Blood Vessel Exam Review
Why do fluids leave the capillaries at the arterial end?
The net filtration pressure of the blood is higher at the arterial end than it is at the venous end.
What is(are) the physiological purposes of vasoreflexes?
To cause a generalized raising or lowering of blood pressure throughout the body and to selectively modify the perfusion of a particular organ by rerouting blood from one region of the body to another
The ____________ is the first vessel blood enters upon exiting the heart.
aorta
Just prior to entering capillary beds, ____________ have become extremely thin and present only a few layers of smooth muscle.
arterioles
True or False: Heart rate and stroke volume decrease with a decrease in parasympathetic stimulation.
false
True or False: Increased sympathetic stimulation causes vasodilation, bringing elevated blood pressure back to normal.
false
True or False: The lymphatic capillaries reabsorb as much as 20% of the fluid lost by the blood capillaries.
false
This shift in fluid balance at the arterial end is referred to as ______________ pressure.
hydrostatic
Where are arterial anastomoses, in which two arteries merge, found?
in the coronary circulation
The ____________ expand and recoil with every heart beat due to a histologically dominant network of elastic tissue in the tunica media.
large (elastic) arteries
The superior vena cava is an example of a ____________ that includes smooth muscle circularly and longitudinally arranged in the tunica media and externa, respectively.
large vein
This is the physical force exerted by a _______________ against a surface like a capillary wall.
liquid
Vasoconstriction primarily results from contraction of smooth muscle in the tunica __________.
media
The ____________ contain abundant but irregularly spaced smooth muscle with frequent valves present in the tunica interna.
medium veins
True or False: The net osmotic pressure is equal at both the arterial and the venous ends of the capillary.
true
The action potential from the brain to the heart travels along which nerve(s)?
vagus nerve
Fluid will then osmotically reenter at the ___________ end.
venous
After exiting the capillary, ____________ contain no muscle and are the first vessel that blood enters on its way back to the heart.
venules
This fluid delivers materials to the cells and removes its _____________
waste
Action potentials are conducted from the baroreceptors to the brain via which nerve?
Glossopharyngeal nerve
What are four things that cause increased flow?
- Increasing vessel radius - increasing blood velocity - increasing blood pressure - aldosterone hypersecretion
What is the order in which blood would pass through each vessel when blood enters the systemic circuit after exiting the heart?
1. conducting arteries 2. distributing arteries 3. resistance arteries 4. arterioles 5. capillaries 6. post-capillary venules 7. muscular venules 8. medium veins 9. venous sinuses 10. large veins
Approximately what percent of fluid that exits the capillaries at the arterial end reenters the capillaries at the venous end?
90%
The site of gaseous exchange, or ____________ , are characterized by extremely thin walls with only endothelium and basal lamina, which better suits diffusional requirements.
capillaries
Where are baroreceptors found?
carotid sinuses
Which of the following is not a mechanism that assists venous return? Pressure generated by the heart Gravity The skeletal muscle pump Cardiac suction Central venous pressure being greater than pressure in the venules
central venous pressure being greater than pressure in the venules
How do materials get from the blood to the surrounding tissues?
diffusion, filtration, absorption, and transcytosis
Typically, fluid filters ___________ the arterial end of a capillary.
out