Neuroanatomy

Question 1

Terminology for locations

Answer 1

anterior and posterior: front and behind
dorsal and ventral: back and belly
medial and lateral: midline and to the side

Question 2

Planes of the brain

Answer 2

horizontal (axial) section
Sagittal section: between the 2 hemispheres (> midsagittal or parasagittal)
Coronal (frontal) section: in the plane of the face

Question 3

The neural tube

Answer 3

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

Question 4

Divisions of the brain

Answer 4

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

Question 5

Where are the different ventricular spaces found

Answer 5

Lateral ventricles: telencephalon
3rd ventricle: diencephalon
Cerebral aqueduct: midbrain
4th ventricle: metencephalon and myelencephalon

Question 6

Thomas Willis

Answer 6

wrote Cerebri Anatome
discovered the flow of blood in the cerebral arteries
liked to used metaphors in his descriptions of the brain

Question 7

Shape of skull

Answer 7

shaped around the brain to protect it and has room for the spinal cord to go through it

Question 8

pterion

Answer 8

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

Question 9

Name the Meninges (& the spaces between them)

Answer 9

epidural space > Dura mater > subdural space > Arachnoid > subarachnoid space > Pia mater

Question 10

Dural invaginations

Answer 10

Falx cerebri (separating 2 hemispheres)
Falx cerebelli
Tentorium cerebelli (separating main hemispheres from herebellum)

Question 11

Tonsillar herniation

Answer 11

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

Question 12

Types of intracranial hemmorahage

Answer 12

epidural hematoma, subdural hematoma, subarachnoid hematoma

Question 13

Epidural hematoma

Answer 13

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

Question 14

Subdural hematoma

Answer 14

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

Question 15

Subarachnoid hematoma

Answer 15

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

Question 16

Arterial blood supply

Answer 16

Circle of Willis
Main cerebral arteries: Anterior, middle, posterior (and basilar)

/ _ \ --        --
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Question 17

Cortical lobes + separating structures

Answer 17

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)

Question 18

Function of the lobes

Answer 18

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

Question 19

Language areas

Answer 19

Broca’s area: difficulty speaking, Posterior part of inferior frontal gyrus

Wernicke’s area: speaking fluently, difficulty understanding, Posterior part of superior temporal gyrus

Question 20

Corpus callosum

Answer 20

Split brain patients
Hemispheres work independently

Question 21

Mammillary bodies

Answer 21

Recollective memory – recalling from past experience.
Wernicke-Korsakoff syndrome
> Thiamine B deficiency due to bad nutrition
> Bad nutrition due to alcoholism

Question 22

Homunculus

Answer 22

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

Question 22

Hippocampus

Answer 22

convoluted cortex in the inner round part of the brain

Question 23

Fornix

Answer 23

starts as 2 and connects into one and then back into 2

Question 24

Thalamus

Answer 24

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)

Question 25

Basal ganglia

Answer 25

Striatum > Putamen > Caudate nucleus > ventral striatum (nucleus accumbens) Globus pallidus Substantia nigra Nucleus subthalamus

Question 26

functions of the different lobes

Answer 26

parietal: attending to stimuli temporal: recognize stimuli frontal: planning responses to stimuli + future organization of behavior occipital: visual perception + multimodal sensory processing

Question 27

Cortex divisions

Answer 27

most cerebral cortex is made up of 6 layers called the neocortex Paleocortex: older cortex on the inferior and medial parts of the temporal lobe Archicortex: occurs in the hippocampus

Question 28

What is the internal capsule

Answer 28

axons descending from and ascending to the cerebral cortex assemble into another large fiber bundle tract called the internal capsule

Question 29

What does the entire blood supply of the brain and spinal cord depend on

Answer 29

two sets of branches from the dorsal aorta: 1) internal carotid arteries (anterior circulation, branch to form anterior and middle cerebral arteries) 2) vertebral arteries (posterior circulation, come together at the pons to form the basilar artery)

Question 30

Via which structure does blood from the anterior cirulation go from the brain back to the heart

Answer 30

via the jugular vein

Question 31

What are cisterns

Answer 31

places where the subarachnoid space enlarges to form collections of CSF (major arteries supplying the brain course through the subarachnoid space, making it a frequent site of bleeding following trauma)