Exam 1 9/20 Howard Muscle

Question 1

endomysium

Answer 1

reticular fibers and basal lamina; surrounds each muscle cell

Question 2

perimysium

Answer 2

collagenous CT; surrounds fascicles of muscle fibers

Question 3

Epimysium

Answer 3

dense irrecular collagenous CT; surrounds entire muscle

Question 4

A band

Answer 4

dark

Question 5

I band

Answer 5

light

Question 6

Z disk or line

Answer 6

bisects I band

Question 7

H band

Answer 7

pale area of A band

Question 8

M line

Answer 8

center of H band

Question 9

Sarcomere measured by

Answer 9

z disk to z disk

Question 10

____ along length of alpha helix actin

Answer 10

Nebulin (may assist a-actinin anchor thin filaments to z disk)

Question 11

Tropomyosin

Answer 11

in groove of helix

Question 12

Troponin attached to:

Answer 12

tropomyosin

Question 13

TnT

Answer 13

binds to tropomyosin

Question 14

TnC

Answer 14

binds Calcium

Question 15

TnI

Answer 15

inhibits actin myosin interactions
(helps inhibition of myosin binding to actin by keeping tropomyosin in place)

Question 16

Myosin molecule

Answer 16

2 heavy chains 2 light chains

Question 17

Titin

Answer 17

2500 kD, forms elastic lattice that anchors thick filaments to Z disks

Question 18

a-Actinin

Answer 18

anchors plus end of thin filament to z disk

Question 19

Myomesin; C protein found:

Answer 19

at M band in the middle of H bandW

Question 20

Where do t tubules lie

Answer 20

in the plane of A-I junction

Question 21

___ narrows during contraction

Answer 21

I band

Question 22

____ dissapears during contraction

Answer 22

H band

Question 23

____ get closer during contraction

Answer 23

Z lines

Question 24

____ remains unchanged during contraction

Answer 24

A band

Question 25

Types of cardiac muscle

Answer 25

1. atrial muscle fiber
2. ventricular muscle fiber
3. specialized muscle fiber

Question 26

Cardiac muscle where is nucleus

Answer 26

central oval nucleus occasional binucleate

Question 27

Cardiac cell junction forms

Answer 27

intercalated disk

Question 28

2 types of intercalated disks

Answer 28

transverse, lateral

Question 29

Transverse disks

Answer 29

mechanical junctions, fascia adherens (thin filaments attach, can act as z disks)

Question 30

lateral disks

Answer 30

electrical connections, gap junctions

Question 31

Atrial Natriuretic peptide found in:

Answer 31

atria muscle cells

Question 32

Atrial Natriuretic peptide function

Answer 32

lowers blood pressure, decreases ability of renal tubes to resorb water and sodium

Question 33

Differences in T tubules

Answer 33

Skeletal: A-I junction, dilated terminal cisternae, triad
Cardiac: t-tubule 2.5x larger, diad, diads at z disk, SR terminals approximate t tubules

Question 34

Smooth muscle does not have

Answer 34

striations

Question 35

____ is fusiform

Answer 35

smooth muscle

Question 36

Smooth muscle how many nuclei

Answer 36

just 1

Question 37

True or false; smooth muscle does not have t tubules

Answer 37

true

Question 38

Most common type of smooth muscle

Answer 38

unitary - do not contract independently, gap junctions shared between contiguous cells, nerve supply shared

Question 39

Multiunit smooth muscle

Answer 39

contract independently, unique nerve supply (their own)

Question 40

Caldesmon

Answer 40

present in thin filaments of smooth muscle, same job as tropomyosin (blocks active site of f-actin)

Question 41

Smooth muscle is not:

Answer 41

striated

Question 42

Dense bodies that act as Z disks are called

Answer 42

interwoven array

Question 43

Smooth muscle myosin heads lined up as:

Answer 43

along all molecules not tail to tail

Question 44

Cork screw nucleus occurs in:

Answer 44

smooth muscle

Question 45

Increase in muscle mass from:

Answer 45

increase in size of muscle fiber