Lecture 1

Question 1

Components that make up a muscle fiber (5)

Answer 1

Sarcolemma
Satellite Cells
Sarcoplasm
T-tubules
Sarcoplasm Reticulum

Question 2

Sarcolemma

Answer 2

Plasma membrane that surrounds muscle fiber

Contains myogenic stem cells called satellite cells (exercise induced fiber hypertrophy)

Question 3

Satellite Cells

Answer 3

located between the plasmalemma and the basement membrane.

Muscle growth and development (ex. response to injury, immobilization, training)

Question 4

Sarcoplasm

Answer 4

Fluid and gelatinous-like substances between myofibrils

-stores glycogen, myoglobin, fat, mineral, organelles

Question 5

T-tubules (transverse tubules)

Answer 5

Pathway into the inner part of the muscle to transport glucose, O2, and ions

Question 6

Sarcoplasmic Reticulum (SR)

Answer 6

Ca++ (Ca2+) storage

Question 7

Sacromere

Answer 7

the basic contractile unit of a myofibril and the basic contractile unit of muscle.
-every myofibril is made up of numerous sacromere joined end-to-end at the Z-disks

Question 8

Each sacromere includes these 6 elements found between each pair of Z-disks:

Answer 8

I-band (light zone)
A-band (dark zone)
H-zone (middle of A-band)
M-line (middle of H-zone)
The rest of the A-band
Second I-band

Question 9

Myofibril

Answer 9

runs length of the muscle fiber

-contains sacromeres

Question 10

Muscle Fiber

Answer 10

consists of hundred to thousands myofibrils

Question 11

Endomysium

Answer 11

connective tissue sheath that covers each muscle fiber

Question 12

Perimysium

Answer 12

connective tissue sheath that surrounds each facicle

Question 13

Epimysium

Answer 13

outer connective tissues at holds together he entire muscle

-consists of many bundles called fasciculi

Question 14

Fasciculi

Answer 14

consists of individual muscle cells called muscle fibers

Question 15

Titin

Answer 15

positions and stabilizes the myosin filament

Question 16

Actin

Answer 16

thin filaments

Question 17

Myosin

Answer 17

thick filaments

• two protein strands twisted together
• one ended folded into globular head called the myosin head

Question 18

Nebulin

Answer 18

anchors the Actin filament at the Z-disk

Question 19

Troponin

Answer 19

anchored to Actin

-moves tropomyosin

Question 20

Tropomyosin

Answer 20

covers active site at rest by fitting into a groove between binding sites

Question 21

Proteins that make-up Actin (3)

Answer 21

Actin
Troponin
Tropomyosin

Question 22

Motor Unit

Answer 22

a single a-motor neuron and all muscle fibers it innervates

Question 23

Neuromuscular Junction

Answer 23

site of communication between neurons and muscle