Unit I, Week 2 Flashcards
Cholinergic receptor for:
Heart Blood vessels Lung Eye GI/GU CNS NMJ
Heart - M2 Blood vessels - M3 (no direct innervation - via NO synthesis) Lung - M3 Eye - M3 GI/GU - M3 CNS - M1 NMJ - N-M
Adrenergic receptor for:
Heart Blood vessels Lung Eye GI/GU CNS NMJ
Heart - B1 Blood vessels - a1 and B2 Lung - B2 Eye - a1 GI/GU - B2, a1, B2 CNS - a1 NMJ - B2
Cholinergic agonist effect on:
Heart - (3)
Blood vessels - (1)
Lung - (2)
Heart - decrease HR (SA node), decrease conduction (AV node), decrease contractility (atria only)
Blood vessels - Vasodilation (not innervated by PNS, due to NO synthesis)
Lung - Bronchoconstriction, increase secretions
Cholinergic agonist effect on:
Eye - (3) + one disease it can treat
GI/GU - (3) + 2 diseases it can treat
CNS - (3) + 1 disease it can treat
NMJ - (1) + 1 disease it can treat
Eye - Miosis (constriction), focus (accommodation), increase
[Glaucoma treatment]
GI/GU - salivation, increased detrusor contraction (increase urinary flow), increase GI motility
[Xerostomia (salivation)]
[Paralytic Ileus (GI motility)]
CNS - memory, cognition, movement
[Alzheimers]
NMJ - muscle contraction
[Myasthenia Gravis - ab to postsynaptic ACh receptor]
Cholinergic antagonist effect on:
Heart - (3)
Blood vessels - (1)
Lung - (2) + 2 diseases it can treat
Heart - increase HR (SA node), increase conduction (AV node), increase contractility (atria)
Blood vessels - Vasoconstriction
Lung - Bronchodilation, decrease secretions
[COPD and Asthma]
Anti-Cholinergic effect on:
Eye - (3)
GI/GU - (3) + 2 diseases it can treat
CNS - 2 diseases it can treat
NMJ - (1) + 1 clinical use
Eye - dilation, blurred vision, decrease aqueous humor outflow (NO SEE)
–> makes glaucoma worse, used for eye exams
GI/GU - decrease salivation, block detrusor muscle, decrease GI motility (NO PEE, NO SHIT, NO SPIT)
[OAB]
[Diarrhea]
CNS - Parkinson’s, Anti-Emetic
NMJ - Flaccid paralysis
[surgery, muscle relaxation]
Adrenergic Agonist effect on: (via what receptor)
Heart - (2)
Blood vessels - (2) + 2 diseases it can treat
Lung - (1) + 1 disease
Heart - increase HR, increase contractility (B1)
Blood Vessels -
a1 –> vasoconstriction [hypotensive shock, decongestant]
B2 –> vasodilation
Lung - B2 –> bronchodilation [asthma]
______ and ______ drugs can be used to treat asthma via ____ and ____ receptors
Cholinergic antagonists (M3) Adrenergic agonists (B2)
Adrenergic Agonist effect on: (via what receptor)
Eye
Dilation (Mydriasis) - a1
Adrenergic Agonist effect on: (via what receptor)
GI/GU - (3) + 3 diseases
Detrusor muscle relaxation (B2) - [OAB] Close sphincter (a1) --> [promote continence] Uterine relaxation (B2) --> [premature labor]
Adrenergic Agonist effect on: (via what receptor)
CNS - (2) + 1 disease it treats
NMJ - (1)
CNS - increased vigilance and focus [ADHD]
NMJ - Muscle tremors
Adrenergic Antagonist effect on: (via what receptor)
Heart
Blood vessels
Lung
Heart - (B1 block) decrease HR, decrease contractility
Blood vessels -
(a1 block) –> vasodilation
(B2 block) –> vasoconstriction
Lung -
(B2 block) –> bronchoconstriction
Adrenergic Antagonist effect on: (via what receptor)
Eye - 1 effect, 1 disease it can treat
B1 and B2 –> decrease aqueous humor production (decrease IOP)
[glaucoma]
(*No effect seen with a1 receptor)
Adrenergic Antagonist effect on: (via what receptor)
GI/GU - (1) + 2 diseases it can treat
a1 block –> open sphincter
[micturition disorders, BPH]
Bethanechol and Pilocarpine are (direct/indirect) ________________
DIRECT
cholinergic agonists
Neostigmine and Pyridostigmine are (direct/indirect) ______________
INDIRECT
cholinergic agonists (via acetylcholine esterase inhibition)
Edrophonium and donepezil are (direct/Indirect) _____________
INDIRECT
cholinergic agonists (via acetylcholine esterase inhibition)
Organophosphate nerve gases are (direct/Indirect) _____________
INDIRECT
cholinergic agonists (via acetylcholine esterase inhibition)
activation of Gq via _____ and ______ muscarinic receptors causes what?
M1, M3
Gq –> increase PLC –> IP3 + DAG –> increase Ca2+ into cell and PKC activation
activation of Gi/o via _____ and ______ muscarinic receptors causes what?
M2, M4
Gi/o –> decrease AC –> decrease cAMP –> increase K+ out of cell, and decrease Ca2+ into cell
activation of Gq via _____ adrenergic receptor causes what?
a1
Gq –> increase PLC –> IP3 + DAG –> increase Ca2+ into cell and PKC activation
activation of Gi/o via _____ adrenergic receptor causes what?
a2
Gi protein inhibits AC –> decrease cAMP levels or opens K+ channels (hyperpolarization)
couples to Go to decrease Ca++ movement through L- and N- type channels
activation of Gs via _____ and ______ adrenergic receptor causes what?
B1 and B2
Gs –> increase AC –> increase cAMP, activate PKA
B1 –> increase L-type Ca2+ channels movement of Ca2+ in
Process by which M3 receptor activation can cause vasodilation
M3 receptor activation on endothelial cell –> NO synthesis –> diffuse to smooth muscle cell in vessel wall –> activates G-cyclase –> increase cGMP –> smooth muscle relaxation
Pilocarpine can be used to treat _______ and ______
glaucoma and xerostomia
long acting topical agent
Urinary retention can be treated with _____ and ______
bethanechol and neostigmine
Xerostomia
- salivary gland hypofunction from radiotherapy for cancer or in patients with Sjogren’s syndrome
- can also occur with antimuscarinic side effects
Atropine
antidote - used to block excessive muscarinic receptor stimulation
Adverse effects of muscarinic receptor agonists (6)
SLUDGE BB
Salivation Lacrimation Urination Defecation GI --> cramping and emesis Eye (miosis), Emesis
Initial sign and adverse reactions of indirect acting muscarinic receptor agonists
Initial sign = muscarinic excess and double vision
SLUDGE + BB
Bradycardia Bronchoconstriction (and increased secretions)
Initial sign and adverse reactions of indirect acting nicotinic receptor agonists
Initial sign = muscarinic excess and double vision
MATCH
1) Muscle weakness, fasiculations (NM) –> flaccid paralysis (respiratory failure possible)
2) Adrenal medulla activity increases (NN)
3) Tachycardia (NN)
4) Cramping of skeletal muscle (NM)
5) Hypertension (NN)
Pralidoxime
mechanism of action and use
regenerates AChE –> ANTI cholinergic, increases ACh break down
Prevents over-activation of NM receptors (this over-activation can cause flaccid paralysis and respiratory failure)
Atropine and Scopolamine are (direct/indirect), (selective, nonselective) ____________
can be used to treat ______ and _______
direct, nonselective ANTImuscarinic drugs
severe bradycardia and overdose of muscarinic agonist (e.g. organophosphate nerve gas)
Atracurium, Rocuronium, and Succinylcholine are ________________ that act on the _____ receptor
neuromuscular blockers (N-M receptor) antinicotinic drugs
Effect of muscarinic agonist on sweating? Via what receptor?
what effect about antimuscarinic drugs on sweating?
M3
Increase sweating and heat loss
antimuscarinic drugs can cause an increase in body temperature due to an inhibition of sweating
Ipratropium and tiotropium are _________ and are used to treat _____ and _______
anticholinergic/antimuscarinic drugs
asthma and COPD
Oxybutynin and Tolterodine are __________ and are used to treat ______
anticholinergic/antimuscarinic drugs
overactive bladder (OAB)
Adverse reactions of anticholinergic (antimuscarinic) drugs include…
CNS effects (drowsiness, sedation, delerium)
NO PEE (urinary retention) NO SEE (blurred vision) NO SPIT (dry mouth) NO SHIT (constipation)
Tachycardia - minimal effect on BP because there is no muscarinic tone in vasculature
Epinephrine
acts on what receptors, selective or nonselective?
a1-a2-B1-B2
NON SELECTIVE
Norepinephrine
acts on what receptors, selective or nonselective?
a1-a2-B1
NON SELECTIVE
Isoproterenol
acts on what receptors, selective or nonselective?
B1-B2 NON SELECTIVE
Albuterol
acts on what receptors, selective or nonselective?
B2 selective
Phenylephrine
acts on what receptors, selective or nonselective?
a1-selective
Pseudoephedrine
mechanism?
indirect acting activator of adrenergic system via release of NE at a1 receptor –> vasoconstriction (in nose, etc.)
Dobutamine
acts on what receptors, selective or nonselective?
B1 selective
Dopamine (cocaine)
mechanism?
Adrenergic reuptake inhibitor –> adrenergic agonist
Clonidine
a2 selective agonist (CNS only)
actually is ANTI ADRENERGIC - opposed PNS by inhibiting release of ACh
a1 receptor activators cause _______ –> ______ and _____ which can then result in what side effect?
VASOCONSTRICTION
increase TPR and BP
–> reflex bradycardia
B2 receptor activators cause _______ –> ______ and _____ which can then result in what side effect?
VASODILATION
decrease TPR and BP
–> reflex tachycardia
Doxazosin, Terazosin, Prazosin
what receptor, selective/nonselective?
uses?
a1 - selective ANTAGONIST
–> sphincter relaxation
Urinary obstruction (BPH)
Metoprolol, Atenolol
what receptor, selective/nonselective?
B1 selective
Propranolol
what receptor, selective/nonselective?
B1-B2 nonselective
Labetolol-Carvedilol
what receptor, selective/nonselective?
a1-B1-B2 nonselective
When does myelination occur?
MOST myelination during postnatal development
- Begins during embryonic stages in periphery
- CNS myelination first observed in spinal cord near end of first trimester, by third trimester, myelination present in brain
- Myelination of cortical tracts involved in higher functions occurs AFTER birth
- Corticospinal tract begins to be myelinated prior to birth, but only extends past medulla after birth
Developmental regulation of GABA receptors in adult vs. during development
In adult: equilibrium potential (ECl) near or negative to resting membrane potential → GABA is INHIBITORY
During development: intracellular levels of chloride are elevated, ECl more positive
-GABA → depolarization and EXCITATION
Normal Postnatal Changes in Brain Morphology
At birth, low density of neural connections → in childhood has very high density
Postnatal development leads to a dramatic increase in the number of dendrites and number of interconnections
Autism Spectrum Disorder and postnatal changes in brain morphology
Autism = disease of synapse maturation and maintenance
- At birth - normal or smaller brain size
- First postnatal years - brain size increases abnormally, especially in white matter and neuronal cell bodies are smaller with dendrites branching less
May be due to abnormal pruning and/or synapse maturation processes that require neuronal interactions
Factors that influence axon regeneration in CNS (3)
1) The ability to grow
2) The presence of molecules that promote growth
3) The presence of molecules and receptors that inhibit growth
Are CNS axons CAPABLE or regenerating?
YES -
CNS axons capable of regenerating long distances if peripheral nerve is implanted at site of injury to the spinal cord → CNS axons can grow many centimeters in the peripheral nerve
HOWEVER - CNS axons do not regrow because of the inhibitory molecules present that prevent growth
What molecules are present that promote growth of axons and which cells secrete them?
Glial environment through which the axon grows affects its ability to regenerate
Schwann cell → NGF or other factor to promote axon growth
What molecules are present that inhibit growth of axons and which cells secrete them?
CNS myelin (oligodendrocytes) expresses molecule (Nogo) that prevents axonal regeneration in adult CNS → hostile environment to growth
Growth cone of axon
growing tip of axon
Continuously extends and retracts filopodia that “sniff” biochemical environment to “sense” which way to grow
-NOT a passive growth along a physical matrix
Two types of guidance information the growth cone uses
Long-range chemotaxis and local substrate cues (short-range guidance molecules)
Long Range axon guidance molecules
Attractive (1)
Repulsive (2)
Diffusible
Attractive = Netrins
Repulsive = Semaphorins, netrins
Short-Range Axon Guidance Molecules
bound to cell membrane of extracellular matrix - requires direct cell contact
Attractive Short-Range Axon Guidance Molecules include…
Cell surface = cadherins, cell adhesion molecules (CAMs)
ECM = collagen, laminin, fibronectin, proteoglycans
Repulsive Short-Range Axon Guidance Molecules
Repulsive:
Cell surface = semaphorins, ephrins
ECM = tenascin