Wk 4 Muscle Tissue

Question 1

Sk. muscle: A-band

Answer 1

myosin filaments

Question 2

Sk. muscle: actin filaments

Answer 2

from Z-disks to edge of H-band

Question 3

Sk. muscle: M-line

Answer 3

myomesin, C-protein. interconnects thick filaments to maintain lattice

Question 4

Sk. muscle: Z-disk

Answer 4

alpha-actinin, actin from adjacent sarcomeres connect

Question 5

Actin morphology

Answer 5

G-actin –> F-actin –> F-action double helix w/ nebulin

Question 6

Myosin morphology

Answer 6

4 light chains
2 heavy chains
–>heavy meromyosin = head
–>light meromyosin = straight area

Question 7

Tropomyosin

Answer 7

helically wound around F-actin helices, covers myosin binding areas

Question 8

Troponin

Answer 8

TnT: binds tropomyosin
TnC: binds Ca2+
TnI: binds actin

Question 9

Ca2+

Answer 9

binds TnC, induces troponin conformational change to expose myosin binding site

Question 10

α-actinin

Answer 10

@ Z-disks, binds adjacent actin molecules

Question 11

titin

Answer 11

M-line –> Z-disk, holds myosin fibers @ sacromere

largest protein in body

Question 12

nebulin

Answer 12

bind onto actin filaments, anchor onto Z-disk

Question 13

3 layers of muscle CT

Answer 13

endomysium, perimysium, epimysium

Question 14

Primary synaptic cleft

Answer 14

area of muscle where axon terminal is found

Question 15

What is are the secondary folds in the motor end plate called?

Answer 15

subneural apparatus

Question 16

Neuron:Myocyte ratio

Answer 16

determines fineness of motor control

Question 17

Myasthenia gravis pathology

Answer 17

autoimmune against AChR

Question 18

Muscle spindle: two muscular structures

Answer 18

nuclei chain fibers

nuclei bag fibers

Question 19

Annulospiral fibers

Answer 19

wrap around nuclei chain and bag fibers in muscle spindle

Question 20

Golgi tendon

Answer 20

measures tension in tendons, limits contractility

Question 21

How do sk. muscles grow?

Answer 21

hypertrophy, not hyperplasia

Question 22

C. muscle structure

Answer 22

branched

Question 23

T-tubules in c. muscle

Answer 23

located @ Z-disk (not A-I junction)

Question 24

SR in c. muscle

Answer 24

no terminal cisternae

Question 25

Intercollated discs (tissue and structure)

Answer 25

cardiac muscle, complex of different cell junctions

Question 26

Special endocrine cells in heart and function

Answer 26

atrial granules: | secrete atrial natriuretic peptide--decreases Na+ and water reabsorption

Question 27

Cardiac conductive fiber properties

Answer 27

more sarcoplasm, lack T-tubules

Question 28

What holds sm. muscle cells together?

Answer 28

reticular fibers

Question 29

Replaces Z-disk in sm. muscle

Answer 29

dense bodies

Question 30

What special connective molecule do dense bodies contain?

Answer 30

α-actinin