Biology Ch 10

Front 1

myology

Back 1

the study of the muscular system

Front 2

major purpose of muscles

Back 2

convert chemical energy (ATP) into mechanical energy

Front 3

fascia

Back 3

sheet of connective tissue that separates neighboring muscles or muscle groups form each other and from subcataneous tissue

Front 4

fusiform muscles

Back 4

thick in the middle and tapered at each end

ex: biceps brachii

Front 5

parallel muscles

Back 5

uniform width and parallel fascicles; can span long distances due to these parallel fascicles but cannot generate an impressive amount of force

ex: rectus abdominus

Front 6

triangular muscles

Back 6

fan-shaped muscles; broad at the origin and have a narrow insertion; relatively strong due to large number of fibers in wide part

ex: pectoralis major

Front 7

pennate muscles

Back 7

feather shaped; oblique fascicles, generate a LOT of strength due to more muscle fibers for a given length

There are uni, bi, and multi

Front 8

circular muscles

Back 8

sphincters; form rings around body openings, constrict opening when contracted

Front 9

indirect attachment

Back 9

tendons bridge gap b/w muscles and bone

Front 10

direct attachment

Back 10

little separation b/w muscle and bone (there are collagen fibers b/w bone and muscle but are barely visible)

Front 11

origin

Back 11

bony attachment at STATIONARY END of muscle

Front 12

insertion

Back 12

bony attachment to mobile end of muscle

Front 13

belly

Back 13

middle region of muscle b/w origin and insertion; arteries and veins are located here

Front 14

prime mover, agonist

Back 14

the muscle that produces most of the force during a joint action

Front 15

synergist

Back 15

muscle aid prime mover; "assistant," stabilizes the nearby joint and modifies direction of movement

Front 16

ANTagonist

Back 16

opposes prime mover; can relax to give prime mover more control, prevents excessive movement

Front 17

antagonistic pairs

Back 17

muscles that act on opposite sides of a joint

Front 18

fixator

Back 18

muscle that prevents movement of bone

Front 19

intrinsic muscles

Back 19

muscles that are entirely contained within a region; ie, origin and insertion both in same region

ex: hand

Front 20

extrinsic muscles

Back 20

act on a designated region, but has its origin elsewhere

For example, the fingers are extrinsic muscles who originate in the forearm

Front 21

muscles of facial expression

Back 21

are innervated by cranial nerves, insert in the dermis (so we can see contractions in skin)

Front 22

muscles of chewing

Back 22

are innervated by mandibular nerve; four pairs of muscles allow depression, elevation, protraction, retraction, and lateral/medial excursion

Front 23

hyoid muscles

Back 23

control chewing, swallowing, and vocalizing

Front 24

insertion/origin of muscles that act on the head

Back 24

originate: vertebral column, thoracic cage, and pectoral girdle

insert: on cranial bones

Front 25

diaphragm

Back 25

muscle of respiration

inserts on itself

-extends to a central tendon
contraction flattens it, relaxation makes it rise (expelling air from thoracic cavity)

Front 26

external intercostals

Back 26

elevate ribs/expand thoracic cavity

Front 27

internal intercostals

Back 27

depress and retract ribs/compress t. cavity

Front 28

urogenital triangle

Back 28

anterior half of perneum

Front 29

anal triangle

Back 29

posterior half of perineum

Front 30

hernia

Back 30

condition in which viscera protrude through a weak point in the muscular wall of abdominiopelvic cavity