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