Hierarchical Organization of the Body

Atom

Molecules

Organelles

Cells

Tissues

Organs

Organ system

Organism

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

• Groups of similarly specialized cells form tissues.

Types of TissuesAll animals have 4 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: made of neurons that receive and transfer signals to coordinate body actions

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

Pg 88-89

1. 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 (shown), stomach and glands; may secrete mucus and have finger-like projections, and absorb materials

2. Muscle• Skeletal muscle: cells line up in the

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

• 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

3. Nervous Tissue

• Have various actions:

– Some relay signals from the brain or spinal cord to muscles and glands

– Others detect information from their environment and trigger the body’s responses; ex reacting to touching something hot.

4. 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

Stem Cells• Just as plants have meristematic cells that can give rise to different plant tissues, animals

have stem cells that are unspecialized cells 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• Ex, only skin stem cells can produce cells to repair skin

Pg. 90

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

Hum

an Organ S

ystems

Homework CheckRead Pgs 85-91 and do #1-4 (pg 90) and 2, 4-6 (pg 92)

1. Cell differentiation is the specialization of different cells for different functions.

2. Cell Specialization: effect of environment conditionseffect of neighbouring cellseffect of cytoplasm

3. The four main types of animal tissue are epithelial, muscle, nervous, and connective tissue. Epithelial tissue is found lining surfaces of the body, including internal organs. Muscle tissue is found attached to bone, in blood vessels, and walls of some internal organs, and as the major tissue in the heart. Nervous tissue is found in the brain, the spinal cord, and through the body for the transferring of signals. Connective tissue is found as bone, fat, and blood throughout the body.

4. Skeletal muscle usually contracts or lengthens when a person makes a conscious decision to move a part of his or her body and is therefore called “voluntary” muscle. Smooth muscle is found in blood vessels and internal organs such as the stomach, and contracts to helps these tissues perform their functions (i.e., circulating blood and digesting food).

2. a. D, b. C, c. , d. A

4. If cells of a chick embryo did not specialize, the embryo would not form into a chick.

5. Stem cells are cells that are capable of producing new cells and therefore regenerating tissue. Unlike other cells, they are unspecialized but can produce different specialized cells.

6. Adult Stem Cells: can only produce specific types of cells, not as controversial, can be induced to be pluripotent B Embryonic Stem Cells: totipotent and pluripotent, can produce different types of cells, controversial because it comes from

embryos

The Digestive System

http://www.youtube.com/watch?v=XxvRbxhqoZk

Digestive System Overview• Known as gastrointestinal (GI) tract.

• Open at both ends to the outside world.

• Consists of long convoluted tube with accessory organs.

• Components: mouth, pharynx, esophagus, stomach, small intestine (includes duodenum), large intestine (includes cecum, colon, and rectum) and anus.

• Accessory organs include: salivary glands, pancreas, liver & gall bladder.

Steps in Digestion

1. Ingestion

2. Digestion

3. Absorption

4. Elimination

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.

Oral Cavity

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

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

• A bolus (moistened ball-like mass) forms and is swallowed.• The bolus passes through the pharynx (throat), past the

epiglottis (used to seal off the windpipe when swallowing) and through the esophagus.

Esophagus

• Muscular tube that connects pharynx & stomach.

• The cardiac 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.

http://www.youtube.com/embed/rJS-Kh5wCQU

Stomach• J-shaped stretchable organ.

• Acts as a reservoir for food (holds 1.5 L).

• The second sphincter, pyloric sphincter, located between the stomach and the small intestine (the duodenum), controls the movement of food leaving the stomach.

Cardiac

Stomach con’t

• Made of smooth muscle tissue that allow the stomach to expand.

• Mechanical digestion: Walls churn & squeeze bolus.

• Chemical digestion: Bolus mixes with gastric juices.– Hydrochloric acid (HCl) is secreted by gastric glands.– Pepsin (enzyme) is released that breaks down proteins.

• Bolus becomes a liquefied paste called chyme.

Stomach con’t

• Mucus cells secrete mucus to line & protect stomach from HCl.

• Ulcers: HCl burns a hole through the mucus, irritating the stomach cells below.

Homework Check

• Read Pg 97-99

• Complete Digestion Worksheet

• Work on Medical Imaging brochure that is due on Monday.

Small Intestine

• Major site of digestion & absorption.

• About 7 m long & has a SMALLER diameter (3 cm) than the large intestine.

• Lined inside with tiny finger-like projections called villi (not cilia).

• Microvilli line the villi.

• Villi & microvilli increase the surface area for absorption.

Small Intestine

Consists of three sections:

1. Duodenum:

• 1st meter of small intestine where most of the digestion takes place.

• has ducts connecting to liver, gall bladder and pancreas.

2. Jejunum

3. Ileum

Accessory Organs

• Liver: produces bile which breaks down fat

• Gall bladder: stores bile until needed

• Pancreas: manufactures pancreatic juice which contain many enzymes: Trypsin: breaks down proteins into amino acids Pancreatic Amylase: breaks down carbohydrates into simple sugars Lipase: breaks down fats into fatty acids

• Pancreas is also responsible for the production of bicarbonate (HCO3), which acts to neutralize the acidity of the stomach chyme entering duodenum through the pylorus sphincter.

Large Intestine• Reabsorbs water, salt & some vitamins.• About 1.5 m long & has a LARGER diameter

(6.5 cm) than the small intestine.

• Consists of three sections: 1. Cecum2. Colon3. Rectum

Large Intestine

• Chyme passes from the small intestine into the cecum.

• Waste products accumulate & are compacted into feces.

• Feces is stored in the rectum & exits the body through the anus (opening).

• Appendix attached to cecum, exact function is unknown. At one time, aided in cellulose digestion. Humans now lack the enzyme to digest the carbohydrate cellulose.

• It can become blocked and inflamed which may burst if not removed.

Homework Check

Lesson 12 on Unit Plan

• Read Pg 97-99 and do #1,2 on pg 107

Complete Digestion Worksheet

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.

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. We have a four-chambered heart.

The 3 main parts of the Circulatory system:

• The Heart

• The Blood Vessels

• Blood

Parts of The Heart:• The Atria (receiving chambers)• The Ventricles (pumping chambers)• The Valves (controls flow)• The Septum (divides the heart)

3 Types of Blood Vessels:1. Arteries: -carry blood away from the heart

-arteries do NOT have valves. Why? -the aorta is the largest artery2. Veins: -carry blood to the heart -veins contain valves

-the vena cava is the largest vein3. Capillaries: -known as the “distribution pipes”

Blood Vessels

Where is the highest pressure?

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 artery to the lungs → pulmonary veins leaving the lungs → left atrium → bicuspid valve → left ventricle → aortic semilunar valve → aorta → to the body.

http://youtu.be/JA0Wb3gc4mE

Superior Vana Cava

Inferior Vana Cava

RA

RV

LA

LV

Tricuspid Valve (R AV valve)

Bicuspid Valve (L AV valve)

Lungs

Pulmonary arteries Pulmonary semilunar valve

Right: pulmonary (to lungs) Left: systemic (to body)

Pulmonary veins

Lungs

Aortic semilunar valve

Aorta

Deoxygenated Blood From the body

To the body

To the lungs to get oxygenated

Oxygenated blood from the lungs

Which is the strongest chamber?

• Atria (plural of atrium) are the receiving chambers.• Ventricles force blood out of the heart and are thick

walled.• 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.

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

• Septum divides left chambers from right chambers.• Blood pressure is greatest in the aorta; the wall of the

left ventricle is thicker than that of the right ventricle because it needs to pump blood to the entire body.

Path of blood through the heart

Blood circulation

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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10

20

30

40

50

60

Blood Composition

Plasma Solids

Blood Plasma (55% of blood):

• 97% Water

• Other 3%

-Antibodies and Proteins

- Nutrients and Wastes

Blood Solids (45% of blood):

• Red Blood Cells: -Carry oxygen -Contain Hemoglobin

• White Blood Cells: -Attack bacteria & other invaders

• Platelets: -Control the blood clotting process

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, and heart attack.

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 blood clot to form.

•Arteriosclerosis, also known as hardening of the arteries, occurs when the arterial walls thicken and then harden as calcium deposits form.

•Atherosclerosis is another type of hardening of the arteries in which lipids, particularly cholesterol, build up on the side arterial walls as plaque. Risk factors for atherosclerosis include cigarette smoking, a high fat/high cholesterol diet, and hypertension.

Stroke and Heart Attack

• Thromboembolism is when the blood clot breaks loose and is carried by the blood stream to plug another vessel where it can cause damage. The clot may plug a vessel in the lungs (pulmonary embolism), brain (stroke), gastrointestinal tract, kidneys, or leg.

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

• Most heart attacks occur when a blood clot blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. If the blood flow is blocked, the heart is starved of oxygen and heart cells die.

Coronary Bypass Operations

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

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.

Homework Check

• Read Pg 100-102

• Do Pg 106 #5,6, 8

• Complete Heart Anatomy H/O

• Quiz tomorrow on only the circulatory system

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.

Respiration

• Respiration (breathing) can be broken into internal and external respiration.

• External respiration is the process by which external air is drawn into the body in order to supply the lungs with O2 and used air is expelled from the lungs in order to remove CO2 from the body.

• Internal respiration is the process by which the gases in the air that has already been drawn into the lungs are exchanged with gases in the blood and tissues so that CO2 is removed from the blood and replaced with O2

Internal Respiration

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

dioxide diffuses into the alveoli.• The alveoli must be

moist to allow for diffusion.

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

Ventilation for External Respiration• Inhalation: Oxygen is taken in from the

external environment.

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

Mechanics of Ventilation

Inhalation Exhalation

Chest muscles contract to cause rib cage to lift & expand

Chest muscles relax to cause rib cage to drop & collapse

Diaphragm contracts and pulls down

Diaphragm relaxes and moves up

Volume increases in chest cavity

Volume decreases in chest cavity

Pressure decreases Pressure increase

Air is pulled in Air is pushed out

Anatomy of the Respiratory System• Analogous to an upside-down tree.

• Components:

1. Nose, nasal & oral cavities

2. Pharynx

3. Larynx

4. Trachea

5. Bronchi & bronchioles

6. Alveoli

The Upper Respiratory Tract

1. 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

2. Pharynx- is the part of the throat in the back at the top of the esophagus

3. Larynx- voice box and airway to the lungs

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

The Lower Respiratory Tract5. Bronchi & bronchioles

Structure: 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

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 respiratory system (alveoli) and the circulatory system (capillaries).

7. LungsStructure: 2 large spongy organs

that fill nearly the entire thoracic

cavity (chest)

- the left lung is slightly smaller

(2 lobes) because the heart sits on it,

whereas the right lung has 3 lobes

- the lungs contain the bronchi,

bronchioles, alveoli, and capillaries

Function: expand and contract to fill up with gas

Fish use Gills• Gills are feathery tissue structures that consist of numerous branches. Gases are

exchanged across the thin 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

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.

Treatment

• Surgery

• Radiation therapy

• Chemotherapy

• Prevention: no smoking, avoid second-hand smoke, avoid carcinogens (ex Asbestos)

Other Gas Exchange Systems

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

Homework Check

• Read Pgs 103-105

• Do # 7 on page 106 and 6, 7 on pg 107

The Excretory System

Solid waste is eliminated by the digestive system but some waste is in a liquid form. This liquid waste is eliminated by the excretory system. Liquid waste is formed from the filtration of blood.

1. Blood passes through the kidneys and is filtered.

2. Filtered blood returns to normal circulation and

removed waste is collected in the kidney.

3. The waste then moves down the

ureters and is stored in the bladder.

4. When the bladder is full, the waste

is flushed from the body via the urethra.

The Immune System

• Infectious diseases are caused by pathogens (viruses, bacteria and fungi).

How does your body protect itself from pathogens?• 1. Skin• 2. white blood cells called phagocytes• 3. production of antibodies

Immune System con’t

• When a part of the body is infected, blood carrying white blood cells rushes to that part of the body causing inflammation and redness. The phagocytes chase, engulf and destroy the pathogen.

• How does a white blood cell know who to chase?• Any foreign invader is recognized by white blood

cells because they have protein markers known as antigens.

Antibody Production

• Antibodies are specialized proteins that identifies and attaches to specific antigens. The antigens are prevented from infecting the rest of the body or their is a signal to have the antigen destroyed. Antibodies are made in your bone marrow and have the ability to memorize the antigens of pathogens. Once you develop the antibodies for a specific pathogen, you will already be protected in the event you are infected a second time with the same pathogen.

Vaccines

• A vaccine is given to people to help them develop antibodies to specific pathogens.

What is in a vaccine?

• a weakened or deadened

form of the pathogen

Due to a worldwide vaccination program, smallpox has been virtually eliminated since 1977.

Vaccines con’t

Common Vaccines in Canada:• chickenpox• hepatits B• influenza (flu)• measles·mumps• pertussis (whooping cough)

Not all infectious diseases have vaccines and therefore must be in other ways such as quarantines, bug spray, etc.Some recent diseases without vaccines include:

• SARS• AIDS• West Nile Virus

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 to make a 3D image.

• Ultrasound (sonography): produced by directing high frequency sound wavesat 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

Homework Check