Circulatory System

3 Primary Components

1. Heart2. Blood3. Vessels

-60,000 miles of vessels in our body-100,000 beats/day-6 quarts of blood in our body

Cardiovascular System

FX: allows for blood movement throughout body so that:1. oxygen/nutrients can get to body cells2. waste can be removed from cells

Heart: hollow, cone shaped, muscular pump-located in the thoracic cavity, behind

the sternum-2nd rib to the 5th inter costal space-about as large as your fist4 Layers:1. Pericardium: connective tissue

around the heart2. Epicardium: upper layer of

heart3. Myocardium: middle layer that

contains cardiac muscle and vessels

4. Endocardium: inner layer that lines the interior of the heart

Heart Chambers

Evolution1. open circulatory systems (arthropods)2. closed circulatory systems (vertebrates)

ex. Fish, amphibian, reptile, and mammal hearts

Four Chambered Heart

-Two Atria: left and right – receive blood from veins – thin wall

-Two Ventricles: left and right – send blood to the interior

-Septum: separates right and left halves

-Arteries: send oxygenated blood from the heart (except pulmonary artery)

-Veins: bring deoxygenated blood back to the heart (except pulmonary vein)

Pulmonary Circulation

Right Ventricle Pulmonary Artery

Lungs

Pulmonary VeinLeft Atrium

Left Ventricle

General Heart Anatomy

1. Aorta- large muscular vessel that carries oxygenated blood away

2. Vena Cava- large vein that carries deoxygenated blood to heart (superior/inferior)

3. Atrium-thin walled chamber

4. Ventricle-thick muscle walled chamber

Valves: mechanical devices that control fluid flow by opening/closing

Cuspid Valves (point)(Atrioventricluar)1. Tricuspid Valve2. Bicuspid Valve

P. 665/666

Semilunar Valves1. Pulmonary Semilunar2. Aortic Semilunar

Blood Pathway Through the Heart

1. Right atrium receives deoxygenated blood from the body tissue via the inferior/superior vena cava

2. Blood in right atrium passes through the atrioventricular oriface. Tricuspid valves open into right ventricle when right atrium contracts

3. Right AV oriface has a tricuspid valve which when closed, prevents back flow of blood into R atrium

Blood Pathway Through the Heart

4. When the ventricle contracts, blood is forced into the pulmonary trunk. The pulmonary trunk leads to the pulmonary arteries which take deoxygenated blood to the lungs for oxygen.

5. Oxygenated blood returns to the heart via pulmonary veins to the left atrium

6. Atrium wall contracts and moves the blood past the bicuspid valves to the left ventricle

7. Left ventricle contracts (bicuspid close) and blood passes into the aorta and systemic ciculation

Actions of the Heart

Heart chambers don’t function independently

-atrial walls contract-while the ventricle walls

relax

Heart Sounds

-two distinguishable sounds “lub-dub”

-associated with closing of valves- “lub” – AV valves close: onset

of systole (ventricular contraction)

- “dub” – semilunar valves snap shut: diastole (ventricular relaxation)

- Heart murmur: a malfunctioning valve – blood flows silently unless obstructed

Cardiac Cycle

1. Medulla oblongata: sends impulse to the sino-atrial node (SA node) on the right atrium (atrial contraction)

2. SA sends depolarization signal to atrio-ventricular node (AV node). 0.6 sec delay allows for atria to relax

3. AV node sends impulse to Bundle of His signal to branches which causes ventricular contraction

Medulla-oblongata

Vagus nerve

SA node

AV node

Bundle of HIS

Bundle Branches

Electro Cardiogram (ECG)- P-Wave: depolarizaiton of

the atria before atrial contraction

- QRS Complex: ventricular depolarization before ventricular contraction

- T-Wave: ventricular repolarization

- PR interval: atrial contraction

- QT interval: ventricular contraction

Blood Vessels

Arteries Arteriolescapillariesvenulesveins

-exchange nutrients, gases, waste occurs in the capillaries

-Veins/venules drain blood from capillaries and return it to right atria

-arteries carry blood away from heart

Vasoconstriction vs. Vasodilation

- Vasoconstriction: decrease in blood vessel diameter(smooth muscle contracts; sympathetic nerve fiber)

- Vasodilation: increase in blood vessel diameter(smooth muscle relaxes)

Heart Disease

1. Myocardial infarction (heart attack)

- 50% of U.S. deaths- Sedentary lifestyle

(outdoor indoor)- Tissues that die due to

obstructions in blood vessels (pumps blood to itself)

Heart Attack Symptoms

- Pressure in chest, tightening behind sternum

- Radiating pain to nech, arms, shoulders, elbow, and back

- Nausea and difficulty breathing

- Some are silent

Risk Factors

1. High cholesterol2. Sugar diabetes (Type II)3. Hypertension (high

blood pressure)4. Stress5. Smoking6. Family history7. Sedentary lifestyle8. Male

Preventative Maintenence

1. Know family history2. Watch your diet3. Exercise4. Periodic checkups5. Don’t smoke6. Reduce stress

(decrease your load; pray/meditate)

2. Thrombus: a blood clot abnormally forms in a vessel- Coronary thrombus:

heart (MI)- Cerebral thrombus:

cerebrum (stroke)- Pulmonary thrombus

3. Embolus: a blood clot that breaks away and is carried by blood flow

- anticoagulants: chemicals used to thin blood (aspirin, heparin, wharfarin)

4. Atherosclerosis: build up of fat deposits in arteriesCauses:-excessive saturated fats-high cholesterol

Cholesterol:-High density lipoprotein

(HDL) = bad- Low density lipoprotein

(LDL) = good

5. Ischemia: blood oxygen deficiency in myocardial tissue

Heart Procedures

1. Open heart surgery

2. By-pass surgery of coronary arteries

3. Cardio myoplasty

4. Angioplasty Procedures

Blood: connective tissue with cells in a fluid matrix

Centrifuged Blood:-45% cells (hematocrit)-55% fluid (plasma/yellow)-average adult has 5 liters-8% of our body weight-mean T = 38 C (100.4 F)

Functions

1. Transport:

- Oxygen and carbon dioxide

- Waste to liver and kidneys

- Carries hormones to target cells

- Carries heat to the skin- Nutrients from digestive

system

2. Protection:

a) Role in inflammation (diseases ending in “itis”)

b) Immunity:-leukocytes destroy viruses, bacteria, and protist-antibodies neutralize pathogens

c) Clotting-platelets initiative clotting

3. Regulation:

-water to and from tissues-buffers acids and bases-electrolyte and salt

balance

Blood Cell Types

- Made in bone marrow1. RBC – erythrocytes2. WBC –leukocytes3. Platelets – cell

fragments

Red Blood Cells - Erythrocytes

FX: pick up oxygen in lungs and carry it to tissue/pick up CO2 and unload it in lungs

- Contains hemoglobin- Biconcave disc that lack

nuclei- RBC counts determine

disease diagnosis

RBC Life Cycle

- Circulates 120 days- Removed by

macrophages in liver and spleen

- New RBC controlled by erthropoietin hormone and proper diet

Associated conditions:1. Anemia – deficiency in

RBCs2. Hypoxia – inadequate

oxygen in tissues

White Blood Cells - Leukocytes

FX: immune system – phagocytosis –

-can move out of vessels and leave circulation

Five Types of WBCs

1. Monocytes: (Agranulocyte)

-activate immune system-contain lysosomes-phagocytize foreign

particles

Five Types of WBCs

2. Lymphocytes: (Agranulocyte)

-specific immunity function

-destroy cancer cells, virus, and foreign cells

-attacked by HIV

Five Types of WBCs

3. Basophil: (Granulocyte)

Two types:-contains heparin –

inhibits blood clotting-contains histamine –

increases blood flow to injured tissue

Five Types of WBCs

4. Eosinophils: (Granulocyte)

-control inflammation from blood tissue damage

-control allergic reactions

Five Types of WBCs

5. Neutrophil: (Granulocyte)

-phagocytize pathogens-multi-lobed nucleus

WBC Disorders

1. LeukemiaAcute – spreads rapidlyChronic – spreads slowly-death is caused by

internal bleeding and infection

-vinblastine/vincristine used in treatment

WBC Disorders

2. Mononucleosis:- Viral disease (Epstien-

Barr)- Young adults- Excessive number of

monocytes- Tired, achy, fever, sore

throat- Rest for weeks – no

cure

Blood Types and Transfusions

Early problem of transfusion:Agglutination: clumping of red blood cells causing

deathCaused by two proteins:1. Aggluntinogens: in red blood cells2. Agglutinins: found in plasma

Blood type determines the agglutinogens which cause transfusion reactions

Blood Types

- Each blood type has an “anti” factor in blood plasma – agglutinins

Two Types of Agglutinogens: A and B Two Types of Agglutinins: Anti A and Anti BType A bonds with Anti A = agglutination=deathType B bonds with Anti B= aggluntination=deathType AB has no agglutininType O has both agglutinins

Transfusion:

A A O

B B O

AB AB A,B,O

O O none

Blood Type Preferred Donor Possible Emergency

Rh Factor

- Another blood type- Discovered in Rhesus

monkeys- 85% of Americans are

Rh+ (Rh agglutinogens)- Rh- has no

agglutinogens- Rh- can receive Rh+

blood not vice versa

Rh factor and Pregnancy

- Maternal and fetal blood mix

- If Rh- mother recieves Rh+ blood agglutination will occur (or vice versa)

- 1st pregnancy typically unaffected

- Mother is sensitized for second

- Treated wit ROGAM