Unit 10 Cardiovascular Flashcards
Describe the function of the cardiovascular system.
The primary function is transport of materials such as nutrients, water, and gases from external environments from cell to cell within the body.
What are the differences of veins and arteries?
Arteries are BVs that carry blood away from heart.
Veins are BV that carry blood to heart
Describe the flow of blood for Pulmonarmy circulation.
Blood enters the Right Atrium (From superior and inferior vena cava) ➡️ Right Ventricle ➡️ Pulmonary Artery (blood becomes oxygenated) ➡️ Pulmonary veins (left side)
Describe the flow of blood for Systemic Circulation.
Pulmonary veins➡️ Left atrium ➡️ Left ventricle ➡️ Aorta
What is the flow of liquid and gas in the cardiovascular system?
Liquids and glasses flow down to pressure gradients from regions of higher pressure to regions of lower pressure.
What is the mean BP in the aorta and vena cava?
~93 mmHG in the aorta
~2 mm HG in the vena cava
The heart creates higher pressure when it contracts (blood flows out of the heart into closed loop of blood vessels which are lower pressure)
Pressure is lost as blood moves through system
What is Hydrostatic pressure?
Fluid not moving and pressure is exerted in all directions
What is pericardial fluid?
Fluid that lubricates the external surfaces of the heart (the pericardium)
Pericarditis is inflammation of the pericardium, this may reduce this lubrication allowing friction rub.
What is myocardium?
Cardiac muscle covered by thin layers of epithelium and connective tissue
What’s is the role of the heart valves?
They prevent back flow of blood
Where are the AV, Tricuspid, and Bicuspid valve?
Av (Atrioventricular Valve): Guards between atrium and ventricles
—Tricuspid valve: separates the right atrium and right ventricle
— Bicuspid valve (Mitral valve): separates the left atrium and left ventricle
What are semilunar valves?
Semilunar valves are crescent moon-shaped; between ventricles and arteries
—Aortic valve: Between left ventricle and aorta
—Pulmonary valve: Between right ventricle and pulmonary trunk
What is chordae tendinae
Collagenous tendons that are attached to edges of valve flaps.
What are Papillary muscles?
Ventricular muscles that chordae are attached to and provide stability for, they cannot actively open and close the valve, they prevent back flow to the atrium.
What are autorhythmic cells ?
They make up 1% of cardiac muscle cells, called “pacemakers” and they set the rate of heartbeat and send signals for myocardial contraction.
These cells are small and contain few contractile fibers.
They do NOT have organized sarcomeres and do NOT contribute to contractile force of the heart
What are contractile muscles?
They make up 99% of the cardiac muscles (has lots of mitochondria) they are smaller than skeletal muscles and are striated, branched, and attached by intercalated disc
Describe intercalated disc and it’s components.
Cell junctions that consist of interdigitated membranes that have two components:
Desmosomes- Strong connections that tie adjacent cells together allow force created in one cell to be transferred to the adjacent cell.
Gap junctions: allow electrical signals to pass rapidly from cell to cell.
Describe the myocardial action potential.
In both autorhythmic and contractile contraction myocardium, Calcium plays an important role in action potential.
(Contrary to skeletal muscle and neurons which depends on Na and K)
Myocardial cells have longer action potentials due to Ca entry.
Phase 1: Depolarization; membrane potential becomes more positive. (+20)
Phase 2: Initial repolarization; cell begins to repolarize.
Phase 3: The plateau; the action potential flattens
Phase 4: The resting membrane potential stabilized back to -90
Describe the mechanism of the cardiac cycle.
(Heart at rest ; Completion of ventricular filling)
Heart at rest: Atrial and ventricular diastole
Completion of ventricular filling: Atrial systole
What is end-diastolic volume?
It is determined by venous return; depends on skeletal muscle pump, respiratory pump, sympathetic Innervation of veins.
What is stroke volume?
Amount of blood pumped by ventricles during single contraction
(70mL normal stroke volume)
What is systolic and diastolic?
Systolic is blood out of the heart
Diastolic is blood in the heart
Describe the sphygmomanometer measure of arterial pressure and define Korotkoff sounds.
Korotkoff sounds are create by the pulsating blood flow through the compressed artery.
First sounds heard represent the highest pressure in the artery and is recorded as the systolic pressure.
When the sound disappears is the lowest pressure in the artery and is recorded as the diastolic pressure.
BP: Systolic/Diastolic
What are the factors that influence cardiac output?
Heart rate and stroke volume