LECTURE 7: capillaries and lymphatics Flashcards
arteriole
things that drain into capillary beds, the smallest arteries
what is the most common capillary in the body
continuous capillary
purple dots in continuous capillary diagram
nuclei
blood flow through lymph node
afferent to efferent
what does the absence of RBC’s indicate
lymphatic system as lymph channels are a lot thinner
venous drainage and pulmonary circuit
bringing deoxygenated blood back to right side of heart, carried via artery in pulmonary circuit to lungs for reoxygenation carried back via pulmonary vein to left side of heart to distribute back into systemic circuit.
gas exchange
a passive process to move oxygen from red blood cells into interstitial space. To be done efficiently you want them as close to one another as possible
best example of sinusoidal capillaries
liver
do sinusoidal capillaries allow for passage of RBC’s?
No- the gaps won’t allow red blood cells out of capillaries even though they are bigger
are sinusoidal capillaries exchanging gas or other stuff? why?
usually other stuff
- Lumen diameter is much greater so not as interested in gas exchange
structural advantage of fenestrated capillaries for RBC’s
structurally designed to bring red blood cell close to wall
difference between fenestrated capillaries and continuous capillaries
the fenestrations that are holes in cytoplasm of endothelial cell that are so small a blood cell can’t pass through
how many RBC’s can fit through a continuous capillary? why?
One red blood cell at a time can fit down the hole. Structurally designed to fit one blood cell down lumen at a time. Capillary wants to bring blood cell as close to wall of capillary as possible to limit distance for exchange
can passive diffusion occur in continuous capillaries?
No- Need vesicles that carry things that cannot move by passive diffusion
