ModE 1

 Na+, Ca2+, Cl-

These ions are at a higher concentration on the OUTSIDE of the resting nerve cell:

Ka+, anions(-)

These ions are at a higher concentration on the INSIDE of the resting nerve cell:

down

Channels only allow things to move ______ their concentration gradient.

high , low

This means that they move from an area of ___ concentration to an area of ____ concentration.

sodium

 A sodium channel will only allow ______ to move across the cell membrane

into

When a sodium channel is open, this ion will move ______ the cell.

Ka+

A potassium channel will only allow____ to move across the cell membrane

out

When a potassium channel is open, this ion will move ________ the cell.

action potential

If the dendrites of a nerve cell receive a stimulus/stimuli that is/are sufficient to move the membrane potential past threshold,

-70

The resting membrane potential of a nerve cell is around__ millivolts

sodium, into

During depolarization, ____ channels open, allowing sodium to rush____ the nerve cell

Ka+, out

During repolarization,___ channels open, allowing potassium to rush ____the nerve cell

All-or-None Law

 if the stimulus is strong enough to push the membrane potential across its threshold, a full-strength AP will be generated in the nerve cell.

Excitatory Post-Synaptic Potentials (EPSPs)

these signals move the membrane potential of the post-synaptic neuron closer to threshold and increase the chances of an AP

Inhibitory Post-Synaptic Potentials(IPSPs)

these signals move the membrane potential of the post-synaptic neuron further away from threshold and decrease the chances of an AP

Temporal summation

a single pre-synaptic axon firing really fast

Spatial summation

multiple pre-synaptic axons firing simultaneously

alpha-motor neurons

CNS decides that it is time for you to move and activates_____

action potential (AP)

When an alpha (α)-motor neuron is activated, an ______ travels along the axon

skeletal muscle fibers

The action potential gets to the end of the axon and a signal is sent to the

contract

If an action potential is generated in an α-motor neuron, all of the skeletal muscle fibers innervated by that α-motor neuron will _____

Motor Unit

A ______is defined as an α-motor neuron and all of the skeletal muscle fibers it innervates

dendrites, cell body, axon

A neuron is made up of the following parts:

dendrites

receive information from the brain or sensory neurons; located in spinal cord.

the spinal cord

where is the cell body located

axon

stretches/carries signal (in form of action potential) from the spinal cord to the skeletal muscle fiber it innervates.

collateral branches

The axon of the alpha-motor neuron splits in to_______

Innervation Ratios

____refers to the number of skeletal muscle fibers innervated by a single α-motor neuron. Expressed as a ratio (e.g., 3:1 or 3-to-1)

less

Fine motor skills, which require precise control, use motor units with___ innervation ratios

more

Gross motor skills, which require less control, use motor units with_____ innervation ratios

multiple

One neuron can innervate ___ skeletal muscle fib

1, all

 A motor unit = ____motor neuron plus ___ the muscle fibers (i.e., myofibers) it innervates.

three

How many motor units are their