Semester 2 Final

Question 1

Functions of the muscular system?

Answer 1

provides muscle tone
propels body fluids and food
generates a heartbeat
distributes heat

Question 2

Sarcolemma

Answer 2

(Cell membrane) membrane covering muscle fibers

Question 3

Sarcoplasm

Answer 3

(cytoplasm) Material within a muscle fiber

Question 4

Sarcoplasmic recticulum

Answer 4

(ER) network of channels and tubes throughout the muscle fiber

Question 5

Synapse

Answer 5

junction between two neurons

Question 6

Motor unit

Answer 6

Motor neuron and its muscle fibers

Question 7

Neurotransmitter

Answer 7

chemicals that axons secrete on effectors or other neurons

Question 8

Motor end plate

Answer 8

specialized region of muscle fiber membrane

Question 9

Steps of skeletal muscle contraction

Answer 9

Botor Neuron
ACh Binds
Sodium ions enter
T tubules
Release calcium
Expose myosin bind sites
Binds to actin
Nerve impulses stop
Calcium is actively transported
Relax

Question 10

What is the role of creatine phosphate as an energy source for muscles?

Answer 10

stores excess energy from mitochondria
HIGH ATP = creatine phosphate stores energy
LOW ATP = creatine phosphate transfers stored energy to ADP to make more ATP (P + ADP = ATP)

Question 11

How do muscles store oxygen?

Answer 11

Due to myoglobin (pigmented protein in muscles)

Question 12

How and why do muscles become fatigued?

Answer 12

HOW: when a muscle loses its ability to contract
WHY: accumulation of lactic acid in the muscle
lowers pH….. preventing contraction

Question 13

Myogram

Answer 13

Recording of an electrically-stimulated muscle contraction

Question 14

Threshold stimulus

Answer 14

Muscle remains unresponsive until the stimulus reaches a certain point

Question 15

Twitch

Answer 15

Single, short contraction involving a few motor units

Question 16

Latent Period

Answer 16

Time between application of stimulus and beginning of muscle contraction

Question 17

Summation

Answer 17

increased force of contraction by a skeletal muscle fiber when a twitch occurs before the previous twitch relaxes

Question 18

Recruitment

Answer 18

increased number of activated motor units within a muscle at higher intensities of stimulation

Question 19

Sustained contraction

Answer 19

both summation and recruitment

Question 20

muscle tone

Answer 20

state of tension that is maintained continuously; achieved by continuous, sustained contraction of motor units within a muscle

Question 21

Prime mover

Answer 21

muscle that does the majority of the work

Question 22

antagonist

Answer 22

opposing muscle

Question 23

synergist

Answer 23

helper muscle; works with the prime mover to produce a movement

Question 24

Origin

Answer 24

one end of the skeletal muscle is attached to a fixed point on a movable joint

Question 25

Insertion

Answer 25

one end of a skeletal muscle that is attached to the movable part of the joint

Question 26

How can relationships between muscles change depending on movement?

Answer 26

when you move muscles in different ways, they have different response
EXAMPLE:
pectoralis major and latissimus dorsi are antagonistic for flexion and extension of the shoulder, but they are synergists for medial rotation of the shoulder