Human Biology Chapter 8: Definitions

Front 1

Fascia

Back 1

Fibrous connective tissue; separates muscle and holds them in place

Front 2

Tendon

Back 2

Cord like structure that attaches muscle to bone

Front 3

Aponeroses

Back 3

Sheet of fibrous connective tissue that attaches muscle to bone

Front 4

Actin

Back 4

Protein that with myosin, contracts muscle fibers, thin

Front 5

Myosin

Back 5

Protein that with actin, contracts muscle fibers, thick

Front 6

Sarcolemma

Back 6

Cell membrane

Front 7

Sarcomere

Back 7

Structural and functional unit of myofibril (between striations)

Front 8

Sarcoplasmic Reticulum

Back 8

ER

Front 9

Sarcoplasm

Back 9

Cytoplasm

Front 10

T-Tubles

Back 10

Transverse Tubules = canal system for extra-cellular fluids

Front 11

Motor Neuron

Back 11

Nerve fiber that stimulates muscle fiber

Front 12

Neuromuscular Junction

Back 12

Site where muscle and nerve meet

Front 13

Neurotransmitter

Back 13

Stores chemicals at ends of nerve fibers

Front 14

Motor End Plate

Back 14

Special muscle fiber; membrane forms with lots of mitochondria and many fluids

Front 15

Acetylcholine

Back 15

Type of neurotransmitter; transmits nerve messages across synapses

Front 16

Ca++

Back 16

Reacts with active filaments and forms cross-bridges between actin and myosin

Front 17

ADP

Back 17

Adenosine Diphosphate - molecule produced when ATP loses terminal phosphate

Front 18

Cholinesterase

Back 18

Enzyme at neuromuscluar junction that prevents a single nerve impulse from causing a continued stimulation of muscle (decomposes acetylcholine)

Front 19

Myoglobin

Back 19

Pigment in muscle cells that loosely bonds oxygen for temporary storage; reduces need for continuous blood supply

Front 20

Hemoglobin

Back 20

Loosely bonds oxygen within RBC

Front 21

Oxygen Debt

Back 21

Inadequate function of respiratory and circulatory system

Front 22

Liver

Back 22

Lactic acid to liver by blood where it can change back into glucose, but this requires ATP

Front 23

ATP

Back 23

Adenosine Triphosphate - organic molecule that stores and releases energy for use in cellular processes

Front 24

Skeletal Muscle

Back 24

Type of voluntary muscle tissue in muscles attached to bones

Front 25

Fatigue

Back 25

Lose of ability to contract

Front 26

Creatine Phosphate

Back 26

Primary source of engery to regenerate ATP from ADP+P --> stores mitochondria and engergy

Front 27

Cramp

Back 27

Painful condition in which muscle contracts spasmodically but doesn't relax completely

Front 28

Myogram

Back 28

Muscular response - "picture" of muscle contracting

Front 29

All-or-none Resonse

Back 29

Muscle fibers are stimulated either responds to its fullest or no contraction

Front 30

Twitch

Back 30

Single contraction that lasts 1/10 of a second

Front 31

Threshold Stimulus

Back 31

Minimal stimuli strength to cause a contraction

Front 32

Impulse

Back 32

Wave of depolarization conducted along a nerve or a muscle fiber

Front 33

Latent Period

Back 33

Time lag between application of stimulus to time muscle responds

Front 34

Period of Contraction

Back 34

Muscle pulls at its attachments (shortens)

Front 35

Period of Relaxation

Back 35

Returns to former length

Front 36

Tone/Tonus

Back 36

Partial contraction of small numbers of muscle fibers; maintaining posture if lost the body will collapse (unconscious)

Front 37

Smooth Muscle

Back 37

Single nucleus/fiber - look at section D in notes

Front 38

Cardiac Muscle

Back 38

Striated cells joined end to end - look at section E in notes

Front 39

Origin

Back 39

Immovable end to which skeletal muscle is attached

Front 40

Insertion

Back 40

Movable part on the other side of a joint

Front 41

Prime Mover

Back 41

Muscle responsible for most movement

Front 42

Synergists

Back 42

muscles that assist prime movers

Front 43

Antagonists

Back 43

Muscle capable of resisting prime mover's action; movement in opposite direction

Front 44

Isotonic

Back 44

Tone remains the same but length of muscle changes; work and movements is produced; moving a heavy box

Front 45

Isometric

Back 45

Muscle length remains same but the tension increase; no work is done; pushing the wall

Front 46

Spastic

Back 46

Result of forceful exercise that increases size of individual muscle fibers not an increase in number of fibers (spastic)

Front 47

Flaccid

Back 47

Muscle decreases in size, strength and number of cell organelles due to lack of use (flaccid)

Front 48

Epimysium

Back 48

A layer of connective tissue at the muscle; at an entire skeletal muscle

Front 49

Perimysium

Back 49

A layer of connective tissue at the muscle; at bundle of muscle fibers

Front 50

Endomysium

Back 50

A layer of connective tissue at the muscle; at each muscle fiber cell

Front 51

Motor Unit

Back 51

Motor neuron + muscle fibers

Front 52

Muscle Fiber

Back 52

Muscle cell - shape of a fiber