Nervous system Flashcards
on exam one
Central Nervous System
composed of the brain and the spinal cord
Peripheral Nervous System
composed of everything that is not the brain or spinal cord
Sensory nerves
react to a feeling and sends it to the brain
Afferent
the signal is sent to the brain
Efferent
the brain tells you what to do
Are efferent nerves voluntary or involuntary?
they can be both
The two branches of the autonomic nervous system
sympathetic and parasympathetic
What does the somatic nervous system control?
movement
Sympathetic nervous system deals with what?
fight or flight
Parasympathetic nervous system deals with what?
speeding up or slowing down (leaving and returning to normal)
What part of a neuron receives impulses?
dendrite
What part of a neuron transmits messages?
Soma
This is where graded potentials stay
the axon hillock
Where is an electric action potential created?
the axon
What is at the end of every axon on the terminal bulbs?
acetolcholine
What mineral is outside of the neuron? (extracellularly)
Sodium, Na+
What mineral is inside the neuron? (intracellularly)
Potassium, K+
What does the sodium potassium pump regulate and what is the numerical value?
resting membrane potential, -70
When is the sodium potassium pump working the hardest?
when you aren’t doing anything
What is myelin made up of?
Schwann cells
What is the first thing that happens when your muscle gets a message?
depolarization
What is depolarization?
Sodium rushes into the cell and makes the stimulus more positive to reach the action potential threshold
What is it called if a signal doesn’t reach the action potential threshold?
it becomes a graded potential and does not pass the axon hillock
A graded potential has a voltage change of
8-10 millivolts
What is the numerical value for the action potential threshold?
-55
What is the second stage of a signal that has reached the treshold?
repolarization
What is repolarization?
Potassium rushes out of the cell
The refractory period follows repolarization, what is this?
too much potassium rushes out and the sodium potassium pump must bring it back to normal
Another name for the refractory period?
hyperpolarization
What type of neurons transmit faster?
myelinated neurons
A disease that happens when myelin degrades
multiple sclerosis
Nodes of ranvier
the spaces between myelin that impulses jump from
What is it called when impulses jump from one node to the next?
saltatory conduction
The chemical signal turns from ____ to ____ at the synaptic cleft
electrical; chemical
If the action potential reaches the synapse, what is sent out as a chemical signal?
acetylcholine
Acetylcholine triggers the next dendrite as?
an electrical signal
What three parts make up a synapse?
pre-synaptic cleft, synaptic cleft, post-synaptic cleft
What is a neuron that connects to a muscle?
alpha motor neuron
What part of the nervous system is an alpha motor neuron in?
peripheral somatic nervous system
Alpha motor neurons are
efferent because they have an effect
