Chapter 32: Circulation & Cardiovascular System

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Human Heart: Values

Values open & close to control blood flow

through heart

Atriventicular values

Tricuspid……. Right

Bicuspid………Left

Semilunar Values

Pulmonary

Aortic

Blood returning to heart from systemic circuit

Enters right atrium

Right atrium pumps through tricuspid value to

right ventricle

Right ventricle pump blood through pulmonary

value to the pulmonary circuit

Blood returning to heart from pulmonary circuit

Enters left atrium

Left atrium pumps though mitral value to left ventricle

Left ventricle pumps blood through aortic value

to the systemic circuit

Oxygen poor blood never mixes with oxygen rich

blood in humans

Heartbeat

Systole: Contraction of the heart chambers

Diastole: Relaxation of heart chamber

Pulse: Two-part pumping action that takes about

a second

Blood collect in atria, the atria contacts

pushes blood through tricuspid & mitral values into the resting lower

ventricles

This phase (the longer of the two) is called

diastolic

Second part begins when ventricles fill

Ventricles contract

This is called systole

After blood moves into the pulmonary artery & aorta the

ventricles relax

Stages in the Cardiac Cycle

SA Nodes (Sinoatrial Nodes): keeps the heartbeat regular

AV Nodes (Artioventricular node): signals ventricles to contract-

Purkinje Fibers

ECG (Electrocardiogram)

: A recording of electrical changes that occurring in myocardium during cardiac

cycle

Branches of Ventricular Bundle:

Parking Fibers:

Ventricular Fibrillation:

Rhymetic Contraction due to cardiac conduction system

When SA node triggers an impulse the atrial fibers

produce an electrical charge (p Wave)

Human Cardiovascular System includes two major circular

pathways:

Takes oxygen poor blood to the lungs

The beat of the heart supplies pressure that keeps blood

moving in the arteries

Systolic Pressure: result from blood forces into

the arteries during ventricular systole

Diastolic Pressure: is the pressure in the

arties during ventricular diastole

Skeletal muscle contraction pushes blood in the vein toward

the heart

Blood Pressure

Normally measured with a sphygmomanometer on the

brachial artery

Expressed in form of systolic & diastolic

Hypertension: High Blood Pressure

Atherosclerosis: Accumulation of fatty material in inner lining of arties

Stroke: Cranial arteriole bursts or is blocked

by ab embolus

Heart Attack: (Myocardial Infarction) coronary artery

becomes partially blocked

Angina Pectoris: Painful squeezing

Transprt substances to and from capillaries for exchange

with tissue fluid

Guard against pathogen invasion regulated body

temp

Buffers body PH

Maintains osmatic pressure

Clots prevent blood loss

Red Blood Cells

Small, Biconcave disk

Lack a nucleus & contains hemoglobin

Hemoglobin contains

4 globin protein chains

Each associated with an iron containing heme

Manufactured continuously in bone marrow of

skull, ribs, vertebrae & end of long bone

Carry oxygen, nutrients, and waste

White Blood Cells

Most types larger than red blood cells

Contain nucleus and lack hemoglobin

Lymphocytes protect cells from infection

WBC: Leukocytes

RBC: Erythrocytes)

Platelets

Involved in coagulation

Blood Clots consists of :

Platelets

Red Blood Cells

Red Blood Cells

Fiber

Capillaries very narrow- Tiny RBC’s must go through single

file

Wall of capillaries are very thin to facilitate diffusion of

nutrients, gases & waste

Oxygen & nutrients exit a capillary near the

atrial end

Carbon Dioxide & waste molecules enter a

capillary near the venous end

Determined by the presence or absence of surface antigens (agglutinogens)

Antigen A,B,& Rh(D)

Antibodies in the plasma