Intro To Nervous System Flashcards
What structures are part of the central nervous system
Brain and spinal cord
What structures are part of the peripheral nervous system
Cranial and spinal nerves
What is the somatic nervous system?
Sends signals to skeletal muscle
Is the somatic nervous system voluntary or involuntary?
Voluntary
What is the autonomic nervous system?
the part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
Is this voluntary or involuntary?
Involuntary
What are the two divisions of the autonomic nervous system
Sympathetic and Parasympathetic
What’s the role of the Parasympathetic nervous system
Rest and digest- brings the body back to homeostasis
What is the role of the sympathetic nervous system?
Fight or flight- brings body away from homeostasis
What is a neuron?
A nerve cell, basic building block of the nervous system
What are the parts of a neuron?
cell body, dendrites, axon, myelin sheathe
What does the cell body do?
Process information and contains the nucleus
What do dendrites do?
Receive messages from other cells
What does the axon do?
Sends messages to other neurons, cells, glands, or muscles
What does the myelin sheathe do?
Covers the axon of neurons and helps speed neural impulses
What is a synapse?
junction/space between two neurons
What are neurotransmitters?
Chemical released at synapse
What do interneurons do?
connect sensory and motor neurons and carry impulses between them
How do neurons send signals?
Neurotransmitters cross the synapse and bind with receptors on the postsynaptic dendrite.
What type of glial cells provide the myelin sheathe to the central nervous system?
Oligodendrites
What type of glial cell removes excess ions amongst other housekeeping duties
Astrocytes
Which glial cell helps with the immune response?
Microglia
which glial cells support neurons in the CNS?
astrocytes, oligodendrocytes, ependymal cells, microglia
Which glial cells support neurons in the PNS?
Schwann cells, satellite cells
What type of glial cells provide myelin to the axons in the PNS?
Schwann Cells
What type of glial cells provide the myelin sheathe to the peripheral nervous system?
Schwann
What is Multiple Sclerosis
A disease in which the immune system eats away the protective covering of the axon
What part of the neuron is affected in MS
myelin sheath
What is the definition of a membrane potential?
The difference in charge across a membrane
How is a ligand gated channel activated?
Specific for a particular ion and only open in response to a chemical
How is a voltage gated channel activated?
Specific for a particular ion and only open in response to an electrical stimulus
What is a ligand?
any molecule that binds specifically to a receptor site of another molecule
How is a mechanically gated channel activated
specific for a particular ion and only open in response to deformation of membrane
How is a leakage gated channel activated?
Opens and closes randomly
What is special about the NA/K pump in terms of the concentration gradient of Na and K?
is important in maintaining a rest point, uses ATP to move Na and K against it’s concentration gradient
What is the resting membrane potential of a neuron in mV?
-70 mV
How is the resting membrane potential maintained
The sodium potassium pump is constantly pumping 3 Na out and 2 K in
Define an action potential
Change in membrane potential overtime
What is the trigger for an action potential to start
External stimulus causes other channels to open up letting more ions in, the charge becomes more positive.
Describe what happens in terms of the movement of Na+ during depolarization?
Na+ floods into the neurons as the gated sodium channels open
What needs to occur exactly for voltage-gated Na+ channels to open?
Depolarization is necessary to open the channel
What if ligand-gated Na+ channels opened but the membrane potential only changed from -70mV to -61mV? Would an action potential happen, why or why not?
An action potential would not occur because it has not reached the threshold of -55mV
During repolarization, what type of channel opens?
Potassium ion channels
What effect does the opening of potassium channels have on the membrane potential?
Repolarizes the membrane potential, making it more negative
What is hyperpolarization?
The potassium channels stay open for a little too long, the membrane potential going lower than normal. Another action potential can’t occur until it goes back to -70 mV
