Ch 9 Muscle Physiology Parts 1 & 2 Flashcards
3 Muscle tissue types
Skeletal, Smooth, Cardiac
3 Myocyte structures
Sarcolemma = plasma membrane
Sarcoplasm = cytoplasm
Myoofibrils = Contractile structure of a cell
What are T-tubules
invaginations of sarcolemma
T-tubule function
Transfer of action potentials
What’s the triad
T-tubule between two terminal cisternae
What is terminal cisternae
Sacs adjacent to t-tubules
What is the sarcoplasmic reticulum
Internal membrane complex (smooth ER)
Two types of filaments
thick and thin
Thick filament is called what
Myosin
Thin filament is called what
Actin
3 parts of thin filament structure
Troponin, Tropomyosin, Actin
What does Nebulin do
Plays a role in filament assembly
What does troponin do
Regulates contraction
What does tropomyosin do
Regulates contraction
What is myosin composed of
two large polypeptide heavy chains
Globular heads do what
Form cross bridges: for contact with thin filament
What are sarcomeres
Functional units of myocytes
What are Z discs
Proteins that anchor thin filaments
What are alpha motor neurons
Neurons whose axons innervate skeletal myocytes
Neuromuscular junction cell bodies are located in…
The brainstem and spinal cord
Are all motor neuron axons myelinated?
Yes
What is the axon terminal
Synaptic vesicles and active zones
What is the synaptic cleft?
Space between axon and sarcolemma
What is the motor end plate
ACH receptors and junctional folds
