Skeletal Muscle and Nerve Tissue

Question 1

Makes up muscle cells

Answer 1

myofibrils; chains of sarcomeres (contractile unit) linked together form one fiber; surrounded by endomysium

Question 2

Makes up a fascicle

Answer 2

groups of myofibers (muscle cells) surrounded by perimysium

Question 3

Makes up a muscle

Answer 3

groups of fascicles surrounded by epimysium

Question 4

Makes up myosin (thick filaments)

Answer 4

2 heavy chains with globular heads (have actin binding site with ATPase domains) and 2 light chains

Question 5

What holds myosin in place

Answer 5

Titin proteins connected to the Z disc

Question 6

Makes up sarcomere

Answer 6

actin and myosin

Question 7

Makes up actin

Answer 7

F-actin monomers; form double stranded chains

Question 8

Nebulin

Answer 8

determines the length of the actin filament

Question 9

Role of tropomyosin in actin

Answer 9

wrap around the actin strands

Question 10

Role of troponin in actin

Answer 10

sits on top of the tropomyosin and covers the myosin binding sites

Question 11

M-line

Answer 11

attachment site for myosin

Question 12

Z-disc/line

Answer 12

separates sarcomeres and is the attachment site for actin and titin

Question 13

H-band

Answer 13

space on each side of M line with no actin present

Question 14

A-band

Answer 14

distance from end of myosin head to opposite myosin head (overlap in middle)

Question 15

I-band

Answer 15

space on either side of Z disc without myosin

Question 16

How does muscle contraction occur

Answer 16

Ca2+ is released from the SR which binds troponin causing a conformational change; the actin binding sites are then accessible to the myosin heads

Question 17

Sarcolemma

Answer 17

Membrane around each muscle cell

Question 18

Transverse (T) tubules

Answer 18

penetrates muscle class to deliver electrical impulses from Sarcolemma into the cell

Question 19

Sarcoplasm

Answer 19

cytoplasm of muscle cell

Question 20

Sarcoplasmic reticulum

Answer 20

tubular system acting as smooth ER; terminal cistern are flattened SR space on each side of T tubule

Question 21

Triad

Answer 21

T tubule and the 2 terminal cisternae attached

Question 22

End feet

Answer 22

connect T tubule with the SR for Ca release

Question 23

Neuromuscular spindle apparatus role

Answer 23

Reflexive response to prevent overstretching of a muscle

Question 24

Extrafusal muscle fibers

Answer 24

contract the muscle

Question 25

Intrafusal muscle ribers

Answer 25

sense length and rate of change of the muscle

Question 26

1a sensory nerve fibers

Answer 26

A-fferent (sensory) innervation of the intrafusal fibers

Question 27

gamma-motor nerve fibers

Answer 27

E-fferent innervation of intrafusal fibers

Question 28

Schwann Cells

Answer 28

surround axon creating myelin sheath in PNS; wraps around one part of the axon

Question 29

Oligodendrocyte

Answer 29

Surrounds axon creating myelin sheath in CNS; wraps around MANY axons