Ventricles & CSF

Question 1

Parts of Lateral Ventricles (5)

Answer 1

Anterior (frontal) horn
Body (frontal and parietal lobes)
Posterior (occipital) Horn
Inferior (temporal) Horn
Antrum (trigone) - body, posterior horn, inferior horn connection

CSF - Lateral ventricles drain through interventricular foramina (of monro) into 3rd ventricle

Question 2

3rd Ventricle

Answer 2

Narrow slit-shaped ventricle of midline between diencephalon

CSF - caudal and inferior from foramina of Monro to Cerebral Aqueduct, through midbrain to 4th Ventricle

Question 3

4th Ventricle

Answer 3

Between cerebellum, pons, and rostral (open) medulla

Median aperture - Unpaired, medial
Lateral aperture - paired, lateral

CSF - from cerebral aqueduct caudal and inferior to both median and lateral apertures into subarachnoid space

Question 4

Function of the Choroid Plexus

Answer 4

Manufactures CSF within ventricles

Question 5

Describe the 3 layers of the Choroid Plexus

Answer 5

Ependymal Cells - transformed into secretory cells (surrounded by tight junctions)

Pia Mater - Incomplete

Capillaries - fenestrated (large holes) for fluid movement

Question 6

Location of the Choroid Plexus

Answer 6

• Floor of lateral ventricles & inferior horn
• Posterior wall of interventricular foramen
• Posterior roof of 3rd ventricle
• Posterior roof of 4th ventricle

Question 7

CSF Function

Answer 7

• Helps suspend the brain within the skull (making it “weightless”)
• Provides cushioning/shock absorption
• Regulates/maintains extracellular fluid
• Route for widely distributed chemical messengers

Question 8

Describe CSF

Answer 8

• Clear, colorless liquid, low in cell number and proteins; similar to blood plasma
• Ion concentration in CSF is very constant - even if plasma levels are fluctuating