Wk 3 Vocab

Question 1

A band

Answer 1

Large, dark bands in a skeletal muscle fiber that alternate with lighter I bands to give a striped appearance to skeletal muscle fibers under a microscope. Composed of thick filaments of the contractile protein myosin.

Question 2

Abductor muscle

Answer 2

A muscle that moves away from the median plane

Question 3

Actin filament

Answer 3

A protein that forms microfilaments. It is fond in the cytoskeleton, in myofibrils of muscle fibers, and in spindle fibers during cell division.

Question 4

Adductor muscle

Answer 4

A muscle that moves toward the median plane

Question 5

Adenosine diphosphate

Answer 5

The discharged form of ATP. A nucleotide that contains 2 phosphoric acid groups.

Question 6

Adenosine triphosphate

Answer 6

A hight-energy molecule produced in the mitochondria of cells. it is a nucleotide that contains three phosphoric acid groups. When a phosphate group is split from an ATP molecule to produce ADP, energy is released that powers the sliding of the actin and myosin filaments in muscle over each other.

Question 7

Aerobic metabolism

Answer 7

Oxygen consuming metabolism. More efficient

Question 8

Agonist

Answer 8

Prime mover - directly produces a desired movement

Question 9

Anaerobic metabolism

Answer 9

Non-oxygen dependent metabolism.

Question 10

Antagonist

Answer 10

directly opposes the action of an agonist

Question 11

Aponeurosis

Answer 11

A broad sheet of fibrous connective tissue that attaches certain muscles to bones or to other muscles.

Question 12

Brachium

Answer 12

The upper arm. The area of the thoracic limb between the elbow and the shoulder.

Question 13

Creatine phosphate

Answer 13

(CP) The molecule in muscle cells that splits to release the energy necessary to reattach the detached phosphate group to an adenosine diphosphate (ADP) molecute to convert it back to the high-energy molecule adenosine triphosphate (ATP).

Question 14

Cutaneous muscle

Answer 14

“Skin muscles”; thin muscles in the connective tissue beneath the skin. When a cutaneous muscle contracts, it causes the skin to twitch.

Question 15

Diaphragm

Answer 15

The thin, dome-shaped sheet of muscle that forms the boundary between the thoracic and abdominal cavities.

Question 16

Endomysium

Answer 16

The thin, delicate layer of connective tissue that surrounds each individual skeletal muscle fiber.

Question 17

Epimysium

Answer 17

The tough connective tissue layer that covers and delineates individual muscles. It surrounds groups of skeletal muscle fascicles.

Question 18

Expiratory muscle

Answer 18

A muscle whose action is to decrease the size of the thoracic cavity; this squeezes air out of the lungs, thereby producing expiration (exhalation).

Question 19

Fascicle

Answer 19

A group of skeletal muscle fibers bound together by a layer of fibrous connective tissue called the perimysiym

Question 20

Fixator

Answer 20

A muscle that stabilizes a joint so that other muscles can produce effective movements of other joints

Question 21

H band

Answer 21

various visible bands on fillaments

Question 22

I band

Answer 22

Large, light bands in a skeletal muscle fiber that alternate with the darker A bands to give a striped appearance to skeletal muscle fibers under a microscope. The I bands are composed of thin filaments of the contractile protein actin.

Question 23

Inspiratory muscle

Answer 23

A muscle whose action is to increase the size of the thoracic cavity; this causes air to be drawn into the lungs, thereby producing inspiration (inhalation).

Question 24

Lactic acid

Answer 24

A waste byproduct of anaerobic metabolism in skeletal muscle; an end product of the metabolism of carbohydrates. It is created by the conversion of the pyruvate into lactic acid after the fermentation of cellulose. The buildup of lactic acid in a muscle that has been forced into anaerobic mode by over-strenuous activity can cause discomfort.

Question 24

Lactic acid

Answer 24

A waste byproduct of anaerobic metabolism in skeletal muscle; an end product of the metabolism of carbohydrates. It is created by the conversion of the pyruvate into lactic acid after the fermentation of cellulose. The buildup of lactic acid in a muscle that has been forced into anaerobic mode by over-strenuous activity can cause discomfort.

Question 25

Linea alba

Answer 25

The sheet of fibrous connective tissue (aponeurosis_ that connects the abdominal muscles from each side on the ventral midline.

Question 26

Motor unit

Answer 26

One nerve fiber and all the skeletal muscle fibers it innervates. Motor units with small numbers of muscle fibers per nerve fiber are capable of fine, delicate movements.

Question 27

Multi-unit smooth muscle

Answer 27

The type of smooth muscle composed of individual smooth muscle cells or small groups of cells. Found where small, delicate involuntary contractions are needed. Requires nerve impulses to stimulate its contractions.

Question 28

Myofibril

Answer 28

Microscopic, fiberlike structures that occupy most of the cytoplasm (sarcoplasm) in skeletal muscle cells. Composed of filaments of the contractile proteins actin and myosin and are packed together longitudinally in the muscle cells.

Question 29

Myoglobin

Answer 29

A protein in muscle cells that has properties similar to hemoglobin. It can store and release large quantities of oxygen to fuel aerobic metabolic processes in the muscle cells.

Question 30

Myosin filament

Answer 30

One of two contractile proteins of muscle that slide over each other to produce the shortening of the muscle cell that we refer to as muscle contraction.

Question 31

Neuromuscular junction

Answer 31

The “connection” between the end bulb of a motor nerve fiber and a skeletal muscle cell.

Question 32

Perimysium

Answer 32

The fibrous connective tissue layer in skeletal muscle that surrounds groups of muscle fivers and binds them into groups called fascicles.

Question 33

Sarcolemma

Answer 33

The cell membrane of a muscle cell.

Question 34

Sarcomere

Answer 34

The basic contracting unit of skeletal muscle. It consists of the actin and myosin filaments between Z lines in a muscle cell. Myofibrils are composed of many sarcomeres stacked end to end.

Question 35

Sarcoplasm

Answer 35

The cytoplasm of a muscle cell.

Question 36

Sarcoplasmic reticulum

Answer 36

The organelle in a muscle cell that is equivalent to the endoplasmic reticulum of other cells. It stores calcium ions (Ca2+) necessary to initiate the muscle contraction process. Release of Ca(2+) from the sarcoplasmic reticulum is stimulated by a nerve impulse.

Question 37

Synergist

Answer 37

Something that aids the action of something else. A synergistic muscle contracts at the same time as a prime mover and assists it can carrying out its action.

Question 38

Tendon

Answer 38

Fibrous connective tissue bands that connect skeletal muscles to bones.

Question 39

Transverse tubule

Answer 39

A system of tubules in a skeletal muscle cell that exted from the sarcolemma (cell membrane) into the depths of the cell. They help carry an impulse caused by nerve stimulation of the muscle cell into its interior.

Question 40

Twitch contraction

Answer 40

A single skeletal muscle fiber contraction. It can be divided into three phases: a brief, latent phase; a longer. contracting phase; and an even longer relaxation phase.

Question 41

Viscera

Answer 41

the internal organs in the main cavities of the body, especially those in the abdomen, e.g. the intestines

Question 42

Visceral smooth muscle

Answer 42

The type of smooth muscle found in the walls of many soft internal organs, such as the intestine, urinary bladder, and uterus. Its cells are linked to form large sheets that show rhythmic waves of contraction without external nerve stimulation.

Question 43

Z line

Answer 43

The dark line in the center of the light band (I band). Discs to which the actin filaments are attached. They look like lines because of the angle they are viewed.