ANS & muscle

Question 1

neurochemical simlarity & difference btw PSNS & SNS

Answer 1

(+): release ACh at ganglions

(-): @ postganglion neurons, PSNS release ACh it at muscarinic receptor while SNS release norepinephrine to a receptor

Question 2

ANS VS somatic nervous system: anatomy & neurochemical signailing

Answer 2

ANS requires post- and pre- gangionic neurons. SNS ALSO requires 2 neurons.

but motor neuron synpse to muscle cell

Question 3

unique abt ANS control of adrenal gland?

Answer 3

only 1 SNS preganionic neuron to adrenal gland, which secretes epinephrine w/ lil NE

Question 4

whole muscle is made up of _____ contains bundle of _____ which is composed of a bundle of _____

Answer 4

fascicle / muscle cell / myofibrils

Question 5

sarcoplasmic reticulus wraps around _____ and is where ___ is stored

Answer 5

myofibril / Ca

Question 6

____ travels down interior of muscle cell and wrap around each _____; allow ___ to travel from surface down inside muscle cell

Answer 6

transverse tubules / myofibril / AP

Question 7

troponin C binds to ___ / T to____/ A to ___

Answer 7

calcium / tropomyosin / actin

Question 8

what is a power stroke?

Answer 8

when myosin head undergoes conformational change to generate contraction

Question 9

what is sliding filament theory?

Answer 9

myosin head binds to G-actin

when sacomere contracts, myosin head undergoes a power stroke (push) -> thin myofilament slides over the thick -> sacomere contracts, muscle contractwsw

Question 10

describes what happened in Excitation Contraction Coupling in skeletal muscle?

Answer 10

AP from NMJ propagtes from sarcolemma to T-tubule cell
voltage sensor senses AP and changes shape
..opens the Ca++ channel and releases Ca
Ca tore the tropomyosin away from myosin binding site
sliding filemtn theory occurs
nyscle contracts

Question 11

cause of rigor mortis?

Answer 11

no O -> no ATP
=> Ca+ cant be pumped back into SR
actin and myosin can’t dissoiciate
muscle permenatly fused until began decon

Question 12

how to increase force of contraction?

Answer 12

more motor unit recruitment
=> more muscle fibers contract whcih increase contractile force
summation of twitch contractio: increased stimulus frequency

Question 13

contrast how ANS vs somatic nervous system is controlled

Answer 13

ANS: regulation centre compares these signals and activates the hypothalamus (master controller of ANS) -> outputs to SNS & PSNS -> innervate smooth and cardiac muscle

s.m.s: activates the motor cortex -> output to alpha and gamma motor neurons -> innercates skeletal muscle

Question 14

CONTRAST the effects of PSNS vs SNS

Answer 14

PSNS:
- less light enters the eye
- decreases heart rate
- increases digestion and absorption of nutr
- contracts bladder

SNS:
- more light enters eye
- increases heart rate
- shuts down digestion
- holds urine

Question 15

describe the thin myofilament?

Answer 15

contains G-actin: form an alpha-helical chain. each has a myosin binding site
tropomyosin: cover the myosin binding site
and troponin

Question 16

what needs to happen for muscle to relax?

Answer 16

Ca2+ needs tb actively pumped back into SR via Ca ATPase against the concentration gradient

when that happens, tropomyosin cover the myosin binding site again

Question 17

Z-line holds _____ myofilement while M-line holds ____ myofilament

Answer 17

thin / thick

Question 18

what happens in summation of twitch contraction?

Answer 18

muscle twitch has less time to relax before another one comes
stack up each other -> to increase contraction

Question 19

contrast unfused tetanus vs complete tetanus

Answer 19

high frequency AP vs very high frequency AP
has time to relax vs no relaxation at all
vs all twitches summate to produce a smooth, sustained contraction

Question 20

contrast skeletal muscle vs smooth muscle

Answer 20

Skeletal:
voluntary
striated, multinucleated
sticks to skeleton

Smooth muscle:
unvoluntary
nonstriatd, spindle-shaped, and uninucleated
Covers of internal cell wall
caveola

Question 21

smooth muscle has ___ potential and ___ potential, which is alternating hyperpol & ____ due to changes in the ___ permeability.

when threshold reach, trigger ____ & _____

Answer 21

pacemaker / slowave / depol / Na+

AP / muscle contract

Question 22

ECC in smooth muscle?

Answer 22

Ca+ from ECF binds to calmodulin
activates kinase to phosphorylate myosin
cross bridge formation and power stroke
muscle contracts: filament slide past e/o + pull on dense bodies