Chapter 4: Circulation (Cardiovascular System)Mr. Gagnon

4.1 The Body’s Transportation SystemKey Terms:- Cardiovascular System- Atrium- Ventricle- Vena Cava / Aorta- Pulmonary Arteries/Veins- CapillariesKey Concepts:- What is the function of the

cardiovascular system?- What role does the heart play

in the cardiovascular system?- What path does the blood take

through the c.s.?

Movement of Materials The cardiovascular system carries

needed substances to cells and carries waste products away from cells.

There are 3 major materials moved: Needed Materials- oxygen, glucose, etc. Waste products- Carbon dioxide Disease Fighters- White blood cells

(WBC) that fight disease causing microorganisms.

What is the Force of the Movement? The Heart is the

muscle that pumps blood throughout the body.

Each time a heart beats it pushes the blood through the cardiovascular system.

What Are the Structures of the Heart?

The Atrium receives blood into the heart.

The Ventricle pumps blood out of the heart.

The Valves separate the atriums and ventricles.

The body’s Arteries are blood vessels that carry blood away from the heart.

The body’s Capillaries exchange materials from the blood to the body cells.

The body’s Veins bring blood back to the heart.

The 2 Blood Loops in the BodyLoop 1: Heart to Lungs

Loop 2: Heart to Body

The LoopsLoop 1:

Blood travels from the heart to the lungs (deoxygenated).

CO2 leaves the blood and goes into the lungs.

O2 enters the blood and the blood returns to the heart (oxygenated).

Loop 2: Blood is pumped from

the heart (oxygenated) throughout the body, and then returns again to the heart (deoxygenated).

Anatomical Structure of the Heart

SeptumTri-Cuspid Valve

Bi-Cuspid Valve

4.2 Blood VesselsKey Terms:- Arteries- Veins- Capillaries- Coronary Arteries- Pulse- Blood PressureKey Concepts:- What are the functions of

arteries, capillaries, and veins?

- What causes blood pressure?

Arteries When blood leaves the

heart it travels through the arteries.

The arteries carry blood away from the heart.

The aorta sends blood through coronary arteries, the first set of arteries leaving the heart.

Arteries Arteries are generally

very thick. Arteries consist of 3

layers: Innermost: smooth

tissue that allows the blood to flow smoothly.

Middle: muscle tissue.

Outer: flexible connective tissue.

Arteries You may check your

pulse by lightly pressing on you wrist or neck.

When the ventricles of the heart contract, they send a spurt of blood out of the heart.

The artery walls expand to allow the blood flow and then narrow after it passes.

The muscles in the middle wall regulate blood flow.

The muscles contract to allow less blood flow to organs not active at the moment.

When you eat the arteries going to the stomach and intestines relax to allow more blood flow to fuel the digestive process.

Capillaries After blood flows

through the arteries, it goes to the capillaries.

In the capillaries, materials are exchanged between blood and body cells.

The materials are exchanged via diffusion.

Diffusion is the process by which molecules move from an area of high concentration to low concentration.

Example: There is a higher O2 level in the blood than in the cell. The O2 goes into the cell and CO2 leaves the cell.

Veins After blood goes

through the capillaries, blood flows through the veins to return to the heart.

Vein walls are thinner than artery walls, but still have 3 similar layers.

Blood flows though veins via 3 ways: 1- Muscles within the

vein contract. 2- Veins are located

near skeletal muscles and their contraction pushes the blood along.

3- Larger veins have valves, making sure the blood does not flow backwards.

Blood Pressure Pressure is the force

that something exerts over a given area.

The blood flow exerts force against the walls of blood vessels.

Blood pressure is caused by the force by which the ventricles contract.

Blood pressure is highest in the arteries and lowest in the veins.

Blood pressure is measured by an instrument called a sphygmomanometer.

4.3 Blood and LymphKey Terms:- Plasma- Red Blood Cells- White Blood Cells- Platelets- Hemoglobin- Fibrin- Blood Transfusion- Lymph- Lymph NodesKey Concepts:- What are the 4 components of

blood?- What determines the type of blood

that a person can receive in transfusion?

Blood Blood consists of:

Plasma Red Blood Cells White Blood Cells Platelets

Plasma Plasma is the liquid

part of the blood.

10% is dissolved materials.

90% is water.

The dissolved materials are molecules from digested foods like glucose and fats.

Chemical messengers are also carried in the plasma.

Proteins in the blood: Help regulate water. Created by WBC to fight

disease. Work with platelets to

form blood clots.

Red Blood Cells (RBC) RBC are primarily

used to transport O2 from the lungs to the rest of the body.

CO2 is carried primarily by plasma, however some hemoglobin carry CO2.

RBC’s are mostly made of hemoglobin, which is an iron-containing protein that binds chemically to oxygen molecules.

Hemoglobin turns bright red when oxygenated, dark red when deoxygenated.

White Blood Cells (WBC) WBC’s are the body’s

disease fighters. WBC’s have different

jobs: Alert others of a

foreign object. Produce chemicals to

fight invaders. Surround and kill the

invader.

There are fewer WBC’s than RBC’s at a 1 : 500-1,000 ratio.

WBC’s are larger than RBC’s

WBC’s have nuclei, RBC’s don’t.

WBC’s live for months and even years.

Platelets Platelets are cell

fragments that are found in the blood and form blood clots.

When platelets stick together to form a blood clot they release a chemical, creating a reaction that forms fibrin.

Fibrin weaves fibers creating a net that collect and stops blood cells.

Blood Types Why would you need

to know your blood type? If you lose a lot of

blood, you may need a blood transfusion.

A blood transfusion is the transference of blood from one person to another.

There are 3 types of blood: Type A: Can receive

blood from A and O. Type B: Can receive

blood from B and O. Type AB: Can receive

blood from A, B, AB, and O.

Type O: Can receive blood only from O.

Blood Types: Blood types are

determined by marker molecules found on the exterior of the blood (RBC’s).

Someone may become ill if a different type of blood is transmitted into the body.

The Lymphatic System: The lymphatic

system is a network of vein-like vessels that returns the fluid that leaks out of the cardiovascular system back into the blood stream.

Lymph is the fluid in the lymphatic system that consists of water and dissolved materials (ie: glucose).

Lymph nodes filter the lymph, trapping bacteria and other microorganisms that could cause disease.

4.4 Cardiovascular HealthKey Terms:- Artherosclerosis- Heart Attack- Cardiac Arrest- HypertensionKey Concepts:- What behaviors can help maintain cardiovascular health?

Cardiovascular Disease: Atherosclerosis is a

condition in which an artery wall thickens as a result of the buildup of fatty materials.

Cholesterol, a waxy fat like substance sticks to artery walls and makes a clog in the artery.

A heart attack occurs when blood flow to part of the heart muscle is blocked.

Cardiac arrest is when the heart seizes to pump blood effectively.

Cardiovascular Disease: Hypertension is

a disorder in which a person’s blood pressure is consistently higher than normal (>140/90).

In order to reduce your chance of cardiovascular disease you should: Exercise regularly Eat a well

balanced diet Don’t smoke