Autonomic and heart physiology Flashcards
Hypothalamic nuclei
Blue, green, red, yellow and purple etc. haha
Hypothalamus-Pituitary axis
Hypothalamic nuclei, infundibulum, hypophyseal portal veins, anterior pituitary, posterior pituitary
How many hormones in hypothalamus?
9
How many hormones in pituitary?
7
portal system
capillaries → portal vein → capillaries
process of hypothalamus-pituitary axis releasing hormone(into blood system, slower than neuron drive system)
Hypothalamic nuclei(neurosecretory cell) → hormones in axon termini ready to go down → hypophyseal portal vein → secondary plexus → anterior pituitary → adrenal cortex
Adrenal medulla release Epinephrine and Norepinephrine stimulated by
Acetylcholine from sympathetic preganglionic neurons
Adrenal cortex release Mineralocorticoids(aldosterone) stimulated by
change balance for K+ and angiotensin II in blood( increase K+ and angiotensin II)
Adrenal cortex release Glucocorticoids(cortisol) stimulated by
Hypothalamus → CRH → anterior pituitary → ACTH → adrenal cortex → cortisol → negative feedback to anterior pituitary by inhibit anterior pituitary release ACTH → negative feedback to hypothalamus(hypothalamic neurosecretory cell) by inhibit hypothalamus(hypothalamic neurosecretory cell) release CRH
result of adrenal cortex release Mineralocorticoids(aldosterone)
increase Na+ and water, decrease K+ in blood, increase blood volume and pressure
In PNS, sensory neurons are also called
Afferent
In PNS, motor neurons are also called
Efferent
Structure of neurons
Dendrites → cell body → Axon → Myelin sheath(made by Schwann cell) → Axon terminals
Synaptic transmission process
AP to pre-synaptic axon terminal → voltage gated Ca2+ channels open at terminal → Ca2+ release cause vesicles release Acetylcholine(neurotransmitter aka NT) via exocytosis → Acetylcholine diffuses cross synaptic cleft → Ach(NT) binds receptor on post-synaptic cell membrane → Ligand-gated ion channel open on post-synaptic cell membrane and Na+ flow into post-synaptic cell → postsynaptic potential to threshold, AP fire → impulses continue propagate
- Internal sensing → hypothalamus → spinal cord → pre-ganglionic neuron(myelinated, sympathetic, cholinergic, autonomic motor neuron) → Acetylcholine to Nicotinic receptor of post-ganglionic neuron(unmyelinated, sympathetic, adrenergic, autonomic motor neuron) in the autonomic ganglion → post-ganglionic neuron(unmyelinated, sympathetic, adrenergic, autonomic motor neuron) send Norepinephrine to Adrenergic receptor of effector cell → alarm response(fast version)
Alarm response, sympathetic
- Internal sensing → hypothalamus → spinal cord → pre-ganglionic neuron(myelinated, sympathetic, cholinergic, autonomic motor neuron) → Acetylcholine to Nicotinic receptor of post-ganglionic neuron(unmyelinated, sympathetic, CHOLINERGIC, autonomic motor neuron) in the autonomic ganglion → post-ganglionic neuron(unmyelinated, sympathetic, CHOLINERGIC, autonomic motor neuron) send Acetylcholine to Muscarinic receptor of cell of sweat gland
Sweat gland sympathetic pathway
- Internal sensing → hypothalamus → spinal cord → pre-ganglionic neuron(myelinated, para-sympathetic, cholinergic, autonomic motor neuron) → Acetylcholine to Nicotinic receptor of post-ganglionic neuron(unmyelinated, para-sympathetic, CHOLINERGIC, autonomic motor neuron) in the autonomic ganglion → post-ganglionic neuron(unmyelinated, para-sympathetic, CHOLINERGIC, autonomic motor neuron) send Acetylcholine to Muscarinic receptor of effector cell
Parasympathetic pathway
Raynaud Disease
Chronic vasoconstriction, finger and toes become ischemic, cause by too much sympathetic stimulation, didn’t turn off immediately
Lipid-soluble hormones effect body
travel in blood(with transport protein MUST) → diffuse into cell → binds receptor(associate gene transcription element on DNA) inside nucleus → change gene expression((turn on or turn off) → mRNA formed → ribosomes use new mRNA make new protein to alter cell activity → physiological behavior changes
Important thing is lipid-soluble hormones need right receptor inside the nucleus, if no right receptor can bind inside nucleus, then can not change gene expression in that cell thus can not change behavior
water-soluble hormone effect body
can not diffuse into cell but it can travel in blood free → bind receptor on the SURFACE of the cell → activate G protein → activate adenyl cyclase → adenyl cyclase turn ATP to cAMP(second messenger) → cAMP activate protein kinases → protein kinases add phosphate to other enzymes(phosphorylate) → physiological response → phosphodiesterase turn off cAMP(when hormone left the cell surface) → back to normal
If cell SURFACE don’t have receptor can let this type of hormone to bind, then the hormone can not act on this cell
Cholera toxin binds G protein
Chronic diarrhoea
Stress response component
Alarm response(fight or flight), alarm extension response(adrenal medulla), resistance reaction(cortisol)
alarm extension response(adrenal medulla) process
Hypothalamus(stimulus) → spinal cord → sympathetic preganglionic neuron(myelinated) → Acetylcholine to adrenal medulla → Chromaffin cells(modified post-ganglionic ‘neurons’ act as secretory cells in medulla) release Norepinephrine and Epinephrine into blood stream → extension alarm response
Cardiac output formula
CO = HR(heart rate) x SV(stroke volume)
pulse pressure formula
pulse pressure = systolic pressure - diastolic (eg. 120-80=40 mmHg)
Preload
Stretch before contract, blood into ventricle to stretch the wall of ventricle before ventricle contract(use left ventricle as example)
Contractility/inotropy
forcefulness of contraction(left ventricle as example)
afterload
Force that can pump blood out of left ventricle to the aorta and against the push back pressure in the aorta(arteriole pressure)
Frank-starling law
More in → more out(more preload, more contractility/inotropy, more afterload, more blood pump out, without damping) or we could say “The more blood fills in the heart during diastole, the greater force of contraction in the heart during systole”(left side heart do the same thing as right side heart, the law apply same to the two side of heart)
exercise → increase contractility → increase stroke volume
True or False?
True
ability to maintain stable heart rate and stable contractility is?
ionic composition of plasma of the blood circuit around(Na+, K+, Ca2+) (increase Ca2+ in plasma → increase contractility, ‘+inotropy’) (increase K+ → reduce contractility, ‘-inotropy’)
large change K+ levels
heart stop
Stroke volume formula
Max filling - Min rest volume
ejection fraction formula
SV / Max filling
defibrillator
restore heart rhythm
Refractory period
max heart rate can achieve
Contract period
Depolarization must occur to initiate ventricular individual myocyte to contract
Pacemaker generate depolarization
Sinoatrial node (SA node)
P wave
atria contraction
T wave
Repolarization
P-Q interval
time delay between atrium contraction and ventricular contraction
QRS complex
Ventricular depolarization(starts before ventricular contraction)
Vagus
Parasympathetic(response faster than sympathetic in the heart, majority) → heart → decrease heart rate
Cardiac accelerator
Sympathetic(increase HR + increase SV, this will increase cardiac output) → heart → increase contractility → SA node, AV node and ventricular myocardium
Vasomotor nerves
Sympathetic(increase HR + increase SV, this will increase cardiac output) → blood vessels(arteriole) → vasoconstriction → Norepinephrine → alpha1 receptor
Baroreceptor location and function
Locate in arch of aorta and carotid sinus
function is sensing stretch of artery wall and feedback to cardiovascular center to regulate blood pressure and heart rate
Pressure drives?
Supply
Pressure also drives?
Exchange
Blood pressure measurement to measure where?
Artery(arteriole pressure 80 mmHg - 120 mmHg)
Blood reservoirs
Systemic veins and venules 60%(major veins, do not have much smooth muscle around)
Exchange happens in?
Capillaries
Largest blood pressure change in body locate?
arterioles
Before arteriole(from aorta start) pressure around?
80 mmHg - 120 mmHg
Smooth muscle (lots of) and connective tissue in arterioles(and make tension-vascular tone)(resistance vessel)
True or False
True
Change radius of vessel(decrease radius) → increase tone → massive resistance in the vessel
True or False
True
resistance varies inversely as the 4th power of the radius
correct?
Yes
resistance in blood vessel meaning
If blood from left to right flow
then on right side → less flow → less pressure
on left side → more flow stick together → high pressure → high resistance
Blood pressure formula
BP(blood pressure) = CO(cardiac output) x TPR(total peripheral resistance)
Stand up for long time
Increase net filtration occurs → Lymph vessel pick that excessive fluid → but too many fluid → therefore lots of fluid stick on interstitial spaces between cells → less absorption → you go home → feet up → the fluid reabsorbed again → not swell ankle
Starling’s law of the capillaries
filtration(arteriole) = BHP(blood hydrostatic pressure) + IFOP(interstitial fluid osmotic pressure)
reabsorption(venous) = BCOP(blood colloid osmotic pressure) + IFHP(interstitial fluid hydrostatic pressure)
Net filtration(total) = [BHP(blood hydrostatic pressure) + IFOP(interstitial fluid osmotic pressure)] - [BCOP(blood colloid osmotic pressure) + IFHP(interstitial fluid hydrostatic pressure)]
Net filtration(total) has different value in ARTERIOLE end and VENOUS end
Use Net filtration(total) formula, if result is positive, then this is filtration. If result is negative, then this is reabsorption.
Usually positive result occurs in ARTERIOLE end, negative result occurs in VENOUS end
Main difference of Net filtration(total) in ARTERIOLE end and in VENOUS end is BHP(blood hydrostatic pressure), and usually BHP(blood hydrostatic pressure) in ARTERIOLE end larger than in VENOUS end
Capillaries feature
leaky, allow nutrients out, but protein and cells can not leak out
Blood hydrostatic pressure meaning
blood push arteriole wall
Blood colloid osmotic pressure meaning
proteins, cells(colloid) try to filter in arteriole wall but their size too large, can not go in, this force push the arteriole wall
Interstitial fluid osmotic pressure meaning
interstitial fluid from inside arteriole wall trying to filter out into interstitial space with force
Interstitial fluid hydrostatic pressure meaning
interstitial fluid outside arteriole wall trying to push arteriole wall(not filter in the arteriole wall) with force
Net pressure formula
Net pressure = hydrostatic pressure + colloid osmotic pressure
velocity in cross sectional area such as capillary is much slower, because like river analogy, big pool split out many small branches, each branches has same velocity but much slower than big pool, and when blood flow out of capillary back to vein, velocity start increasing, then back to heart with same velocity before according to Frank-Starling law, input = output.
True or False
True
nerves connect smooth muscle in the arteriole to control vasoconstriction and vasodilation
Yes
Venule has less smooth muscle but still has some smooth muscle there
Yes
blood supply always change, but total amount of blood supply remains the same. Eg, 4 L/min blood supply A, B, C, D area, but when you exercise A, C, D area need more blood, then B area blood supply will cut a little bit to share to A, C, D area, B area blood supply will decrease, A, C, D area blood supply will increase, but total amount of blood supply is still 4 L/min unchanged
True or False
True
Total blood in human
5 L, if you losing half L which is 500 ml, this means you losing 10% of your blood in body
Three factors and formula of homeostasis of blood pressure
Three factors: HR(heart rate), SV(stroke volume), TPR(total peripheral resistance)
formula: BP(blood pressure) = CO(cardiac output) x TPR(total peripheral resistance)
CO(cardiac output) = HR(heart rate) x SV(stroke volume)
BP(blood pressure) = HR(heart rate) x SV(stroke volume) x TPR(total peripheral resistance)
How to change TPR(total peripheral resistance)?
by changing diameter(or radius, same) of arteriole
decrease diameter of arteriole → increase TPR(total peripheral resistance)
increase diameter of arteriole → decrease TPR(total peripheral resistance)
Beta1 receptors are on SA node, AV node, Cardiac muscle.(Norepinephrine)
Beta2 receptors are on arterioles of cardiac and skeletal muscle.(Epinephrine)
Alpha1 receptors are on arterioles of abdomen and skeletal muscle.(Norepinephrine)
Muscarinic receptors are on SA node and AV node for heart(receive Acetylcholine), also on Sweat gland(receive Acetylcholine)
True or False
True
Vasomotor nerves(sympathetic) act on both alpha 1 and beta 2 receptors of arterioles
True or False
True
Vagus nerves(parasympathetic) use Acetylcholine act on Muscarinic receptor to slow heart rate
True or False
True
In hot day, you feel faint, describe process
I feel faint → blood pressure drop → baroreceptor(locate in arch of aorta and carotid sinus) sensing blood pressure change → baroreceptor feedback to cardiovascular center with afferent neurons(Glossopharyngeal IX nerves) → CV reduce parasympathetic activity(Vagus) with efferent neurons(Vagus X nerves, decrease Acetylcholine act on Muscarinic receptors) to increase heart rate → CV increase sympathetic activity with cardiac accelerator nerves(NE to beta 1 receptor on SA, AV node and Ventricular myocardium) and vasomotor nerves(NE to alpha 1 receptor in skin, abdomen arterioles; Epinephrine to beta 2 receptors in arteriole of cardiac and skeletal muscle) to cause vasoconstriction on arterioles → CV to adrenal medulla → chromaffin cells release Norepinephrine and Epinephrine into blood stream → increase blood pressure → back to normal → negative feedback to baroreceptor
Cardiopulmonary baroreceptor location, function
Major vein, sensing blood volume, go to CV and change sympathetic activity of kidney
If patient has hypertension, what is the treatment?
drug(ACE inhibitor) directly target on specific enzyme to reduce Angiotensin II level in the blood
Chromaffin cells can be stimulated by two different areas
Hypothalamus and Cardiovascular center
Inducibility(autonomic)
Maladaptive
heart brain blood vessels digestion immunity behaviour perceptions
reduce megastress
breath slowly
exhale longer than inhale
body scan
change cognitive function
Breathing in
sympathetic nerves system on → heart rate up slightly →
Breathing out
parasympathetic nerves system on → heart rate low slightly
