Central Nervous System (CNS) Overview

Flashcards covering key concepts about the Central Nervous System (CNS), its structures, functions, and relevant medical conditions based on the lecture notes.

What two structures make up the CNS?

The brain and spinal cord.

What are the meanings of rostral and caudal?

Rostral refers to the front end or 'toward the nose,' while caudal refers to the back end or 'toward the tail.'

What region comprises the bulk of the volume of the human brain?

The cerebrum.

What is the difference between a gyrus and a sulcus?

A gyrus is a raised ridge on the brain's surface, while a sulcus is a groove that separates gyri.

What is a fissure in the brain?

A deep groove that separates large sections of the brain.

What is the difference between nuclei and tracts in the brain?

Nuclei are clusters of neuronal cell bodies, whereas tracts are bundles of axons.

Compare and contrast grey and white matter in the brain.

Grey matter contains neuronal cell bodies and is involved in processing information, while white matter consists of myelinated axons and facilitates communication between different brain regions.

List the three meninges.

Dura mater, arachnoid mater, and pia mater.

Which of the three meninges is located deepest (closest to the brain)?

Pia mater.

Under which layer does CSF circulate?

In the subarachnoid space, between the arachnoid mater and pia mater.

Under which of these layers are the dural sinuses located?

In the dura mater.

Where would a subdural hematoma occur if someone got hit in the head?

Between the dura mater and the arachnoid mater.

Label the locations of the Lateral ventricle, Third Ventricle, and Fourth Ventricle.

Lateral ventricle is in each hemisphere; Third Ventricle is in the center of the brain; Fourth Ventricle is between the brain stem and cerebellum.

What two ventricles of the brain are connected by the Interventricular foramen?

The lateral ventricles.

What two ventricles of the brain are connected by the Cerebral aqueduct?

The third ventricle and the fourth ventricle.

What might happen if the Interventricular foramen or Cerebral aqueduct were to become occluded?

It could lead to an increase in cerebrospinal fluid (CSF) pressure, causing hydrocephalus.

Where is cerebrospinal fluid made?

In the choroid plexus of the ventricles.

How is cerebrospinal fluid circulated, and what is its purpose in the CNS?

It's circulated through the ventricles and subarachnoid space and serves to cushion and protect the brain, as well as to remove waste.

What is the role of arachnoid villi and arachnoid granulations?

They help in the reabsorption of cerebrospinal fluid into the venous system.

What causes hydrocephalus?

Obstruction of cerebrospinal fluid flow or absorption.

Describe the pathophysiology of meningitis. Why might a spinal tap be performed?

Meningitis is inflammation of the meninges, often caused by infection; a spinal tap may be performed to collect CSF for diagnostic testing.

Compare and contrast the structures and functions of the blood-brain barrier and the blood-CSF barrier.

The blood-brain barrier protects the brain by limiting substances that can enter, formed by tight junctions in brain capillaries; the blood-CSF barrier is formed by choroid plexus epithelial cells and controls the composition of CSF.

What are circumventricular organs (CVOs)?

Brain structures that lack a blood-brain barrier, allowing for the monitoring of blood composition and regulation of homeostatic functions.

What are fenestrated capillaries?

Capillaries with small pores that allow for the exchange of substances; found at CVOs for easier access to the bloodstream.

Which portions of the brain make up the brain stem?

The midbrain, pons, and medulla oblongata.

What functions is the midbrain responsible for?

Visual and auditory processing, as well as motor control.

What is the major function of the pons?

The pons is involved in regulating breathing and relaying signals between different parts of the brain.

Which portion of the brain stem adjusts the force and rate of heartbeat, vomiting, sneezing, etc.?

The medulla oblongata.