Scalp, Cranial Cavities & Meninges

Question 1

What is the scalp?

Answer 1

Consists of skin & subcutaneous tissue from the superior nuchal line of the occipital bone to the supraorbital margins of the frontal bone

Question 2

What are the 5 layers of the scalp, from outer to inner?

Answer 2

Skin, (Dense) Connective Tissue, Epicranial Aponeurosis, Loose Connective tissue, Pericranium

Question 3

What is the dense connective tissue in the scalp?

Answer 3

Subcutaneous layer rich in neurovascular structures

Question 4

What is epicranial aponeurosis?

Answer 4

Tendon & muscle of the occipitofrontalis, prevents superficial wounds from gaping open

Question 5

What is the loose connective tissue in the scalp?

Answer 5

Loose areolar tissue that allows free movement of outer layers over the underlying calvaria (skull)

Question 6

What is the pericranium?

Answer 6

The external periosteum of the skull (vascular connective tissue)

Question 7

what are emissary veins and why are they important?

Answer 7

Emissary veins allows for venous communication between the veins of the scalp and dural venous sinuses

Question 8

What is the cutaneous nerve supply for the face & scalp?

Answer 8

Innervated by CN V (v1, v2, v3) & Cervical nerves C2 & C3

Question 9

What is the arterial supply for the face & scalp?

Answer 9

Internal Carotid Artery:
- Supraorbital artery
- Supratrochlear artery

External Carotid Artery:
- Superficial temporal artery
- Posterior auricular artery
- Occipital artery

Question 10

What is the venous drainage of the face & scalp?

Answer 10

Venous is the same as the arterial

External jugular vein:
- Supraorbital vein
- Supratrochlear vein
- Superficial temporal vein
- Posterior Auricular vein

Internal jugular vein:
- Occipital vein

Question 11

what is the lymphatic drainage of the scalp?

Answer 11

2 means of lymphatic drainage:-

Posterior: Mastoid & occipital nodes drain to deep cervical nodes

Anterior: Pre-auricular & parotid nodes

Question 12

what are the 3 cranial fossae within the skull?

Answer 12

Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa

Question 13

What are the main components & features of the anterior cranial fossa?

Answer 13

• Frontal, ethmoid & sphenoid bones
• Shallowest part of the cranial base
• Occupied by frontal lobes

Question 14

What are the main components & features of the middle cranial fossa?

Answer 14

• Sphenoid & temporal bones
• Occupied by temporal lobes

The HYPOPHYSEAL (pituitary) fossa houses the pituitary gland

Question 15

What are the main components & features of the posterior cranial fossa?

Answer 15

• Sphenoid, occipital & temporal bones
• Occupied by the cerebellum & brainstem

Foramen magnum (brainstem passes through)

Question 16

What are bone buttresses?

Answer 16

Thicker portions of cranial bone (pillars) that transmit forces around weaker regions of the cranium (bypassing orbits & nasal cavity)

Question 17

what are the types of buttresses? (Hint: Around 4 of them)

Answer 17

• Frontosagittal buttress
• Occipital buttress
• Frontonasal buttress
• Zygomatic arch-lateral orbital margin buttress

Question 18

Describe the order of meninges? (Starting inside to outside)

Answer 18

Pia mater -> Subarachnoid space -> Arachnoid mater -> Dura mater

Question 19

What is dura mater?

Answer 19

Outermost layer that lies under the periosteum (bone of skull). In contact with the arachnoid mater below it

Question 20

What is arachnoid mater?

Answer 20

• Lines the dura mater
• Has a spider like resemblance [arachne - spider]

Question 21

What is the subarachnoid space?

Answer 21

• Fluid filled space containing CSF & blood vessels
• Arachnoid villi reabsorb CSF into the venous system

Question 22

What is the pia mater?

Answer 22

• thin membrane attached to surface of brain
• adheres to brain surface as it enters the sulci of the brain

Question 23

What is the blood supply of the dura & calvaria?