Muscle physiology and receptors

Question 1

what are the classifications of muscle fibers?

Answer 1

type I muscle fibers
type II (a and b) muscle fibers

Question 2

type I muscle fiber characteristics:
aerobic or anaerobic: __
color of fibers: __
response of fiber to stimuli: __
type of twitch: __
energy system used: __

Answer 2

aerobic
red
tonic
slow
slow-oxidative

Question 3

type II muscle fiber characteristics:
aerobic or anaerobic: __
color of fibers: __
response of fiber to stimuli: __
type of twitch: __
energy system used: __

Answer 3

anaerobic
red (type IIa) and white (type IIb)
phasic
fast
fast glycolytic

Question 4

slow twitch muscle fiber

Answer 4

primarily used for endurance based activities
-slow contraction
-high endurance (fatigue resistant)
-aerobic respiration
-long distance running, cycling and walking

Question 5

fast twitch muscle fiber

Answer 5

primarily used for short bursts of power and speed
-fast contraction
-low endurance (tire quickly)
-anaerobic respiration
-sprinting, jumping, powerlifting

Question 6

tonic muscle receptor

Answer 6

respond continuously to sustained stimuli
maintain posture and support joints

Question 7

phasic muscle receptor

Answer 7

respond only to changes in stimuli, adapting quickly
detect and respond to dynamic movements and environmental changes

Question 8

type I muscle fiber functional characteristics:
__ fatigability
__ capillary density
__ myoglobin content
__ fiber size
__ blood supply
__ amount of mitochondria
functional examples: __, __

Answer 8

low fatigability
high capillary density
high myoglobin content
smaller fiber size
extensive blood supply
large amounts of mitochondria
ex. marathon, swimming

Question 9

type I muscle fiber functional characteristics:
__ fatigability
__ capillary density
__ myoglobin content
__ fiber size
__ blood supply
__ amount of mitochondria
functional examples: __, __

Answer 9

high fatigability
low capillary density
low myoglobin content
larger fiber size
less blood supply
fewer mitochondria
ex. high jump, sprinting

Question 10

what are the types of muscle receptors

Answer 10

muscle spindle
golgi tendon organ

Question 11

what is the function of a muscle spindle

Answer 11

to send info to the nervous system about muscle length and/or the rate of change of its length

Question 12

the muscle spindle plays an important role in the control of __ and, with the help of the gamma system __ movements

Answer 12

posture; involuntary

Question 13

where are muscle spindles specifically located/distributed?

Answer 13

they are distributed throughout the belly of the muscle

Question 14

what is a golgi tendon organ

Answer 14

an encapsulated sensory receptor through which muscle tendons pass immediately beyond their attachment to muscle fibers that are specifically sensitive to tension produced by muscle fibers from active muscle contraction

Question 15

a golgi tendon organ is a sensory receptor that is specifically sensitive to/stimulated by what?

Answer 15

tension produced by muscle fibers from active muscle contraction

Question 16

what is the specific function of a golgi tendon organ

Answer 16

they transmit info to the nervous system about the degree of tension or rate of change of tension within each small muscle segment of each muscle

Question 17

how many muscle fibers are typically connected in series with each golgi tendon organ?

Answer 17

an average of 10-15 muscle fibers