Questions and Answers
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.
Approximately what percent of fluid that exits the capillaries at the arterial end reenters the capillaries at the venous end?
90%
The lymphatic capillaries reabsorb as much as 20% of the fluid lost by the blood capillaries.
False
The net osmotic pressure is equal at both the arterial and the venous ends of the capillary.
Signup and view all the answers
Which of the following is not a mechanism that assists venous return?
Signup and view all the answers
Which of the following does not aid in venous return?
Signup and view all the answers
How do materials get from the blood to the surrounding tissues?
Signup and view all the answers
Where are baroreceptors found?
Signup and view all the answers
Action potentials are conducted from the baroreceptors to the brain via which nerve?
Signup and view all the answers
The action potential from the brain to the heart travels along which nerve(s)?
Signup and view all the answers
Heart rate and stroke volume decrease with a decrease in parasympathetic stimulation.
Signup and view all the answers
Increased sympathetic stimulation causes vasodilation, bringing elevated blood pressure back to normal.
Signup and view all the answers
Where are arterial anastomoses, in which two arteries merge, found?
Signup and view all the answers
What is(are) the physiological purposes of vasoreflexes?
Signup and view all the answers
Typically, fluid filters _______ the arterial end of a capillary.
Signup and view all the answers
Fluid will then osmotically reenter at the _______ end.
Signup and view all the answers
This fluid delivers materials to the cells and removes its _______.
Signup and view all the answers
This shift in fluid balance at the arterial end is referred to as ____________ pressure.
Signup and view all the answers
This is the physical force exerted by a _______ against a surface like a capillary wall.
Signup and view all the answers
The ________ is the first vessel blood enters upon exiting the heart.
Signup and view all the answers
The ____________ expand and recoil with every heartbeat due to a histologically dominant network of elastic tissue in the tunica media.
Signup and view all the answers
Just prior to entering capillary beds, _____________ have become extremely thin and present only a few layers of smooth muscle.
Signup and view all the answers
The site of gaseous exchange, or ____________, are characterized by extremely thin walls with only endothelium and basal lamina, which better suits diffusional requirements.
Signup and view all the answers
After exiting the capillary, _________ contain no muscle and are the first vessel that blood enters on its way back to the heart.
Signup and view all the answers
The __________ contain abundant but irregularly spaced smooth muscle with frequent valves present in the tunica interna.
Signup and view all the answers
The superior vena cava is an example of a ________ that includes smooth muscle circularly and longitudinally arranged in the tunica media and externa, respectively.
Signup and view all the answers
Vasoconstriction primarily results from contraction of smooth muscle in the tunica __________.
Signup and view all the answers
Study Notes
Capillary Dynamics
- Fluids exit capillaries at the arterial end due to higher net filtration pressure compared to the venous end.
- Approximately 90% of fluid leaving capillaries at the arterial end reenters at the venous end.
- The net osmotic pressure remains equal at both ends of the capillary.
Lymphatic System
- Lymphatic capillaries do not reabsorb as much as 20% of fluid lost by blood capillaries; this statement is false.
Venous Return Mechanisms
- Central venous pressure must not be greater than pressure in venules to assist venous return.
- Venule suction does not aid in venous return.
- Venous return involves mechanisms like muscle contractions, respiratory movements, and the presence of valves in veins.
Transport of Materials
- Materials move from blood to surrounding tissues via diffusion, filtration, absorption, and transcytosis.
Baroreceptors and Nerve Pathways
- Baroreceptors are located in carotid sinuses and help monitor blood pressure.
- Action potentials from baroreceptors travel to the brain via the glossopharyngeal nerve.
- The vagus nerve conveys action potentials from the brain to the heart.
Sympathetic Stimulation and Heart Function
- A decrease in parasympathetic stimulation does not lead to a decrease in heart rate and stroke volume.
- Increased sympathetic stimulation does not cause vasodilation; it typically constricts blood vessels to raise blood pressure.
Arterial Anatomy
- Arterial anastomoses occur where two arteries merge, primarily found in coronary circulation.
- Large elastic arteries expand and recoil due to elastic tissue in the tunica media.
Capillary Structure and Function
- Arterioles become extremely thin with few smooth muscle layers before entering capillary beds.
- Capillaries, the site of gaseous exchange, possess very thin walls composed of only endothelium and basal lamina.
Venous System
- After capillaries, venules lack muscle and are the initial vessels returning blood to the heart.
- Medium veins exhibit irregularly spaced smooth muscle and frequent valves in the tunica interna.
- The superior vena cava is an example of a large vein featuring both circular and longitudinal smooth muscle arranged in the tunica media and externa, respectively.
Vascular Physiology
- Vasoconstriction results from the contraction of smooth muscle in the tunica media.
- Hydrostatic pressure drives the shift of fluid balance at the arterial end of capillaries.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge about blood vessel functions with these flashcards. Focus on fluid dynamics in capillaries, including filtration pressures and reabsorption percentages. Perfect for students studying anatomy or physiology.
