A 2 year old man presents with superficial gash on his forehead. The
wound is bleeding profusely, but examination reveals no fracture. The
physician suspects a hypersensitive cardiac reflex. The patient’s
epicranialaponeurosis (galeaaponeurotica) is penetrated, resulting in
severe gaping of the wound. The structure overlying the
epicranialaponeurosis is which of the following?
A. A layer containing blood vessels.
B. The dura mater.
C. The periosteum (pericranium).
D. The tendon of the epicranial muscles (occipitofrontails).
A. A layer containing blood vessels.
B. The dura mater.
C. The periosteum (pericranium).
D. The tendon of the epicranial muscles (occipitofrontails).
Ans. A.
A
layer containing blood vessels
• A mnemonic device for remembering the
order in which the soft tissues overlie the cranium is SCALP: Skin, Connective
tissue, Aponeurosis, Loose connective tissue, and Periosteum.
• The scalp proper is composed of the
outer three layers, of which the connective tissue contains one of the richest
cutaneous blood supplies of the body.
• The occipitofrontal muscle complex
inserts into the epicranialaponeurosis, which forms the intermediate tendon of
this digastric muscle. This structure, along with the underlying layer of loose
connective tissue, accounts for the high degree of mobility of the scalp over
the pericranium.
•
If the aponeurosis is lacerated transversely, traction from the muscle bellies
will cause considerable gaping of the wound. Secondary to trauma or infection,
blood or pus may accumulate subjacent to the epicranialaponeurosis. Bone is too
deep, as is the dural mater.
