Neuroanatomy Cerebral Cortex & Ventricular System.

What structures make up the cerebrum?

• Cerebral cortex (gray matter)

• Underlying white matter

• Deep cerebral structures

What is the cerebral cortex?

The outer gray matter layer of the cerebrum.

-gyrus

-sulcus (fissure)

Why we have gyri and sulci?
(Why not a smooth surface brain?

Increasing the cortical area
for the total number of neurons

Structures of Major Sulci

• Longitudinal fissure

• Central sulcus (Rolando sulcus)

• Lateral sulcus (Sylvian fissure)

• Parieto-occipital sulcus

• Preocciptital notchus

Memory trick: LCLP

(Longitudinal → Central → Lateral → Parieto-occipital)

What does the central sulcus separate?

• Frontal lobe (anterior)

• Parietal lobe (posterior)

What does the lateral sulcus separate?

Frontal

parietal

temporal

What does the longitudinal fissure separate?

Left and right cerebral hemispheres.

4 main lobes

Frontal

parietal

occipital

temporal

For Major Gyri what is the precentral gyrus?

• Primary motor cortex

• Part of the frontal lobe

For Major Gyri what is the postcentral gyrus?

• Primary Somatosensory Cortex

• Part of the Parietal Lobe

Label Frontal Lobe

Lateral View

• Frontal Pole

• Precentral gyrus

• Precentral Sulcus

• Superior frontal sulcus

• Inferior frontal sulcus

• Superior frontal gyrus

• Middle frontal gyrus

• Inferior frontal gyrus : divided into 3 parts Orbital part, triangular part, Opercular part

Label Frontal Lobe

Medial View

• Anterior Paracentral Lobule

• Orbital gyri

• Olfactory Sulcus

• Gyrus Rectus

Frontal Lobe Functional Areas

• Primary Motor Cortex (M1): Pre-central gyrus: Sends out motor commands to your muscles

• Secondary Motor Areas: In frontal of pre-central gyrus: Motor planning planning

-Supplementary Area (SMA)

-Premotor Cortex (PMC)

• Broca’s Area: Controls your language motor output. around the inferior frontal gyrus, specifically the triangular part, opercular.

What is Motor homunculus?

Map that allows you to know on this primary motor cortex

KNEE TO TONGUE Look slide 15

Frontal lobe

Functional area PREFONTAL CORTEX parts

• Lateral part: DORSOlateral Prefrontal Cortex, VENTROlateral Prefrontal Cortex

• Medial part: DORSOmedial Prefrontal Cortex, VENTROmedial Prefrontal Cortex

• Orbitofrontal Cortex

Label Parietal Lobe

Lateral View

• Postcentral Gyrus

• Postcentral Sulcus

• Intraparietal Sulcus

• Superior Parietal Lobule

• Inferior Parietal Lobule

Label Parietal Lobe

Medial View

• Posterior Paracentral Lobule

• Precuneus

• Marginal branch of the Cingulate Sulcus

• Subparietal Sulcus

Parietal Lobe Functional Areas

• Primary Somatosensory Cortex: Sensory info

• Secondary Somatosensory Area: analyze sensory Info

Look at sensory homunculus page 25!

Label Temporal Lobe

Lateral View

• Temporal Pole

• Superior Temporal Sulcus

• Inferior Temporal Sulcus

• Superior Temporal Gyrus

• Middle Temporal Gyrus

• Inferior Temporal Gyrus

Label Temporal Lobe

Medial View

• Occipitotemporal Sulcus

• Occipitotemporal gyrus (parietal)

• Collateral sulcus

Temporal Lobe Functional Areas

• Primary Auditory Cortex: Identify auditory info

• Secondary Auditory Area: further analyze auditory info

• Wernicke’s Area: Understand language

• Rest parts:

-Middle Temporal Gyrus: Memory

-Inferior Temporal Gyrus: Process higher levels of visual info

Occipital Lobe

Lateral view

Lateral Occipital Gyri

Label Occipital Lobe

Medial View

• Occipitotemporal Gyrus (parietal)

• Lingual Gryus

• Calacrine sulcus: separates rest of occipital lobe into 2 areas

• Cuneus

Occipital Lobe

Functional Areas

• Primary Visual Cortex : Idenify & recieve visual info from eye nerve

• Seconday Visual Area: further analyze Visual info

Limibic Lobe is primarily composed of

• Cingulate Gyrus : Isthmus

• Parahippocampal Sulcus

Limbic Lobe is part of the what System

Limbic System; which contains hippocampus and amygdala

What is not part of the limbic lobe

• Corpus Callosum

• Callosal Sulcus

Label Limbic lobe

Subparietal sulcus

Cingulate sulcus and gyrus

paraterminal gyrus

subcallosal area

Corpus Callosum

Uncus

Rhinal sulcus

Parahippocampal Gyrus

Collateral sulcus

Isthmus

Where is the insula? and function

Deep inside the lateral fissure.

Interception (conscious awareness of body and sensation)

insula is covered by?

• Frontal operculum

• Parietal operculum

• Temporal operculum

Lateral ventricles shape and parts

Long C-shaped cavities

• 5 parts

• Anterior Horn (frontal horn)

• Body

• Posterior Horn( occipital horn)

• Atrium (trigone)

• Inferior horn (temporal horn)

Key Anatomical Relationship

• Roof of the anterior horn and body: CORPUS CALLOSUM

• Medial wall of anterior horn: SEPTUM PELLUCIDUM

• Floor and medial wall of the inferior horn : HIPPOCAMPUS

Third Ventricle shaped?

Narrow, slit -shaped cavity

Third Ventricle located where?

Located in the midline of the diencephalon

What connects the lateral ventricles to the third ventricle?

Interventricular foramina.

Third ventricle contains what space?

Interthalamic adhesion

Cerebral aqueduct is what?

Narrow Channel connecting the 3rd and 4th ventricles

Located behind the midbrain

most common site of ventricular obstruction

What surrounds the fourth ventricle?

Anterior:

• Pons

• Medulla

Posterior:

• Cerebellum

Fourth Ventricle “Open “ Cavity that communicates with

Subarachniod space through 1 MEDIAN APERTURE and 2 LATERAL APERTURES

What is the central canal?

Continuation of the fourth ventricle into the spinal cord.

Cerebropsinal Fluid

-Clear, colorless fluid

• 150 ml of CSF is present in adult CNS

• 25 ml is located within ventricles (only little in ventricles ). REMAINDER occupies the subarachnoid space

• Produced at 500 mL/day ( turned 3-4 times daily)

Cerebrospinal Fluid Functions

Provides buoyancy (SPATIAL BUFFERING) and supports for the CNS

Assists in the transport of nutrients and removal of waste products

Cerebrospinal Fluid all ventricles contain

highly vascular, folded structures called CHOROID PLEXUS( in all 4 ventricular), which produce CSF