Human Brain anatomy short answer question And Answers

Question 1. Describe superolateral surface of cerebrum.
Answer:

Cerebrum:

• Cerebrum is made of two cerebral hemispheres which are incompletely separated from each other by the median longitudinal fissure

External features:

• Each cerebral hemisphere has the following external features
• Three surfaces
  • Superolateral
  • Inferior
  • Medial
• Four borders
  • Superomedial
  • Inferolateral
  • Medial orbital
  • Medial occipital

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• Three poles
  • Frontal pole
  • Occipital
  • Temporal
• Four lobes
  • Frontal
  • Parietal
  • Occipital
  • Temporal
  • These lobes are best appreciated on the superolateral surface of cerebrum

 

Superolateral surface:

Question 2. Describe the gross features, relations, blood supply & constituent fibres of corpus callosum (or) Parts of corpus callosum
Answer:

Corpus Callosum:

• It is the largest commissure of the brain
• It connects the two cerebral hemispheres

Gross Features:

• Parts of corpus callosum
  1. Genu
     • It is the anterior end
     • It lies 4 cm behind the frontal pole
  2. Rostrum
     • It is directed downwards & backwards from the genu
  3. Trunk or body
     • It is the middle part between the genu & Splenium
     • Its superior surface is convex from before backwards & concave from side to side
     • Its inferior surface is concave from before backwards & convex from side to side
       Attachments:
     • It provides attachment to the septum pellucidum & the fornix
  4. Splenium
     • It is the posterior end forming the thickest part of the corpus callosum
     • It lies 6 cm in front of the occipital pole

Relations:

Fibres:

1. Forceps minor

• It is made up of fibres of the genu that connect the two frontal lobes

2. Forceps major

• It is made up of fibres of the Splenium connecting the two occipital lobes

3. Tapetum

• It is formed by some fibres from the trunk & Splenium
• It forms the roof & lateral wall of the posterior horn & the lateral wall of the inferior horn of the lateral ventricle

4. The Rostrum connects the orbital surfaces of the two frontal lobes

Question 3. Corpus callosum
Answer:

• It is largest commissure of the brain
• It connects the two cerebral hemispheres

Parts:

• Genu
  • It is the anterior end
  • It lies 4 cm behind the frontal pole
• Rostrum
  • It is directed downwards and backwards from the genu
• Trunk or body
  • It is the middle part between genu and splenium
  • Its superior surface is convex from before backwards and concave from side to side
  • Its inferior surface is concave from before backwards and convex from side to side
• Splenium
  • It is the posterior end forming the thickest part of the corpus callosum
  • It lies 6 cm in front of the occipital lobe

Fibres:

• Forceps minor
  • Made up of fibres of the genu that connect the two frontal lobes
• Forceps major
  • Made up of fibres of the splenium connecting the two occipital lobes
• Tapetum
  • Formed by some fibres from the trunk and splenium
  • Forms the roof and lateral wall of the posterior horn and the lateral wall of the inferior horn of the lateral ventricle
• The rostrum connects the orbital surfaces of the two frontal lobes

Question 4. Central sulcus
Answer:

Course:

• It begins at the superomedial border of the hemisphere a little behind the midpoint between the frontal & occipital poles
• It runs on the superolateral surface obliquely downwards & forwards & ends a little above the posterior ramus of the lateral sulcus

Question 5. Name the nuclei of cerebellum
Answer:

• Grey matter of cerebellum consists of four pairs of nuclei
• Nucleus dentatus – it is neocerebellar
• Nucleus globosus
• Nucleus emboliformis- paleocerebellar
• Nucleus fastigii- it is archicerebellar

Question 6. Name any four tracts passing through inferior cerebellar peduncle
Answer:

Afferent Tracts:

• Posterior spinocerebellar
• Cuneocerebellar
• Olivo cerebellar
• Parolivo cerebellar
• Reticulo cerebellar
• Anterior external arcuate fibres
• Striae medullares
• Trigemino cerebellar

Efferent Tracts:

• Cerebellovestibular
• Cerebelloolivary
• Cerebelloreticular

Question 7. Choroid plexus
Answer:

• The tela choroidea of fourth ventricle with vascular fringes is covered by secretory ependyma to form choroid plexus
• It consists of
  1. Vertical limb
     • Lies next to midline
     • Both sides limbs lie side by side to form T-shaped structure
     • This projects into subarachnoid space
  2. Horizontal limb
     • Extends into lateral recesses

Arterial supply:

• Posterior inferior cerebellar arteries

Question 8. Name arteries supplying pituitary gland
Answer:

• Pituitary gland is supplied by branches of internal carotid artery

Question 9. Name muscles supplied by spinal accessory nerve
Answer:

Muscles supplied by spinal accessory nerve are:

• Sternocleidomastoid
• Trapezius

Question 10. Name all cranial nerves
Answer:

• I – Olfactory nerve
• II – Optic nerve
• III – Oculomotor nerve
• IV – Trochlear nerve
• V – Trigeminal nerve
• VI – Abducent nerve
• VII – Facial nerve
• VIII – Vestibulocochlear nerve
• IX – Glossopharyngeal nerve
• X – Vagus nerve
• XI – Accessory nerve
• XII – Hypoglossal nerve

Question 11. Multipolar neuron
Answer:

• Multipolar neuron is a neuron having multiple processes
• Most of the neurons of man are of this type
• Example: all motor and internuncial neuron

Question 12. Parts of internal capsule
Answer:

Parts of Internal Capsule:

1. Anterior limb

• Lies between the head of the caudate nucleus and lentiform nucleus

2. Genu

• It is bend between anterior and posterior limb

3. Posterior limb

• It lies between thalamus and lentiform nucleus

4. Sublentiform part

• Lies below lentiform nucleus

5. Retrolentiform part

• Lies behind lentiform nucleus

Question 13. Name the branches of vagus in neck.
Answer:

Branches of vagus in neck

Question 14. Give any four muscles supplied by hypoglossal nerve.
Answer:

• Muscles supplied by hypoglossal nerve
• Extrinsic muscle of tongue – styloglossus, genioglossus, hyoglossus
• Intrinsic muscles of tongue superior longitudinal, inferior longitudinal, transverse and vertical muscles

Question 15. Name the muscles supplied by oculomotor nerve.
Answer:

• Muscles supplied by oculomotor nerve
• Superior rectus of eyeball
• Inferior rectus of eyeball
• Medial rectus of eyeball
• Inferior oblique muscle
• Part of levator palpebrae superioris

Question 16. Neuro biotaxis
Answer:

• Neurobiotaxis is the tendency for a neuron to grow and develop towards the neuron or tissue it will innervate.