Structure of Muscle Tissue X

Question 1

Muscle Fxns

Answer 1

Movements
Support
Heat

Question 2

Muscle Classification

Answer 2

Skeletal, Cardiac, Smooth
Striated/Non-Striated
Voluntary/ Non-Voluntrary

Question 3

Striated Muscle

Answer 3

Skeletal

Cardiac

Question 4

Involuntary Muscle - types, control

Answer 4

Cardiac
Smooth
Autonomic Nervous System (vs. Cerebral Cortex)

Question 5

Muscle levels (Macro->Micro)

Answer 5

Muscle -> Muscle Fascicle -> Fiber -> Myofibrils -> Sarcomere -> Actin (thin) & Myosin (thick)

Question 6

Epimsyium

**

Answer 6

dense irregular CT surrounding - all fascicles that constitute a muscle-

Question 7

Perimysium

**

Answer 7

dense irregular CT surrounding - individual fascicles -

Question 8

Endomysium

**

Answer 8

Reticular fibers surround - individual muscle fibers

Question 9

CT layers on muscle - types, fxn

Answer 9

Epimysium, Perimysium, Endomysium

Conduit for circulatory and nervous supply to muscle

Question 10

Thin Filaments - COmponents

Answer 10

Actin
Tropomyosin
Troponin Complex

Question 11

Tropomyosin

**

Answer 11

protein - forms double helical structure lying in the groove of actin helix. Acts with troponin complex to regulate myosin- actin binding

Question 12

Troponin complex - components/fxns

**

Answer 12

TnI - actin binding protein - prevent actin to myosin
TnT - tropomyosin binding protein - troponin complex to actin
TnC - calcium binding protein for contraction

Question 13

Thick Filaments - components

Answer 13

Myosin Heavy Chain
Myosin Light Chain 1
Myosin Light Chain 2

Question 14

Myosin Heavy Chain - def, fxn

**

Answer 14

protein with alpha helical ‘rod’ and globular ‘head’

binds ATP and actin

Question 15

Myosin Light chain 1 & 2 - fxn

Answer 15

phosphorylation helps regulate calcium stimulation of contraction. (smooth muscle)

Question 16

Sacromere - Components

Answer 16

Z line/disc
I band
A band
H band
M-line

Question 17

Z line

Answer 17

anchor for actin

Question 18

M line

Answer 18

center of sacromere

anchor for myosin

Question 19

I band

Answer 19

thin filaments NOT overlapping with thick filaments

light staining

Question 20

A band

Answer 20

length Myosin
thick filament and overlapping thin filaments
dark staining

Question 21

H band

Answer 21

thick filament NOT overlapped by thin filaments

straddles center

Question 22

Effect of Contraction on sacromere components

Answer 22

I and H bands shorten
Z lines move together (towards M center)
A DOES NOT change

Question 23

Transverse Tubeles - def., fxn

***

Answer 23

Tubular invagination of the muscle cell plasma membrane closely aligned with cisternae of sarcoplasmic reticulum
T-tuble allows for changes in membrane electrical potentials to reach SR (a Ca2+ reservoir) thereby regulating calium concnetration anf nuscle contraction

Question 24

Triad

**

Answer 24

triple structure consisting of two terminal cisternae flanking a T-Tubule at the A-I band junction

Question 25

neuromuscular junction - def, a.k.a | **

Answer 25

synaptic connection between a motor axon and the muscle fiber motor end plate

Question 26

junctional folds - def

Answer 26

where axon terminates on the muscle cell

Question 27

Denervation Atrophy

Answer 27

loss of stimulation to the muscle cell at the neuromuscular junction leading to muscle atrophy

Question 28

Muscle spindle - fxn, sturcture, significance | **

Answer 28

Detect the amount of stretch of a muscle Basis of stretch reflexes Modified muscle fibers inside inner of two capsules allows for proprioception

Question 29

Hypertrophy - action, affected by | **

Answer 29

increases the size of myofibrils and the number of myofibrils per muscle cell Age Nutrition Hormones

Question 30

Myasthenia gravis | **

Answer 30

autoimmune disease with progressive muscular weakness and atrophy reduction in # of ACH receptors in sarcolemma at NMJ

Question 31

Muscular Dystrophy | **

Answer 31

congenital muscle disease Severe weakness atrophy and destruction of muscle fibers caused by genetic mutations in transmembrane proteins of dystrophin-glycoprotein complex

Question 32

Cardiac Muscle - components | **

Answer 32

one centrally located nucleus Intercalated disks Dyads Increased mitochondria, lipid droplets, glycogen and myoglobin contraction controlled by both autonomic nervous system and circulating horones

Question 33

Intercalated Disks - fxn | **

Answer 33

highly specialized attachments that join cardiac muscle fibers together

Question 34

Junctional Complexes in Cardiac Muscle | **

Answer 34

Fasciae Adherens Maculae Adherens Gap Junctions

Question 35

Smooth Muscle - components | **

Answer 35

Fusiform Lack of cross-striations and T-tubules Single centrally located nucleus

Question 36

Smooth Muscle - locations

Answer 36

``` tubuar organs - lining iris and ciliary body of the eye scrotum blood vessels hair follicles ```

Question 37

Gap Junctions in Smooth muscle - fxn

Answer 37

allow intercellular communication regulating contraction of sheets

Question 38

Smooth muscle capable of hyperthrophy and hyperplasia | **

Answer 38

KNOW

Question 39

Regenration in muscle | **

Answer 39

Skeletal - Yes Smooth - Sort of Cardiac - None

Question 40

Promotion of Muscle Fiber Shorterning

Answer 40

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Question 41

Hyperplaisia

Answer 41

Increase in cell number | Smooth muscle capable of hyperplasia and hypertrophy