Motor neurons stimulating skeletal muscles to contract

What does it mean to be an excitable cell

The cells respond to external stimuli by changing their resting membrane potential

What is the action potential

A large change in membrane potential that spread rapidly over long distances within a cell

Do action potentials travel between cells

NO, they do not go from one cell to another!

How do action potentials travel between cells

The signal has to be converted to a chemical signal - a chemical messenger called a neurotransmitter that can diffuse across the small gap between excitable cells (synapse) to start the signal again

What NT do motor neurons use to tell skeletal muscles to do stuffs

Acetylcholine

What are the two types of channels responsible for allowing ions to pass through the membrane

Chemically gated ion channels and voltage-gates ion channels

What are chemically gated ion channels

They are opened by chemical messages (NTs). They open in response to binding of the appropriate neurotransmitter, like acetylcholine

What are voltage-gated ion channels

Ion channels that open when there is a change in membrane polarization. They usually depend on chemically gated channels to create localized depolarization

What are motor neurons called that activate skeletal muscle fibers

Somatic motor neurons, or motor neurons of the somatic (voluntary) nervous system

Where do somatic motor neurons reside

Brain or spinal cord (ventral horn)

What extends from each motor neuron cell body

The axon

What covers each axon

Myelin sheath

What is the motor end plate

Where the terminal branches of an axon reach the muscle. The axon splits and forms curling branches, called the neuromuscular junction, or motor end plate

How many NT junctions do each muscle fibers have

1

What separates the axon terminal and muscle fibers

synaptic cleft

What fills the synaptic cleft

Gel-like ECM and collagen fibers

What contains the acetylcholine NTs in the axon terminal

Synaptic vesicles

What are junctional folds

Infoldings of the sarcolemma that contain millions of ACh receptors.