1 Circulation Concept Bio Ch. 19. Vocabulary 1. plasma 2. hemoglobin 3. platelet 4. pulmonary circulation 5. systemic circulation 6. atrium 7. ventricle.

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CirculationCirculation

Concept BioCh. 19

Vocabulary1. plasma2. hemoglobin3. platelet4. pulmonary

circulation5. systemic

circulation6. atrium7. ventricle8. valve9. pacemaker10. aorta11. artery

12.capillary13.vein14.lymph15.lymph nodes16.edema

I. Circulatory System Function

A. Larger organisms cannot rely on diffusion to move oxygen, nutrients, and wastes

B. Circulatory system transports materials using the heart, blood vessels, and blood

II. Blood

A. 3 General functions: 1. Transportation

a. Carries oxygen (from lungs) and nutrients (from digestive system) to body, and carbon dioxide from body to lungs

b. Carries waste products from cells to kidneys

2. Regulationa. pH

b. temperature

c. H2O levels

3. Protection

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B. Blood Characteristics

1. Blood Volume:a. 4-6 liters (ex: two or three 2-

Liter bottles of soda)

2. Blood Compositiona. 55% Plasma (liquid portion

of blood)1) 92% water2) carries nutrients, salts,

hormones, enzymes, wastes

b. 45% Blood Solids1) red blood cells2) white blood cells

3) platelets

Whole Blood Sample

Red blood cells

White blood cells

Platelets

Plasma

Sample Placed in Centrifuge

Blood Sample That Has Been Centrifuged

The separation of bloodThe separation of blood

C. Red Blood Cells (RBCs)

1. Function - most abundant cells in blood, transports oxygen and CO2

2. RBC Structurea. Shape - donuts w/o a hole,

maximizes surface areab. hemoglobin = a protein that

contains iron which binds to oxygen, red blood cells are made of this

3. only live for 100-120 days

4. RBCs are made in the bone marrow at a rate of 2 million/sec

5. dead RBCs are recycled in liver and spleen

D. White Blood Cells (WBCs)

1. Functiona. protection by

engulfing pathogen or creating antibodies

2. WBC Structurea. Larger than RBCs,

but not as common

E. Platelets

1. Function: a. Combines with plasma

proteins to initiate blood coagulation (formation of a blood clot/scab)

2. The processa. Takes between 5-15

minutes.

b. Platelets clump at a break in blood vessel and stimulate fibrin.

c. Fibrin forms the actual clot.

Blood Clotting Diagram

Break in Capillary Wall

Blood vessels injured.

Clumping of Platelets

Platelets clump at the site.

Clot Forms

Fibrin causes a clot. The clot prevents further loss of blood.

III. Circulation (movement of blood)A. Heart pumps over 1 million gallons

per year B. Over 60,000 miles of blood vesselsC. Major pathways:

1. Coronary circulation: blood flowing in the heart

2. Pulmonary circulation: the heart pumps oxygen-poor blood to the lungs where it is oxygenated and returned to the heart

3. Systemic circulation: oxygen-rich blood flows from the heart to the organs and tissues of the body, and oxygen-poor blood returns to the heart from the body

The Circulatory systemThe Circulatory system

PulmonaryPulmonary SystemicSystemic

IV. HeartA. The heart is divided

into two sides by the septum

1. Septum – A thick wall of tissue that separates the heart into left & right sides

2. Prevents oxygen-rich blood from mixing with oxygen-poor blood

SeptumSeptum

B. Four-chambered heart1. Two upper chambers

are called atriaa. Receive blood from

body and lungs

Right AtriumRight Atrium

Left AtriumLeft Atrium

2. Two lower chambers called ventricles

a. Pump blood to body and lungs

Right VentricleRight Ventricle

Left VentricleLeft Ventricle

3. The atrium & ventricle on the right have oxygen-poor blood returning from the body

Oxygen poor bloodOxygen poor blood

4. The atrium & ventricles on the left have oxygen-rich blood returning from the lungs

a. Left ventricle is more muscular since it pumps blood through the majority of the body

Oxygen rich bloodOxygen rich blood

C. Blood flows in one direction from atrium to ventricle and is controlled by one-way valves

Review!Review!Label Label Your Your

Heart!Heart!

The Circulatory systemThe Circulatory system

PulmonaryPulmonary SystemicSystemic

D. Heart Conduction

1. self-enervating organ - it maintains it’s own rhythm

2. pacemaker = a group cardiac muscle cells in the right atrium that are responsible for setting the contraction rhythm

3. impulses from the pacemaker spread through the walls (septum) of the heart.

4. impulse goes across the atria, then down to the ventricles

V. Blood Vessels (3 Main Types)A. Arteries

1. Carry blood AWAY from the heart to tissues and organs

2. Thick walled and muscular3. Aorta - largest artery, carries blood

from the heart to the rest of the body.

ArteryArteryCapillaryCapillary

VeinVein

B. Capillaries1. walls are very thin and porous to

exchange CO2 & O2

2. All exchange of materials happens in the capillaries What materials?

3. connect veins & arteries

ArteryArtery CapillaryCapillary VeinVein

C. Veins1. Carry blood to the heart.2. Thin-walled and muscular. 3. Many are located near and between

skeletal muscles (WHY?)4. Large veins contain valves to prevent

backflow of blood.

ArteryArtery CapillaryCapillary VeinVein

D. Blood Pressure1. Force of blood on the walls of blood

vessels2. Highest in arteries, lowest in veins3. Rises and falls with heart beat4. Normal is 120/80

a. First number is blood is being pumpedb. Second number is the heart refilling w/ blood

VI. Cardiovascular Disease

A. Atherosclerosis1. Atherosclerosis is

caused by fatty deposits which build up on the inner walls of the arteries (cholesterol)

2. The most common cause of heart attacks today

3. Kills over 1/2 million Americans a year

B. Hypertension1. High blood pressure2. Damages blood vessels and makes the heart work harder3. 95% of cases we don’t know exact cause, but salt intake

seems to be a factor4. No symptoms, but can cause strokes & contribute to heart

attacks.5. 25% of Americans have hypertension

C. Aneurysm1. Weakened, bulging artery wall; can burst and cause stroke or

heart attack2. Hypertension increases chances3. No symptoms!

D. Stroke1. Interruption of blood to the brain2. Caused by aneurysm, blood clot, or atherosclerosis3. Can lead to partial paralysis or death

E. Risk Factors1. Age2. Gender3. Genetics4. High fat or salt diet5. High blood pressure6. Smoking7. Stress8. Alcohol9. Obesity10. Inactivity

VII. Lymphatic SystemA. Fluid leaks into tissues

from the bloodB. Lymphatic system

collects fluids lost by blood and returns it to the circulatory system

C. lymph = fluidD. lymph nodes = trap

pathogens and produce WBCs

E. edema = when lymph vessels are blocked fluid builds up in the tissues

Lymphatic System

F. Thymus: releases lymphocytesG. Spleen: filters blood and, like the thymus, releases lymphocytes.H. Tonsils: are made up of groups of lymphatic tissues that help to defend the body against infection.