October 23, 2023

Question 1

fused tetanic contractions typically happen at how many Hz

Answer 1

20-40 Hz

Question 2

Unfused Tetanic contractions typically happen at how many Hz

Answer 2

20 Hz or less

Question 3

what are the 3 different types of motor units in human and mammalian muscle

Answer 3

Slow-Twitch Oxidative (Type I)

Fast-Twitch Oxidative Glycolytic (Type IIA)

Fast-Twitch Glycolytic (Type IIB or IIX)

Question 4

Draw out the fatigue curves and Twitch responses for the 3 different types of MU’s in human and mammalian muscle

Answer 4

review page 76

Question 5

Give 3 characteristics of Slow-Twitch Oxidative (Type I) MU

Answer 5

slow contraction speed.

highly fatigue-resistant and can sustain contractions for an extended period.

primarily responsible for activities that require endurance and low-intensity, long-duration efforts, such as maintaining posture or aerobic activities like long-distance running or cycling.

Question 6

Give 3 characteristics of Fast-Twitch Oxidative Glycolytic (Type IIA) MU

Answer 6

moderately fast contraction speed and a moderate level of fatigue resistance.

They are involved in activities that require both strength and endurance, such as sprinting or resistance training with moderate loads.

These motor units contain muscle fibers that have a balance of aerobic and anaerobic capacity and are intermediate in terms of their fatigue resistance and contractile speed.

Question 7

Give 3 characteristics of Fast-Twitch Glycolytic (Type IIB or IIX) MU

Answer 7

Fast-twitch glycolytic motor units contract rapidly and have a low resistance to fatigue.

They are primarily involved in high-intensity, short-duration activities that require a burst of power, like sprinting, jumping, or lifting heavy weights.

Muscle fibers in fast-twitch glycolytic motor units rely on anaerobic metabolism and have limited endurance capacity.

Question 8

what is the size principle

Answer 8

the orderly recruitment of motor units according to size, starting with the smallest, then intermediate then large

Question 9

what intensity of exercise is required to recruit Slow-Twitch Oxidative (Type I) MU

Answer 9

low to high intensity (0%-40%)

These are the smallest motor units and they are recruited first according to size principle

Smaller Motor Neurons: Small motor neurons have a relatively high ratio of excitatory input to their cell body area. They are the first to be recruited when a muscle needs to produce a low level of force or perform a low-intensity task.

Question 10

what intensity of exercise is required to recruit Fast-Twitch Oxidative Glycolytic (Type IIA) MU

Answer 10

low-moderate to high intensity (40%-70%)

Question 11

what intensity of exercise is required to recruit Fast-Twitch Glycolytic (Type IIB or IIX) MU

Answer 11

moderate to high intensity (70%-100%)

Question 12

If you recruit another small MU to generate more force will this result in small or large increases in force? Will you have good or bad motor control

Answer 12

small increase in force

good motor control

Question 13

If you recruit another large MU to generate more force will this result in small or large increases in force? Will you have good or bad motor control

Answer 13

large increases in force

more power but less motor control

Question 14

small motor units are good for fine motor movements. true or false

Answer 14

true

Question 15

what are two ways we generate more force in regards to MU

Answer 15

increase the firing frequency of single MU

increase the recruitment of more MUs, of gradually increasing “size”

Question 16

are those with higher percentage of type 2 fibres (Type IIA + Type IIX) at higher or lower risk for obesity, hypertension, and insulin resistance

Answer 16

higher risk

Question 17

are those with higher percentage of type 1 fibres (Type I) at higher or lower risk for obesity, hypertension, and insulin resistance

Answer 17

lower risk

Question 18

what is a biopsy

Answer 18

A biopsy is a medical procedure in which a small sample of tissue or cells is removed from a person’s body for examination under a microscope or through other laboratory techniques.

Question 19

explain the muscle needle biopsy technique

Answer 19

A muscle needle biopsy is a medical procedure in which a small sample of muscle tissue is collected for diagnostic or research purposes

It is often performed during exercise (usually on a bicycle ergometer)

Question 20

what are the parts of a biopsy needle

Answer 20

syringe = to generate suction

reaming tool

plunger

outer needle

Question 21

staining muscle biopsy? what is it

Answer 21

Staining muscle biopsy samples is a crucial step in the histological examination of muscle tissues. It allows pathologists and researchers to visualize and identify different muscle components, including muscle fibers, connective tissues, blood vessels, and any abnormalities.

Question 22

review page 82