ch 20 pt 3 Flashcards
What are the 3 types of capillaries?
Continuous, fenestrated, and sinusoid
What are continuous capillaries?
Form a continuous lining and tight junctions connect cells for smaller molecules (glucose) to pass
What is intercellular clefts?
Gaps between endothelial cells of capillary wall
Where is continuous capillaries found?
In muscle, skin, lungs, central nervous system
What is fenestrated capillaries?
Continuous lining but cells have fenestrations (pores) and allow movement of smaller plasma proteins
Where is fenestrated located?
Intestine and kidney capillaries
What is sinusoids?
Incomplete lining with large gaps and allows large substances to pass
Where is sinusoids located?
Bone marrow and spleen
What are capillary beds?
Groups of capillaries functioning together
What is metarteriole?
A vessel branch of an arteriole
What do thoroughfare channels not have?
No smooth muscle cells
What does postcapillary venule do?
Draining bed
What is precapillary sphincter?
Smooth muscle ring at true capillary origin
Sphincter relaxation does what
Permits blood to flow into true capillaries
Sphincter contraction does what
Causes blood to bypass capillary bed
