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1
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
5
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.