A&P Exam 3

Question 1

Myotube

Answer 1

muscle fiber

Question 2

myoblast

Answer 2

fased,

multiple nuclei

Question 3

tendon

Answer 3

at each end of a muscle

dense regular connective tissue

Question 4

fascia

Answer 4

dense irregular connective tissue

Question 5

epimysium

Answer 5

outside sheath

Question 6

perimysium

Answer 6

in between layers

Question 7

endomysium

Answer 7

smallest bundles

Question 8

contractions

Answer 8

actin pulls on by myosin, 2 disks get closer to each other

Question 9

tropomyosin

Answer 9

protein that turns off contractions

Question 10

How do you start a contraction?

Answer 10

• neuron releases neurotransmitter, acetylcholine on muscle cell’s receptors
• muscles will bind acetylcholine, then let in Na+ ions
• Na+ travels in tubules within muscle cells

Question 11

How do you stop a contraction?

Answer 11

put Ca+ back inside smooth ER

Question 12

All or None principle

Answer 12

a muscle fiber contracts, or not, there is no inbetween

Question 13

summation

Answer 13

more fibers contract -> stronger contraction at muscle

Question 14

tetany

Answer 14

maximal summation

Question 15

fatigue

Answer 15

stress/maimal effort ->lactic acid

Question 16

muscle tone

Answer 16

always a few fibers contracted

Question 17

Denerveation

Answer 17

lose nerve input to muscles

Question 18

slow twitch muscle fibers

Answer 18

endurance, posture, shorter muscle fibers, darker color, larger motor units, increased blood supply, mitochondria, and myoglobin

Question 19

fast twitch muscle fibers

Answer 19

sprinting, precision, longer fibers, smaller motor units, more lactic acid enzymes, lighter color

Question 20

frontalis

Answer 20

facial expressions

Question 21

orbicularis oculi

Answer 21

close eyelids

Question 22

zygomaticus major

Answer 22

elevate angle of the mouth and abduct :)

Question 23

orbicularis oris

Answer 23

closed mouth & pucker

Question 24

masseter

Answer 24

chewing, elevates the mandible/crush

Question 25

temporalis

Answer 25

elevates mandible but with a “hinge” action

Question 26

pteragoids

Answer 26

jaw opening + side movements

Question 27

styloglossus

Answer 27

retract tongue

Question 28

intrinsic muscles

Answer 28

within the tongue

Question 29

trapezius

Answer 29

extend + hyperextend, rotating, elevate scapula

from occipital bone to thoracic 12

Question 30

splenius capitus

Answer 30

under trapezius

extend + hyperextend neck with some rotating

Question 31

scalene

Answer 31

(ant, post, middle)

flexes neck, side flex, rotate or fixes + elevates upper ribs

Question 32

thoracic outlet

Answer 32

where the nerves to arm + arteries come out

Question 33

sternocleidomastoid

Answer 33

sternum/clavicle/temporal bone
flexes the neck, rotates, side flexes
covers jugular vein
landmark: carotid pulse

Question 34

pectoralis major

Answer 34

greater tubercle