Week 2 Flashcards
(50 cards)
What embryonic tissue is the heart derived from?
Splanchnic mesoderm
what embryonic tissue is basically everything around and associated with the heart developed from?
Neural Crest mesenchyme
What do the right and left aortic arches in a fetus become in an adult
right = subclavian artery left = mature aortic arch
What aortic arch forms the ductus arteriosus, which then becomes the ligamentum arteriosum?
the left 6th aortic arch
what in a fetus becomes the medial umbilical ligaments?
umbilical arteries
What does the umbilical vein become in adults
round ligament of the liver (ligamentum teres)
What becomes the foramen ovale, and what becomes the valve of the foramen ovale?
secondary septum becomes foramen ovale
primary septum becomes the valve
In what layer of the heart are the purkinje fibers?
endocardium
name of the tissue between myocytes
endomysium
The contractile state of vascular smooth muscle mainly depends on what molecule?
Myosin light chain, and how much it is phosphorylated. If it is more phosphorylated, the muscle is more contracted
pathway when nor epi hits an alpha 1 receptor
NE binds alpha 1 (alpha 1 less sensitive to epi
g-protein
phospholipase c
PIP2 -> IP3
IP3 stimulates Ca release from SR, contraction
Pathway when epi hits a beta2 receptor
Epi binds beta2 (beta 2 less sensitive to NE)
g-protein (Gs in this case)
adenelyl cyclase
ATP -> cAMP
Ca uptake by SR, also Ca released from cell, membrane hyperpolarization, relaxation
*only found in some organs, less of these in the vasculature than alpha 1
Mech of Nitric Oxide
what cells does it come from
Easily diffuses across cell membrane and stimulates cGMP production
cGMP inhibits Ca2+ entry, activates K+ channels -> hyperpolarization
activates MLC phosphatase
ednothelial cells of the vessels
what system is most important in reflex control of the vascular smooth muscle
sympathetic
Pharmacomechanical coupling in VSM is able to induce contraction through two mechanisms: opening of ROCs and the release of calcium via the sarcoplasmic reticulum. What component of this pathway is necessary to induce either of these mechanisms?
G proteins
do baroreceptors play a role in long term control of arterial pressure?
for boards, no
for her quiz, yea. after sustained increases in blood pressure they “incompletely” set that high pressure as being normal.
cushing reflex
rise in intercranial pressure results in a rise in blood pressure to keep the vessels in the brain from constricting
superficial pain results in a ___ in blood pressure
deep pain (visceral) results in a ___
increase for superficial
decrease for deep
primary sympathetic responses vs secondary
secondary sympathetic responses are anything that happens outside the medulary centers
RAAS pathway
Angiotensinogen —-Renin—-> angiotensin I
Angiotensin I —-ACE—> Angiotensin II
angiotensin II —-> release of aldosterone and resorption of sodium in the kidneys
mech of vasopressin (ADH)
acts on renal collecting ducts (V2 receptors) to increase water permeability (cAMP dependant pathway - like beta 2 receptors). this leads to decreased urine formation and increased blood volume.
Acts on V1 receptors and causes vasoconstriction through the IP3 pathway (like alpha 1 receptors), which increases arterial pressure
(normal concentration of ADH do not cause vasoconstriction. It happens in hypovolemic shock)
Three layers of a blood vessel
tunica intima
tunica media
tunica adventitia
what are weibel-palade bodies
storage granules of endothelial cells in the vessels of the heart. They store and secrete vWf and P-selectin
what part of the vessels have have a bunch of little “fenestrated” holes like swiss cheese
tunica media
