Neuroanatomy

Medical surface (sagittal section) of the brain

What is the difference between medial and lateral?

Lateral view of the brain

What is the primary function of the brainstem?

It controls basic physiological functions such as respiration, cardiovascular regulation, and alertness.

Which vital functions does the brainstem regulate?

Respiration, cardiovascular activity, alertness, arousal, sleep, and pain sensitivity.

How does the brainstem interact with other brain regions?

It acts as an output centre for ‘newer’ brain regions, relaying signals to the body

What happens in the case of brainstem death?

Loss of all brainstem functions, leading to the inability to sustain independent life functions.

Where is the hypothalamus located?

The hypothalamus is located below the thalamus and above the brainstem, forming part of the diencephalon.

What does the Hypothalamus do?

• Bridge between neuro and endocrine
• Wired into pituitary, brainstem, autonomic
• Thermoregulation, Hunger, Thirst, etc

Where is the cerebellum located?

The cerebellum is located at the back of the brain, beneath the occipital lobes and behind the brainstem.

Motor coordination - role of the cerebellum (simplified)

Where are the ventricles in the brain located

The ventricles are deep within the brain: the lateral ventricles are in the cerebral hemispheres, the third ventricle is in the centre of the diencephalon, and the fourth ventricle is between the brainstem and cerebellum.

What fills the ventricles in the brain?

cerebrospinal fluid (CSF)

What produces cerebrospinal fluid (CSF)?

CSF is produced by ependymal cells, which line the ventricles.

What are the functions of cerebrospinal fluid (CSF)?

CSF acts as a shock absorber, supplies nutrients, and helps flush waste from the brain

How much cerebrospinal fluid (CSF) is present in the brain at any one time?

Around 125ml of CSF is present at any given time

How much cerebrospinal fluid (CSF) is produced daily?

Approximately 500ml of CSF is produced per day

Where is most cerebrospinal fluid (CSF) found?

Most CSF is found outside the ventricles, surrounding the brain and spinal cord.

Blood supply - main arteries

Circle of Willis

Meninges

Dural sinuses - venous drainage

Where is the thalamus located in the brain?

The thalamus is located deep in the brain, near the centre, just above the brainstem and between the cerebral hemispheres.

Recall the different cortexes of the brain

Where is the somatosensory cortex located?

The somatosensory cortex is located in the anterior parietal cortex, just behind the central sulcus.

What is the sensory homunculus?

The sensory homunculus is a map of the body in the somatosensory cortex, where different areas correspond to sensations from specific body parts.

Where is the motor homunculus located?

The motor homunculus is located in the posterior frontal cortex, specifically in the primary motor cortex (precentral gyrus).

What does the motor homunculus represent?

The motor homunculus is a map of the body in the primary motor cortex, showing which areas control movement in specific body parts.

Cerebral hemispheres

What is the corpus callosum?

The corpus callosum is a large bundle of nerve fibres that connects the left and right cerebral hemispheres, allowing communication between them

Where is the corpus callosum located?

The corpus callosum is located deep in the brain, beneath the cerebral cortex and above the ventricles.

What is dysarthria?

Inability to move the muscles of the face and tongue that mediate speaking

What is aphasia?

• Difficulty in naming objects

• Repetition of words is impaired

Wernicke’s Area

Broca’s Area

Broca vs Wernicke - Consequences of damage