Layers of the Scalp Anatomy

Scalp Structure

• The scalp's connective tissue layer contains fibrous septa that unite the skin to the underlying epicranial aponeurosis.
• The skin is thickest in the occipital region of the scalp.
• The arteries of the scalp are supplied by blood vessels from the external and internal carotid arteries.
• A 'black eye' appearance can be caused by blood tracking down the subaponeurotic space, often due to fracture of the scalp or skull.
• The scalp's dermal layer is hair-bearing and contains numerous sebaceous glands.
• The loose areolar tissue in the scalp allows for movement of the scalp over the underlying bone.
• The posterior auricular nerve is responsible for supplying sensory innervation to the skin behind the ear.
• The occipitofrontalis muscle is responsible for elevating the eyebrows and wrinkling the forehead.

Skull and Nasal Cavity

• The scalp is covered by the outer surface of the skull bones.
• The emissary veins in the scalp allow for drainage of blood from the scalp into the cranial venous sinuses.
• The main function of the nose in the upper respiratory tract is to warm, humidify, and filter the air we breathe.
• The olfactory epithelium is located in the superior nasal cavity.
• The nasal septum divides the nasal cavity into right and left cavities.
• The sinuses and nasolacrimal ducts drain into the nasal cavity.
• The supporting framework of the nasal cavities is composed of bone and cartilage.
• The cribriform plate of the ethmoid bone separates the nasal cavity from the anterior cranial fossa.
• The Kiesselbach's area, also known as Little's area, is responsible for 90% of all anterior nasal bleeds due to ruptured blood vessels.
• The nasal cavity receives ordinary sensation from the trigeminal nerve.
• The nasal bone forms the anterior slope of the nasal cavity's roof.
• A congenital clefting of the hard and/or soft palate can result in a defect in the floor of the nose.