Lect 1 Intro to CNS Flashcards
Frontal/coronal plane
results in a front piece and a back piece
sagittal plane
separates brain down the middle, results in a left and right sides
can be midsagittal which displays both hemispheres or off center
horizontal plane
results in a top piece and bottom piece
parasagittal
off the mid line
brain main components
cerebrum
cerebellum
brainstem
Cerebrum components
Cerebral hemispheres - cerebral cortex, subcortical grey matter
Diencephalon: thalamus, hypothalamus
Brainstem components
midbrain, pons, medulla
cerebral hemispheres
2
each is divided into 4 (or 5) anatomical lobes
4/5 lobes of the hemisphere
frontal parietal occipital temporal -limbic lobe is also described
Frontal–>Parietal–>Occipital = Anterior and go rostral to caudal
temporal inferior to F & P, rostral to Occipital
Central sulcus
separates the frontal from the parietal lobe
Lateral sulcus
Sylvian fissure
separates teh temporal from the frontal and parietal lobes
Parietooccipial sulcus
(see medial view)
separates the occipital from the parietal lobe
Gyrus
each ridge of brain
evaginations
sulcus
invagination, groove between ridges
Fissures
deep sulci
corpus callosum
major axonal bundles joining the 2 cerebral hemispheres
limbic lobe forms rim around CC
Major fossae of cranial cavity
Anterior
Middle
Posterior Cranial fossa
Anterior cranial fossa
sits above orbitals and dasal cavity, frontal lobe fills this fossa
Middle cranial fossa
contains temporal lobe
large depression
Posterior cranial fossa
holds cerebellum, entrance of brain stem
cerebellum
inferior to the tentorium cerebelli and within posterior cranial fossa
tentorium cerebelli
occipital lobes are supported inferiorly by the tentorium cerebelli
occipital lobes support and location
supported by tentorium cerebelli
rostral/superior to TC
Bones of anterior cranial fossa
Frontal
Ethmoid bone - rostral to sphenoid, root of nose
Sphenoid bone
Middle cranial fossa bone make up
Sphenoid
temporal bone
(parietal bone is not considered part of middle fossa)
bones of the posterior cranial fossa
sphenoid bone
temporal bone
occipital bone (largest)
Cerebral cortex
referes to layers of neurons that reside along the outer surface of the cerebrum
most of the human cortex is a six layer cortex (neocortex) numbered from outside in
neocortex
six layer cortex numbered from pial surface to inner surface
layers defined by types of neurons in each layer
gray matter
neuronal cell bodies in CNS, outer layers of pial surface
white matter
axons, often myelinated
pia mater
grey matter, adhered to surface of brain, not classified as brain matter
Cerebral Cortex Transverse Nissl stain
Surface of brain (cortex) is comprised of neurons = grey matter – stains purple
- see purple invaginations as well
white matter- axons are unstained
Myelin stain coronal section
Gray matter - unstained
white matter - black
White matter regions of cerebral hemisphere
corona radiata
internal capsule
much of interior of cerebrum is right matter
Corona radiata
radiating white matter immediately deep to the cortex that fans out like a ‘crown’
Internal capsule
deep to the corona radiata
deep white matter tracts that course between nuclei of the basal ganglia and thalamus
5 Anatomical regions:
Anterior limb, Genu, Posterior limb, retrolenticular, (rostral to caudal) & sublenticular
Organization of cerebral cortex
highly organized
Brodmann’s anatomical areas of human cortex - helps people talk about different sections of the brain
Information processing of cerebral cortex
first processed in primary sensory cortices
then travels to association cortices (higher order cortical areas) where integration occurs
parts of brain that process more info are larger - olfactory is much larger in rats, association corticee much larger in humans
diencephalon
hidden in an intact brain from gross inspection
includes: thalamus, hypothalamus, epithalamus, subthalamus
thalamus appearance
forms wall of 3rd ventricle
mid-sagittal section exposed, cannot see most of it though
better viewed from coronal section
Thalamus characteristics
bilateral & highly organized
comprised of many nuclei
Gateway to cerebral cortex - great majority of sensory and motor pathways relay through thalamus before reaching the cerebral cortex
also receives info from cortical regions
hypothalamus
comprises part of the diencephalon
important in maintaining internal environment in a physiological range (homeostasis)
lots of nuclei, with specific function (not responsible for these nuclei)
cerebellum
aka little brain
receives extensive sensory input
projects to subcortical structures (indirectly) to cortical regions
influences motor, cognitive and behavioral functions
Brainstem organization
Rostral to caudal Midbrain Pons Rostral medulla Caudal Medulla - three pairs of nuclei on dorsal surface
Spinal cord
continuous with the brainstem at the caudal medulla
spinal nerves emerge from the spinal cord to peripheral nerves that carry sensory/motor info to/from the CNS
ipsilateral
same side
contralateral
opposite side
bilateral
both sides
unilateral
one side
Ventricles
series of continuous spaces deep in the brain that contain cerebro-spinal fluid (CSF)
2 lateral ventricles coming together creates the 3rd ventricle
4th ventricle
Ventricles produce the cerebrospinal fliud
cerebral acqueduct
connects the 3rd and 4th ventricle
Layers of meninges
dura mater
arachnoid
pia mater
Dura mater
External meningeal layer - thickest layer
Arachnoid
intermediate meningeal layer (together with dura mater cover the surface of the brain)
transparent - can see blood vessels
pia mater
internal meningeal layer
adheres to surface of brain
only layer that goes into gyri and sulci
