Cardiovascular Physiology Flashcards
What is the function of cardiovascular system?
Transport:
- gases (oxygen, carbon dioxide)
- substrates for energy production (glucose, ATP, etc)
- Waste products
- Water and minerals (sodium, potassium, calcium, magnesium, phosphate, sulfate)
- Hormones
- Immunocompetent cells, globulins, albumin
- Heat
What are the differences between right and left pump?
Left pump is a low pressure system as it pumps to pulmonary circulation while right pumps to body
It is a low resistance system- pumps 5 liters of blood to pulmonary arteries, this is possible because there is little resistance in pulmonary arteries
Describe the heart
Consists of two pumps-the ventricles, connected in series
- ventricles are encircled by musculature and equipped with valves
- valves ensure a unidirectional flow of blood
- the septum divides the heart into two halves, each including one ventricle and one atrium
- Atria collect the blood returning to the heart
- The right ventricle pumps blood through the lungs (=pulmonary circulation )
- The left ventricle pumps blood through all body tissues (=systemic circulation)
How much of the blood is pumped from atria to ventricle?
About 25% to one third
What is the function of spiral arrangement?
The spiral arrangement of ventricular arrangement of ventricular muscle allows ventricular contraction to squeeze the blood upward from the apex of the heart
Briefly describe coronary circulation
- Coronary circulation: receives about 5% of CO
- Originates from base of aorta behind cusps of aortic valves. Left coronary blood flow is highest during diastole, right coronary blood flow
When does heart gets it nourishment?
Right ventricles releases oxygenated blood during systole which some of flows through coronary vessels
Right heart is during systole (due to being less muscular)
Left side of heart is more muscular, is when diastole occurs
Describe the base of the heart
- the base of the heart is formed by the heart ‘skeleton’
- All four valves are attached to it
- It consists of fibrous and cartilaginous structures
Explain the cardiac cycle
- Late diastole: both sets of chambers are relaxed and ventricles fill passively about 75% or 2/3 full(passive filling)(atrial pressures higher then ventricular pressure)
- Atrial systole: atrial contraction forces a small amount of additional blood into ventricles
- Isovolumic ventricular contraction: first phase of ventricular contraction pushes AV valves(all valves closed)(pressure rises to above 80mm/Hg to trigger ventricular ejection) closed but does not create enough pressure to open semi lunar valves
- Ventricular ejection: as ventricular pressure rises and exceeds pressure in the arteries, the semilunar valves open and blood is ejected
- Isovolumeric ventricular relaxation: as ventricles relax, pressure in ventricles falls, blood flows back into cups of semilunar valves and snaps them closed
What 8s the top number in blood pressure?
Top- peak systolic pressure
What is residual volume?
Residing blood in ventricle after blood is ejected
Describe the heart sounds
S1 and S2 (normally heard)
Heart sounds according to coratid pulse(lab then dub)
Opening if the valve is usually silent unless it’s pathological (calcified )
Heart sound also due to turbulence and volume blood flow
S1- closure of AV valves, (M1 and T1 component)
S2- closure for semilunar valves
S3 and S4 are not normally heard
S3 is in children and young adults up to 35-blood flows into ventricles(rapid filling)(it is physiologic, after 35 is pathologic
S4- atrial contraction (usually pathological) stiff ventricle causes turbulence when blood enters
What is between S1 and S2?
Systole
What is between S2 and S1?
Diastole
Why is diastole longer?
Waiting for ventricles to fill
