Central Nervous System - E4 Flashcards
Rostral
Caudal
toward the forehead/nose
toward the spinal cord
4 major parts of the CNS
- Brain Stem
- Diencephalon
- Cerebrum
- Cerebellum
What are ventricles?
spaces filled with cerebrospinal fluid and lined with ependymal cells
Lateral ventricles location
separated by the septum pellucidum
Interventricular foramina
connects the lateral ventricles to the third ventricle
Cerebral aqueduct (in relation to ventricles)
connects the third and fourth ventricles
Fourth ventricle location
continuous with the central canal of spinal cord and connects to subarachnoid space via median and paired lateral apertures
Subparts of the brain stem
- Medulla oblongata
- Pons
- Midbrain
Medulla oblongata
conduction pathway of the CNS (decussation of pyramids)
holds nuclei for CN VIII-XII
Pyramids vs Olives
pyramids are anterior bulges (contain tracts)
olives are lateral bulges (contain nuclei)
both pertaining to medulla oblongata
“Pons”
bridge
Pons function
connects medulla to midbrain
holds nuclei for CN V-VIII
“peduncles”
little feet
“colliculi”
little hills
“folia”
leaf
CN in midbrain
CN III and IV
Corpora quadrigemina
apart of the midbrain
- superior colliculi - visual reflexes
- inferior colliculi - auditory reflexes
Functions of the cerebellum
- regulates voluntary, skilled movements
- regulates posture and balance
- other sensory and motor functions
50% of brain’s neurons, but only 10% of its mass
“Arbor vitae”
tree of life
white matter of the cerebellum
Subparts of the diencephalon
- thalamus
- hypothalamus
- epithalamus
- third ventricle
Thalamus
“gateway to the cerebral cortex”
relay center for all sensory info except smell
Hypothalamus
regulates autonomic nervous system and endocrine system
Infundibulum
connects the hypothalamus to pituitary gland
Pineal gland
“pine cone”
part of the epithalamus
sleep regulation
Third ventricle
“donut” pierced by interthalamic adhesion
gray/white matter location in the brain vs spinal cord
Brain - gray outside of white
Spinal cord - gray inside of white
Cerebral cortex
outer rind of the gray matter of the cerebrum
conscious mind
Insula
“island”
deep in lateral sulcus
Sulcus vs gyrus
sulcus for grooves
gyrus for folds
white matter tract types
association tracts are in the same hemisphere
commissural tracts are between hemispheres
projection tracts are outside of the cerebrum
basal nuclei
several large nuclei embedded w/i white matter of the cerebrum
Limbic system
limbic = “border”
bilateral interconnected rings of structures
includes hippocampus and fornix
Hippocampus
“seahorse”
memory
Fornix
“arch”
link between limbic system and diencephalon
Cerebrum functions
- sensory: interpret and localize
- motor: initiate movement
- association: emotion and intellect
- basal nuclei: gross, autonomic movement
- limbic: emotional behavior related to survival/memory
Meninges
connective tissue coverings that protect the brain
Layers of the meninges
outermost to innermost
- dura mater
- arachnoid
- pia mater
Dura mater
“tough mother”
dense, irregular c.t.
periosteal (most superficial) and meningeal
Extensions of the dura that help w/anchoring
- falx cerebri - between hemispheres in long. fissure
- falx cerebelli - between cerebellar hemispheres
- tentorium cerebelli - in transverse fissure
Arachnoid
“spidery”
gives rise to collagen and elastic c.t.
subarachnoid space is filled with CSF
Pia mater
collagen and few elastic fibers
adheres tightly to the brain surface
thinnest layer
Cerebrospinal fluid
suspends the brain
absorbs shock
exchange of gases, nutrients, waste
Ependymal cells
within choroid plexuses
produce CSF
Path of CSF
- lateral ventricles
- interventricular foramen
- third ventricle
- cerebral aqueduct
- fourth ventricle
- lateral apertures, median aperture, or central canal
- subarachnoid space
- arachnoid granulations
- dural venous sinuses
Blood brain barrier
continuous capillaries that have no clefts
spinal cord location
begins at foramen magnum (continuation of medulla)
ends at L1
31 segments
Cauda equina
“horse tail” the inferior portion of nerves after the spinal cord ends
filum terminate
thin c.t. layer than anchors the spinal cord inferiorly
funiculi of the white matter
“columns”
dorsal, ventral, and lateral funiculi
ascending vs descending tracts
ascending are sensory = spinal cord to brain
descending are motor = brain to spinal cord
horns of the gray matter
ventral horn - skeletal motor neuron cell bodies
lateral horn - smooth, cardiac, and gland motor neuron cell bodies
dorsal horn - interneurons
- ventral root
- dorsal root
- dorsal root ganglion
- carries motor axons from CNS (efferent)
- carries sensory axons into CNS (afferent)
- sensory cell bodies
denticulate ligaments
lateral extensions of the pia mater in the spinal cord
suspend and anchor the spinal cord
Spinal cord functions
- conduction pathway
2. integration center (spinal reflexes and locomotion)
spinal reflexes
fast, automatic, predictable response to stimuli
locomotion
central pattern generators for coordinating repetitive muscle activity
integration pathway
- sensory receptor
- sensory neuron (posterior root, afferent)
- integrating center (gray matter)/
- motor neuron (anterior root, efferent)
- effector