The Human Brain

Question 1

What are the components of the brainstem?

” hindbrain”

Answer 1

Midbrain, medulla, pons

Pons, medulla, cerebellum

Question 2

Primary Motor; somatosensory; auditory; visual cortices locations and arrangement?

Answer 2

Motor: Precentral gyrus; motor homunculus (lower third face, middle third hand/arm; final leg/trunk)

Somatosensory: postcentral gyrus; sensory homunculus (somatotopically)

Auditory: Transverse gyrus of Heschl; tonotopically

Visual: between calcarine sulcus (most medially); visuotopically arranged (peripheral is deeper) surrounded by supplementary cortices

Question 3

What are the verbal language association areas located on the dominant/left hemisphere?
note wernickes connected by arcuate fasciculus (conductance aphasia)

Answer 3

Wernickes: Speech recognition (sensory/fluent function). Damage would cause fluent aphasia
Brocas: Motor function of speech, IFG, non fluent aphasia
SMAGLA: On inferior parietal lobule, reading and writing recognition
Exners: motor function of writing

Question 4

What is represented in the non dominant (right) hemisphere and lesions can cause what?

Answer 4

Non verbal language (95%)- loss of
Emotional expression- speech lacks it
Spatial skills- disorientation and inability to recognise familiar objects
Conceptual understanding
Artistic/musical skills- loss of appreciation

Question 5

Frontal Association Cortex

Answer 5

Intelligence; mood; behaviour; cognitive function

Question 6

Parietal Association Cortex (sup lobule more?)

Answer 6

Spatial Skills; 3D recognition; shapes faces

Question 7

Temporal Association cortex (inferior area?)

Answer 7

memory; mood; aggression; intelligence

Question 8

What do the cerebral arteries contribute to laterally?

Answer 8

Anterior: leg thigh and foot in terms on homculus, stops at SPL
Middle: lateral 2/3 of the cerebral cortex. Stops at level of the ‘trunk’ (homunculus)
Posterior: Does visual cortex and lower part of temporal

Question 9

Cerebral Arteries and medial view

Answer 9

Anterior: From POS to frontal pole
Middle:
Posterior: primary visual cortex and supplementary cortices plus temporal lobe e.g mood memory.

Question 10

What are the two (broad) types of neurones in the brain (grey matter) and what are their characteristics?

Answer 10

Pyramidal neurons: Triangular base, with an apical dendrite and many basal dendrites. Have a long axon as such are efferent neurons, Connect with other parts of the cortex.

Granule/ Stellate neurones: Very small, round cells, small axon. Are local circuit neurones/ interneurons. Communicate with close neurons.

Question 11

What are association/ commissural fibres?

Answer 11

Pyramidal neurons (effferents) located in the layer in the neocortex.
Commissural: Efferent messages to the other hemisphere
Association: efferent messages to the same hemisphere

Question 12

What are projection fibres? (corticofugal)

Answer 12

Pyramidal neurons found in layer 5.

Long axons that communicate with the basal ganglia, thalamus, brainstem and spinal cord

Question 13

Where are the granule neurons located?

Answer 13

Layers 2 and 4`

Question 14

What are the two types of heterotypical cortex with examples?

Note thay homotypical cortex foud in parietal/temporal cortex and pre frontal

Answer 14

Agranular cortex: Increased pyramidal cell numbers in layers 3 and 5. Less granular cells, due to more outputs. Precentral gyrus, so primary motor cortex.

Granular cortex: Increased granular cells in layers 2 and 4, particularly 4. Less pyramidal. Found in the primary somatosensory (PoCG), visual (CS) and auditory (TGoH, STG) cortices.

Question 15

What pathway does the auditory pathway take through the thalamus?

Answer 15

Information goes through the medial geniculate body. Then information conveys to the primary auditory cortex. The PAC conveys fibres to the MGB to modulate what information it receives.

Question 16

What pathway does the visual pathway take through the thalamus?

Answer 16

To the LGB to the primary visual cortex. Note the visuoptopical arrangement and that vsual cortex has afferents to the LGB to modulate

Question 17

What pathway does movement control take through the thalamus?

Note that VA and VL arranged similar to PMC

Answer 17

The VA and VL take inputs fom the cerebellum and the basal ganglia both of which are involved with movement control. The thalamus then communicates with the primary motor cortex, which in turn can modulate what information it gets with the thalamus, or will send information to LMN’s.

Question 18

What pathway does sensory info take thrugh the thalamus?

Answer 18

Goes through VP then to the PSC. PSC has fibres to VP to modulate also (different parts of sensation).

Question 19

What is the ‘fan’ system of neurons as they track through the internal capsule?

Answer 19

Internal capsule is only connecting point of cortex to thalamus/basal ganglia and other structures below.

Corona Radiata

Question 20

What are the different compartments of the anterior limb?

Answer 20

Anterior limb
Genu
Posterior Limb
Retrolenticular
Sublenticular