Scalp

Question 1

Extent of the scalp

Answer 1

• Superior nuchal line
• Supraorbital margins
• Superior temporal line

Question 2

Layers of the scalp

Answer 2

• Skin
• Dense connective tissue
• Aponeurosis
• Loose connective tissue
• Pericranium

Question 3

Skin

Answer 3

• Thin (except in occipital region)

- Contains sweat and sebaceous glands and hair follicles

Question 4

Dense connective tissue

Answer 4

• Thick, richly vascularised subcutaneous layer
• Well supplied with cutaneous nerves
• Abundant arterial supply
• Good venous and lymphatic drainage

Question 5

Aponeurosis (epicranial)

Answer 5

• Strong tendinous sheet that covers the calvaria

- Broad intermediate tendon of occipitofrontal/epicranius and superior auricular muscle

Question 6

Loose connective tissue

Answer 6

• Sponge-like layer which allows free movement of scalp proper (SCA) over underlying calvaria
• Potential spaces that may distend with fluid (injury/infection)

Question 7

Periosteum/cranium

Answer 7

• Dense CT layer of cranium

- Continuous with fibrous tissue of cranial sutures

Question 8

Innervation of the scalp

Answer 8

• Anterior: CN V1,2,3
• Posterior: C2,3 (ant. and post. rami)
• C1 has almost no dermatomal innervation

Question 9

Arterial supply

Answer 9

Branches of ECA:
- STA, posterior auricular, occipital
Branches of ICA:
- supratrochlear, supraorbital 
- Rich anastomoses in dense CT
- Regulates body temperature

Question 10

Venous drainage

Answer 10

• Anastomose and form posterior auricular and retromandibular veins (EJV)
• Anastomose with diploid veins in the skull (drain to venous sinuses) through valveless emissary veins