Module 3: Lecture 7 Flashcards
what are the two components of the nervous system?
- central nervous system (CNS)
- peripheral nervous system (PNS)
what part of us is our central nervous system?
the brain and spinal cord
what part of us is our peripheral nervous system?
nerve fibers
- all the extra nervous tissue, predominantly nerves
what brings information either toward or away from the spinal cord?
the peripheral nervous system
what does ‘afferent’ in regards to the peripheral nervous system mean?
you are carrying information towards the spinal cord
- ex. touch receptors - from periphery to the CNS
what does ‘efferent’ in regards to the peripheral nervous system mean?
you are carrying information away from the spinal cord
ex. walking around - motor commands from CNS that allows us to move around and communicate
what is the peripheral nervous system?
connection between the CNS and effectors/receptors located in other parts of the body
when do we refer to specific nerve bundles?
when talking about the PNS
what is a pathway/tract?
groups or bundles of nerves or axons within the CNS
what are the two divisions of the efferent division of PNS?
- somatic nervous system
- autonomic nervous system
what are the two divisions of the autonomic nervous system?
- sympathetic nervous system
- parasympathetic nervous system
which systems of the efferent division do you have conscious and voluntary control over vs unconscious and involuntary?
conscious and voluntary- somatic
unconscious and involuntary- autonomic
do the pathways of the efferent and afferent divisions utilize the same neurons?
no, different neurons
what is the pathway of the afferent division?
- from a receptor to the CNS
what is the pathway of the efferent division?
- carries information away from the CNS toward the end effector organs or muscles
what does the somatic nervous system control?
skeletal muscles
the cell bodies of the neurons of the somatic nervous system are located where?
in the brainstem and the ventral horn of the spinal cord
- spinal cord
what are the neurons of the somatic nervous system?
motor neurons
what does the autonomic nervous system innervate?
- all of your internal organs that have some sort of neural input on them
ex:
- the smooth and cardiac muscles
- glands
- adipose tissue, liver, other neurons from the gastrointestinal tract
what is the structure of the afferent neuron in PNS?
- sensory receptor within the periphery that generates the action potential which will travel towards the CNS
- has a long peripheral axon which is the information traveling back to the CNS
- cell body located next to the CNS next to the spinal cord
- axon terminals project slightly into CNS
what does a sensory receptor do?
generates an action potential in response to a stimulus
how does an afferent neuron get into the CNS?
the touch receptor (sensory receptor) generated an action potential in response to that stimulus and then the axon terminals will project into the CNS, into the spinal cord, where it will synapse
how does the cell body of an afferent neuron in PNS look like?
- adjacent to the spinal cord
- has no dendrites