Autonomics Flashcards
Adrenergic, noradrenergic definition
A nerve ending that releases norepinephrine as the primary transmitter, or a synpase where norepi is the primary transmitter
Adrenoceptor, adrenergic receptor
A receptor that binds and is activated by catecholamines-and related drugs
Norepi, epi, dopamine
Baroreceptor reflex
Homeostatic mechanism that maintains a constant mean arterial blood pressure
Cholinergic
Acetylcholine both releases or synapse as the primary NT
Cholinoceptor, cholinergic receptor
Receptor that binds to Acetycholine and related drugs
Dopaminergic
Dopamine is the primary NT
Nonadrenergic (NANC)
Nerve fibers associated with autonomic nerves that release ANY OTHER NT than ACTH/Norepinephrine
Sympathetic Nervous system
Origin: TI-L2: Thoracolumbar region-Lateral horn
Short cholinergic pre-Long adrenergic Post
Ganglia located near CNS
Ratio of pre to post fibers: 1:20
Primary NT of postganglionic neurons is:NorEpi
Muscarinic Receptors of the PNS
M1, M3, M5
Activated by ACh
Leads to activation of Gq protein
PIP2–> IP3, DAG
DAG–>increase protein kinase C
IP3–> releases Ca2+ and leads to cellular contraction
Phospholipase C pathway
Muscarinic Receptors of the PNS
M2, M4
Activation of Gi protein by ACh.
Decrease in adenyl cyclase
Decrease in cAMP levels
Leads to hyperpolarization d/t opening of K+ channels
Sweat Gland exception
Uses M3 receptor from sympathetic innervation
Renal Vascular Tissue Exception
Uses dopaminergic-1 receptors (sympathetic)
Adrenal Medulla Exception
No post-ganglionic innervation
Pre-Ganglionic sympathetic axons synapse on chromaffin cells
Clinical Correlate: Pheochromocytoma-abnormal amts of chromaffin cells. Can lead to Multiple Endocrine Neoplasia or Von Hippel Lindau
MEN Syndrome/ VHL
What does ingestion of Oragnophosphate Compounds do?
Insecticides
Irreversibly inhibit Acetycholinesterase
Muscarinic: diarrhea, urination, miosis (pin point)
Nicotinic: skeletal muscle paralysis
CNS effects: lethary, seizures, coma, RESPIRATORY DEPRESSION
Organization of PNS- sensory
- Sensory neurons arise principally in the skin or joints.
- Cell bodies and nuclei in the dorsal root ganglia and project onto neurons in the dorsal horn of the spinal cord
M2 Location, function/effect/signal mechanism
Location: HEART mainly in the atria
Function: decrease HR/contractility of atria
Gi-protein: decrease cAMP
Example: stimulation of the vagus nerve to the heart slows HR and conduction
Alpha 1 receptor: Location, function/effect/signal mechanism
Vascular Smooth Muscle
Function/Effect: smooth muscle contraction
Gq-protein: Increase IP3/DAG/Ca2+
Alpha 1 receptor: Function/effect/signal mechanism
EYE
Dilator pupillae muscle
Function: Pupillary dilation
Gq-protein: Increase IP3/DAG/Ca2+
Alpha 1 receptor: Function/effect/signal mechanism
Intestine and bladder
Instestinal and bladder sphincter contraction
Gq-protein: Increase IP3/DAG/Ca2+
Alpha 1 receptor: Function/effect/signal mechanism
Arrector pili muscle of skin
Piloerection
Gq-protein: Increase IP3/DAG/Ca2+
Beta-1 Receptors Location/Function/Signal mechanism
Heart
Effect: Increase HR/ Contractility
Gs protein: increase cAMP
Beta-1 Receptors Location/Function/Signal mechanism
Kidney (Juxtagolemerular Cells)
Increase Renin Release
Gs protein: increase cAMP
Beta-1 Receptors Location/Function/Signal mechanism
Adipocytes
Increase Lipolysis
Gs protein: increase cAMP
Beta-1 Receptors Location/Function/Signal mechanism
Ciliary Epithelium
Increase aqeuous humor production
Gs protein: increase cAMP
Beta 2-receptors: Function/Signal mechanism
Bronchial Smooth Muscle
Bronchial dilation
Gs protein: increase cAMP
Beta 2-receptors: Function/Signal mechanism
Blood vessels of skeletal muscles
Vasodilation
Gs protein: increase cAMP
Beta 2-receptors: Function/Signal mechanism
Uterine smooth muscle (myometrium)
Decrease in uterine tone
Gs protein: increase cAMP
Beta 2-receptors: Function/Signal mechanism
Ciliary Epithelium
Increase Aqueous Humor production
Gs protein: increase cAMP
Beta 3 receptor: Function/Signal Mechanism
Brown Adipose Tissue
Thermogenesis: Lipolysis
Gs protein: increase cAMP
Alpha 2-receptors: Function/Signal Mechanism
Presynaptic Nerve Terminal (neurons)
Decrease NE release
GI protein: Decrease cAMP
Alpha 2 receptor: Function/Signal Mechanism
Pancreatic B-cells
Decrease insulin release
GI: decrease cAMP
M3: Function/Signal Mechanism
Exocrine glands
Function: increase gland secretions (lacrimal, sweat, salivary, gastric acid)
Gq-protein: Increase IP3/DAG/Ca2+
M3: Function/Signal Mechanism
Pancreatic B Cells
Increase insulin release
Gq-protein: Increase IP3/DAG/Ca2+
M3: Function/Signal Mechanism
GI Smooth Muscle
Increase peristalsis
Gq-protein: Increase IP3/DAG/Ca2+
M3: Function/Signal Mechanism
Detrusor Muscle
Increase bladder contraction
Gq-protein: Increase IP3/DAG/Ca2+
M3: Function/Signal Mechanism
EYE: pupillary sphincter muscle, ciliary muscle
Pupillary constrction and accomodation
Gq-protein: Increase IP3/DAG/Ca2+
M3: Function/Signal Mechanism
Bronchial Smooth Muscle
Bronchial Constriction
Gq-protein: Increase IP3/DAG/Ca2+
M3: Function/Signal Mechanism
Endothelial Cells
Endothelium NO-mediated vasoldilation
Gq-protein: Increase IP3/DAG/Ca2+
M1: function/signal mechanism
Brain (neurons)
Higher cognitive functions
Gq-protein: Increase IP3/DAG/Ca2+
M1: function/signal mechanism
Autonomic ganglia (neurons)
Stimulates enteric nervous system
Gq-protein: Increase IP3/DAG/Ca2+
Effector Organ/ Predominant Tone/Effect if predominate tone lost
Blood Vessels
Sympathetic
IF LOST: Hypotension
Effector Organ/ Predominant Tone/Effect if predominate tone lost
Heart SA node
Parasympathetic
IF LOST: Increase HR
Effector Organ/ Predominant Tone/Effect if predominate tone lost
Heart Ventricles
Sympathetic
IF LOST: Decrease contractility
Effector Organ/ Predominant Tone/Effect if predominate tone lost
GI tract
Parasympathetic
IF LOST: Decrease motility/secretions
Effector Organ/ Predominant Tone/Effect if predominate tone lost
Iris of the Eye
Parasympathetic
IF LOST: Dilated pupil (mydriasis)
