Organization of the Nervous System Flashcards
Central Nervous System (CNS)
Nerves encased in bone (spinal cord, brain)
Peripheral Nervous System (PNS)
Nerves coming from the CNS (off the Spine and Brain) leading to/ from the extremities of the body
Somatic Nervous System (SNS)
Part of the PNS-interacts with the external environment
afferent nerves
nerves that carry info IN to the CNS from the muscles
in the SNS
efferent nerves
carry motor signals OUT to the muscles
in the SNS
autonomic nervous system (ANS)
part of the PNS-regulates the body’s internal environment
-automatic functions (blinking, breathing, heart, etc)
sympathetic nerves
nerves in the ANS that come from the CNS (lumbar) and (thorac) regions of the spinal cord
parasympathetic nerves
nerves that come from the CNS (brain and sacral regions)
cranial nerves
12 pairs of nerves that project from the brain
meniges
3 membranes covering/protecting the brain and spinal cord
dura mater
1st layer of meninges
- a tough membrane
- “tough mother”
arachnoid membrane
2nd layer of meninges
-spiderweb-like
subarachnoid space
between the 2nd and 3rd layers of meninges
-a space filled with blood vessels and cerebrospinal fluid
pia mater
3rd layer of meninges
- most delicate layer
- adheres to brain/spinal cord
cerebrospinal fluid (CSF)
fills the subarachnoid space
-protects the CNS
central canal
small central channel that runs the length of the spinal cord
cerebral ventricles
4 large internal chambers in the brain
choroid plexuses
networks of cappillaries that protrude into ventricles from the pia mater
blood-brain barrier
cells of the blood vessel walls are very tightly packed, they form a barrier to prevent potential poisons and unknown particles from entering
dorsal
out the top of the head, out the back of the spine
ventral
out the bottom of the head, out the front of the body
anterior
out the face, upwards from the spine
posterior
out the back of the head, downward of spine
medial
inward