peripheral circulation Flashcards
what are the categories of capillary structure
continuous, fenestrated and discontinuous
what is a continuous capillary
no cleft or pore (brain), cleft only (muscle)
what is a frenestrated capillary structure
clefts and pores (intestine)
what is a discontinuous capillary structure
clefts and massive pores (liver)
how much fluid is lost due to bulk flow a day
3 l
what are four causes of oedema
raised central venous pressure, lymphatic obstruction, hypoproteinaemia and increased capillary permeability
what are the two levels of control over smooth muscle surrounding the arterioles
local and central
what are the four triggers for local smooth muscle control
active metabolic hyperaemia, pressure autoregulation, reactive hyperaemia and injury
what triggers active metabolic hyperaemia
increase in exercise causes increased metabolite concentration in blood
what triggers pressure autoregulation
a decrease in pressure causing a build up of metabolites
what triggers reactive hyperaemia
blockage in blood supply
what is the purpose of the local injury response
to deliver leukocytes to injured area
what are central controls of smooth muscle control
sympathetic nerves (a1 receptors and constriction) and adrenaline (a1 receptors and constriction)
what are the four special regions of smooth muscle control
coronary circulation (b2 receptors prevent constriction), cerebral circulation (pressure regulation), pulmonary circulation (constriction when low in O2) and renal circulation (pressure autoregulation)
