Chapter 6 - PNS and CNS Systems Flashcards
Fill in the blank: The nervous system is divided into the … system and the … system.
- Central Nervous System
- Peripheral Nervous System
What is the central nervous system composed of?
- Brain
- Spinal cord
What is the role of the central nervous system?
- Integrates incoming info
- Coordinates involuntary + voluntary nervous functions
What is the peripheral nervous system composed of?
Ganglia + Spinal + Cranial nerves that branch from the CNS
What is the role of a spinal nerve?
Where does it end?
What does it carry?
How many are there?
List the 6 different parts of the spinal cord.
- Take impulses to/away from the spinal cord + brain
- Ends between the 1st + 2nd lumbar vertebrae
- Sensory + motor fibers
- 31 mixed pairs
- Cervical - C8, Thoracic - T12, Lumbar - L5, Cauda equina - above L5, Sacral spinal nerves (S1-S5), Coccygeal
Where does a sensory fiber travel to and from?
Enters the dorsal side of the spinal cord through the dorsal root
Where does a motor neuron travel to and from?
Leaves the ventral side of the spinal cord through the ventral root
What is the role of a cranial nerve?
Where are they located?
How many are there?
Which pair of cranial nerves extends past the other 11 pairs?
- Take electrical impulses to/from the brain
- Located in the head + neck area
- 12 pairs
- Vagus nerves extend to the thoracic + abdominal cavities
What are ganglia?
Collections of nerve cell bodies
What is the role of the peripheral nervous system?
Keeps CNS in contact with the rest of the body
What is a neuron?
Excitable nerve cells that generate + transmit messages
What is a neuroglial cell?
Glial cells that provide structural support, growth factors + insulating sheaths around axons
What is a nerve?
Bundles of myelinated axons that connect the brain + spinal cord (CNS) to the rest of the body.
What type of movements does the somatic motor division of the PNS involve?
Voluntary movements
What type of movements does the autonomatic motor division of the PNS involve?
Involuntary movements - Cardiac + Smooth muscle glands + Digestive System
What are the 2 sub-categories of the autonomic motor division? What is the difference between the 2? How do they both work?
- Parasympathetic (digest + defecate + diuresis) dominates during calming/relaxing times
- Sympathetic (Fight or flight system + exercise + excitement + emergency + embarrassment) dominates during stressful times
- Does not switch on or off but responds to info provided by the sensory system
Which type of muscle is the effector in somatic pathways?
Skeletal
Which type of muscle is the effector in autonomic pathways?
Smooth + cardiac glands
What is white matter? What is its role (in the brain)?
– Consists mostly of myelinated axons + dendrites
– Allows for communication between areas of the brain, and between the brain + spinal cord
What is gray matter (in the brain)?
Includes neuroglial cells, nerve cell bodies, and
unmyelinated axons
Where is the gray and white matter located in the brain?
Gray matter: outer tissue
White matter: inner tissue
What is white matter (in the spinal cord)?
- Composed of myelinated axons
- Sensory (afferent) tracts direct impulses toward
brain - Motor (efferent) tracts carry impulses from brain to
skeletal muscles
What is gray matter (in the spinal cord)? (3 points) - Explain pathway.
- Composed of cell bodies
- Dorsal horns contain interneurons (receive info from sensory neurons located in the dorsal root -housed in dorsal root ganglion)
- Ventral horns contain motor neurons of the somatic (voluntary) nervous system (send info out the ventral root)
Where is the gray and white matter located in the spinal cord? 2 = gray + 1 = white.
Gray matter: inner tissue –> central canal where CSF is
White matter: outer tissue