Muscle Terms

Question 1

Cardiac Muscle

Answer 1

Intercalated Discs, (allow the spread of electrical signals through the heart), very interconnected, Involuntary

Question 2

Smooth Muscle

Answer 2

Lack Striation (smooth), Involuntary

Question 3

Skeletal Muscle

Answer 3

Striated, Voluntary, supplied by Nerve, Artery, 2 Veins

Question 4

Myofibrils

Answer 4

Bundles of thick and thin filaments

Question 5

Muscle Cells (Fibres)

Answer 5

Bundles of Myofibrils

Question 6

Fascicles

Answer 6

Bundle of Muscle Fibers (Cells)

Question 7

Muscles

Answer 7

Bundle of fascicles

Question 8

Endomysium

Answer 8

Surrounds Muscle Fiber (cell)

Question 9

Perimysium

Answer 9

Surrounds Fascilce

Question 10

Perimysium

Answer 10

Surrounds Fascicle

Question 11

Epimysium

Answer 11

Surrounds Muscle

Question 12

Tendon

Answer 12

Formed by Epimysium, Perimysium, Endomysium

Question 13

Muscle Fibers (Cells)

Answer 13

Elongated, cylindrical cells arranged in parallel
(1 muscle fiber = Bundles of myofibrils).

Question 14

Sarcolemma

Answer 14

Plasma membrane that covers a muscle cell

Question 15

Myofibrils

Answer 15

Long cylindrical structures that contain THIN & THICK filaments
(Protein fibers)

Question 16

Sarcomeres

Answer 16

Separated by Z Discs, Region formed by filaments overlapping in specific patterns

Question 17

Transverse Tubules (T - tubules)

Answer 17

Tunnels from the sarcolemma to the center of each muscle cell
(electrical propagation)

Question 18

Triad

Answer 18

One t-tubule and two terminal cisterns make up the TRIAD.

Question 19

Sarcoplasm:

Answer 19

Gel-like substance that that surrounds each myofibril and it contains
a high number of mitochondria that produce ATP.

Question 20

Sarcoplasmic Reticulum (Ca2+ storage site)

Answer 20

A network of fluid-filled tubules that stores calcium ions required
for muscle contraction.

Question 21

Thick Filament

Answer 21

Myosin

Question 22

Actin (Thin)

Answer 22

active sites bind with myosin

Question 23

Tropomyosin (thin)

Answer 23

blocks active site during rest

Question 24

Troponin (thin)

Answer 24

controls the position of tropomyosin

Question 25

Sarcomere (contractile unit)

Answer 25

Repeating units of myofilament down the length of a
myofibril (from Z Disc to Z Disc)
Myofibrils

Question 26

A band

Answer 26

The length of the Myosin, doesn’t change length when contracted

Question 27

M Line

Answer 27

Middle of Myosin

Question 28

I band

Answer 28

Gap between Myosin Filaments, shortens when contracted

Question 29

H Zone

Answer 29

Gap between Actin Filaments shortens when muscles are contracted

Question 30

Motor Neuron

Answer 30

A nerve cells which
innervates skeletal
muscle fibres

Question 31

NMJ

Answer 31

Motor Neuron + Muscle Cell

Question 32

Motor Neurons

Answer 32

Myelinated, largest diameter in body, propagate action potentials,connects brain/spinal cord to skeletal muscle

Question 33

Synaptic End Bulb

Answer 33

The end point of the neurons axon where the signal ends

Question 34

Motor End Plate

Answer 34

The region of the muscle cell (muscle fibre) plasma membrane that lies directly under the axon terminal

Question 35

Neuromuscular Junction

Answer 35

The Junction of an axon terminal with the motor end plate is known as a neuromuscular junction

Question 36

Acetylcholine

Answer 36

Released from the synaptic end bulb

Question 37

Action Potential

Answer 37

Sodium Ions moving into the cell

Question 38

How is ACh released

Answer 38

Na+ Ions open voltage-gated calcium ion membrane channels. When the channels open Ca2+ can fill the cell causing the release of ACh