Exam 1

Question 1

list the skeletal muscle components from inner-most to outer-most structures

Answer 1

myofilament
myofibril
myofiber
fascicle 
whole muscle

Question 2

list the connective tissue within the skeletal muscle from inner-most to outer-most layers

Answer 2

endomysium
perimysium
epimysium

Question 3

what is the muscle cell?

Answer 3

myofiber

Question 4

name the neurotransmitter that is released into synapses between adjacent motor neurons

Answer 4

norepinephrine

Question 5

explain one situation in which ATP is needed during a skeletal muscle contraction

Answer 5

ATP allows for the myosin head to achieve the cocked position needed for the power stroke to occur

Question 6

a change in cell membrane potential of greater than 15-20mV is called a(n):

Answer 6

action potential

Question 7

in comparison to type II muscle, type I fibers would have a higher concentration of:

Answer 7

isocitrate dehydrogenase

Question 8

what accounts for the less forceful contraction from a type I muscle fiber?

Answer 8

myosin ATPase is less abundant than in type II
the sarcoplasmic reticulum is less developed than in type II fibers
fewer active sites for which the myosin head can bind are revealed per AP than in type II

Question 9

during the propagation of the AP, potassium leaves the cell during:

Answer 9

repolarization

Question 10

which neurotransmitter is required for proper activation of the skeletal muscle at the level of the neuromuscular junction?

Answer 10

acetylcholine (ACh)

Question 11

describe the steps of the sliding filament theory in the correct order

Answer 11

1. action potentials spread across the sarcolemma
2. down t-tubules
3. calcium is released
4. the active site for the myosin head is revealed
5. muscle shortens

Question 12

which skeletal muscle fiber type is the most fatigue resistant?

Answer 12

type I

Question 13

a motor neuron and all fo the muscle fibers it innervates is known as:

Answer 13

the motor unit

Question 14

which skeletal muscle fiber type has the largest motor unit, and the most developed sarcoplasmic reticulum development?

Answer 14

type II

Question 15

what is typically the most abundant energy substrate within the body?

Answer 15

fat

Question 16

in which state does the muscle have the capacity to generate the greatest amount of force?

Answer 16

eccentric

Question 17

proteins are broken down via oxidation and enter these processes at the level of the:

Answer 17

Krebs cycle

Question 18

which energy system has a SLOWER rate of energy synthesis?

Answer 18

beta oxidation

Question 19

at REST, the substrate utilized to provide the body with energy is determined by:

Answer 19

mass action effect

Question 20

what can be considered a rate limiting enzyme for the breakdown of glucose?
(think about what enzymes are used in glycolysis)

Answer 20

hexokinase (HK)

phosphofructokinase (PFK)

Question 21

when the ratio of CO2 expired to O2 utilized is at or above 1, an individual is utilizing __________ as their primary energy source.

Answer 21

glucose/glycogen

Question 22

the PCr reaction takes place within:

Answer 22

the cytosol of the cell

Question 23

the ETC reaction takes place within:

Answer 23

the mitochondria of the cell

Question 24

an individual is performing HIGH INTENSITY running intervals. what happens to the lactic acid that is produced during this workout?

Answer 24

70-75% of lactate is utilized as an energy source

it is shuttled to the liver and concerted into glucose via the Cori cycle

Question 25

which energy system is dominant in high intensity running intervals?

Answer 25

glycolysis

Question 26

you are participating in the polar plunge. as the even announcer gives the “start” signal to your group, you sprint to the water, submerge yourself, and sprint right back out taking only about 15 seconds. What is the dominant energy substrate during this event?

Answer 26

PCr

Question 27

which skeletal muscle fiber type is most likely to rely the LEAST on FFA’s for energy?

Answer 27

type I

Question 28

during times when glucose or glycogen availability is LOW, what can be utilized as an energy substrate by the brain and CNS?

Answer 28

ketone bodies

Question 29

breakdown of the triglyceride

Answer 29

lipolysis

Question 30

breakdown of the FFA

Answer 30

beta-oxidation

Question 31

breakdown of ATP into inorganic phosphate and ADP

Answer 31

hydrolysis

Question 32

formation of glucose from non-carbohydrate sources

Answer 32

gluconeogenesis

Question 33

breakdown of stored glycogen

Answer 33

glycogenolysis

Question 34

breakdown of glucose/glycogen

Answer 34

glycolysis

Question 35

formation of glycogen

Answer 35

glycogenesis

Question 36

what is the energy system that would be utilized for the majority of a 20-minute walk at low intensity?

Answer 36

oxidation of fat/beta-oxidation

aerobic

Question 37

what is the energy system that would be utilized for the majority of an 800-m (1/2 miil) race?

Answer 37

glycolytic system

anaerobic

Question 38

what is the energy system that would be utilized for the majority of a 45 minute run at moderate intensity?

Answer 38

oxidation of carbs until your body does not have any carbs readily available, then it would switch over to fats/beta-oxidation

Question 39

rank the energy systems from fastest to slowest

Answer 39

ATP-PCr
Glycolytic
Oxidation of carbs
Oxidation of fats

Question 40

rank the energy systems from most ATP produced to least ATP produced

Answer 40

oxidation of fats
oxidation of carbs
glycolytic
ATP-PCr

Question 41

explain why there are differences in energy produced when breaking down carbohydrates aerobically verses breaking down fats aerobically (oxidation).

Answer 41

–

Question 42

what are the components of actin/what is attached to the actin to allow SFT to happen?

Answer 42

troponin
tropomyosin
nebulin
more??