Cto #12

Front 1

three types of muscle

Back 1

1. striated voluntary skeletal muscle
2. striated involuntary skeletal muscle
3. involuntary smooth muscle

Front 2

functions of muscle tissue in animals

Back 2

1. producing body mvmts
2. stabilizing body positions
3. regulating organ volume
4. regulating the flow of substances within the body
5. the production of heat

Front 3

how is heat produced by one of the muscle types?

Back 3

involuntary contractions of skeltal muscle (SHIVERING)

Front 4

epimyseum

Back 4

dense CT sheath encasing most skeletal muscle, corresponds to deep fascia

Front 5

fasicles

Back 5

bundles of muscle fibers encased by perimyseum

Front 6

perimyseum

Back 6

CT layer encasing fasicles of muscle fibers

Front 7

muscle fibers

Back 7

are the muscle cells, each separated by surrounding endomysium by an external lamina

Front 8

sarcolemma

Back 8

cell membrane of a muscle fiber or muscle cell

Front 9

endomysium

Back 9

layer of loose connective tissue that ensheaths a muscle fiber and is composed mostly from reticular fibers

Front 10

tendons

Back 10

dense, regular CT, attach muscle to bone, provide stability for muscle contraction and transmit the force of movement from muscle to bone

Front 11

myoblasts

Back 11

type of stem cells that can fuse together to form multinucleate skeletal muscle fibers
Myoblasts that do not form muscle fibers differentiate into satellite cells.

Front 12

skeletal muscle nuclei

Back 12

multiple (multinucleate)
located on the fiber periphery, immediately beneath the sarcolemma (plasma membrane)

Front 13

myofibrils

Back 13

bundles of myofilaments within the muscle cell, arranged in consistent alignment of repeated sarcomeres

Front 14

sarcomeres

Back 14

fundamental units of contraction

Front 15

major myofilaments of the sarcomeres

Back 15

(thin) actin and (thick) myosin II (with associated proteins)

Front 16

thin filaments of sarcomere

Back 16

actin filaments anchored by their + ends (barbed ends) to the Z-line

associated with nebulin (scaffolding protein)

and bound to troponin-tropomyosin regulatory complex

Front 17

how and where is actin anchored in sarcomere?

Back 17

by + ends (barbed ends) to the Z-line

Front 18

nebulin

Back 18

scaffolding protein associated with actin in sarcomeres

Front 19

myosin II

Back 19

thick filaments of sarcomeres

Front 20

titin

Back 20

protein associated with myosin II in sarcomere. prevemts sarcomere from overstretching

Front 21

A band

Back 21

(anisotropic) darker band in center of sarcomere associated with myosin (thicker fiber)

Front 22

I band

Back 22

lighter bands between Z discs and A band, contain only actin filaments

Front 23

H zone

Back 23

"Heller" (lighter) region in the middle of the A band, brighter (only myosin, no overlap

Front 24

Z disc

Back 24

"Zwischen discs" protein disks between each sarcomere

Front 25

M line

Back 25

"Mittel" of sarcomere, proteins including myomesin, titin and creatine kinase, structural proteins help titin and myosin maintain their 3-dimensional structure

Front 26

sarcolemma is stabilized by

Back 26

a membrane cytoskeleton composed of actin, dystrophin and other proteins

Front 27

muscular dystrophy is characterized by defects in what?

Back 27

dystrophin

Front 28

dystrophin

Back 28

protein essential for maintaining connection between cytoskeleton of muscle fiber and ECM (deficiency leads to muscular dystrophy)

Front 29

myotendinous junction

Back 29

integrins connect actin filaments of terminal sarcomere and the ECM

Front 30

motor unit

Back 30

a single axon, together with all the muscle fibers it innervates

Front 31

neuromuscular junctions

Back 31

location of motor end plate, where axon and muscle fibers meet

Front 32

what triggers depolarization of the sarcolemma?

Back 32

release of acetylcholine

Front 33

myasthenia gravis

Back 33

disease where autoantibodies against acetylcholine receptor result in impaired muscle function

Front 34

Transverse tubules

Back 34

invaginations of the membrane that facilitate the propogation of the depolarization of the sarcolemma throughout the muscle fiber

Front 35

triads

Back 35

found in skeletal muscle
association of two terminal cisternae of the sarcoplasmic reticulum with a T-tubule
facilitates calcium release from the SR

Front 36

power stroke

Back 36

the molecular contraction event, when crossbridge moves toward H zone
(myosin hydrolyzes ATP and goes through a series of conformational changes)

Front 37

rigor state

Back 37

when actin and myosin are strongly bound

Front 38

characteristics of cardiac muscle cells

Back 38

centrally located single nucleus (uninucleate)
branching
intercellular junctional complexes through intercalated disks

Front 39

intercalated disks

Back 39

combination of desmosomes, fascia adherens and gap junctions

Front 40

dyads

Back 40

association of the terminal cisternae of the SR and T-tubules of cardiac muscle cells (less elaborate then triads of skeletal muscle)

Front 41

characteristics of smooth muscle cells

Back 41

single, often fusiform cells
centrally located nucleus
often connected by gap junctions
no sarcomeres
no calcium-regulated troponin-tropomysin system

Front 42

what provides structural framework for smooth muscle cells?

Back 42

intermediate filaments

Front 43

dense plaques

Back 43

sites on plasma membrane of smooth muscle cells where actin filaments (interdigitating with myosin) are anchored

Front 44

smooth muscle cells are activated by

Back 44

the stimulation of myosin light chains by a myosin light chain kinase (MLCK) that triggers acto-myosin contraction

Front 45

examples of possible activation of MLCK pathway

Back 45

calcium-calmodulin pathway or cAMP activation

Front 46

multiunit type of smooth muscle

Back 46

under tight control, heavily innervated (such as pupillary muscles)

Front 47

visceral or unitary type of smooth muscle

Back 47

less-densely innervated, but has more gap junctions to permit a slow, coordinated contraction of the smooth muscle (as in peristalsis)

Front 48

type of innervation associated with skeletal muscle

Back 48

voluntary

Front 49

type of innervation associated with cardiac muscle

Back 49

involuntary

Front 50

type of innervation associated with smooth muscle

Back 50

involuntary

Front 51

efferent innervation of skeletal muscle

Back 51

somatic

Front 52

efferent innervation of cardiac muscle

Back 52

autonomic

Front 53

efferent innervation of smooth muscle

Back 53

autonomic

Front 54

regulation of skeletal muscle contraction

Back 54

binding of Ca2_ to TnC, causes tropomyosin movement and exposes myosin-binding sites on actin filaments

Front 55

regulation of cardiac muscle contraction

Back 55

binding of Ca2_ to TnC, causes tropomyosin movement and exposes myosin-binding sites on actin filaments

Front 56

regulation of smooth muscle contraction

Back 56

by phosphorylation of myosin light chian by myosin light chain kinase in the presence of Ca2+-calmodulin complex

Front 57

what types of muscle can undergo mitosis?

Back 57

only smooth muscle can undergo mitosis under normal conditions

Front 58

What types of muscle cells can undergo regeneration?

Back 58

smooth muscle cells
and limited capacity in skeletal muscle sattelite and myogenic cells from bone marrow

Front 59

What types of muscle have cell-to-cell junctions?

Back 59

1. The intercalated disks of cardiac muscle have: fascia adherens, macula adherens, and gap junctions
2. Smooth muscle cells are joined via gap junctions (nexus)

Front 60

morphology of skeletal muscle cell

Back 60

large, elongate
10-100 micrometers in diameter
up to 100 cm in length

Front 61

morphology of cardiac muscle cell

Back 61

short, narrow cell
10-15 micrometers in diameter
80-100 micrometers in length

Front 62

morphology of smooth muscle cell

Back 62

short, elongate, fusiform cell
0.2-2 micrometers in diameter
20-200 micrometers in length