Flashcards in Autonomic Nervous System Physiology Deck (26):
Number of Synapses for ANS vs Somatic?
Inputs of ANS
Nucleus of the solitary tract (in medulla): conveys visceral sensory input
Other brainstem nuclei: convey environmental stimuli
Hypothalamus (in forebrain): conveys internal goals/states
Sympathetic: Four F's- Fight, Flight, Fright and Sex
Parasympathetic: Rest and Digest
Enteric: Not covered now
Sympathetic Division Spinal Roots
T1 - L2
Parasympathetic Division Spinal Roots
Cranial Nerves VII, IX and X. Also S2 - S4.
Ratio of Pre- to Post-Ganglionic Neurons (Sym and Para)
Sympathetic: Near spinal cord
Parasympathetic: Near target organ
Preganglionic Neurotransmitters (Sym and Para)
Acetylcholine (Ach) for BOTH!
Postganglionic Neurotransmitters (Sym and Para)
Sympathetic: Norepinephrine (NE) and Epinephrine
Nicotinic vs Muscarinic
Alpha- and Beta-adrenergic
Methods of CV Regulation via Nervous system
Sym and Para control of heart rate and blood pressure
Humoral Response (via bloodstream)
Sympathetic Stimulation causes? (via NE)
Increased HR, BP and inotropy. (contraction of blood vessels)
Parasympathetic Stimulation causes? (via Ach)
Decreases HR, BP, and inotropy.
Sympathomimetic Definition and Example
Mimic sympathetic activation.
Atropine: muscarinic (M2) antagonist in heart; increases heart rate.
Parasympathomimetic Definition and Example
Mimic parasympathetic activation.
Propranolol: β-adrenergic (β1 and β2) antagonist in heart; decreases heart rate
Hypothalamus regulates release of hormones via the....?
Low BP detected by...?
Subfornical organ. Not behind the BBB.
Also known as ADH (anti-diuretic hormone). Causes vasoconstriction and acts on kidneys to increase water retention.
Converts Angiotensinogen to Angiotensin I. Released from kidneys in response to low BP.
ACE Definition and Function of end product.
Angiotensin Converting Enzyme. Converts Angiotensin I to Angiotensin II (the active form).
- Constricts blood vessels
- Acts on kidney to increase water retention
- Activates neurons in subfornical organ
Adrenal medulla Innervation and Function
Innervated by preganglionic sympathetic neurons
Releases norepinephrine and epinephrine into bloodstream
Widespread sympathomimetic effects (e.g., increased heart rate)
Epinephrine is Synthesized from?
Norepinephrine is synthesized from?
Dopamine. Tyrosine -> L-dopa -> Dopamine -> Norepinephrine
Baroreceptor Reflex Functions
Low BP -> Increase Sympathetic Output
High BP -> Increase Parasympathetic Output