cardiovascular system; bv circulation pathways

simple circulatory pathway

heart

arteries

arterioles

capillary bed

venules

veins

tunica interna

innermost

lines the lumen (blood)

what kind of epithelium does tunica interna have 

simple squamous

what does the tunica interna do

selectively permeable 

secretions allow vasoconstriction or vasodilation 

tunica media 

middle layer 

smooth muscle 

what is important for the tunica media

collagen and elasticity

tunica externa

outermost layer

connective tissue

what does the tunica externa do

passageway for transport

anchors vessels

3 types of vessels

veins arteries capillaries

veins 

low blood pressure 

thin walls 

what happens if skeletal muscle is activated

valves are activated

arteries

elastic due to vasoconstriction and dilation

how do arteries change with age 

they stiffen 

carotid sinus

baroreceptor

control bp

carotid bodies

chemoreceptor

o2 ph co2

what nerve controls the carotid body and sinus

glossopharyngeal

what nerve controls the aortic body and baroreceptor 

vagus 

which part does info go to control blood

medulla

capillaries

exchange thru vessel walls

only made of endothelium and basement membrane

very close together for easier transport

can capillaries supply blood to tissues simulatenoiusly at once 

no

how much percent of capillaries are shut down at any given time

75

types of capillaries

fenestrated continuous sinusoid

continuous 

tight junctions between endothelium 

perictyes 

intercellular clefts 

intercellular cleft

allows small solutes to pass

perictye location

surround capillaries 

pericyte function

have contractile proteins which have actin and myosin

this changes the diameter which therefore regulates blood flow and blood pressure

that can pericytes do

trasnform into different cells when needed

ie: muscle and endothelium cells

growth and repair

fenestrated 

filtration and reabsorption 

sinusoids

irregular blood filled spaces

wide endothelial gaps

cells fenestrated

what can kind of cells can pass thru sinusoids

large molecules

like albumin

capillary exchange movement

2 way movement

from blood to tissue

from tissues to blood

diffusion

main

high to low

lipid soluble substances

transcytosis

endocytosis transport and exocytosis

large molecules ; insulin

filtration occurs on 

arterial end 

filtration needs

hydrostatic pressure

hydrostatic pressure

the force of blood pushing against the capillary wall

drives fluid out

Reabsorption

Occurs at the venous end of the capillary.

filtration takes fluid

out of capillary

reabsorption is driven by

osmotic pressure

caused mainly by plasma proteins (albumin).

reabsorption pulls 

fluid back into the capillary from the tissue space

hydrostatic pressure on arterial end

high

hydrostatic pressure on venous end

low

colloid osmotic pressure

draws fluid into capillary

oncotic pressure

blood cop-tissue cop

portal system 

blood passes thru 2 consecutive capillary networks before returning to the heart 

where are portal systems found

hypothalamus

liver

anastomosis

shortcut in the circulatory system where vessels meet and blood can take an alternate route if one path is blocked or narrowed.

hepatocytes can

remove glucose or add protein to blood 

hepatic portal system

Gastric vein Splenic vein Superior mesenteric vein Inferior mesenteric vein Hepatic portal vein Hepatic sinusoids Hepatic central veins Interlobular vein Hepatic vein inferior vena cava

hepatic sinusoids is processed by

hepatocytes

hepatocytes need 

o2 

portal venule needs portal arteriole for

oxygen

hepatocytes flow in

opposite direction of blood

edema 

fluid retention swelling 

causes of edema

heart failure

kidney failure

protein deficiency

liver failture

pregnancy

right ven fails

systematic

left fails 

pulmonary