Scalp

Question 1

What does the scalp extend to anteriorly?

Answer 1

Supra-orbital margins of frontal bone

Question 2

What does the scalp extend to posteriorly?

Answer 2

Superior nuschal line of occipital bone

Question 3

What does the scalp extend to laterally?

Answer 3

Zygomatic arches

Question 4

How many layers is the scalp made up of?

Answer 4

Five

Question 5

What are the five layers of the scalp?

Answer 5

Skin

Dense connective tissue

Epicranial aponeurosis

Loose areolar connective tissue

Pericranium

Question 6

How are the different layers of the scalp related to each other?

Answer 6

First three are connected to each other

Question 7

What does the dense connective tissue layer of the scalp contain?

Answer 7

Arterial blood supply

Sensory innervation

Question 8

What is the epicranial aponeurosis made up of?

Answer 8

Tendinous sheet

Question 9

What does the epicranial aponeurosis run between?

Answer 9

Frontal belly of occipitofrontalis

Occipital belly of occipitofrontalis

Question 10

How do the frontal and occipital bellies of occipitofrontalis affect the epicranial aponeurosis?

Answer 10

Frontal belly pulls it anteriorly

Occipital belly pulls it posteriorly

Question 11

What does the loose areolar connective tissue layer contain?

Answer 11

Potential spaces

Emissary veins

Question 12

What is the pericranium made up of?

Answer 12

Dense connective tissue

Question 13

How does the pericranium relate to the calvaria?

Answer 13

It is the periosteum of the calvaria

Question 14

What is the arterial supply of the scalp?

Answer 14

Supra-trochlear artery

Supra-orbital artery

Occipital artery

Posterior auricular artery

Superficial temporal artery

Question 15

What do the arteries supplying the scalp arise from?

Answer 15

External carotid artery

• occipital artery
• posterior aurticular artery
• superficial temporal artery

Internal carotid artery, opthalamic artery

• supra-trochlear artery
• supra-orbital artery

Question 16

What can the venous drainage of the scalp be divided into?

Answer 16

Superficial

Deep

Question 17

What is the superficial venous drainage of the scalp?

Answer 17

Veins accompanying arteries

have same name

Question 18

What is the deep venous drainage of the scalp?

Answer 18

Pterygoid venous plexus

Emissary veins

Question 19

What does the pterygoid venous plexus drain into?

Answer 19

Maxillary vein

Question 20

What do the emissary veins drain into?

Answer 20

Diploic veins

Question 21

Where are diploic veins located?

Answer 21

Diploic cavity of calvaria

Question 22

Where do the emissary veins travel?

Answer 22

From the veins of the scalp, through the outer table and diploic cavity of the calvaria
into the diploic veins

Question 23

Do emissary veins have valves?

Answer 23

No

Question 24

What do the diploic veins drain into?

Answer 24

Dural venous sinuses

Question 25

Where do the diploic veins travel?

Answer 25

From the diploic cavity, through the inner table, periosteal layer of the dura
into the dural venous sinuses

Question 26

How much does a scalp laceration bleed?

Answer 26

Bleeds a lot

Question 27

Why do scalp lacerations bleed a lot?

Answer 27

Lots of anastamoses between arteries supplying it

Walls of arteries attached to dense connective tissue, so cannot vasoconstrict to limit blood flow

Epicranial aponeurosis pulled in opposite directions by frontal and occipital bellies of occipitofrontalis, prevents closure of ruptured artery

Question 28

What is the danger area of the scalp?

Answer 28

Loose areolar connective tissue layer

Question 29

Why is the loose areolar connective tissue layer of the scalp known as the danger area?

Answer 29

Because blood and pus can easily accumulate and spread in it

Also contains emissary veins, which drain into the dural venous sinuses, so infection can spread into the cranial cavity

Question 30

Where can blood in the loose areolar connective tissue layer travel to?

Answer 30

Eyelids

Root of nose

Question 31

Why can blood in the loose areolar connective tissue layer spread to the eyelids and the root of the nose?

Answer 31

Because the occipitofrontalis muscle attaches to the skin and subcutaneous tissue, not bone

this creates a passageway for the blood into this area

Question 32

What is the sign of blood accumulated around the eyelids?

Answer 32

Purple-black colour around the eyes

called peri-orbital ecchymosis

Question 33

Where can infection in the loose areolar connective tissue layer of the scalp not travel to?

Answer 33

Neck

Question 34

Why can infection in the loose areolar connective tissue layer of the scalp not travel to the neck?

Answer 34

Because the occipital belly of the occipitofrontalis muscle inserts into bone

Because the epicranial aponeurosis is continuous with temporal fascia which inserts into the zygomatic arches

Question 35

Why does a haematoma in the dense connective tissue layer of the scalp form a tight lump?

Answer 35

Because the dense connective tissue layer contains lots of collagen fibres
these contain the blood
blood accumulates in a smaller area

Question 36

With a scalp laceration, how are the wound margins affected if they involve the epicranial aponeurosis? Why?

Answer 36

Wound margins are pulled apart
because of epicranial aponeurosis being pulled in opposite directions by frontal belly and occipital belly
this layer is connected to the more superficial layers of the scalp

Question 37

With a scalp laceration, how are the wound margins affected if they do not involve the epicranial aponeurosis?

Answer 37

Wound margins are held together
by the epicranial aponeurosis
since it attaches to the more superficial layers of the scalp