scalp

Question 1

where does the scalp extend from?

Answer 1

it extends from the supra orbital margin anteriorly to external occipital protudance and superior nuchal line posteriorly on each side to superior temporal line

Question 2

what are the layers of the scalp?

Answer 2

1. ) skin
2. ) connective tissue
3. ) aponeurosis (epicranial)
4. )loose areolar tissue
5. ) pericranium

Question 3

describe the skin.

Answer 3

which and hairy

firmly attached to the epicranial aponeurosis through dense fascia

has a lot of sebaceous glands which is why sebaceous cyst is common

Question 4

describe connective tissue .

Answer 4

it is made of fibrous fascia and septa which unite the skin and the underlying aponeurosis of the occipitofrontalis muscle

it contains a lot of arteries and veins

bleeding in this area can be stopped by applying local pressure

Question 5

why is it difficult to stop bleeding of a scalp wound?

Answer 5

because the arterial walls are attached to fibrous septa

Question 6

describe the structure of the aponeurosis (epicranial) .

Answer 6

thin , sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle

lateral margins of aponeurosis are attached to the temporal fascia

Question 7

what is the subaponeurotic space ?

Answer 7

potential space beneath the spicranial aponeurosis

Question 8

describe the structure of the occipitofrontalis .

Answer 8

frontal and occipital bellies of the occipitofrontalis are connected by the aponeurosis .

it consists of four bellies . 2 occipital and 2 frontal

the occipital bellies are smaller and arise from the nuchal line on the occipital bone and pass forward to be attached to the aponeurosis

the frontal bellies are larger and closer to each other . they arise from the skin and superficial fascia of the eye brow and pass backwards to be attached to the aponeurois

Question 9

how is the occipital belly supplied with nerves ?

Answer 9

by the posterior auricle branch of the facial nerve

Question 10

how is the frontal bellied supplied with nerves?

Answer 10

by temporal branch of facial nerve

Question 11

describe the loose areolar tissue .

Answer 11

it is called the dangerous area of the scalp

occupies the subaponeurosis space and extends anteriorly to the eyelids

contains emissary veins

Question 12

what are emissary veins ?

Answer 12

valveless veins that connect the superficial veins of the scalp with the diliic veins of the skull bones

Question 13

why is the loose areolar tissue called the dangerous are of the scalp?

Answer 13

because infections can spread to sinuses (inter cranial venous sinus ) and cause sinus thrombosis through the emissary veins .

Question 14

what paths can an infection in the scalp take?

Answer 14

an infection or fluid can spread only to the eyelids and the roof of the nose because of the attachment of the frontal into the skin and not the bone .

it cannot spread posteriorly into the neck because of the attachment of occipitals muscle to the occipital temporal bone

nor laterally because of the attachment of aponeurosis to temporal fascia

Question 15

what covers the outer surface of the skull?

Answer 15

pericranium is the periosteum covering the outer surface of the skull bones .

the periosteum on the outer surface of the bones becomes continuous with the periosteum on the inner surface of the skull bones .THEREFORE if there is any fluid collection beneath the pericranium (Cephalhaematoma) it will take the shape of the related bone
.

Question 16

what are the 5 arteries on each side of the scalp?

Answer 16

3 in front auricle :

1. ) supratrochlear
2. )supraorbital
3. ) supratemporal

2 behind auricle :

1. )post auricle
2. )occipital

veins follow the artery

Question 17

list all the nerves in the scalp.

Answer 17

in front of auricle :

1. )supraatrochlear nerve (S)
2. )supraorbital nerve (S)
3. )auriculotemporal nerve(S)
4. )Temporal branch of facial nerve (M)

behind auricle :
1.) lesser occipital nerve (S)

2. ) Greater occipital nerve (S)
3. ) Third occipital nerve (S)
4. ) posterior auricular branch of facial nerve (M)

Question 18

what are the lymphatic drainage area in the scalp?

Answer 18

anterior: preauricular (parotid)group of lymph nodes

posterior part :
posterior(mastoid) group of lymph nodes and occipital group of lymph nodes