Ch.9: Muscles and Muscles Tissue Part 2

Question 1

A _______ consist of one motor neuron and all the muscle fibers it innervates or supplies

Answer 1

Motor unit

Question 2

true or false: when a motor neuron fires (transmit an action potential), all the muscle fibers it innervates contract

Answer 2

True

Question 3

Contraction where muscle length changes and tension is constant

Answer 3

Isotonic contractions

Question 4

Contraction where muscle length stays the same yet tension increases

Answer 4

Isometric Contractions

Question 5

Skeletal muscles are described as voluntary, but even relaxed muscles are almost always slightly contracted

Answer 5

Muscle tone

Question 6

Three pathways for generating ATP during muscle activity

Answer 6

Direct phosphorylation, Anaerobic pathway, Aerobic pathway

Question 7

Characteristic of Direct Phosphorylation

Answer 7

Creatine Phosphate and ADP
energy source: CP
no oxygen use
Product 1 ATP per CP
15 Second duration

Question 8

Characteristic of Anaerobic Pathway (quick money)

Answer 8

Gylcolysis and lactic acid formation
energy source: glucose
No oxygen use
Product: 2 ATP per glucose, lactic acid
30-40 seconds duration

Question 9

Characteristic of Aerobic Pathway(bank)

Answer 9

Aerobic cellular respiration
energy source: glucose, pyruvic acid, free fatty acid, amino acids
oxygen use required
products 32 ATP per glucose, CO2, and H2O
duration hours

Question 10

_______ responsible for muscle soreness during intense exercise

Answer 10

lactic acid

Question 11

______ state of physiological inability to contract even though the muscle still may be receiving stimuli

Answer 11

Muscle Fatigue

Question 12

For a muscle to return to its resting state all the following must occur

Answer 12

Oxygen reserves in myoglobin must be replenished
lactic acid must be reconverted to pyruvic acid
glycogen stores must be replaced
ATP and creatine phosphate reserves must be resynthesized

Question 13

Three types of Skeletal Muscle Fibers

Answer 13

Slow oxidative fibers, Fast oxidative fibers, Fast glycolytic fibers

Question 14

Characteristic of Slow oxidative fibers

Answer 14

contracts slowly, depends on oxygen, high endurance, red

Question 15

Characteristic of Fast Glycolytic fibers

Answer 15

contracts rapidly, does not use oxygen, depends on glycogen, tires quickly

Question 16

this type of exercise result in more efficient muscle metabolism and in greater endurance,strength, and resistance to fatigue

Answer 16

aerobic endurance exercise

Question 17

this type of exercise results to muscle hypertrophy, bulging muscles. strength not stamina is important

Answer 17

resistance exercise

Question 18

overload principle

Answer 18

forcing a muscle to work hard increases muscle strength

Question 19

The alternating contraction and relaxarion of these layers mixes substances in the lumen and squeezes them through the organs internal pathways this propulsive action is called

Answer 19

peristalsis

Question 20

Differences of Smooth muscle myofilaments and Skeletal muscle

Answer 20

thick filaments are fewer but have myosin heads along their entire length
no troponin
thick and thin filaments are arranged diagnolly
intermediate filament- dense body network (anchor)

Question 21

Special Features of Smooth muscle contraction

Answer 21

• Stress-relaxation response (great volume without causing strong contractions that would expel its content)
• lack of sarcomeres, able to stretch a total range of 150%
• Hyperplasia, divide to increase their numbers

Question 22

a group of inherited muscle-destroying diseases that muscles initially enlarge due to deposits of fat and connective tissue but the muscle fiber atrophy and degenerate

Answer 22

Muscular dystropy

Question 23

The most common and serious form is _____ , inherited as a sex link recessive disease. Rarely live beyond their 20s

Answer 23

Duchenne muscular dystrophy