Section of brain😍

Coronal Section

Lateral Ventricles

• 2 lateral ventricles are present.
• Located in telencephalon (cerebral hemispheres).
• Both open into 3rd ventricle via the foramen of Monro.

• Floor of the Lateral Ventricle
• Formed by:
• Caudate nucleus
• Thalamo-striate vein
• Choroid plexus
• Thalamus

• Lateral ventricle has no lateral wall.

Septum pellucidum:

• Thin septum between right and left lateral ventricles.

• Foramen is present beneath it.

• Septum pellucidum and foramen forms medial wall of the lateral ventricle.

Transverse Section of Brain

Transverse Section of Brain

Corpus Callosum Connections

• Largest commissural fiber

• Connects the two cerebral hemispheres

• Develops from lamina terminalis
• Point where anterior neuropore closes

• Formation: between 12th to 16–20th weeks of gestation

 

ㅤ	Forms
Forceps minor	Anterior wall of anterior horn of lateral ventricle
Forceps major	Superior wall of posterior horn of lateral ventricle

Part	Connections	Named Fibers	Ventricular Relations
Genu	Frontal lobe	Forceps minor	• Anterior bend of CC
Body	Parietal / Temporal lobe	Tapetum fibers (laterally)	• Forms Roof of body of lateral ventricle • Connects Occipital to lower part of temporal lobe
Splenium	Occipital lobe (striate cortex)	Forceps major	• Thickest part Fibers form: • Bulb of posterior horn • Elevation on medial wall of posterior horn

• Tapetum fibers
• Tapetum fibers lie lateral to posterior horn
• Tapetum connects to occipital and lower temporal lobes

• Genu → Frontal → Forceps minor

• Body → Tapetum → Lateral wall/roof contribution

• Splenium → Occipital → Forceps major → Bulb of post. horn

Middle Part

• Internal capsule:
• White matter fibers between:
• Caudate nucleus
• Thalamus
• Lentiform nucleus

• External capsule: Present outside lentiform nucleus.

• Extreme capsule: Present outside external capsule.

• Claustrum:
• Thin sheet of grey matter.
• Between external and extreme capsule.

• Insula:
• Hidden lobe of cerebrum.
• Posterior insula: Granular
• Anterior insula: Agranular
• Forms base of Sylvian cistern
• Lies between frontal and temporal lobes
• Receives: from entire body
• Somatosensory
• Viscerosensory
• Homeostatic
• Nociceptive inputs

Loss of insular ribbon sign

Transverse Section of the Midbrain

• Dorsally: Superior Colliculi

• Ventrally: Interpeduncular fossa

Middle:

• Aqueduct of Sylvius
• Red nucleus: In the center
• Tectum: Behind aqueduct
• Tegmentum: In middle
• Cerebral peduncle: On either side of interpeduncular fossa
• Grey matter: Substantia nigra
• White matter: Crus cerebri

Substantia nigra

• In midbrain.

• Contains melanin (precursor of dopamine).

• Secretes dopamine

Transverse Section of Midbrain at Superior Colliculus

At the level of Superior colliculus	At the level of Inferior colliculus
• III cranial nerve orginates • 3 lemnisci • Red nucleus	• 4 lemniscus • 4th CN originates ↳ Has internal decussation ↳ Only CN with dorsal origin

Transverse Section of Midbrain at Inferior Colliculus

Questions

Transverse Section of Medulla

• Posteriorly
• Elevation → Rhomboid fossa → 4th ventricle

• Anteriorly → 2 elevations
• Pyramid
• Olive (due to inferior olivary nucleus)
• Crumpled paper bag shape
• (Dorsal nucleus also has crumpled paper bag shape)

Medial Surface of Cerebral Hemisphere

• Cingulate sulcus is in front of the corpus callosum.
• Forms Cingulate gyrus.
• Splits into 2 and encloses a lobule:
• Paracentral lobule.
• Represents perineum and lower limb.
• Highest center for urination and defecation
• Supplied by MCA

• Uncus
• Area 28: Primary Olfactory Area