Lecture 5 Flashcards
Three types of muscle tissue
Skeletal
Cardiac
Smooth
Skeletal and smooth muscle cells are elongated and are called
muscle fibers
Muscle contraction depends on these 2 myofilaments
-Actin
-Myosin
Muscle plasma membrane
sarcolemma
membrane of muscle fiber
sarcolemma
ctyoplasm of a muscle cell
sarcoplasm
Three muscle scientific prefixes
Myo
Mys
Sarco
4 Ways that types of muscle differ
Structure
Fxn
Location
Activation
Skeletal muscle tissue moves
the body skeleton
Muscle cell and muscle fiber are
The same thing
Muscle’s obvious visible stripes
Striations
Skeletal muscle is controlled
Voluntarily
Cardiac muscle shape and size
Short, striated, quadrangular
Cardiac muscle control is controlled how?
Autonomic influence
Contraction rate set by the heart’s pacemaker
Autorhythmic
Cardiac muscle contracts how?
Syncytium (all-at-once)
involuntary muscle twitches
vesiculation
Places where cardiac muscle fibers anchor
Intercolated discs
intercolated discs are made of
desmosomes and gap jxns
Electrical synapse point b/t two cells
gap junctions
Ability to recieve and respond to stimuli
excitability
ability to shorten forcibly
contractibility
ability to propogate electrical signals over membrane
conductivity
the ability to be stretched or extended
shortening is contraction [muscles do not “flex”]
Extensibility
ability to recoil and resume original resting length
elasticity
Skeletal Muscle: Three connective tissue sheaths
fine sheath of connective tissue composed of reticular fibers surrounding each muscle fiber
Endomysium
Three kinds of connective tissue skeletal muscle
fibrous connective tissue that surrounds groups of muscle fibers called fascicles
perimysium
Three kinds of connective tissue skeletal muscle
an overcoatof dense regular connective tissue that surrounds the entire muscle
epimysium
Each muscle is served by how many nerves, arteries and veins?
One each
Name a nerve for a muscle
Motor Neuron
Each skeletal muscle tissue is supplied with a
nerve ending
Arteries are found in what layer of muscle?
endomysium layer
epimysium of the muscle is fused to the periosteum of a bone
Direct attachment of skeletal muscle
connective tissue wrappings extend beyond the muscle as a tendon or aponeurosis
indirect attachment of skeletal muscle
a unique oxygen-binding protein
myoglobin
Units of muscle and their names
Organ
Muscle
Portion of Muscle
Fascicle
Muscle Cell
Muscle Fiber
Contractile organelle
Myofibril
Contractile unit
Sacromere
Actin and Myosin
Myofilaments
Muscle fibers contain
contractile elements
myofibrils
stores Ca2+ ions
Sarcoplasmic reticulum
allows action potentials to quickly penetrate to the interior of the cell
T Tubules
Dark bands in muscles
A Band
Light Bands
I Bands
Smallest contractile unit (sub-myofibril)
sarcomere (from I band to I band)
Actually from z-disc to z-disc in the middle of the I bands
Thick myofilaments
Myosin
Thin myofilaments
Actin
Holds myosin together in the A band
M Line
Holds actin together in the I band
Z-disc
No thin filaments in the
H Zone
Protein that holds Myosin together in M lines
Desmin
Elastic filament (protein) that anchors Myosin to Z-disc
Titin
biggest single-molecule protein in the body
structural protein that anchors thin filaments to sarcolemma [and the extracellular matrix] endomysium
dystrophin
Thick filament made up of how many myosin proteins?
500 molecules
Myosin filaments heads and tails. heads are called
cross bridges
Regulatory proteins in thin filaments
tropomyosin and troponin
Ion that articulates regulatory proteins
Calcium
Mysosin looks like
Golf clubs
Actin looks like
Olives
Troponin looks like
Corn kernels
Tropomyosin looks like
Spaghetti
The salt is
Calcium
smooth endoplasmic reticulum that mostly runs longitudinally and surrounds each myofibril
Sarcoplasmic reticulum
SR
Calcium stored in
Terminal cisterns of the SR
calcium transmitted by the
Tubule of the SR
calcium transmitted by the
Tubule of the SR
conducts action potential to the deepest regions of the muscle cell
T tubules
What percent does skeletal muscle shorten
30%
what percent does smooth muscle shorten
80%
E-C-C
sequence of innervation of muscles
motor neuron
nerve ending
propogated along sarcolemma
along T tubule to release Ca2+
name of skeletal neurons
lower motor neuron
axons of motor neuron enters muscle here
motor entry point
neuromuscular junction made up of these two parts
axonal endings
motor end plate
Neurotransmitter used by motor neurons
acetylcholine
enzyme that destroys ACh
acetylcholenesterase
ACh-esterase allows for what
muscle to recoil
EPP
End Plate Potential
MAP
Muscle Action Potential
Protein (or enzyme) changing shape
conformational change
E-C-E-C-C-C is
Electrical (nerve action potential)
Chemical (ACh from nerve ending to sarcolemma)
Electrical (EPP->MAP)
Chemical (Ca2+ allows cross-bridge attachment w ADP)
Contraction (increase in overlap b/t myosin+actin)
Coupling (cross-bridge detatchment thru ATP)
Each myosin head can cycle how many times per second
5