferior vena cava → right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary trunk and arteries to the lungs → pulmonary veins leaving the lungs → left atrium → bicuspid valve → left ventricle → aortic semilunar valve → aorta → to the body.

• N.B. The pulmonary artery is the only artery in the body that carries deoxygenated blood.– The Pulmonary vein is the only vein that carries

oxygenated blood.

http://www.bishopstopford.com/faculties/science/arthur/Heart%20drag&drop.swf

Page 39: Tissues and Organ Systems

• The pumping of the heart sends out blood under pressure to the arteries.

• Blood pressure is greatest in the aorta; the wall of the left ventricle is thicker than that of the right ventricle and pumps blood to the entire body.

• Blood pressure then decreases as the cross-sectional area of arteries and then arterioles increases.

Page 41: Tissues and Organ Systems
Page 42: Tissues and Organ Systems

The Composition of Blood

• The Plasma (Fluid) makes up 55% of the blood volume.

• The Solids (Cells) make up 45% of the blood volume.

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Blood Composition

Plasma Solids

Page 43: Tissues and Organ Systems

Blood Plasma

• 97% Water

• Other 3%

-Antibodies and Proteins

- Nutrients and Wastes

Page 44: Tissues and Organ Systems

Blood Solids

• Red Blood Cells

-Carry oxygen

-Contain Hemoglobin

• White Blood Cells

-Attack bacteria & other invaders

• Platelets

-Control the blood clotting process

Page 45: Tissues and Organ Systems

Blood Solids• Red Blood Cells -Carry oxygen -Contain Hemoglobin• White Blood Cells -Attack bacteria & other invaders• Platelets -Control the blood clotting process

Page 46: Tissues and Organ Systems

Cardiovascular Disorders

• Cardiovascular disease (CVD) is the leading cause of death in Western countries.

• Modern research efforts have improved diagnosis, treatment, and prevention.

• Major cardiovascular disorders include atherosclerosis, stroke, heart attack, aneurysm, and hypertension.

Page 47: Tissues and Organ Systems

Atherosclerosis• Atherosclerosis is due to a build-up of fatty material (plaque), mainly cholesterol, under the inner lining of arteries.

• The plaque can cause a thrombus (blood clot) to form.

• The thrombus can dislodge as an embolus and lead to thromboembolism.

Atherosclerosis Calcification

Page 48: Tissues and Organ Systems

Stroke, Heart Attack, and Aneurysm

• A cerebrovascular accident, or stroke, results when an embolus lodges in a cerebral blood vessel or a cerebral blood vessel bursts; a portion of the brain dies due to lack of oxygen.

• A myocardial infarction, or heart attack, occurs when a portion of heart muscle dies due to lack of oxygen.

Page 49: Tissues and Organ Systems

Coronary Bypass Operations

• A coronary bypass operation involves removing a segment of another blood vessel and replacing a clogged coronary artery.

• It may be possible to replace this surgery with gene therapy that stimulates new blood vessels to grow where the heart needs more blood flow.

Page 50: Tissues and Organ Systems

Coronary bypass operation

Page 51: Tissues and Organ Systems

Clearing Clogged Arteries

• Angioplasty uses a long tube threaded through an arm or leg vessel to the point where the coronary artery is blocked; inflating the tube forces the vessel open.

• Small metal stents are expanded inside the artery to keep it open.

• Stents are coated with heparin to prevent blood clotting and with chemicals to prevent arterial closing.

Page 53: Tissues and Organ Systems

The Respiratory System

Page 54: Tissues and Organ Systems

The Respiratory System

• Respiration: The exchange of oxygen & carbon dioxide between an organism & its external environment.

• The respiratory system supplies oxygen to cells & removes carbon dioxide.

Page 55: Tissues and Organ Systems

Breathing (Ventilation)• Inhalation: Oxygen is taken in from the

external environment.

• Exhalation: Carbon dioxide is removed from the internal environment.

Page 56: Tissues and Organ Systems

External Respiration

• Gas exchange between the alveoli & blood.• Oxygen diffuses into the alveoli & carbon

dioxide diffuses out.• The alveoli must be

moist to allow for diffusion.

• The blood carries the oxygen from the lungs to the body cells.

Page 57: Tissues and Organ Systems

External Respiration

Page 58: Tissues and Organ Systems

Internal Respiration

• Gas exchange between the blood &the body cells.

• Oxygen diffuses out of the blood & carbon dioxide diffuses in.

• Allows cellular respiration to occur.

Page 59: Tissues and Organ Systems

Anatomy of the Respiratory System

• Analogous to an upside-down tree.• Components:

– Nose– Nasal & oral cavities– Pharynx– Larynx– Trachea– Bronchi & bronchioles– Alveoli

Respiratory Basics - Learning Activity - Flash Player Installation

Page 60: Tissues and Organ Systems

The Upper Respiratory Tract1. NoseStructure: Two nostrils separated by

cartilage and soft bone

Functions: Air that is breathed in through the nose is:

a) Warmed by heat in the capillaries in the nose

b) Dampened when it passes over the mucus lining of the nose

c) Cleaned by cilia that sweep dirt into the mucus

d) Filtered by hairs that remove large particles

Page 61: Tissues and Organ Systems

4. TracheaStructure: a 10 cm tube extending from the

larynx to the branches of the bronchi

All breathing tubes are held open by C-shaped rings of cartilage that prevent the tubes from collapsing

Function: passage way

for air

Page 62: Tissues and Organ Systems

The Lower Respiratory Tract5. BronchiStructure: the base of the

trachea divides into 2 tubes called bronchi

-one bronchus goes into the left lung and one to the right lung

-inside the lungs, the bronchi branch out into smaller tubes called bronchioles which spread all over the lungs

Function: passageway for air

Page 63: Tissues and Organ Systems

6. AlveoliStructure: inside of our two lungs are 300

million air sacs called alveoli, found in clusters at the ends of bronchioles (allows more surface area)- each alveolus is surrounded by blood capillaries- each alveolus is covered in a film of moisture

Function: the oxygen in the air that enters the alveoli during inhalation dissolves in the moisture and diffuses into the capillaries- the O2 is absorbed by molecules of hemoglobin, a pigment in red blood cells, and transported to the heart.- CO2 dissolved in water, passes from the capillaries into the alveoli to be breathed out

Therefore, this process is called gas exchange, and the two systems involved are the alveoli and the capillaries.

Page 65: Tissues and Organ Systems

7. LungsStructure: 2 large spongy organs

that fill nearly the entire thoracic

cavity (chest)

- the left lung is slightly smaller

(2 lobes) b/c the heart sits on it,

whereas the right lung has 3 lobes

- the lungs contain the bronchi, bronchioles, alveoli, and capillaries

- enveloped in layers of tissue called pleura

Function: expand and contract to fill up with gas

Page 66: Tissues and Organ Systems

Lung Cancer• More Canadian men and

women die from lung cancer than from any other form of cancer.

• There is uncontrolled growth of cells and the solid mass of cancer cells in the lungs greatly decreases the surface area for diffusion.

• Tumours may actually block bronchioles, reducing airflow to the lungs and potentially causing the lungs to collapse.

Page 67: Tissues and Organ Systems
Page 68: Tissues and Organ Systems

Treatment

• Surgery

• Radiation therapy

• Chemotherapy

• Prevention: no smoking, avoid second-hand smoke, avoid carcinogens

Page 69: Tissues and Organ Systems

Other Gas Exchange Systems

• Birds, many amphibians, reptiles and other mammals have lungs just as humans do.

Page 70: Tissues and Organ Systems

Earthworms

• Diffusion of gasses occurs through their thin, moist skin.

• Mucous & other body fluids are excreted onto skin. • Emerge only at night when the evaporating potential

of the air is low.• Light-sensitive tissues near their head enable it to

detect light, so they can avoid coming out in the sun.

Page 71: Tissues and Organ Systems

Gills• Some organisms have protective coats that

decrease the surface area for gas exchange• Gills are feathery tissue structures that

consist of numerous branches. Gases are exchanged across the thing gill membranes

• In most gilled animals, water flows only one way over the gills, which reduces the amount of energy needed to move the water over the respiratory surface

• When an oxygen-containing medium is moved over the respiratory surface, it is called ventilation.

Page 72: Tissues and Organ Systems

2. The Tracheal Respiratory System

• It is harder to respire on land than in the water because it is more difficult to keep the respiratory surface moist.

• A series of external pores can resolve this problem. The spiracles lead to an internal network or tubes called tracheae.

• Gas is exchanged through these pores and moves through the network of tracheae. These tubes come into close contact with all the living cells to allow gas exchange by diffusion.

• This system does not require the use of the circulatory system.

Page 73: Tissues and Organ Systems

Grasshoppers

• Air enters tracheal tubes through spiracles.• The tracheae carries air directly to individual

cells where diffusion of gases occurs.• Contraction of abdominal muscles

compresses the air sacs & forces air out of the tracheae.

• As the muscles relax, the air sacs return to its normal volume & air is drawn in.

Page 74: Tissues and Organ Systems

3. The Lung

• The lung is an internal respiratory system connected to the air by means of internal passageways

• All lung systems have three common characteristics:

1. Moist respiratory surface2. A means of forcibly bringing air into contact with

the lung surface3. A circulatory system to carry the gases between

the lungs and the other cells of the body

Page 75: Tissues and Organ Systems

Frogs

Inner Lining of Mouth• Roof of mouth has rich supply of blood vessels.• Constant movements of throat brings air in through

the nose & into the mouth, where diffusion occurs.• The air is then released through the nose.

• The passage to the

lungs is kept closed.