Neuroanatomy Flashcards
Terminology for locations
anterior and posterior: front and behind
dorsal and ventral: back and belly
medial and lateral: midline and to the side
Planes of the brain
horizontal (axial) section
Sagittal section: between the 2 hemispheres (> midsagittal or parasagittal)
Coronal (frontal) section: in the plane of the face
The neural tube
4 embryological divisions of the CNS
> 3 develop into the brain:
- prosencephalon (forebrain)
(telencephalon, diencephalon)
- mesencephalon (midbrain)
- rhombencephalon (hindbrain)
(metencephalon, myelencephalon)
> rest gives rise to spinal cord
Lumen of the tube remains in the adult brain as the ventricles filled with CSF
Divisions of the brain
Telencephalon: cerebral cortex, basal ganglia, amygdala, basal forebrain
Diencephalon: thalamus, hypothalamus, retina
Midbrain: superior and inferior collucili, red nucleus, substantia nigra
Metencephalon: pons, cerebellum
Myelencephalon: medulla oblongata
Brain stem: midbrain, pons, medulla
Where are the different ventricular spaces found
Lateral ventricles: telencephalon
3rd ventricle: diencephalon
Cerebral aqueduct: midbrain
4th ventricle: metencephalon and myelencephalon
Brainstem
> target or source for the cranial nerves that deal with sensory and motor function in the head and neck
provides a ‘throughway’ for all of the ascending sensory tracts from the spinal cord; sensory tracts for the head and neck; the descending motor tracts from the forebrain; and the local pathways that link eye movement centers
regulating the level of conciousness
Thomas Willis
wrote Cerebri Anatome
discovered the flow of blood in the cerebral arteries
liked to used metaphors in his descriptions of the brain
Shape of skull
shaped around the brain to protect it and has room for the spinal cord to go through it
pterion
junction where all different skull lobes come together = most vulnerable part of skull, relatively thin, major artery is right there
located just behind the temple
Name the Meninges (& the spaces between them)
epidural space > Dura mater > subdural space > Arachnoid > subarachnoid space > Pia mater
Dural invaginations
Falx cerebri (separating 2 hemispheres)
Falx cerebelli
Tentorium cerebelli (separating main hemispheres from herebellum)
Tonsillar herniation
happens next to brain stem
> brain is pushed so it gets stuck to dura
Tonsillar herniation of the cerebellum: it is the worst because it puts pressure on the brainstem (gets compressed) = vital functions can just stop e.g heart rate, breathing
Solution: surgery to release pressure
Types of intracranial hemmorahage
epidural hematoma, subdural hematoma, subarachnoid hematoma
Epidural hematoma
Cause: Severe trauma
Image manifestation: Small compartment (looks like bulge into brain)
Artery affected: Often a. meningia media
Clinic: lucid interval (period where it seems as though they are getting better)
Epidemiology: Often in children
Subdural hematoma
Types: acute or chronic
Image manifestation: larger area, less comparmentalized (long and skinnyish)
Indicator: Bridging vein
> With atrophy, brain is shrinking but all veins connected to skull gain pressure = they then snap
> Bridging veins can rupture all at once in acute vs in chronic over time
Epidemiology: Often in elderly or alcoholics with atrophy
Subarachnoid hematoma
Cause: Often aneurism
Image manifestation: dura compartmentalized is affected (Existing compartment), hematoma in dural folds
Indicator: Blood in liquor space (CSF)
Clinical picture:
– vomiting
– loss of consciousness
– severe headache
Arterial blood supply
Circle of Willis
Main cerebral arteries: Anterior, middle, posterior (and basilar)
/ _ \ -- -- m
Cortical lobes + separating structures
Frontal, parietal, temporal, occipital (insula)
Sylvian fissure between frontal and temporal
Central sulcus between frontal and parietal
Parieto-occipital sulcus between parietal and occipital
Temporal parietal notch between temporal and parietal and occipital (highest point in curve)
Function of the lobes
Occipital cortex: visual processing
Parietal cortex: somatosensory processing, visuospatial processing
Temporal cortex: understanding of language (not production), auditory, memory
Frontal cortex: executive functioning
Insula (cortex): limbic, autonomic functions, cognition, a lot of things
Language areas
Broca’s area: difficulty speaking, Posterior part of inferior frontal gyrus
Wernicke’s area: speaking fluently, difficulty understanding, Posterior part of superior temporal gyrus
Corpus callosum
Split brain patients
Hemispheres work independently
Mammillary bodies
Recollective memory – recalling from past experience.
Wernicke-Korsakoff syndrome
> Thiamine B deficiency due to bad nutrition
> Bad nutrition due to alcoholism
Homunculus
parts of your body are mapped into the primary motor cortex and primary somatosensory cortex e.g your leg movement and sensation lies along the midline of the two hemispheres
Hippocampus
convoluted cortex in the inner round part of the brain
Fornix
starts as 2 and connects into one and then back into 2
Thalamus
is a subcortical region
Central station
> Lots of connections going in and out, projecting to diff regions of brain
> Highly connected consisting of subdivisions connected to other regions
Located under the lateral ventricles (big patch)
Basal ganglia
Striatum
> Putamen
> Caudate nucleus
> ventral striatum (nucleus accumbens)
Globus pallidus
Substantia nigra
Nucleus subthalamus
