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)