Physiology Of The Muscular System

Front 1

What is a muscle fiber?

Back 1

Highly specialized skeletal muscle cells

Front 2

Characteristics of Skeletal Muscles

Back 2

Voluntary Control, Has Striations, Many Nucleus near Sarcolemma, Narrow T tubules that form triads with SR, Extensive SR that stores and releases Ca ions, Rapid Twitch Contractions stimulated by a neuron

Front 3

Characteristics of Cardiac Muscles

Back 3

Involuntary Control, Has Striations, Single Nucleus, Large T tubules that form diads with SR and regulate the Ca ion entry into sarcoplasm, less extensive SR than skeletal muscles, slow separate contractions

Front 4

Characteristics of Smooth Muscles

Back 4

Involuntary Control, No Striations, Single nucleus near the center of cell, No T tubules, Poorly Developed SR, Visceral contractions are electrically coupled sheets of contract autorhythmically, multiunit contractions are individual fibers contract when stimulated by neuron

Front 5

functions of skeletal muscles

Back 5

movement, posture, heat production

Front 6

3 characteristics of skeletal muscle

Back 6

excitability or irritability, contractility, and extensibility

Front 7

excitability

Back 7

ability to be stimulated

Front 8

contractility

Back 8

ability to contract or shorten

Front 9

extensibility

Back 9

ability to extend or stretch

Front 10

What type of neuron innervates skeletal muscle?

Back 10

sommatic motor neuron

Front 11

Sarcoplasm

Back 11

cytoplasm of a muscle fiber

Front 12

sarcolemma

Back 12

plasma membrane of a muscle fiber

Front 13

myofibrils

Back 13

bundles of very fine muscles in cytoplasm of fiber with thick and thin filaments running parallel and the T tubules running perpendicular

Front 14

thin filaments

Back 14

made of actin, tropomyosin, and troponin
actin looks like beads and the tropomyosin looks like thick string with the troponin spaced along the tropomyosin

Front 15

What zone is in the middle of the a band

Back 15

H zone

Front 16

H zone

Back 16

he middle region of the thick filaments where they do not overlap the thin filaments

Front 17

Glucose is stored in muscles as

Back 17

glycogen

Front 18

Z line

Back 18

dense plate or disk to which the thin filaments directly anchor and is a usefull landmark for separating one sarcomere from the next

Front 19

A band

Back 19

the segment that runs the entire length of the thick filaments

Front 20

I band

Back 20

the segment that includes the Z line and the ends of the thing filaments where they do not overlap the thick filaments

Front 21

sarcomere

Back 21

a segment of the myofibril between two successive Z lines

Front 22

Thick filaments

Back 22

made up of myosin molecules which are shaped like golf clubs with their long shafts bundled together to form a thick filament and their "heads" sticking out from the bundle

Front 23

What protein molecules form cross bridges?

Back 23

myosin heads which form with actin

Front 24

what structures make up a triad?

Back 24

a T tubule sandwiched between sacs of the SR

Front 25

What does troponin bind to?

Back 25

Ca ion

Front 26

What is the function of the protein tropomyosin?

Back 26

blocks the active sites on the actin molecule

Front 27

What is the major rold of the SR?

Back 27

pumps Ca ions from the Sarcoplasm and stores them within its sacs

Front 28

What is the function of T tubules?

Back 28

allow electrical signals, or impluses, traveling along the sarcolemma to move deeper into the cell

Front 29

When a muscle contracts, what structures are pulled toward the center of the sarcomere?

Back 29

thin filaments

Front 30

In the sliding filament theory, what slides past what?

Back 30

thin filaments slide past the thick filaments, heading toward center of the sarcomere

Front 31

What is acetylcholine?

Back 31

neurotransmitters that contacts the sarcolemma of the adjacent muscle fiber

Front 32

Ca ions attach to what protein of the thin filament

Back 32

Troponin

Front 33

Events of Muscle Contraction in order

Back 33

1)energized myosin heads of the thick filaments bind to actin molecules in the nearby thin filaments 2)The myosin heads bend with great force, literally pulling the thin filaments past them 3)Each head then releases itself, binds to the next active site, and pulls again

Front 34

Where does calcium go after muscle contraction?

Back 34

back into the sacs of the SR

Front 35

What is the neuromuscular junction?

Back 35

type of connection called a synapse, characterized by a narrow gap, of synaptic cleft, across which neurotransmitter molecules transmit signals.

Front 36

hypertrophy

Back 36

increased size of an organ or part caused by an increase in the size of its cell

Front 37

atrophy

Back 37

wasting away of tissue, decreased in size of a part

Front 38

In excitation-contraction coupling, where is Ca ions released? What does Ca ions bind to? What blocks the myosin heads?

Back 38

Ca ions are released into the SR where it binds to the troponin molecules, the tropomyosin blocks the myosin heads

Front 39

myoglobin

Back 39

large protein molecule containing iron groupd that attract oxygen molecules and hold them temporarily

Front 40

What is a motor unit?

Back 40

motor neuron plus the muscle fibers to which is attaches

Front 41

White fibers

Back 41

fast muscle fibers iwht little myoglobin

Front 42

red fibers

Back 42

slow muscle fibers with high levels of myoglobin

Front 43

tetanus

Back 43

smooth, sustained contractions caused by high frequency stimulation

Front 44

isotonic contractions

Back 44

tone or tension within a muscle remains the same as the length of the muscle changes, the muscle gets shorter

Front 45

isometric contractions

Back 45

muscle length remains the same while the muscle tension increases

Front 46

treppe

Back 46

gradual steplike increase in the srength of contraction that can be observed in a series of twitch contractions that occur about 1 second apart

Front 47

cramps

Back 47

painful muscle spasms when a muscle organ is mildly inflamed, but they can be symptom of any irritation or ion and water imbalance

Front 48

Endurance training

Back 48

aerobic training

Front 49

aerrobic respiration

Back 49

catabolic process in the stage of cellular respiration requiring oxygen taking place in the sarcoplasm and the mitochondria

Front 50

anaerobic respiration

Back 50

catabolic process in the stage of cellular respiration not requiring oxygen, byproduct of lactic acid, liver changes the acid back into glucose

Front 51

muscle fatigue

Back 51

muscle does not respond to the strongest stimuli, repeated stimulation of muscle in time lessens its excitability and contractillity, lack of ATP

Front 52

Three phases of twitch contraction

Back 52

latent period, contraction phase, relaxaion phase

Front 53

Graded strength principle

Back 53

skeletal muscles contract with varying degrees of strength at different times
metabolic condition of individual fibers with high ATP influences their capacity to generate force, amount of load place on muscle, length tension relationship, number of fibers contracting simultaneously

Front 54

muscle sructures

Back 54

myofilament, myofibril, muscle fiber, fascle muscle