1 Circulation Concept Bio Ch. 19

Vocabulary 1. plasma 2. hemoglobin 3. platelet 4. pulmonary circulation 5. systemic circulation 6. atrium 7. ventricle 8. valve 9. pacemaker 10. aorta 11. artery 12.capillary 13.vein 14.lymph 15.lymph nodes 16.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. Regulation a. pH b. temperature c. H 2 O 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 Composition a. 55% Plasma (liquid portion of blood) 1) 92% water 2) carries nutrients, salts, hormones, enzymes, wastes b. 45% Blood Solids 1) red blood cells 2) 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 blood

C. Red Blood Cells (RBCs) 1. Function - most abundant cells in blood, transports oxygen and CO 2 2. RBC Structure a. Shape - donuts w/o a hole, maximizes surface area b. hemoglobin = a protein that contains iron which binds to oxygen, red blood cells are made of this 3.only live for 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. Function a. protection by engulfing pathogen or creating antibodies 2. WBC Structure a. 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 process a. 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 vessels C. 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 system Pulmonary Systemic

IV. Heart A. 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 Septum

B. Four-chambered heart 1. Two upper chambers are called atria a. Receive blood from body and lungs Right Atrium Left Atrium

2. Two lower chambers called ventricles a. Pump blood to body and lungs Right Ventricle Left Ventricle

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

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

Review! Label Your Heart!

The Circulatory system Pulmonary Systemic

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 muscular 3. Aorta - largest artery, carries blood from the heart to the rest of the body. Artery Capillary Vein

B. Capillaries 1. walls are very thin and porous to exchange CO 2 & O 2 2. All exchange of materials happens in the capillaries What materials? 3. connect veins & arteries Artery CapillaryVein

C. Veins 1. 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. ArteryCapillary Vein

D. Blood Pressure 1. Force of blood on the walls of blood vessels 2. Highest in arteries, lowest in veins 3. Rises and falls with heart beat 4. Normal is 120/80 a. First number is blood is being pumped b. Second number is the heart refilling w/ blood

VI. Cardiovascular Disease A. Atherosclerosis 1. 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. Hypertension 1. High blood pressure 2. Damages blood vessels and makes the heart work harder 3. 95% of cases we don ’ t know exact cause, but salt intake seems to be a factor 4. No symptoms, but can cause strokes & contribute to heart attacks % of Americans have hypertension C. Aneurysm 1. Weakened, bulging artery wall; can burst and cause stroke or heart attack 2. Hypertension increases chances 3. No symptoms!

D. Stroke 1. Interruption of blood to the brain 2. Caused by aneurysm, blood clot, or atherosclerosis 3. Can lead to partial paralysis or death E. Risk Factors 1. Age 2. Gender 3. Genetics 4. High fat or salt diet 5. High blood pressure 6. Smoking 7. Stress 8. Alcohol 9. Obesity 10. Inactivity

VII. Lymphatic System A. Fluid leaks into tissues from the blood B. Lymphatic system collects fluids lost by blood and returns it to the circulatory system C. lymph = fluid D. 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 lymphocytes G. 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.