and Answers All Correct
What are the nerve plexuses? - Answer-Once the spinal nerves exit the vertebral
column, fibres from the anterior roots (motor) come together and then redistribute into
new networks of nerves (plexuses) that mostly innervate muscles of the limb
What do the nerve plexuses contain? - Answer-Each plexuses therefore contains fibres
(a collection of axons) from a combination of spinal nerves
What is the functional importance of the nerve plexuses? - Answer-In the case of injury,
the contribution of multiple spinal nerves into the nerve plexuses ensures innervation to
the muscle
What nerve plexuses correspond to the cervical enlargement? - Answer-The cervical
and brachial plexuses correspond to the cervical enlargement
What nerve plexuses correspond to the lumbosacral enlargement? - Answer-Lumbar
and sacral plexuses correspond to the lumbosacral enlargement
What does "two neuron pathway" mean? - Answer-Between the CNS and any target
organ, there are two neurons
What is an example of a "two neuron pathway"? - Answer-The automatic nervous
system
What is the preganglionic neuron? - Answer--has its cell body within the CNS
-The axon enters into the PNS and travels to the autonomic ganglion
What is the autonomic ganglion? - Answer--where the preganglionic and postganglionic
neurons meet and communicate
-located in the PNS
What is a postganglionic neuron? - Answer--entirely in the PNS
-its cell body is in the autonomic ganglion, while its axon travels to the target organ
What are the three steps of the nervous system? - Answer-1. Sensory input
2. Integration
3. Motor output
, What is sensory input? - Answer-Sensory input from the environment is detected by
sensory nerves and travels through the body to communicate with other nerve cells
What is integration? - Answer-Processing and interpretation of sensory input
What is motor output? - Answer-a response to integrated stimuli; the response activates
muscles or glands by sending motor output through motor nerves
What are the two principal subdivisions of the nervous system? - Answer-Central
Peripheral
What is the function of the CNS? - Answer-»Where all signals come to and from
»Where they are integrated
»Where information can be stored
What is the function of the PNS? - Answer-System that brings those signals to and from
the CNS
What are the two divisions that the PNS can be further broken down into? - Answer-
Sensory (afferent) division
Motor (efferent) division
What does the sensory division do? - Answer-Relays information to CNS
Sensing things such as sight, smell, touch and even pain
Sends the information to the CNS through sensory neurons
What does the motor division do? - Answer-Relays information from CNS to target cells
The actual response that is elicited
Signal comes from the CNS, the brain, or spinal cord and is relayed to a target cell
through efferent neurons
What subdivisions can the motor (efferent) division be further divided into? - Answer-
Somatic
Autonomic
What is the function of the somatic nervous system? And how does it do that? - Answer-
Controls voluntary movement
Signal comes from the CNS through the efferent neurons to a target skeletal muscle
cell, eliciting movement of that muscle
What is the function of the autonomic nervous system? - Answer-Controls involuntary
movement
What can the autonomic nervous system be further divided into? - Answer-Sympathetic
- fight or flight