Physiology - Specialised circulations Flashcards
what two intrinsic factors control vascular resistance ?
a. autoregulation, mechanical compression
b. nervous , hormonal
c. perfusion pressure, mechanical compression
c. nervous and autoregulation
a.autoregulation, mechanical compression
the ability of an organ to maintain blood flow despite changes in perfusion pressure in the abscence of extrinsic factors is known as?
a. mechanical compression
b. autoregulation
c. regulatory mechanisms
b.autoregulation
sympathetic activation to the heart results in..
a. vasodilation
b. vasoconstriction
a.vasodilation
increased metabolic activity
vasodilation> SNS vasoconstriction
how much of the cardiac output us dedicated to the coronary blood flow?
a. 10%
v. 5%
c. 2%
d. 15%
v.5%
what condition is most significant in patients with coronary artery disease due to low coronary flow reserve?
a. heart failure
b. tachycardia
c. bradycardia
d. MI
b.tachycardia
true or false local metabolism increase eg lactic acid , hypoxia,k+ leads to vasodilation in skeletal muscle?
a. true
b. false
a.true
Sympathetic noradrenergic vasoconstrictor nerves act on which receptors?
a. a adrenoceptors
b. b2 adrenoceptors
a.a adrenoceptors
adrenaline acts on which receptor in skeletal muscle?
a. a adrenoceptors
b. b2 adrenoceptors
b. b2 adrenoceptors
which nerves are active at the start of excercise and can cause fainting?
a.Sympathetic noradrenergic vasoconstrictor nerves
bparasympathetic noradrenergic vasoconstrictor nerves
c. Sympathetic cholinergic vasodilator nerves
d. Parasympathetic cholinergic vasodilator nerves
c.Sympathetic cholinergic vasodilator nerves
which function does the splanchnic system serve?
a. capacitance
b. conduit
a.capacitance
which nerves act on the splanchnic system in hypotension/ ecercise to increase SV and CO?
a.Sympathetic vasoconstrictor nerves
bparasympathetic noradrenergic vasoconstrictor nerves
c. Sympathetic cholinergic vasodilator nerves
d. Parasympathetic cholinergic vasodilator nerves
a.Sympathetic vasoconstrictor nerves
true or false blood flow through the lungs = cardiac output
a. true
b. false
a.true
which is true of the pulmonary circulation?
a. low compliance and flow, low resistance and pressure
b. high compliance and flow, low resistance and pressure
b.high compliance and flow, low resistance and pressure
what happens to pulmonary vessels in hypoxic conditions to allow for V/Q matching?
a. vasoconstriction
b. venoconstriction
c. vasodilation
a.vasoconstriction
hypothalamus output to sympathetic NS makes up the nervous control of BF to which organ?
a. brain
b. skin
c. lungs
d. splanchnic system
b.skin
decreased O2 in the cerebral blood flow leads to..
a. vasoconstriction
b. venoconstriction
c. vasodilation
c.vasodilation
what happens when MAP in th brain <60 mmHg?
a. syncope
b. stroke
c. oedema
a.syncope
what happens when MAP in th brain <160 mmHg?
a. syncope
b. stroke
c. oedema
c.oedema
how is blood flow in the brain controlled?
a. neural and metabolic
b. metabolic and myogenic
b.metabolic and myogenic
what happens to cerebral vessels when MAP increases?
a. constrict
b. dilate
a. constrict
what happens to cerebral vessels when MAP decreases?
a. constrict
b. dilate
b.dilate
what does functional hyperaemia refer to?
a.active regions of brain giving more sympathetic output
b. inactive regions of the brain receiving increased blood flow
c. active regions of the brain recieving increased blood flow
d. active regions of the brain recieving more sympathetic tone
c.active regions of the brain recieving increased blood flow
what effect does increased intracranial pressure have on cerbral BF?
a. increase
b. decrease
b.decrease
bv compressed
what does an increase in brain volume lead to?
a. oedema
b. hydrocephalus
c. blockage in venous drainage
a.oedema
