Chapter 9: Muscular System

Question 0

Sternocleidomastoid

Function

Answer 0

Turns head

Question 1

Masseter

Fuction

Answer 1

Closes jaw

Question 2

Latissimus dorsi

Function

Answer 2

Adduction of arm

Question 3

Trapezius

Function

Answer 3

Raise shoulders

Question 4

Pectorals

Function

Answer 4

Adduction of arms

“flex”

Question 5

Triceps

Function

Answer 5

Extend arm

Question 6

Biceps

Function

Answer 6

Flexes elbow and supinates forearm

Question 7

Deltoids

Function

Answer 7

Abducts arms

Rotation

Question 8

Obliques

Function

Answer 8

Stabilize spine

Question 9

Rectus abdominis

Function

Answer 9

Stabilize core

Question 10

Vastus lateralis

Function

Answer 10

Extend and stabilizes knee

Question 11

Quadriceps femoris

Function

Answer 11

Knee extension “flex”

Hip flexion

Question 12

Hamstrings

Function

Answer 12

Flexion of the knee

Extension of hip

Question 13

Tibialis anterior

Function

Answer 13

Dorsiflexion and inversion of the foot

Question 14

Gastrocnemius

Function

Answer 14

Plantar flexion

Question 15

Gluteus maximus

Function

Answer 15

Sitting and climbing

Question 16

Synaptic cleft

Answer 16

Space between the nerve and motor end plate

Question 17

Muscle contraction

Answer 17

Myosin heads of the thick filaments pull on the thin filaments causing you to slide towards the center

Question 18

Muscle contraction requires…

Answer 18

Calcium and ATP

Question 19

Myosin

Answer 19

Thick filament

Question 20

Actin

Answer 20

Thin filament

Contains two other proteins: tropomyosin and troponin

Contains a myosin-binding site where myosin can attach

Question 21

Myofibrils

Answer 21

Cylindrical structures that contain two types of proteins:

Actin

Myosin

Question 22

Sarcoplasmic reticulum

Answer 22

“SR”

Fluid filled membrane enclosed tubules that store calcium for muscle contraction

Question 23

Sarcoplasm

Answer 23

Muscle fibers cytoplasm, packed with mitochondria which produce large amounts of ATP

Question 24

Transverse tubules

Answer 24

T-tubules Tunnel in from the surface towards the center of the muscle fibers

Question 25

Sarcolemma

Answer 25

Plasma membrane that covers the muscle fiber

Question 26

Tendon

Answer 26

Dense regular connective tissue that attaches muscle to a bone

Question 27

Muscle fiber

Answer 27

Elongated, cylindrical cells arranged parallel to each other

Question 28

Endomysium

Answer 28

Connective tissue, surrounds each individual muscle fiber

Question 29

Perimysium

Answer 29

Connective tissue that surrounds bundles of muscle fibers called fascicles

Question 30

Epimysium

Answer 30

Connective tissue, wraps around the entire muscle

Question 31

Skeletal muscles | structure

Answer 31

Skeletal muscle tissue Nervous tissue Blood Connective tissue

Question 32

Functions of muscular tissue

Answer 32

Producing contraction Stabilize a body positions Storing and moving substances within the body Produce heat

Question 33

Three types of muscle

Answer 33

Cardiac Smooth Skeletal

Question 34

Neuromuscular junction

Answer 34

"NMJ" The synapse between the neuron terminals and the motor end plate of the motor muscle fiber

Question 35

4 steps that occur in the neuromuscular junction (NMJ)

Answer 35

1- Release of Acetylcholine (Ach) 2- Ach binds to the motor end plate opening the sodium channels and releasing Na 3- Na generates a motor action potential 4- Breakdown of Ach by an enzyme called acetylcholinesterase

Question 37

Physiology of muscle contraction

Answer 37

1- Motor neuron is activated and releases Ach into the synaptic cleft 2- Ach diffuses across sarcolemma and binds to the binding sites and triggering action potential 3- Acetylcholinesterase breaks down the Ach 4- The muscle action potential travels down the T-tubule opening the Ca channels in this SR 5- Ca floods into the sarcoplasm and binds to the thin filaments (troponin) exposing the binding sites for myosin 6- Myosin binds to actin and power strokes towards the center (contraction) 7- Ca channels are closed in the SR and Ca is actively pumped back into the SR (uses ATP) 8- Troponin-tropomyosin complex slides back into position and blocks myosin from binding to actin 9- Muscle relaxes

Question 38

Muscles involved in breathing

Answer 38

External intercostals Internal intercostals Diaphragm

Question 39

Exterior intercostals

Answer 39

Lie superficially between ribs They elevate the ribs during inspiration

Question 40

Interior intercostals

Answer 40

Lie deeper than the external intercostals They depress the ribs during forced exhalation

Question 41

Diaphragm

Answer 41

Enlarges the thorax to trigger inspiration

Question 42

Homeostasis of Ca in blood

Answer 42

Calcium too low: Parathyroid gland secretes Parathyroid hormone Calcium too high: Thyroid gland secretes Calcitonin