Neuromuscular Physiology

Question 1

the Motor nerves EFFERENT exit the _____-

Answer 1

Ventral cord

Question 2

The Sensory nerves AFFERENT enter the ______

Answer 2

Dorsal Cord

Question 3

The release of NT from all nerve terminals, including the motor nerve terminals, depends on the entry into the terminal of _____ ions

Answer 3

Calcium Ca++

“Calcium goes in, Neurotransmitter goes out”

Question 4

_____calcemia is associated with a decrease in the amount of NT released, and _____calcemia is associated with an increase in the amount of NT released

Answer 4

Hypocalcemia

Hypercalcemia

Question 5

____magnesemia is associated with an increase in the amount of NT released, and _____magnesemia is associated with a decrease in the amount of NT released

Answer 5

Hypomagnesemia

Hypermagnesemia

Question 6

Calcium and magnesium are (antagonistic/agonistic) at the nerve terminal ( presynaptically)

Answer 6

Antagonistic

Question 7

it takes ___ molecules of ACh to open the ACh-gated channel of the skeletal muscle motor end-plate

Answer 7

2

Question 8

In addition to ACh, acetylcholinesterase also degrades ___, _____, _____, ____, and ______.

Answer 8

Ester LA
Neostigmine
Edrophonium
Remifentanil
Esmolol

Question 9

At the neuromuscular junction, does the presynaptic action of SCh enhance or antagonize it’s postsynaptic action?

Answer 9

SCh, by stimulating the presynaptic nicotinic receptor, AUGMENTS the release of ACh. Since the released ACh opens channels and depolarizes the motor end plate like SCh, the presynaptic action of SCh ENHANCES its postsynaptic action.

Question 10

when the channel of the motor end-plate opens ___ and ___ diffuse into the cell and ___ diffuses out.

Answer 10

Na+ and Ca++

K+

Question 11

Metabolism is the primary route of elimination for what 4 Neuromuscular relaxants

Answer 11

Sch
Atricurium
Cisatracurium
Mivacurium

All besides SCh are CURIUM

Question 12

Billary excretion is the primary route of elimination for what 2 Neuromuscular relaxants

Answer 12

Vecuronium
Rocuronium

Both CURONIUM

Question 13

Renal excretion is the primary route of elimination of what 6 Neuromuscular relaxants

Answer 13

Pancuronium
Then all of the other weird ones not in current use
d-tubocurarine
Metocurine
Gallamine
Doxacurium
pipecuronium

Question 14

how is Atracurium eliminated?

Answer 14

Ester hydrolysis (nonspecific esterases, biological elimination)
and
Hoffman Elimination ( pH & temp depenent degradation, chemical elimination)

Question 15

How is Cisatracurium eliminated

Answer 15

Hoffmann elimination ONLY

non-specific esterases are NOT involved in the elimination

Question 16

is ELIMINATION the same as TERMINATION OF ACTION?

Answer 16

Fuck no

Question 17

What 2 neuromuscular relaxants produce autonomic ganlionic bockade?

Answer 17

d-tubocurarine and Metocurine
–block the nicotinic receptors at the autonomic ganglia–

In th future these neuromuscular relaxants are always together for a choice

Question 18

which 5 neuromuscular relaxants elicit a release if histamine?

Answer 18

SCh
Mivacurium
Atracurium
d-tubocurarine
Metocurarine

Question 19

what neuromuscular relaxants produces bradycardia? and why?

Answer 19

SCh

- it mimics the action of ACh and directly stimulates muscarinic receptors of the SA node

Question 20

What 5 neuromuscular relaxants produce Tachycardia and why?

Answer 20

Atracurium, d-tubocurarine, and Metocurine -Produce reflex tachycardia
Pancuronium and Gallamine- competitively antagonize ACh, which are refered to as direct VAGOLYTIC, or more specifically ANTIMUSCARINIC actions

Question 21

Which 3 neuromuscular relaxants produce significant HYPOtension

Answer 21

SCh
d-Tubocurarine
Metocurine

Question 22

what 2 neuromuscular relaxants produce significant HYPERtension

Answer 22

Pancuronium

gallamine

Question 23

Plasma K+ concentrations may increase by ____ in normal patients and by ____ in burn, trauma, or head injury patients following the administration of SCh

Answer 23

0.5 mEq/L

5-10 mEq/L

Question 24

Why isn’t cardiac muscle directly involved in Malignant Hyperthermia?

Answer 24

Cardiac myocytes express the RyR2 isoform of the ryanodine receptor (MH targets the RyR1)

Question 25

what things decrease NDMR block?

Answer 25

anticonvulsants (chronic use)
Thermal burn injury
(basically anything and everything else causes an increase in block)

Question 26

What things decrease the DMR block?

Answer 26

Nondepolarizing agents (besides Panc)
MG
(basically anything else increases the block)

Question 27

A phase II block will mimic the response seen in what type of blockade?

Answer 27

Nondepolarizing