Ch. 9 Muscle Tissues (E2) Flashcards
Name the 4 functions of muscle tissue.
1) Movement
2) Posture
3) Stabilize joints
4) Generate heat
Name the 4 characteristics of muscle tissue.
1) Excitability
2) Contractility
3) Extensibility
4) Elasticity
A bundle of muscle fibers, i.e., myocetes, covered by perimysium.
What are fascicles?
Sarcolemma acts as the…
Cell membrane
Sarcoplasm acts as the…
Cytoplasm
Thread-like, parallel structures that are fundamental to muscle contraction.
What are myofibrils?
Myofibrils are composed of repeating segments/units called…
Sarcomeres
Sarcomeres contain the { }: actin and myosin.
Myofilaments
End boundary of a sarcomere.
What is a Z-disc?
Describe actin.
Thin, light bands attached at the Z-disc
Describe myosin.
Thick, dark banks at the center of a sarcomere
How do troponin and tropomyosin block muscle contraction?
They surround actin, preventing it from latching onto myosin
Nerve cell + muscle fiber =
Motor neuron
What is the function of the sarcoplasmic reticulum?
To act as a specialized smooth ER that runs parallel to myofibrils and stores calcium
What is the function of transverse tubules?
To pass through muscle cells to conduct electrical signal for contraction
The synaptic connection between a muscle fiber and its motor neuron.
What is the neuromuscular junction?
Process in which neurotransmitters are exocytosed from the end of the motor neuron onto the muscle fiber.
What is synaptic transmission?
Motor neuron stimulation begins with the…
Action potential
What are the 5 major components of excitation/contraction coupling?
1) Action potential
2) Post-synaptic cholinergic receptors
3) Muscle impulse
4) Calcium release
5) Contraction
What is the name of the neurotransmitter involved in excitation/contraction coupling?
Acetylcholine (Ach)
Enzyme that breaks down acetylcholine.
What is acetylcholinesterase?
How do Ach receptors contribute to the action potential?
They open ion channels that allow the action potential to move throughout the muscle fibers
How does botulism affect muscle contraction?
It inhibits Ach release, which prevents the action potential from moving to other muscle fibers
How does snake venom affect muscle contraction?
It blocks Ach binding
