muscles vocab

Question 1

antagonist

Answer 1

These muscles act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position

Question 2

hamstrings

Answer 2

any one of the three posterior thigh muscles in between the hip and the knee (from medial to lateral: semimembranosus, semitendinous, and biceps femoris)

Question 3

belly

Answer 3

the widest part of a muscle

Question 4

insertion

Answer 4

the place where one end of a muscle is attached to the freely moving bone of its joint

Question 5

serratus anterior

Answer 5

very thin and covers the side of the ribcage. also known as the boxer muscle

Question 6

biceps brachii

Answer 6

commonly known as the biceps, is a large, thick muscle on the ventral portion of the upper arm

Question 7

latissimus dorsi

Answer 7

a broad, flat muscle occupying most of the lower posterior thorax. the muscles primary function is to move the upper extremity, but it is also considered an accessory muscle of respiration.

Question 8

semitendinosus

Answer 8

one of the three muscles that make up the hamstrings muscle group, and it is located at the posterior and medial aspect of the thigh. The semitendinosus is so named due to it having a long tendon of insertion

Question 9

sternocledidomastoids

Answer 9

each of a pair of long muscles that connect the sternum, clavicle, and mastoid process of the temporal bone and serve to turn and nod the head

Question 10

biceps femoris

Answer 10

a muscle of the posterior compartment of the thigh, and lies in the posterolateral aspect

Question 11

complete tetany

Answer 11

The stimulus frequency is so high that the relaxation phase disappears completely, contractions become continuous.

Question 12

myocyte

Answer 12

a muscle cell

Question 13

synaptic vesicle

Answer 13

small, electron-lucent vesicles that are clustered at presynaptic terminals. they store neurotransmitters and release them by calcium-triggered exocytosis

Question 14

conductivity

Answer 14

ability to cross space in between neurons

Question 15

myofibril

Answer 15

a cylindrical bundle of contractile filaments within the skeletal muscle cell. they myofibrils are composed of individual contractile proteins called myofilaments

Question 16

temporal summation

Answer 16

the effects of impulses received at the same place can add up if the impulses are received in close temporal succession

Question 17

contractility

Answer 17

the ability of muscle cells to forcefully shorten

Question 18

myofilament

Answer 18

threadlike structures that comprise the myofibril inside the muscle cell. there are 2 main types of myofilaments: thin filaments and thick filaments. in skeletal muscle, the myofilaments are arranged in a repeating pattern of light and dark bands

Question 19

tendon

Answer 19

a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to bone

Question 20

contraction phase

Answer 20

a single muscle twitch has a latent period, a contraction phase when tension increases, and a relaxation phase when tension decreases

Question 21

myoglobin

Answer 21

a protein that’s found in striated muscles, which includes skeletal muscles and heart muscle. Its main function is to supply oxygen to myocytes

Question 22

elasticity

Answer 22

the ability to recoil or bounce back to the muscle’s original length after being stretched

Question 23

myosin

Answer 23

a fibrous protein that forms (together with actin) the contractile filaments of muscle cells and is also involved in motion in other types of cells

Question 24

endomysium

Answer 24

the key element that separates single muscle fibres from one another. it allows their autonomous gliding during muscle contraction

Question 25

myosin ATPase

Answer 25

an enzyme that causes ATP hydrolysis which provides energy for actomyosin contraction

Question 26

epimysium

Answer 26

a sheath of fibrous elastic tissue surrounding a muscles

Question 27

neuromuscular junction

Answer 27

a synaptic connection between the terminal end of a motor nerve and a muscle (skeletal/ smooth/ cardiac)

Question 28

threshold stimulus

Answer 28

the minimum strength required for the stimulus to initiate the response of muscle contraction

Question 29

oxygen debt

Answer 29

the difference between the amount of oxygen needed by the muscles and the actual amount present

Question 30

titan

Answer 30

a molecular spring in muscle cells. Titin binds calcium at specific sites, thereby increasing its stiffness

Question 31

extensibility

Answer 31

the ability of a muscle to be stretched

Question 32

masseter

Answer 32

a muscle which runs through the rear part of the cheek from the temporal bone to the lower jaw on each side and closes the jaw in chewing

Question 33

synergist

Answer 33

Assists the agonists muscle or “primary mover” for a specific action of a joining. this muscle is not the main muscle involved in the action, but works in synergy with the primary muscle.

Question 34

deltoid

Answer 34

a large triangular-shaped muscle that lies over the glenohumeral joint and which gives the shoulder its rounded contour

Question 35

origin (head)

Answer 35

The proximal site that stays more stable and relatively fixed during muscle contraction. the head is a portion at the end of the origin muscle where it fixes to the bone

Question 36

temporalis

Answer 36

A fan-shaped muscle which runs from the side of the skull to the back of the lower jaw and is involved in closing the mouth and chewing