Flashcards in CV Week 1 Deck (198)
Which of the following is not a role or function of the cardiovascular system?
a) dispose of CO2 and other byproducts of metabolism
b) vehicle for hormone transport and regulation of specific functions on target tissues
c) maintenance of body fluid
d) regulation of body temperature
e) provide adequate O2 supply and essential nutrients to select tissues
E - ALL TISSUES
The heart composed of two pumps organized in ______ and flow is described as ______
Elasticity of arteries has one impact on the intermittent nature of blood flow from heart?
reduces the force (attentuates)
Elasticity allows for a more _____ flow to tissues due to their ____ during the relaxation phase of the cardiac cycle
How is blood provided to the heart?
In systole, aorta and large arterial branches store part of energy by mechanical distension then in diastole energy is released like a rubber band when ventricles are relaxing back to heart.
True/False: All blood vessels control their internal diameter via precise control of smooth muscle
FALSE - capillaries don't!
Arteries have a thicker wall, are stiffer, and have a strong contractile apparatus due to what two features?
presence of elastic fibers and a more prominent smooth muscle layer
Why does pressure fall more quickly in the terminal segments of small arteries and arterioles in comparison to large arteries?
Increase in frictional resistance and increase in cross sectional area from extensive branching and multiplication
What causes dampening of pulsatile arterial flow at capillary level?
Distension of large arteries (compliance) and resistance of small arteries and arterioles - non-pulsatile flow
As cross-sectional area _______, velocity of blood flow _______
area, decreases [watch out!!! increases in respect to diameter tho!]
Where is the majority of blood found in CVS and why?
Majority of blood found in the veins and venules (67%) because systemic veins and venules act as a large reservoir of blood that can be rapidly mobilized upon demand
True/False: In the pulmonary vascular bed, most of the blood is found in the veins
FALSE - equally distributed btwn arteries, veins and capillaries
Why is the right ventricular wall much thinner and weaker than the left ventricular wall?
Left ventricle sustains pressures in the order of 100mmHg at rest whereas right ventricle pressures are around 15mmHg
What directly measures blood pressure?
pressure in the aorta
When is the LUB or S1 produced?
When the AV valves close
When is the DUB or S2 produced?
When the aortic and pulmonary valves close
What may produce S3?
rapid filling of the ventricles
What may produce S4?
Contraction of the atrium to get final bits of blood out
Where is the SA node located?
The SA node is located in the right atrium on the upper lateral side near the superior vena cava
The effective pumping of blood into the circulatory system depends on the ______
Arrhythmias can compromise mechanical performance and lead to life threatening decreases in ?
cardiac output and blood pressure
Action potential acts as a trigger for contraction of individual cardiac muscle cells through _______. This is important because it synchronizes contraction of the whole heart.
How are action potentials (and resting membrane potentials in myocytes generated?
Via the opening and closing of ion channel proteins - reason why important target for therapeutic drugs
Which myocytes are specialized for conduction of electrical impulse? (5)
SA node, cells of internal conduction track, AV node cells, Bundle of his, Purkinje Cells
Why is SA node considered the primary pacemaker of the cell?
It is SPONTANEOUS
The _______ carry electrical impulses that initiate atrial contraction
cells of internal conduction track
Describe the pathways of the cells of internal conduction track
Flow through 3 internal pathways and one interatrial conduction tract to activate AV node and left atrium
Where is the AV node located?
at the junction between the right atrium and IV septum
What is the delay time for AV node activation of ventricles?