7: Muscles

Question 1

Skeletal muscle connective tissue layers

Answer 1

Epimysium
Perimysium
Endomysium

Question 2

What’s in the epimysium

Answer 2

Nerves, artery’s, veins
Perimysium
Muscle fascicle

Question 3

What’s in a muscle fascicle

Answer 3

Endomysium

Muscle fiber

Question 4

What’s in a muscle fiber (8)

Answer 4

Nucleus/stem cell/ mitochondria
Capillaries/ axon of nerve
Sarcolemma/ sarcoplasm
Myofibrils

Question 5

2 types of connective tissue attachments

Answer 5

Tendon- fiber bundles (muscle-bone)

Aponeurosis- fiber sheets (muscle-muscle), (muscle to flat bone)

Question 6

Sarcolemma

Answer 6

Specialized plasma membrane

Question 7

Myofibrils parts (6)

Answer 7

Z band 
A band 
I band 
Thick filament (myosin) 
Thin filament (actin) 
Sarcomere

Question 8

Sarcoplasmic reticulum

Answer 8

Contains Ca+

Question 9

Contraction cycle

Answer 9

1. Action potential travels over Sarcolemma down into the T tubes
2. Triggers release of Ca from the terminal cisternae of the sarcoplasmic Reticulum
3. Ca binds to troponin which moves the tropomyosin out of the way and exposes active sites for myosin heads

Question 10

3 steps to slide thin filament with thick filament

Answer 10

1. Myosin heads of thick filament bind to active sites on thin filaments (this produces cross-bridges)
2. Heads pivot toward center of sarcomere pulling the thin filament in that direction
3. Cross-bridges detach and return to original position

Question 11

5 steps of motor neuron stimulation of muscle fiber

Answer 11

1. Action potential arrives at axon terminal at neuromuscular junction (AP TRAVELS THROUGH NEURON TO NEUROMUSCULAR JUNCTION)
2. ACh is released and binds receptors on Sarcolemma (AP USE EXOCYTOSIS TO EXIT AXON)
3. Ion permeability of Sarcolemma changes (AP BINDS TO APPROPRIATE RECEPTORS)
4. Local change in membrane voltage occurs (depolarization) (AP IS IN RECEPTOR AND DEPOLARIZES TO SARCOLEMMA)
5. Local depolarization ignites action potential in Sarcolemma (end of potential) (AP IS NOW IN SARCOLEMMA)

Question 12

4 steps of excitation contraction coupling occurring

Answer 12

1. Action potential travels across the entire Sarcolemma (AP TRAVELS THROUGH SARCOLEMMA)
2. Action potential travels along T tubules (AP TRAVELS THROUGH T TUBULES)
3. SR releases Ca which binds to the troponin and exposes myosin-binding sites (AP HITS SARCOPLASMIC MEMBRANE, RELEASES CA WHICH BIND TO TROPONIN AND MOVE TROPOMYOSIN)
4. Myosin heads bind to actin and contraction behind (MYOSIN HEAD ATTACHES TO G ACTIN WITH ATP, DOES POWER STROKE, LETS GO USING ATP)

Question 13

Muscle tone

Answer 13

Muscle are relaxed and in the contracted position

Question 14

Atrophy

Answer 14

Muscle dies from not being stimulated by nerves

Question 15

Isotonic contraction

Answer 15

Muscle length changes bc force applied is greater than load

Question 16

Isometric contraction

Answer 16

Muscle length does not change because force applied is less than or equal to load

Question 17

Temporalis

Answer 17

Assist in chewing

Question 18

Frontals

Answer 18

Raise eyebrows

Question 19

Sternocleidomastoid

Answer 19

Turns head side to side

Question 20

Occipitals

Answer 20

Moves scalp back

Question 21

Trapezius

Answer 21

Holds head up and raises shoulders

Question 22

Pectoralis major

Answer 22

Flexes shoulder

Question 23

Rectus abdominis

Answer 23

Flexes vertebral column

Question 24

External oblique

Answer 24

Rotate vertebral column

Question 25

Latissimus dorsi

Answer 25

Extends shoulders

Question 26

Deltoid

Answer 26

Abducts shoulder

Question 27

Biceps Brachii

Answer 27

Flexes forearm

Question 28

Triceps brachii

Answer 28

Extends forearm

Question 29

Pronator teres

Answer 29

Rotates forearm palm down

Question 30

Flexor carpi radialis

Answer 30

Flexes wrist

Question 31

Flexor digitorum

Answer 31

Flexes finger

Question 32

Extensor digitorum

Answer 32

Extends fingers

Question 33

Sartorius

Answer 33

Flexes the hip

Question 34

Rectus femoris

Answer 34

Extends the knee

Question 35

Tibialis anterior

Answer 35

Dorsiflexes foot

Question 36

Name the 3 hamstrings

Answer 36

Biceps femoris Semimembranosus Semitendinous

Question 37

Gastrocnemius

Answer 37

Plantar flexes foot

Question 38

Sarcolemma

Answer 38

Muscle cell membrane

Question 39

Sarcoplasm

Answer 39

Interior muscle cell fluid

Question 40

Sarcomere

Answer 40

Z disc to z disc on a Myofibril

Question 41

Sarcoplasmic reticulum

Answer 41

Where the Ca is stored on a myofibril

Question 42

Rigor Mortis

Answer 42

Full muscle contraction/ stiffening of dead person

Question 43

Slow fibers

Answer 43

``` Red Small Aerobic Low glycogen storage High myoglobin content Slow contraction ```

Question 44

Fast fibers

Answer 44

``` White Large Anaerobic High glycogen Low myoglobin Fast fatigue ```

Question 45

Cardiac cell appearance

Answer 45

Intercalated discs Striated Branched

Question 46

Smooth cell appearance

Answer 46

Spindle shaped Single nucleus In organs it forms sheets, bundles, sheaths Orients directionally per function

Question 47

Skeletal cell appearance

Answer 47

Striated | Multinucleic