cardiovascular system
Post on 15-Nov-2014
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JEEVAN KISHORETBILISI STATE MEDICAL UNIVERSITY, GEORGIA
PHYSICS OF CARDIOVASC
ULAR SYSTEM
Cardiovascular
systemBLOOD
VESSELS
HEART
BLOOD
• SUPPLY ENERGY…
[FUEL FROM FOOD]
•SUPPY OF OXYGEN FROM THE AIR WE BREATHE…
• DISPOSE BY PRODUCT OF
COMBUSTIONS… [CO2, H2O, Heat, etc…]
HEART
DOUBLE PUMP
PROVIDES FORCE FOR CIRCULATION OF BLOOD
2 MAJOR SYSTEM OF CIRCULATION…
ù Pulmonary circulation ù Systemic circulation
4 CHAMBERED ù Right atrium ù Left atrium ù Right ventricle ù Left ventricle
BLOOD VESSELS
FLOW REGULATI
ON
and
ARTERIES
ARTERIOLES
VEINS AND VENULES
CAPILLARIES
ARTERIES…
Thick compliant walls…ù Must
withstand high BP
ù Puncture can be fatal
ù High BP damages
arterial walls, leading to
vessel disease
Large diameter…ù Low flow resistance
ù Transmits entire heart pressure to arterioles
ARTERIAL BLOOD PRESSURE
2 typesSystolic
ventricles contract, arteries expand, hold 2/3
of stroke volume
Diastolicventricles relax, arteries
recoil, squeezing blood to arterioles
VEINS AND VENULES…
ù very large radius and thin wallùLargest cross-sectional areaù Negligible flow resistanceù Large volume: holds 75% of blood and acts as blood reservoir
Maximize exchange… ù Huge surface area (~ football field) ù Thin walls (no smooth muscle) to facilitate diffusion ù Low blood velocity (~ 1 mm/s) gives more time for exchange
Flow is regulated by precapillary sphincter…
Only 1 of 30 capillaries is open in resting muscle…
CAPILLARIES…
Congestive heart failure
CHF is characterized by a heart that is weak and
enlarged due tov greatly increased ventricular filling.
But for a very high ventricular filling, cardiac output falls.Heart attackdeath of heart muscle
due to blockage of coronary arteries
Vessel disease
Cardiovascular
Disease
Symptoms of heart attack
ùThe most common symptom (> 80%) is a heavy, persistent pressure in the center of the chest, lasting 10 min or more.
ù The pain often radiates upward to the neck, jaw, or left arm and shoulder. Weakness and profuse sweating are also common.
ù Sometimes the pain is a burning sensation, similar to heartburn.
ù Rarely associated symptoms: brief and sharp pain, pain on breathing
THANK U
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