brain structure

Question 1

Limbic system

basal ganglia functins

Answer 1

thamulus - priortises sensory imput - reduces sensory overload

thalamic stroke - differential diagnosis for neurological defiecets - infract in thamulus region

deep branches of posterior cerebral artery - supply thamaulus

Question 2

What is the Limbic system ?

Answer 2

Location - deep within the cerebral cortex , above brainstem.

FUNCTION

Regulating emotions & motivation e.g fear , anger , hunger , sexual behaviour.

0 Involved in memory & learning.

SOME OF THE IMPORTANT STRUCTURES IN LIMBIC SYSTEM.

0 Amygdala - bilateral - emotional center - learn to fear something.
(anger , fear , anxiety etc)
- Damage to this - cause disinhibited behaviours

0 Hippocampus - forming and storing new memory

& turning short memories to long term memory
( DAMAGE - ANTERIOR GRADE AMNESIA - inability to form new memories - keep old memories)

0 Fornix

0 Hypothamulus - endocrine system control

• autonomic system
  o temperature control , fight and flight response

0 Thalamus - relay station - sensory (expect smell) & motor info sent to and fro from cerebrum , spinal cord via thamulus etc.
- does not interpret , priotises info.(prevents senory overload)

0 Cingulate gyrus (just above corpus callosum)
- drive bodies conscious response to unpleasant experiences
(avoid negative consquences)

• aids in regulation of pain and emotion.

Question 3

Damage to thalamus ?

Answer 3

0 Sensory issues such as tingling, numbness,

0 hypersensitivity, and pain

0 Vision loss or light sensitivity

0 Motor impairments

0 Tremors

0 Attention problems

0 Memory loss

0 Insomnia

Because the thalamus controls sleep and arousal, severe damage to it can also result in a coma[4].

Question 4

What are the important nuclei of the thalaus

Answer 4

Lateral geniculate nucleus
1. optic nerve —————> chaism———————-> synapse in LATERAL GENICULATE NUCLEUS IN THALAMUS ———————> Primary visual cortex (occipital lobe)

Medial geniculate nucleus
1. Vesibularcochlea n.——————> goes through other stuff —————–> medial geniculate nuclues in thalamus ————————–> auditory cortex in temporal lobe.

Ventral , posterior Lateral N.
Ventral posterior Medial N.
————> sending info (pain , temp , priopreception, to somatosensory cortex in parietal lobe.

(VPM - sensation to head and neck , also send info to Primary gustatory complex( responsible for taste) (right near somatosensory)

VPL - sensation to periphery (body and extremeties)

Dorsal medial nuclues
(part of limbic system - relays info to and from there)
- determines how we feel about the sensations & controls inapporiate behaviour
- send efferent n. t frontal cortex , - so involved in attention, drive , motivation , inhibition.

0 Ventral Anterior
0 Ventral Lateral
(sending info to primary motor cortex)

VA —–> planning & complex behaviours

VL ———> Movement & language

Intralaminar n. - alertness and conciousness.

Question 5

mlml

Answer 5

Internal capsule separates thalamus from putamen & Globus Plallidus.

Internal capsule - projection fibres that connect cortex to spinal cord.

• as internal capsule / projection fibres move towards cortex become corona radiata

3 sections of internal capsule :

• Anterior limb
• genu
• posterior limb

in contains :
Frontopotine fibres - from frontal lobe to pons

• Corticobulbar tract (in genu)- head eqivalent to corticospinal tract (in posterior limb).

info to somatosensory cortex travels via internal capsule.