NERVOUS SYSTEM STRUCTURES
- To Know
The following is the list of structures you need to know for the lab practical. As much as possible,
I have followed the order of presentation in the textbook.
Neuron structures:
Cell bodies, dendrites, axons, terminals
Glial types:
CNS
-- astrocytes, microglia, oligodendrocytes (myelin sheath), ependymal cells
(CSF)
PNS -- Schwann cells (myelin
sheath w/ nodes of Ranvier), satellite cells (in DRG†)
VENTRICLES:
Each has its own choroid plexus (patch of ependymal cells)
- lateral (1 & 2) ( in cerebrum)
- septum pellucidum (divider between lateral ventricles)
- third (in diencephalon) and fourth (surrounded by brain stem & cerebellum)
- cerebral aqueduct (through midbrain [see below]; connects third and fourth
ventricles)
CEREBRUM - encloses lateral ventricles; cranial nerves I
(olfactory) & II (optic) from here
GENERALIZED FEATURES:
Gyri --
precentral, postcentral
Sulci -- central, lateral
Fissures -- longitudinal, transverse
Hemispheres
Lobes -- frontal, parietal, occipital, temporal, insula CORTICAL REGIONS (gray matter):
Primary motor area (precentral gyrus), Primary somatosensory area (post-central
gyrus), premotor
cortex, prefrontal cortex, visual (occipital) cortex, auditory cortex
Association Areas WHITE MATTER (tracts):
Commissures -- corpus callosum, interthalamic adhesion* (see diencephalon below)
Association and Projection fibers
(tracts) -- decussation of pyramids
Olfactory Bulbs and tracts
Optic nerves/Optic chiasma
DIENCEPHALON -- two halves enclose third ventricle
THALAMUS*:
interthalamic adhesion represents commissure between two halves
HYPOTHALAMUS: associated structures include mammillary bodies, infundibulum
(stalk) for pituitary gland
EPITHALAMUS: pineal gland, choroid plexus (in roof of third ventricle)
BRAIN STEM
MIDBRAIN: Cerebral peduncles in front of cerebral aqueduct (connects third and
fourth ventricles);
corpora quadrigemina (four bodies), including the superior and
inferior colliculi; superior cerebellar
peduncles9, cranial nerves III & IV from here
PONS: middle cerebellar peduncles 9,
cranial nerves V - VII
MEDULLA OBLONGATA: inferior cerebellar penducles9, cranial nerves
VIII - XII
from here; decussation of pyramids
CEREBELLUM -- with pons and medulla,
surround fourth ventricle
Hemispheres connected by
vermis; folia, lobes and fissures (don=t need to know specifics),
arbor vitae (cerebellar white matter), connections to all three brainstem regions
by cerebellar
peduncles (see 9 above) BRAIN COVERINGS:
Meninges -- dura mater (periosteal and meningeal layers)
with dural sinuses, arachnoid
mater
with arachnoid villi, pia mater
Meningeal spaces
-- subdural, subarachnoid
SPINAL CORD
GENERALIZED FEATURES:
Meninges (as around brain); with epidural space
Conus medullaris,
filum terminale, and cauda equina
Cervical/lumbar enlargements
Anterior median fissure/posterior median sulcus
Central Canal
(through gray commissure)
GRAY MATTER:
gray commissure; posterior
horns (synapses with interneurons from sensory
neurons), lateral
horns (in certain regions only; cell bodies of autonomic
motor neurons),
anterior horns (cell bodies of somatic motor neurons)
WHITE MATTER:
posterior, lateral, anterior funiculi (columns; ascending
[sensory] and descending [motor[)
ROOTS and SPINAL NERVES:
pgs. 508-515
ventral roots (motor neurons); dorsal roots (sensory neurons) and their ganglia†
(cell bodies of sensory neurons, with satellite cells surrounding the cell
bodies),
dorsal and ventral rami (pg. 509), gray and white rami communicantes and sympathetic chain
(paravertebral)
ganglia (Chap. 14, pgs. 538 - 539)