뒤로Exam 4 A&P 3.0
이 집합의 용어 (15)
parts of a sarcomere-Thick filament.
myosin
The difference in electrical charge across a cell membrane.
transmembrane potential
where a motor neuron communicates with a muscle fiber. A nerve impulse causes acetylcholine release, which stimulates an electrical signal in the muscle and leads to contraction.
neuromuscular junction
Breaks down acetylcholine and stops muscle stimulation.
acetylcholinesterase
what stores and releases calcium?
Sarcoplasmic reticulum
What are the steps of excitation-contraction coupling?
Calcium binds to troponin.
Tropomyosin moves away from actin's binding sites.
Myosin attaches to actin.
Myosin pulls actin, causing contraction.
Calcium returns to the sarcoplasmic reticulum, allowing relaxation.
what carry electrical signals deep into the muscle fiber?
T tubules
What neurotransmitter is used at the neuromuscular junction, and how does it work?
Acetylcholine (ACh). It binds to receptors on the muscle membrane and starts an electrical signal.
What two main proteins generate muscle contraction?
Actin and myosin. Myosin attaches to actin and pulls it.
what blocks actin's binding sites when relaxed?
Tropomyosin
Actin slides past myosin, shortening the sarcomere. The filaments themselves do not shorten.
sliding filament theory
What is the role of calcium in muscle contraction?
Calcium binds to troponin, exposing actin's binding sites so myosin can attach.
What are the three main energy sources for muscle contraction?
Stored ATP, creatine phosphate, and cellular respiration.
what binds calcium and moves tropomyosin?
Troponin
the most abundant protein in most eukaryotic cells
actin