Muscle Physiology
The repeating contractile unit found within myofibrils.
What is a sarcomere?
These ion channels open when acetylcholine binds at the motor end plate.
What are ligand-gated sodium channels?
The basic cell responsible for transmitting electrical signals in the nervous system.
What is a neuron?
Chemical messengers secreted by glands and transported in the bloodstream.
What are hormones?
The maintenance of stable internal body conditions.
What is homeostasis?
The region of the sarcomere where thick filaments are primarily located.
What is the A band?
These channels open when the membrane reaches threshold and propagate the action potential down the muscle membrane.
What are voltage-gated sodium channels?
The rapid electrical signal that travels down an axon.
What is an action potential?
The endocrine gland that regulates metabolism by releasing T3 and T4.
What is the thyroid gland?
hese three components make up a physiological feedback loop.
What are receptor, control center, and effector?
The protein that binds calcium and moves tropomyosin during contraction.
What is troponin?
These channels open during repolarization to restore the negative membrane potential.
What are voltage-gated potassium channels?
The phase of the action potential when sodium ions rush into the cell.
What is depolarization?
This pancreatic hormone lowers blood glucose levels.
What is insulin?
The division of the nervous system responsible for involuntary body functions.
What is the autonomic nervous system?
The theory explaining how muscle shortens as filaments slide past each other.
What is the sliding filament theory?
These channels in the sarcoplasmic reticulum release calcium into the cytoplasm to initiate contraction.
What are calcium release channels (ryanodine receptors)?
The insulating structure that increases the speed of nerve conduction.
What is the myelin sheath?
The part of the brain that links the nervous system to the endocrine system.
What is the hypotahalamus?
The branch responsible for “fight or flight.”
What is the sympathetic nervous system?
The molecule required to power cross-bridge cycling and release myosin from actin.
What is ATP?
These channels in the T-tubules detect voltage changes and trigger calcium release from the sarcoplasmic reticulum.
What are dihydropyridine receptors (voltage-sensitive calcium channels)?
The process where impulses jump between gaps in the myelin sheath.
What is saltatory conduction?
The regulatory mechanism where hormone levels inhibit further hormone release.
What is negative feedback?
The hormone released from the adrenal medulla during stress that increases heart rate and blood pressure.
What is epinephrine?