Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
69 Cards in this Set
- Front
- Back
The connective tissue layers that surround muscle fibers
|
Endomysium
Perimysium Epimysium |
|
Delicate layer of reticular fibers that surround individual muscle fibers
|
Endomysium
|
|
Morphologically identical to skeletal muscle but restricted to soft tissues
|
Visceral striated muscle
|
|
Location of skeletal muscle fiber nuclei
|
sarcolemma(cytoplasm)
|
|
Thick connective tissue layer that surrounds a group of muscle fibers to form a fascicle
|
Perimysium
|
|
Layer of dense connective tissue that surrounds a collection of muscle fascicles
|
Epimysium
|
|
The major vasacular and nerve supply penetrates this layer
|
Epimysium
|
|
Fibers characterized by oxidative metabolism contain large amounts of?
|
Myoglobin, mitochondria, and electron transport systems
|
|
Fibers that appear light pink, contain less myoglobin, fewer mitochondria, lots of glycogen, and high anaerobic enzyme activity
|
Type IIb-fast glycolitic fibers: extraocular and digit muscles
|
|
Fibers that contain many mitochondria and a high myoglobin content. They also contain large amounts of glycogen and can undergo anaerobic glycolysis
|
Type IIa-fast oxidative glycolytic fibers
|
|
Fibers appear red and cotain large amounts of myoglobin and mitochondria
|
Type I-slow oxidative fibers: Long muscles of the back to maintain erect posture
|
|
Rank myosin ATPase reaction velocity from slowest to fastest
|
Type I
Type IIa Type IIb |
|
The structural and functional subunit of the muscle fiber
|
Myofibril
|
|
The individual filamentous polymers of myosin II and actin and its associated proteins
|
Myofilaments
|
|
Basic contractile unit of striated muscle
|
Sarcomere
|
|
The functional unit of myofibril
|
Sarcomere-extends from z line to z line.
|
|
Bifringent band that marks the extent of myosin
|
A band
|
|
Band that contains only actin filaments. Seperated by the z line.
|
I band- Isotropic
|
|
Band that bisects the A band and contains only myosin
|
H band
|
|
Line that bisects myosin and H band
|
M line
|
|
Primary metabolic substrate in actively contracting muscle
|
Glucose
|
|
The energy stored in high energy phosphate bonds comes from the metabolism of what?
|
fatty acids and glucose
|
|
Metabolite formed during muscle exertion that results in ischemic pain (cramp)
|
lactic acid
|
|
Energy used by recovering or resting muscle comes from?
|
Oxidative phosphorylation. this process closely follows the B-oxidation of fatty acids in mitochondria
|
|
Smooth endoplasmic reticulum that surrounds myofilaments
|
Sarcoplasmic reticulum
|
|
molecule that polymerizes to form a double stranded helix, the F-actin filament
|
G actin
|
|
The positive end of the actin filament
|
bound to the z line by a-actinin
|
|
The negative end of the actin filament
|
Extends toward the M line and is protected by actin-capping protein
|
|
Myofilament that runs in a groove between the F-actin molecules
|
Tropomyosin
|
|
Binds Ca2+ to initiate contraction
|
Troponin-C
|
|
Key feature of myosin heavy chain
|
Globular head with two binding sites: one for ATP and one for Actin
|
|
Initiates smooth muscle contraction
|
Phosphorylation by myosin light chain kinase of regulatory light chain
|
|
the portion of myofilament which does not contain globular heads
|
H band
|
|
Forms an elastic lattice that anchors thick filaments in the z lines
|
Titin
|
|
Actin binding protein that anchors thin filaments to z line
|
a-actinin
|
|
Attached to Z lines and regulates the length of thin filaments during muscle development. Also anchors them.
|
Nebulin
|
|
Actin-binding protein that caps and regulates the length of actin. Influences physiological properties.
|
Tropomodulin
|
|
Holds thick filaments in register at m line
|
Myomesin
|
|
Links laminin of the external lamina to muscle cell actin filaments
|
Dystrophin
|
|
Rigor mortis is initiated by?
|
Lack of ATP
|
|
What occurs during the power stroke?
|
ADP is lost
|
|
What causes the myosin head to release from actin?
|
Binding of ATP
|
|
Rod shaped protein with a short head and long tail that is bound by F-actin
|
Dystrophin
|
|
Links dystrophin to the extracellular matrix proteins laminin and agrin
|
alpha and beta dystroglycans
|
|
Mutations in the genes found on x chromosome encoding sarcoglycans
|
limb-girdle muscular dystrophy
|
|
Function and location of terminal cisternae
|
Reservoirs for Ca2+ located at the AI junction in the sarcoplasmic reticulum
|
|
Invaginations of the plasma membrane that propagate action potentials
|
T-tubules
|
|
Complex of a T-tubule and two terminal cisternae
|
Triad of skeletal muscle
|
|
Depolarization of T-tubules activates what proteins that open what?
|
Voltage-sensor proteins that undergo a conformational change to open gated Ca2+ channels of the terminal cisternae.
|
|
What occurs directly after Ca2+ binds to Troponin-C
|
TnI disassociates from actin
|
|
At what point is the myelin sheath absent, and the axon is covered by only a thin portion of the neurilemmal cell and its external lamina?
|
Neuromuscular junction
|
|
A single neuron along with its the specific muscle fibers that it innervates
|
motor unit
|
|
Loss of innervation to a muscle fiber results in what?
|
atrophy
|
|
Transmits information about the degree of stretch of a muscle to the brain
|
Muscle spindle cells
|
|
Regulates the sensitivity of the stretch receptor
|
Gamma efferent fibers from the brain and spinal cord. When skeletal muscle is stretched, nerve endings of sensory nerves become activated. They convey their impulses to the CNS, which modulates the activity of motor neurons
|
|
Tendon organs contain only what type of fibers?
|
afferent
|
|
Myoblasts are derived from what?
|
A self-renewing population of multipotential myogenic stem cells that originate in the embryo from unsegmented paraxial mesoderm
|
|
Myoblasts express what during early embryonic development
|
MyoD transcription factor
|
|
Responsible for the skeletal muscles ability to regenerate
|
Satellite cells begin expressing MRF's and become myoblasts as long as the external lamina is intact.
|
|
External lamina disruption
|
During muscle injury, external lamina disruption causes fibroblast repair, and scar formation
|
|
Histological characteristics of cardiac muscle
|
Intercalated disks, Single central nucleus, endomysium connective tissue
|
|
Components of atrial granules
|
Atrial natriuretic factor and brain natriuretic factor
|
|
Attachment sites between adjacent cells
|
Intercalate disks
|
|
Holds the cardiac muscle cells at their ends to form the functional cardiac muscle fiber
|
Fascia adherens: The site at which the then filaments in the terminal sarcomere anchor onto the plasma membrane
|
|
Provide ionic continuity between adjacent cardiac muscle cells
|
gap junctions
|
|
Bind individual muscle cells to one another and help prevent the cells from pulling apart under the strain of contractions
|
Maculae adherentes(desmosomes)
|
|
Characteristics of T-tubules of cardiac muscle that differ from skeletal muscle
|
T tubules much larger and carry external lamina into cell. Located at the z disk. T-tubule does not have surrounding terminal cisternae, but instead a diad.
|
|
How many t-tubules per sarcomere in cardiac muscle?
|
one
|
|
Explain cardiac muscle depolarization
|
Long lasting depolarization activates voltage sensor proteins which become Ca2+ channels that allow Ca2+ from the lumen into the sarcoplasm. The Ca2+ then activates gated Ca2+ release channels of the sarcoplasmic reticulum which allows release of Ca2+ from sER into the sarcoplasm
|