Csd I Exam I

Front 1

epimysium

Back 1

the connective tissue covering the whole muscle

Front 2

perimysium

Back 2

the connective tissue covering of the muscle bundle/fascicle

Front 3

endomysium

Back 3

the connective tissue covering of the muscle fiber

Front 4

actin

Back 4

this protein is located in the thin filament; binds to myosin to produce a cross bridge

Front 5

alpha-actinin

Back 5

this protein anchors actin to the Z disc in the sarcomere

Front 6

Laminin

Back 6

this protein is located in the lamina lucida layer of the basal lamina; it contributes to cell attachment (exists with the costamere)

Front 7

myosin

Back 7

protein located in the center of the sarcomere, and is the major component of the thick filament; it binds to actin to produce a cross bridge

Front 8

tropomyosin

Back 8

protein located in a groove along the length of the actin filament; it covers the myosin binding sites on actin to prevent cross bridges from being formed

Front 9

troponin

Back 9

protein that is bound to both actin and tropomyosin; when calcium binds to it, tropomyosin changes and the actin binding sites are exposed so cross bridges can be formed

Front 10

nebulin

Back 10

protein that is connected to actin; appears to contribute to assembly and regulation of thin filament length

Front 11

titin

Back 11

this protein connects myosin filaments from the M line to the nearest Z disc; it maintains myofibrillar lattice structure and contributes to the passive tension of the muscle

Front 12

Z discs

Back 12

these are the dark lines that bisect the I bands of thin filament; demarcate the sarcomere

Front 13

M line

Back 13

the dense zone in the center of the A band of thick filaments

Front 14

myosin binding proteins

Back 14

proteins that provide a framework/scaffold to stabilize thick filament and guide the filament development during myogenesis

Front 15

desmin

Back 15

this is a protein that is the major part of intermediate filament system; it connects the outer Z disc to the sarcolemma and also tethers the Z disc to the mitochondria and myonuclei; it plays a critical role in maintaining registry between adjacent Z discs

Front 16

dystrophin

Back 16

protein located in the subsarcolemmal region; it stabilizes the membrane ion channels during contraction and relaxation; it links the dystrophin associated proteins to actin

Front 17

dystrophin associated proteins

Back 17

this protein complex spans the sarcolemma and is thought to play a critical role in linking the actin cytoskeleton to the extracellular matrix

Front 18

costamere

Back 18

these structures are located below the sarcolemma; they couple force-generating sarcomeres with the sarcolemma and anchor the sarcolemma with the Z discs, M lines, and at the musculoskeletal junction

Front 19

creatine kinase

Back 19

this is an enzyme located within the thick filament that helps to regulate ATP levels in the muscle cell

Front 20

basal lamina

Back 20

this membrane forms a network that links skeletal muscle proteins to the sarcolemma, providing lateral transmission of force; it maintains muscle integrity as well. It is required for muscle repair and is a selective permeability layer

Front 21

DHP receptors

Back 21

these receptors are located in the T tubule; they sense the change in voltage during an action potential

Front 22

RyR

Back 22

these receptors are located on the sarcoplasmic reticulum and are a calcium release channel

Front 23

calsequestrin

Back 23

this protein is located in the sarcoplasmic reticulum; it binds and stores calcium

Front 24

SERCA

Back 24

this is a calcium ATPase transporter that pumps calcium back into the SR

Front 25

phospholamban

Back 25

this is a protein that regulates the activity of SERCA (when phosphorylated, increases SERCA activity)

Front 26

myoD myfd5

Back 26

these myogenic regulatory factors are involved in determination (create myoblasts)

Front 27

mrf4 and myogenin

Back 27

these myogenic regulatory factors are expressed later and are involved in differentiation (cause myoblasts to proliferate and fuse into myotubes for muscle development to proceed)

Front 28

plasma membrane

Back 28

this cell organelle separates the interior of the cell from the outside; it is an attachment point for the intracellular cytoskeleton; it attaches the ECM to other cells to help group the cells together to form tissues

Front 29

mitochondria

Back 29

this cell organelle generates most of the ATP used to supply the cell; it regulates cell metabolism and can regulate homeostasis of calcium and membrane potential

Front 30

myonuclei

Back 30

these organelles are responsible for a "domain"; they secrete different growth factors that support growth and repair of the cell

Front 31

sarcoplasmic reticulum

Back 31

this organelle is directly involved in the storage of calcium and the removal of calcium from myofilaments to relax muscle; it is the middleman between skeletal muscle activation and relaxation

Front 32

twitch

Back 32

the response of one single muscle fiber to a single action potential

Front 33

unfused tetany

Back 33

when a set of repeating action potentials activates the muscle fiber before the relaxation of the previous twitch; can still distinguish between contractile events

Front 34

fused tetay

Back 34

the time interval between activation of successive twitches has shortened and the twitches fuse into a single, stable level of muscle

Front 35

motor unit

Back 35

the alpha motor neuron and all the fibers it innervates

Front 36

calcineurin/NFAT

Back 36

the main pathway for myofiber transition

Front 37

Akt, mTOR

Back 37

the main pathways for muscle hypertrophy

Front 38

myostatin, FOXO, urfs, atrogin, ubiquitin ligase

Back 38

the main pathways for muscle atrophy

Front 39

Akt

Back 39

these proteins inhibit cell apoptosis and can also induce protein synthesis pathways, so it is therefore a key signaling protein in the cellular pathways that lead to skeletal muscle hypertrophy

Front 40

atrogin

Back 40

this protein mediates proteolysis events that occur during muscle atrophy; it is thought to recognize and bind to some proteins to promote their degradation during atrophy

Front 41

mTOR

Back 41

this protein integrates the input from pathways, senses cellular nutrient and energy levels and determines if there is enough to cause hypertrophy

Front 42

myopathy

Back 42

a muscular disease in which the muscle fibers do not function for reasons, resulting in muscular weakness

Front 43

sarcopenia

Back 43

the degenerative loss of skeletal muscle mass and strength that is associated with aging

Front 44

NCAM

Back 44

this molecule is expressed on the primitive myotubes following denervation to perhaps "guide" incoming nerves to the muscle fiber; thought to signal to induce neurite outgrowth

Front 45

CALPAIN

Back 45

enzymes that are activated when calcium levels rise too high; cause regeneration

Front 46

calcineurin/NFAT

Back 46

this pathway is the activity-dependent transformation of fast fibers into slow fibers

Front 47

epithelial

Back 47

these types of cells form a continuous layer that line the surfaces of organs; form a selective permeability layer, secrete substances, and protect from danage

Front 48

unilaminar

Back 48

epithelial cells that form a single layer in adjacent tissues (squamous, cuboidal)

Front 49

multilaminar

Back 49

epithelial cells that form multiple layers (stratified squamous, stratified cuboidal or columnar)

Front 50

exocrine

Back 50

glands that secrete onto external surfaces through ducts

Front 51

endocrine

Back 51

glands that are ductless and secrete messengers into the blood (insulin)

Front 52

paracrine

Back 52

glands that secrete substances into the extracellular fluid compartment

Front 53

special skeletal

Back 53

this type of connective tissue consists of cartilage and bone and includes chondrocytes, osteocytes, osteoblasts, and osteoclasts; they are found embedded in a matrix that they secrete

Front 54

general type

Back 54

the type of connective tissues that are subdivided into resident and transient immigration cells

Front 55

resident

Back 55

cells of the general type of connective tissues that stay fixed in location and include fibroblasts, adipocytes, macrophages, pericytes, and mast cells

Front 56

transient

Back 56

these types of general type of connective tissues originate in the bone marrow and circulate int he bloodstream, then leave the circulation and enter the connective tissue to perform their specific function; are B and T lymphocytes, plasma cells, neutrophils, eosinophils, basophils, monocytes, and macrophages

Front 57

collagen and elastin

Back 57

these are the insoluble protein fibrils of the extracellular matrix

Front 58

collagen

Back 58

a structural protein that is about 30% of the body's proteins; there are many types and contain hydroxyproline and three polypeptides arranged in helices

Front 59

elastin

Back 59

these fibers are synthesized by fibroblasts and smooth muscle cells; they stretch easily with near perfect recoil, but calcify with age; surrounded by a sheath of microfibrils and are responsible for the elasticity of connective tissue

Front 60

soluble polymers

Back 60

ground substance of the ECM; hydrated gel like material that absorbs compressive forces and composed of three families of macromolecules

Front 61

glycosaminoglycans (GAG)

Back 61

these proteins are negatively charged chains of repeating disaccharide units that possess high osmotic activity and are therefore capable of binding large amounts of water; they resist compression forces

Front 62

proteoglycans

Back 62

sulfated GAGs that form covalent bonds with a protein core; located in the ground substance of the ECM and they resist compression, retard microorganisms, form molecular filters, possess binding sites for signaling molecules and function as cytoskeletal components

Front 63

cell adhesive glycoproteins

Back 63

located in the ground substance of the ECM; allow for cells to adhere to the components of the ECM

Front 64

fibronectin

Back 64

type of glycoprotein that is synthesized by fibroblasts and act as guidance pathways for the embryonic cells and also function in wound repair

Front 65

laminin

Back 65

a glycoprotein that is found in the basal lamina and binds with type IV collagen and the cell membrane

Front 66

tenascin

Back 66

a glycoprotein that is limited to embryonic tissue where it functions as a migratory path for cell migrations and axon growth

Front 67

basal lamina

Back 67

consists of two layers, the lamina lucida and the lamina densa

Front 68

lamina lucida

Back 68

this layer of the basal lamina consists of the extracellular glycoproteins and transmembrane glycoproteins

Front 69

lamina densa

Back 69

this layer of the basal lamina is made up of a meshwork of type IV collagen

Front 70

lamina reticularis

Back 70

this layer is made up of type I, III, and VII collagen, and it serves as an interface between the basal lamina and the connective tissues

Front 71

glycocalyx

Back 71

this is a cell coat that consists of glycoproteins and glycolipids that form an integral part of the plasma membrane; cell antigens may be found here and also specialized adhesion molecules

Front 72

tight junctions

Back 72

these types of junctions regulate the passage of molecules between cells

Front 73

gap

Back 73

these types of junctions allow for communication between adjacent cells

Front 74

demosomes

Back 74

these types of junctions function to hold adjacent cells firmly together in areas of mechanical stress

Front 75

adherence

Back 75

these types of junctions link actin fibers between adjacent cells

Front 76

cell matrix

Back 76

these types of junctions anchor cytoskeletal proteins to ECM macromolecules

Front 77

focal adhesions

Back 77

these junctions link intracellular actin fibers to ECM proteins

Front 78

hemidesmosome

Back 78

these junctions link intracellular cytoskeletal proteins to ECM proteins

Front 79

homeostasis

Back 79

constancy of the internal environment

Front 80

2/3

Back 80

intracellular fluid represents ___ of total body water

Front 81

1/3

Back 81

extracelllular fluid represents ___ of total body water and is composed of two volumes of fluid

Front 82

interstitial fluid

Back 82

one component of extracellular fluid that is 80%

Front 83

plasma volume

Back 83

one component of extracellular fluid that is 20%

Front 84

40-70%

Back 84

TBW comprises __ to __ % of total body mass

Front 85

fibroblasts

Back 85

a type of resident cell that is flattened and irregular with branching processes; it synthesizes most of the ECM of the connective tissue, therefore are highly active; they adhere to collagen and elastin and play a major role in wound repair

Front 86

adipocytes

Back 86

function in synthesis, storage, and release of fat from glycerol, fatty acids, and glucose; synthesize and secrete a number of chemical messengers and are now considered to be a major endocrine organ

Front 87

macrophages

Back 87

resident cells that functions as phagocytes (eliminate foreign substances by engulfing them); play many important roles in inflammation (synthesize and secrete cytokines)

Front 88

pericytes

Back 88

resident cells that surround the endothelial cells of capillaries;they share the basal lamina of endothelial cells and may undergo differentiation to become smooth muscle cells and endothelial cells in the walls

Front 89

mast cells

Back 89

these cells are derived from bone marrow cells, and function in mediation inflammation; they are the largest of fixed connective tissue cells, and secrete many substances

Front 90

excitability, elasticity, contractility, relaxation

Back 90

the four differentiated functions of muscle cells

Front 91

satellite

Back 91

these cells are located out of the plasma membrane but within/below the basal lamina; they are stem cells and are the sole source of postnatal myonuclei

Front 92

3-10%

Back 92

satellite cells represent between __ and __ of all muscle nuclei

Front 93

sarcolemma

Back 93

this skeletal muscle membrane includes both the basal lamina and the plasma membrane

Front 94

myoplasticity

Back 94

the capacity of muscle for adaptive change

Front 95

sugar, phosphoric acid, nitrogen base

Back 95

the three components of nucleotides

Front 96

mRNA

Back 96

RNA that encodes the protein

Front 97

rRNA

Back 97

RNA part of the ribosome that is used to translate mRNA into a protein

Front 98

tRNA

Back 98

RNA that couples the region which binds the mRNA codon and its amino acid; transports the protein coded on mRNA

Front 99

transcription

Back 99

the process of making an RNA copy of a single gene

Front 100

RNA polymerase

Back 100

the enzyme that aids in transcription

Front 101

5-3

Back 101

the direction in which transcription occurs down the DNA molecule

Front 102

exons

Back 102

the parts of the mRNA copy that will be expressed

Front 103

introns

Back 103

the parts of the mRNA copy that will be snipped out and not expressed

Front 104

translation

Back 104

the process of reading the RNA sequence of an mRNA and creating the amino acid sequence of a protein

Front 105

64, 20

Back 105

there are __ possible codons that code for __ different amino acids in the body

Front 106

AUG, methionine

Back 106

the start codon in translation is __, which codes for the protein __

Front 107

N terminal

Back 107

the location on the first amino acid of a protein that contains a free amino group

Front 108

C terminal

Back 108

the location on the last amino acid of a protein that has a free acid group

Front 109

3'

Back 109

the amino acid on the tRNA is attached to the __ end

Front 110

aminoacyl tRNA synthetases

Back 110

enzymes used to charge the tRNA with the proper amino acid

Front 111

release factors

Back 111

during translation, these proteins bind to the stop codon, causing the ribosome, the mRNA , and the new polypeptide to separate

Front 112

polypeptides

Back 112

linear chains of amino acids

Front 113

primary structure

Back 113

the sequence of amino acids in a polypeptide is known as its __ structure

Front 114

peptide

Back 114

the bonds that are formed between the acid group of one protein and the amino group of the other protein

Front 115

secondary

Back 115

this structure is a conformation of a short peptide, mainly determined by hydrogen bonds (alpha helix and beta pleated sheets)

Front 116

tertiary

Back 116

this protein structure is the conformation of a whole polypeptide chain

Front 117

slow twitch (type I)

Back 117

these types of fibers have a slow contraction time, are highly resistant to fatigue, smaller, have high mitochondrial and myoglobin density, high levels of oxidative enzymes and low levels of glycolysis

Front 118

FOG (Type IIA)

Back 118

these types of fibers are moderate in resistance to fatigue and have high mitochondrial density; they are high in creatine phosphate and glycogen, and have high glycolytic and oxidative enzyme activity

Front 119

FG (Type IIB)

Back 119

these types of fibers are sensitive to fatigue and are short anaerobic fibers; they are large and have low mitochondrial density and myoglobin; high in creatine phosphate and glycogen, so high glycolytic enzyme content and low oxidative content

Front 120

fast

Back 120

the SR and T-system occupies 2-3 times more volume in __ fibers

Front 121

intrafusal

Back 121

these types of fibers are part of the muscle spindle and are innervated by gamma motor neurons; they are proprioceptive in nature

Front 122

extrafusal

Back 122

these types of fibers are innervated by alpha motor neurons and contract, generating skeletal movement

Front 123

PEVK

Back 123

this region in titin is the spring-like elastic element

Front 124

nicotinic

Back 124

the receptor on the postsynaptic terminal for ACh is a __ type or receptor

Front 125

myopathy

Back 125

a variation in fiber type size (degeneration and regeneration of muscle fibers)

Front 126

dystrophy

Back 126

replacement of muscle fibers with increased connective tissue

Front 127

atrophy

Back 127

the active process of increase in protein degradation and a decrease in protein synthesis

Front 128

endurance

Back 128

__ training leads to more type I fibers

Front 129

strength

Back 129

__ training leads to more type II fibers

Front 130

type II

Back 130

type __ fibers are selectively atrophied during disuse

Front 131

cachexia

Back 131

a wasting syndrome that is a loss of weight, muscle atrophy, fatigue, weakness, and significant loss of appetite in someone who is not trying to lose weight; basically a loss of body mass that cannot be reversed nutritionally

Front 132

tumor necrosis factor a, or cachexin

Back 132

thought to be the most likely mediator of cachexia

Front 133

sarcopenia

Back 133

muscle weakness and wasting in the elderly possibly due to a decrease in the proliferative capacity or number of satellite cells or accumulating mitochondrial DNA deletion

Front 134

critical illness myopathy

Back 134

muscle weakness that is prevalent in patients receiving intensive care during a critical illness; hallmark is loss of myosin

Front 135

7-10

Back 135

half life of muscle structural proteins is __-__ days

Front 136

days or hours

Back 136

the time course of atrophy is __ or __

Front 137

days

Back 137

the time course of hypertrophy is __

Front 138

FOXO

Back 138

these proteins induce the ubiquitin ligase pathway and cause muscle atrophy

Front 139

ubiquitin ligase

Back 139

the pathway for muscle atrophy that is caused by an attachment of ubiquitin and lysine, targeting specific protein substrates for degradation

Front 140

myostatin

Back 140

a signaling molecule that is secreted by muscle and negatively regulates muscle mass; it is thought to regulate the proliferation of muscle stem cells and decreases satellite cell incorporation and myoblast differentiation; it also inhibits Akt protein synthesis