Clinical anatomy of
scalp
1. Which layers of scalp is known as dangerous
layer of scalp?
·
4th layer, the subaponeurotic
layer of scalp is known as dangerous layer of scalp.
·
Why
?
·
Due to loose spaces blood and pus tent to
collect in this space and this space contain emissary veins which connect veins
of scalp to the venous sinuses of cranium. So infection from this layer spread
into the venous sinuses of cranium.
2. Functional importance of sub aponeurotic
layer of scalp
·
In case children injury of vault, blood from
intra cranial hematoma accumulate in 4th layer of scalp, so no sign
of intracranial pressure rise was seen
3. Why bleeding
under surface of periosteum of skull bone cause cephalohaematoma
It is a hemorrhage of blood between the skull and the
periosteum of particular skull bones. It is a typically harmless condition that causes
blood to pool under a newborn's scalp after a difficult vaginal delivery.
Periosteum of skull bone, the innermost layer of scalp is loosely attach to
bone except near the suture, so hemorrhage below this layer make shape of
individual bone. It is more see in parietal region.
4. Why a blow on head
lead to “black eye’ ?
·
Injury of the scalp causes collection of
blood into the 4th layer of scalp, the sub-aponeurotic layer of
scalp. Frontalis muscle which cover part of forehead of scalp has no bony
attachment and due to gravity blood accumulated in the scalp go downward and
accumulate under the eye.
5. After scalp injury,
why blood accumulate under the eye but not goes laterally and posteriorly.?
·
The epicranial aponeurosis of scalp and
occipitalis muscles have bony attachments to superficial temporal lines and
superior nuchal lines, so blood cannot go laterally and posteriorly but frontalis muscle has no bony attachment
so blood always track downward and settle under the eye.
6. Why wounds of scalp
bleed profusely?
·
It has two causes
·
The scalp is rich in blood supply
·
For epicranial aponeurosis (or galea
aponeurotica) which is a tough layer form by dense fibrous tissue and scalp blood vessel adhere with it which
prevent vasocontriction , so scalp injury bleed more.
7. Why transverse scalp injury tend to create more gap?
Ans Epicranial
aponeurosis (or galea aponeurotica), the 2nd layers of the scalp
which is a tough layer made by dense fibrous tissue which runs from the
frontalis muscle anteriorly to the occipitalis posteriorly. So there is a tension present within the epicranial
aponeurosis from anterior posteriorly. So a large gap is created when injury
occur in transversely but injury occur in anterior posterior direction is not
followed by large gap.
8.
Caput succedaneum is swelling of the scalp in a newborn. It is most often brought on by pressure from the
uterus or vaginal wall during a head-first (vertex) delivery.
9.
Clinical anatomy of Caput succedaneum
It is swelling due to collection of fluid in the 4th layer(loose areolar tissue) of scalp in a newborn. It is most often brought on by pressure from the uterus or
vaginal wall during a head-first (vertex) delivery. It is subsides
with 1-2 days
