Misc Facts Flashcards
Which vascular beds are heavily/densely innervated? (4)
cutaneous, renal, splanchnic, skeletal muscle
Which vascular beds are sparsely innervated? (2)
cerebral, coronary
What nerve sends parasympathetic impulses to the heart? How are the right and left nerves different?
Vagus
R: AV node
L: SA node
Why does conduction slow through the AV node?
to allow the ventricles to fill following atrial contraction
What are 2 factors contributing to the strength of (cardiac) muscle contraction?
- intracellular Ca levels
2. fiber length
Myofilament activation is caused by Ca from what sources?
Extracellular, brought intracellular by voltage-gated Ca channel
Intracellular from sarcoplasmic reticulum, released by Ca binding to RyR
After myocardium contraction, where does the Ca go?
Once troponin is phosphorylated and Ca is released:
- efflux via Na/Ca antiporter
- Efflux via ATP-driven Ca pump
- Reuptake into SR via ATP-driven pump
*note: ATP-driven = pumped against gradient
EDV - ESV = ?
SV
EDV is also called–
preload
Why does increased length result in increased force generation?
Fast response to stretch = increased Ca sensitivity (so less Ca is needed to generate contraction)
Slow response to stretch = Ca channels activated by stretch
When the atrial pressure is greater than the ventricular pressure, the mitral/tricuspid valve is (open/closed)
OPEN
When the ventricular pressure is greater than the atrial pressure, the mitral/tricuspid valve is (open/closed)
CLOSED
When left ventricular pressure is less than aortic pressure, the aortic valve is (open/closed)
CLOSED
When left ventricular pressure is greater than aortic pressure, the aortic valve is (open/closed)
OPEN
Where are alpha receptors found, and what do they do?
blood vessels
constrict
Where are beta receptors found, and what do they do?
skeletal muscle vessels (B2)–relaxes
heart (B1/2)
accelerates SA node + ectopic pacemakers
increases contractility
JGA cells of kidney (B1)
renin release
Pre-HTN?
Stage 1 HTN?
Stage 2 HTN?
Pre: 120-139 OR 80-89
1: 140-159 OR 90-99
2: HTN ≥160 OR ≥100
BP = ____ x _____
HR x TPR
What type of receptors are alpha and beta?
GPCR
Stimulation of what receptor downregulates presynaptic NE?
alpha-2
Stimulation of what receptor upregulates presynaptic NE?
beta-2
What are the effects of postsynaptic activation of receptors by NE in blood vessels?
alpha-1/2: vasoconstriction
beta-2: vasodilation
What causes the first heart sound? What does it sound like?
oscillation of blood and vibration in ventricles after AV valves close
lower pitch, more intense, longer than 2nd heart sound
What causes the second heart sound?
oscillation of blood in aortic and pulmonary arteries after the aortic and pulmonic valves close
