DSA Flashcards
Where are cell bodies located in the CNS? PNS?
- Nuclei
2. Ganglia
What factors lead to faster conduction velocity?
- More myelination
- Greater diameter
*both of these correlate with lower threshold
Axo-dendritic
- most common
- synapse between the presynaptic terminal of an axon and the post-synaptic membrane of a dendrite
- Usually excitatory
Neuromuscular Juncion
- synapse between the presynaptic terminal of an axon and the specialized motor end plate of skeletal muscle
- used as the model for all synapses because of accessibility
Does a reflex require the spinal cord, brain, or both?
just spinal cord
What NT is released by the pre-ganglionic cells in the parasympathetic nervous system?
Acetylcholine
*it binds the nAchR on the post-ganglionic dendrites (same for sympathetic)
varicosities
swellings
What type of receptor does acetylcholine bind on a parasympathetic post ganglionic cell?
mAchR
*this activates a secondary messenger system
What NT does a sympathetic post ganglionic axon release? What receptors does it bond?
- norepinephrine
2. alpha and beta adrenergic
alpha and beta adrenergic receptors
- metabotropic receptors
- have different effects in the body when NE binds
Parasympathetic: NT? Receptors?
- Ach
2. mAch and nAch
Sympathetic: NT? Receptors?
- Epi, NE, DA
- alpha (cardiac and smooth muscle glands) , beta (cardiac and smooth muscle glands) nAch, mAch (sweat glands), dopamine (renal vascular smooth m)
4 steps of cholinergic neurotransmission
Act synthesis, storage, release, destruction
Release of catecholamines from the adrenal medulla is what type of process?
sympathetic q
4 steps of Adrenergic nerve terminal
synthesis, storage, release, reuptake
Reserpine does what?
blocks VMAT-2*
*functions to transport NE, Epi, DA, and serotonin into vesicles
Cocaine does what?
blocks NE transporter*
*serves to import NE into the nerve terminal (this increases [NE] in synapse)
What are the agonists (activators) of alpha 1? 2?
- Epi is greater than or equal to NE
2. Epi is greater than or equal to NE
What are the agonists (activators) of beta 1? 2? 3?
- Epi=NE
- Epi»_space; NE
- NE > Epi
Where do we find alpha 1 receptors?
VASCULAR, GU smooth muscle, liver, intestinal smooth muscle, HEART
-contraction
Where do we find alpha 2 receptors?
Pancreatic beta cells, platelets, nerve terminal VASCULAR smooth muscle
-contraction
Where do we find beta 1 receptors?
Juxtaglomerular cells, HEART
-contraction
Where do we find beta 2 receptors?
Smooth muscle (VASCULAR, GI, GU), SKELETAL muscle
-relaxation
Where do we find beta 3 receptors?
Adipose tissue
-lipolysis
The big three:
- Alpha 1
- Beta 2
- Muscarinic
- stimulate contraction of all smooth muscle; vascular smooth muscle–>vasoconstriction
- relax smooth muscle–>vasodilation
- contract smooth muscle
What sympathetic receptor is associated with smooth muscle of blood vessel innervation? parasympathetic?
- alpha 1
- NONE*
*BVs will relax in response to para release of Ach IF the endothelium is intact
How does BP change in response to phenylephrine? histamine?
- increases baroreceptor, para nervous system; decreases sym nervous system
- decreases baroreceptor, para nervous system; increases sym nervous system
Where does epinephrine synthesis occur?
adrenal medulla, and a few pathways in the brainstem
What receptors do we find at sweat glands?
mAChR—>sweat secretion
M1
a. Location
b. Structural Features
c. Mxn
a. CNS, ganglia
b. GPCR, Gq/11
c. PLC activation—>IP3
M2
a. Location
b. Structural Features
c. Mxn
a. Heart, nerves, smooth m.
b. GPCR, Gi/o
c. AC inhibition–>decreased cAMP, K+ channel activation
* parasympathetic
M3
a. Location
b. Structural Features
c. Mxn
a. glands, smooth m., endothelium
b. GPCR, Gq/11
c. PLC activation—>IP3
* parasympathetic
M4
a. Location
b. Structural Features
c. Mxn
a. CNS
b. GPCR, Gi/o
c. AC inhibition–>decreased cAMP, K+ channel activation
M5
a. Location
b. Structural Features
c. Mxn
a. CNS
b. GPCR, Gq/11
c. PLC activation—>IP3
Nm
a. Location
b. Structural Features
c. Mxn
a. Skeletal m., NMJ
b. Ligand gated ion channel
c. N+, K+ depolarizing ion channel
Nn
a. Location
b. Structural Features
c. Mxn
a. Postganglionic cell body, dendrites, CNS
b. Ligand gated ion channel
c. N+, K+ depolarizing ion channel
What is the function of NET and DAT?
They help with reuptake of catecholamine into nerve terminals
What are cholinomimetic agents?
- drugs that mimic ACh
ex. AChR agonists, acetylcholinesterase inhibitors
What are sympathomimetic agents?
-drugs that mimi or enhance alpha/beta receptor stimulation
What are adrenoceptor blocking drugs?
-alpha and beta receptor antagonists
