Chapter 9.2 Flashcards
What is a contraction of a muscle fiber
- Interaction with chemical and cellular components
* Actin &myosin slide past one another(contraction)shortening sarcomeres
What is Neuromuscular Junction
•Site where an axon of motor skeletal muscle fiber interact
When do skeletal fibers contract?
when simulated by a motor neuron
What are the parts of a NMJ
- Motor neuron (Interaction)
- Motor end plate (Interaction)
- synaptic cleft(physical space)
- Synaptic vesicles( hold N.T’s)
- Neurotransmitters ( chem Msg’s)
What is the acetylcholine
A Neurotransmitter
What is a motor unit
A moron neuron + all fibers it controls
Tetanic Contraction
Continuos forceful contraction with little to no relaxation
What has to happen in order to stimulate muscle
Nerve impulse
Release Ach
Action potential
Release calcium
Myasthenia Gravis (MG)
Autoimmune disease that destroys ACh receptors
What happens to calcium when it is released from SR
Binds to troponin
What is the function of acetylcholine esterase
Break down Ach
Treatments for myasthenia
Drugs that inhibit acetylcholinesterase
Immunosuppressant drugs
What are the 3 energy sorces
1- cellular respiration
2-ATP reserves
3- creatine phosphate
What is oxygen debt
Amount of oxygen to convert lactic acid to glucose
What is fatigue
Inability to contact muscle
- decreased blood flow
- ion imbalances
