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Flashcards in Chapter 11 Deck (76)
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1

origin

the attachment of a muscle's tendon to the stationary bone (origin= usually proximal; insertion is usually pulled toward origin)

2

insertion

the attachment of a muscle's other tendon to the movable bone (insertion= usually distal; insertion is usually pulled toward origin)

3

belly (body)

the fleshy portion of the muscle between the tendons

4

Analogy for origin, insertion and belly

A spring on a door: the part of the spring attached to the frame is the origin; the part attached to the door is the insertion; the coiled middle portion of the spring is the belly.

5

lever

rigid structure that can move around a fixed point: fulcrum

6

fulcrum

fixed point that the lever can move around

7

effort (E)

causes the movement

8

load/resistance

opposes the movement; usually the weight of the body part or resistance that the moving body part is trying to overcome (i.e. weight of a book you're trying to lift)

9

prime mover/ agonist

muscle that contracts to cause an action

10

antagonist

stretches and yields the effects of the prime mover

11

synergists

contract and stabilize the intermediate joints to prevent unwanted movements at intermediate joints or to aid the movement of the prime mover

12

fixator

stabilize the origin of the prime mover sot hat the prime mover can act more efficiently

13

how skeletal muscles are named

Direction, size, shape, action, number of origins, location, origin and insertion

14

occipitofrontalis

location: face

15

frontal belly (frontalis)

location: superficial to the frontal bone
action: draws scalp anteriorly, raises eyebrows, wrinkles skin of forehead horizontally

16

occipital belly

location: superficial to occipital bone
action: draws scalp posteriorly

17

orbicularis oris

location: mouth
action: closes and protrudes lips, compresses lips against teeth, shapes lips during speech

18

zygomaticus major

location: mouth
action: draws angle of mouth superiorly and laterally (smiling)

19

buccinator

location: mouth
action: presses cheeks against teeth and lips (blowing, sucking), draws corners of mouth laterally, assists in chewing (keeps food between teeth)

20

orbicularis oculi

location: orbit/ eyebrow
action: closes eye

21

masseter (origin and insertion too)

location: mandible
action: elevates mandible (closing mouth)
origin: maxilla and zygomatic arch
insertion: angle and ramus of mandible

22

temporalis (origin and insertion too)

location: mandible
action: elevates and retracts mandible
origin: temporal bone
insertion: coronoid process and ramus of mandible

23

sternocleidomastoid (origin and insertion too)

location: neck
action: flex cervical portion of vertebral column, extend head, flex neck and head to same side, rotate head
origin: sternal head: manubrium of sternum; clavicular head: medial third of clavicle
insertion: mastoid process of temporal bone and lateral half of superior nuchal line of occipital bone

24

rectus abdominis (origin and insertion too)

location: pelvis
action: flexes vertebral column, compresses abdomen (aid defecation, urination and childbirth)
origin: pubic crest and pubic symphysis
insertion: cartilage of ribs 5-7 and xiphoid process

25

external oblique

location: abdomen
action: working together: compress abdomen, flex vertebral column, acting alone: laterally flex vertebral column, rotate vertebral column

26

internal oblique

location: abdomen
action: acting together: compress abdomen and flex vertebral column, acting alone: laterally flex vertebral column and rotate vertebral column

27

transversus abdominis

location: abdomen
action: compresses abdomen

28

diaphragm

location: abdomen
action: contraction of diaphragm = flatten resulting in inhalation, relaxation= exhalation

29

external intercostals

location: abdomen
action: contraction= elevates ribs resulting in inhalation, relaxation= depresses ribs resulting in exhalation

30

internal intercostals

location: abdomen
action: contraction= elevates ribs resulting in inhalation, relaxation= depresses ribs resulting in exhalation