Wednesday, September 15, 2010


CARDIOVASCULAR SYSTEM – responsible for the transport of O2 and CO2, nutrients and waste products.

I. Anatomy of the Heart

N  Apex- left at 5th intercostals space
N  Base-towards the shoulder at 2nd rib

Coverings and walls
Pericardium- a double layer sac that encloses the heart

Three layers
[  Epicardium- outer layer
[  Myocardium- middle layer
[  Endocardium- inner layer

Heart Chambers
[  Atria- upper receiving chambers
[  Ventricles- lower pumping chambers

Heart Valves
AV Valves- between atria and ventricles
[  Bicuspid- left AV valve
[  Tricuspid- right AV valve
Semilunar Valves
[  Pulmonic- at the pulmonary trunk
[  Aortic- at the aorta
Cardiac Circulation
[  Coronary arteries- supplies blood to the heart

II. Physiology of the Heart

Conduction System of the Heart

Two types of controlling system
1. Autonomic Nervous System
[  Symphatetic stimulation- increases heart rate
[  Parasymphatetic stimulation– decreases heart rate
2. Nodal System
[  SA Node – atrial contraction
[  AV Node
[  AV Bundle
[  Bundle Branches
[  Purkinje Fibers


Arteries- carries blood away from the the heart
Veins-brings blood back to the heart

[  Interna
[  Media
[  Externa

Physiology of Circulation
Arterial Pulse – alternating expansion and recoil of an artery that occurs with each beat of the ventricles

Blood Pressure – pressure the blood exerts against the inner walls of the blood vessels

[  Systolic Pressure- the pressure in the arteries at the peak of ventricular contraction
[  Diastolic Pressure- the pressure when the ventricles are relaxing

Peripheral Resistance- amount of friction encountered by a blood as it flows through the blood vessels

Factors affecting Blood Pressure
[  Neural factors
[  Renal factors
[  Temperature
[  Chemicals
[  Diet

Variations in Blood Pressure
Hypotension- low BP; systolic BP of below 100 mmHg
Hypertension- 140/90 or higher

Fluid Compartments- main location of water within the body

Intracellular Fluid (ICF)- 2/3 of the body fluids, contained within the living cells

Extracellular Fluid (ECF) – 1/3 of the body fluids;all body fluids outside the cells; includes blood plasma, interstitial, CSF and serous fluids

*Very small changes in electrolyte balance, the solute concentration in various fluid compartments cause water to move from one compartment to another

Sodium- the major extracellular cation, important for water balance, conduction of nerve impulse and muscle contraction

Potassium- the major intracellular cation, necessary for the conduction of nerve impulse and muscle contraction


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