Basic Histology: Muscle Tissues

Question 1

General features of muscle tissue

Answer 1

muscle cells are in bundles, and are elongated and oriented with the long axis, with the nuclei parallel with orientation of the muscle

Question 2

How are muscle cells characterized

Answer 2

the ability of the cell to contract

Question 3

Sarcoplasm

Answer 3

cytoplasm of muscle cell

Question 4

Sarcoplasmic reticulum

Answer 4

smooth ER in muscle cells that are specialized for calcium

Question 5

Sarcolemma

Answer 5

muscle cell membrane and external lamina

Question 6

Contractile proteins in Muscle cytoplasm

Answer 6

actin and myosin

Question 7

Hypertrophy

Answer 7

increase in cell volume from myofibril formation and growth of individual muscle fibers, skeletal muscle

Question 8

Hyperplasia

Answer 8

tissue growth due to increase in number of cells, smooth muscle

Question 9

3 types of muscle tissue

Answer 9

skeletal, cardiac, smooth

Question 10

Skeletal muscle

Answer 10

long mononucleated cells with cross-striations, quick voluntary contractions

Question 11

Cardiac muscle

Answer 11

elongated branched cells with cross-striations, involuntary and rhythmic

Question 12

Smooth muscle

Answer 12

fusiform cells that lack striations, slow involuntary contractions

Question 13

Types of skeletal muscle

Answer 13

epimysium, perimysium, endomysium

Question 14

Epimysium

Answer 14

external sheath of dense connective tissue that surrounds the whole muscle

Question 15

Perimysium

Answer 15

thin connective tissue layer that surrounds muscle fibers

Question 16

Endomysium

Answer 16

thin layer of reticular fibers that surrounds external lamina of muscle fibers

Question 17

Sarcomere

Answer 17

subunit for muscle contractile, separated by Z discs and have thick and thin overlapping filament regions

Question 18

A bands

Answer 18

dark bands with overlapping thick and thin filaments

Question 19

I bands

Answer 19

light bands, contain thin filaments

Question 20

Z disc

Answer 20

darks transverse line that bisects I band

Question 21

Myofibrils

Answer 21

repetitive arrangement of sarcomeres, found as parallel bundles in muscle fibers

Question 22

Types of myofilaments

Answer 22

thick and thin

Question 23

Thick myofilaments

Answer 23

myosin, binds actin to form crossbridges between thick and thin, and binds ATp to catalyze energy release

Question 24

Thin filaments

Answer 24

F-actin

Question 25

Types of thin filaments

Answer 25

alpha-actinin, tropomyosin, troponin

Question 26

Alpha actinin

Answer 26

actin-binding proteins that anchor actin to Z disc

Question 27

Tropomyosin

Answer 27

makes filaments that exist in grooves between F-actin molecules

Question 28

Troponin

Answer 28

complex of 3 subunits

Question 29

3 subunits of Troponin

Answer 29

TnT, TnC, TnI

Question 30

TnT

Answer 30

attaches to tropomyosin

Question 31

TnC

Answer 31

binds calcium

Question 32

TnI

Answer 32

regulates actin-myosin interaction

Question 33

Skeletal muscle contraction

Answer 33

muscle shortens because of contraction cycles that move thin filaments over thick filaments

Question 34

What shortens in contractions

Answer 34

sarcomeres

Question 35

Sarcomere relaxed state

Answer 35

sarcomere, I band and H zone are expanded

Question 36

Sarcomere contraction

Answer 36

Z disc at sarcomere boundaries are drawn closer together as they move toward the end of thick filament A band

Question 37

Myasthenia gravis

Answer 37

autoimmune disease that circulate antibodies against acetylcholine, weakens muscle fiber response to nerve

Question 38

Dystrophin

Answer 38

large actin-binding proteins underneath the sarcolemma, maintains its integrity

Question 39

Duchenne muscular dystrophy

Answer 39

mutation in dystrophin expression

Question 40

Features of cardiac muscle

Answer 40

striated, individual cylindrical, central nucleus, linked by adherent and gap junctions at intercalated disc

Question 41

Features of smooth muscle

Answer 41

individual fibers linked by gap junction, no striation, thin filaments attached to alpha-actin, contraction causes cells to shorten individually