Nervous System Flashcards
2 types of cholinergic receptors
Nicotinic and muscarinic
Nicotinic receptors are _________ linked
Ion channel linked
- ligand gated Na/K channels
Muscarinic receptors are _______ linked
G protein
Types of nicotinic receptors
Muscle type (Nm) Neuronal type (Nn)
Nm receptors are present in ____ and cause _____
Skeletal muscle (NMJ)
muscle contractions
Nn receptors are present in ____ and cause _____
Adrenal medulla - chromaffin cells to release catecholamines
Brain- needed for neuronal development, learning, and memory
Autonomic ganglia- Postganglionic neuron activation
(Parasympathetic and sympathetic)
Types of muscarinic receptors
M1
M2
M3
M1 is G___
Gq
M2 is G___
Gi
M3 is G___
Gq
M1 receptors cause
Enteric (GI) nervous system stimulation
M2 receptors cause
Inhibition of Ach release at presynaptic nerve terminals
Decrease heart rate and contractility
M3 receptors cause
Increase exocrine gland secretions (lacrimal, sweat, salivary, gastric acid)
Increase insulin release from Pancreatic ß cells
Increase gut peristalsis (GI smooth muscle)
Increase bladder contraction (smooth muscle)
Pupillary constriction (Pupillary sphincter and ciliary muscle)
Bronchial constriction (smooth muscle)
Gs pathway
Alpha (GDP) subunit dissociates after GDP -> GTP Activates adenlyl cyclase Takes ATP and convert it into cAMP Increase protein kinase A Phosphorylates stuff
Gq pathway
Alpha (GDP) subunit dissociates GDP -> GTP
Activates phospholipase C
converts PIP into IP3 and DAG
IP3 increase Ca2+ release (SER) which activates protein kinase
DAG increase protein kinase C
Both phosphorylate stuff
The types of adrenergic receptors
Alpha and Beta
Alpha 1 receptors cause
Vascular smooth muscle contraction
Vasoconstriction of skeletal muscle BV
Pupillary dilation
Intestinal and bladder sphincter smooth muscle contraction
Increased Glucogenolysis and Gluconeogenesis in the liver
Alpha 2 receptors cause
Decrease norepinephrine release from presynaptic nerve terminals
Decrease insulin release from pancreatic ß cells
Platelet aggregation
decrease lipolysis
Vascular smooth muscle contraction
Beta 1 receptors cause
Increase HR and contractility
Increase renin release
Increase lipolysis
Beta 2 receptors cause
Bronchial dilation
Skeletal muscles BV dilation
Decreased uterine tone
Increased glucogenolysis and k+ uptake in skeletal muscle
Increase insulin secretion (pancreatic B)
Increase glucagon secretion (pancreatic a)
Increased glucogenolysosis and glucogenesis
Increased lipolysis
Beta 3 receptors cause
Thermogenesis and increased lipolysis in brown adipose tissue
Alpha 1 is G___
Gq
Alpha 2 is G___
Gi
Beta 1 is G__
Gs
Beta 2 is G__
Gs
Beta 3 is G__
Gs
Low concentrations of epi cause
Vasodilation at B2 receptors
B2 more sensitive
High concentrations of epi cause
Vasoconstriction
A1 and B2 active, but A1 predominates
Large dose of Epi given via IV causes
Increased BP:
Increased HR and ventricular contraction via B1
Vasoconstriction via A1
Low dose of Epi given via IV causes
Diastolic BP drop via B2 (decrease peripheral resistance)
Systolic pressure increases via B1 (increased cardiac contractility)
Increase HR (B1)
A small dose of Ach causes
decreases BP via M3 vasodilation effect w/ accompanied tachycardia (baroreceptor reflex wins)
A large dose of Ach
decrease BP via M3 vasodilation effect w/ bradycardia
