Meningeal Coverings of the Brain & Spinal Cord

Question 1

Meninges Function

Answer 1

• Cover and protect CNS
• Protect blood vessels and enclose venous sinuses
• Contain CSF
• Form Partitions of the skull

Question 2

Three Layers of Meninges

Answer 2

Dura Mater - external, thick, dense fibrous (collagen) membrane
Pia - follows contours of brain closely (very hard to remove from brain)
Arachnoid Mater - attached to brain but doesn’t follow contours closesly

Question 3

Four Dura

Answer 3

Falx Cerebri - in longitudinal fissure; attached to crista galli

Tentorium Cerebelli - Horizontal fold, between cerebellum and cerebral hemispheres

Falx Cerebelli - along the vermis of the cerebellum

Diaphragma Selli - covers pituitary gland in the sella turcica

Question 4

Locations and function: Dural Sinuses

Answer 4

• Formed between periosteal and meningeal layers of dura

- Drain blood from brain back to venous system

Question 5

Name the Dural Sinuses (10)

Answer 5

• Superior Sagittal Sinus
• Inferior Sagittal Sinus
• Straight Sinus
• Occipital Sinus
• Confluence of Sinuses (Superior sagittal sinus & Straight sinus)
• Transverse Sinus
• Sigmoid Sinus
• Cavernous Sinus
• Superior Petrosal
• Inferior Petrosal

Question 6

Dural Sinus Flow

Answer 6

Inferior Sagittal Sinus - Straight Sinus - Confluence of Sinuses
Superior Sagittal Sinus - Confluence of Sinuses - Transverse sinuses - Sigmoid Sinus - Internal Jugular Vein

Question 7

Meningeal Headache

Answer 7

• stretch of dura due to a variety of conditions causes headache

Question 8

Migrane Headache

Answer 8

• Stretch of dura due to increased arterial supply

Question 9

Pia Mater

Answer 9

• Layer of delicate vascularized connective tissue that clings tightly to the brain

Question 10

Blood Brain Barrier - Function

Answer 10

Anatomical and physiological barrier that controls movement of extracellular fluid from general body spaces into the CNS
- Mainly formed by the pia mater and the tight junction between adjacent cells

Question 11

Denticulate Ligaments (Spinal Cord)

Answer 11

• Attach pia mater to arachnoid mater and through to dura

Question 12

Where does the spinal pia end?

Answer 12

Filum terminale

Question 13

Site of CSF sampling?

Answer 13

Lumbar cistern - region of spinal nerves only

Question 14

Intracranial Hemorrhage Types

Answer 14

Epidural - between skull and dura mater; lens shaped; usually due to blow to side of the head

Subdural - between dura and arachnoid mater; tearing of cerebral veins from rapid acceleration/deceleration (shearing force); crescent shaped

Subarachnoid Hemorrhage - between arachnoid and pia; sudden halt of head movement, damage to cortical veins draining into sinuses; debilitating headache/unconsciousness; Develop quickly