CNS Neuroanatomy Flashcards
What is the cranium?
Surrounds the brain
What is the vertebral column?
surrounds the spinal cord
What are the meninges?
The meninges are three connective tissue membranes that separate the soft tissue of the CNS from the surrounding bone
Where is the cerebrospinal fluid?
fills the subarachnoid space
What is the function of CSF?
provides a cushion of protection around the CNS and nourishment for the neural tissues
What are the three meninge layers?
Dura mater- outer layer
Arachnoid- middle layer
Pia mater- inner layer
What meningeal layers make up the leptomeninges?
the arachnoid and pia mater
What are the functions of the meninges?
- production, circulation and reabsorption of CSF
- Conveys arterial vesselsinto nervous tissue and return of venous blood via dural sinuses
- Anchors the brain and spinal cord within the cranial and spinal cavities
What are the two layers of the dura mater?
the periosteal and meningeal layer
Where is the periosteal layer of the dura mater?
outer layer, closest to the skull
Where is the meningeal layer of the dura mater?
inner layer, closely affiliated with the arachnoid layer
What is the function of dural reflections?
to stabilize the brain with in the cranium
What is the function of dural sinuses?
to reabsorb CSf and venous and blood
What meningeal layer is the highest level of the innervation?
dura mater
What is the falx cerebri?
The dural refleciton between the two cerebral hemispheres, within the mid-sagittal plane
What is the tentorium cerebelli?
The transverse dural reflection between the cerebrum and cerebellum
What is an epidural hematoma?
When blood collects between the skull and dura mater.
what is a subdural hematoma?
when blood collects between teh dura mater and arachnoid space.
What can subdural and epidural hematomas cause?
can lead to neurological abnormalities associated with space occupying lesion or oxidative damage
What is a falcine herniation?
Where one cerebral hemisphere tries to sneak over to the opposite side
What is a calvarial brain herniation?
When there is herniation through the calvarium (skull cap) via fracture in the skull
What is a transtentorial brain herniation refer to?
relating to the tentorium cerebelli
What is a foramenal brain herniation refer to?
relating to the foramen magnum
What is the subarachnoid space?
located between the arachnoid cellular layer and pia mater, contains CSf
What are arachnoid trabeculae?
Filaments that extend toward the pia mater from teh arachnoid cellular layer.
Where are the arachnoid trabeculae located?
In the subarachnoid space
What structure reabsorbes CSF from the subarachnoid space?
arachnoid villi
hwen does CSF reabsorption occur?
When pressure in the subarachnoid space is greater than pressure in the dural sinus
What are cisterns?
Regions of dilation of the subarachnoid space.
Where is the cerebellomedullary cistern located?
between the cerebellum and medulla oblongata, near the region of the foramen magnum
**can be used for CSF collection
Which meningeal layer follows the brains gryi and sulci as well as the arteries penetrating brain tissue?
pia mater
Pia mater capillaries project into brain ventricals to form
teh choroid plexuses
What kind of cells line pia mater capillaries, involved in CSf production?
ependymal cells
Where (location) is CSF produced?
in the brain ventricles via choroid plexuses and the central canal fo the spinal cord
Where does CSF Circulate?
in teh ventricular systema nd central canal
How does CSF enter the subarachnoid space?
Lateral apertures (foramina of Luschka)- openings of the 4th ventricle
Where are the lateral centricles located?
Within each cerebral hemisphere
How do the lateral ventricles communicate with third ventricle?
the interventricular foramen
how does the third ventricle communicate with the fourth ventricles?
mesencephalic aqueduct (cerebral aquaduct)
Where sit he fourth ventricles located?
Between the ponsa nd cerebellum, extends to teh medulla oblongata
What is the obex?
where the fourth ventrical is continuous with the central canal of the spinal cord
The spinal mengines consist of what layers?
teh three same layers as the cranial menginges: dura, arachnoid and pia
Where is the epidural space of the spinal meninges?
between the dura and periosteal covering of the certebral canal
What exists within the epidural space?
blood vessels and structural fat
How does the spinal dura mater stabilize the spinal cord?
cranially is continuous with the occipital periosteum and caudally attaches to the caudal vertebrae
Denticulate ligaments are part of which spinal meningeal layer?
pia mater
What are teh denticulate ligaments?
segmental extension of the spinal pia mater that fuse with teh arachnoid/dural layers
What laterally stabilizes the spinal cord?
teh denticulate ligaments
What ist eh filum terminale?
a delicate strand of pia that extends from the conus medularis to its attachment at the caudal vertebrae
What is the gray matter of brain tissue consist of?
cell bodies within nuclei and dendrites of neurons
What is the white matter of brain tissue consist of?
axons within tracts, most of which are myelinnated
Axon tracts allow?
for communication between different regions of the CNS
The two hemispheres of the cerebrum communicate via which tract?
corpus callosum
What are gyri?
elevated folds of the convolutions of the cerebrum
what are sulci?
depressed grooves of the cerebrum
The surface of the cerebrum is comprised of gray matter, referred to as
the cerebral cortex
What are the three clusters of nuclei embedded deep wihtin teh white matter of the cerebrum (basal nuclei_
caudate nucelus, putamen, globus pallidus
A lesion to the cerebrum can produce clinical signs associated with?
difficulty in initiating movement or abnormal delivery of movement (ie, Parkinsons in humans)
The sensory fields of the cerebral cortex are involved in
perception of external stimuli
The motor areas of the cerebral cortex are invovled in
movement of skeletal muslce
The association areas of the cerebral cortex are involved in
integration of sensory info and planning of voluntary movement, memory, reasoning, verbalizing, judgement, and emotion
What is the internal capsule of the cerebrum?
white matter of the cerebrum that contains specific tracts
What is the function of the cerebellum?
posture and movement coordination
How does the cerebellum communicate with other parts of the CNS?
Via three pair of nerve tracts called cerebellar peduncles
Rostral, caudal and Middle
What are the four parts of teh brain stem?
- diencephalon
- mesencephalon
- pons
- medulla oblongata
What makes up the diencephalon?
thalamus, hypothalamus, epithalamus
What makes up the mesencephalon?
corpora quadrigemina (rostral and caudal colliculus)
What is the function of the thalamus?
it is the relay center for all afferent (sensory) information except smell
What is the function of the hypothalamus?
homeostasis
How does the hypothalamus communicate with the pituitary gland?
via teh infundibulum
What are the optic tracts/optic chiasm responsible for?
visual sensory
What are the mammilary bodies of the hypothalamus responsible for?
the relay of information from the limbic system and emotion
What is the function of the epiphysis (pineal gland)?
melatonin secretion, circadian rhythms, circannual rhytms and estrus
What is the rostral colliculus responsible for?
visual reflexes
What is the caudal colliculus responsible for?
auditory reflexes
What are teh three regions of the cereral cortex?
Neocortex, paleocortex and archicortex
What the function of the paleocortex of the cerebral cortex?
olfactory funciton
What are the five cortical lobes?
occipital, parietal, frontal, temporal and piriform
What is the function of the occipital lobe?
conscious perception of visual infomration
Where are voluntary and involuntary motor response to visual stimulation generated?
occipital lobe, cerebral cortex
Lesions to the visual cortex of the occipital lobe can cause
cortical blindness
Is PLR normal in a lesion to the visual cortex of the occipital lobe?
yes
What is the function of the parietal lobe?
conscious proprioception: perception of touch, pain, pressure, temperature and noxious stimuli
What lobe is responsible for producing a 3D map of the body’s location in space and its relation to objects in that space?
parietal lobe
Lesions to the parietal lobe cause
abnormalities in spatial perception or delayed intiation of postural reactions
What is the function of the frontal lobe?
voluntary motor functions, behavior and planning nad initation of movement
Lesions to the frontal lobe cause
delay of movement initiation, changes in behavior and contralateral clinical signs
What is the function of the temporal lobe?
perception and interpretation of auditory infomration
Will destruction of one auditory cortex produce deafness?
NO
What is the function of the piriform lobe?
perception and interpretation of olfactory information
Lesion to the piriform lobe can cause
reduce or loss of smell
What lobe plays a major role in survival
piriform lobe
What is the function of the limbic system?
Survival drive and emotion
The limbic system is composed of:
hypothalamus, amygdala, hippocampus, cingulate gyrus and thalamus
What is the function of the amygdala?
emotional memory, aggression
What is the function of the hippocampus?
short term memory to long term
What is the function of the cingulate gyrus?
emotion
How is the limbic system connected to the thalamus?
mammillothalamic tract
What part of the brain is responsible for waking up teh cerebral cortex?
RAS of the thalamus
What spp. is the rete mirabile present in?
cat, pig and ruminants
Venous return from the brain via
the dural sinuses
What is the primary blood supply to the spinal cord?
ventral spinal artery
What is the secondary supply to the spinal cord?
dorsal spinal arteries
Where is the internal certebral venous plexus located?
Within the epidural space
- risk for puncturing with CSF tap
