Scalp Layers and Structure - The scalp is composed of five layers: skin, connective tissue, epicranial aponeurosis, loose areolar tissue, and periosteum. - The skin layer of the scalp is thick and contains numerous hair follicles and sebaceous glands. - The connective tissue layer provides cushioning and protection. - The epicranial aponeurosis is a broad, flat tendon that connects the frontalis and occipitalis muscles. - The loose areolar tissue layer allows for movement and flexibility.

Blood Supply to the Scalp - The scalp is well-vascularised, receiving blood supply from several arteries. - The main arteries supplying the scalp are the superficial temporal artery, occipital artery, and posterior auricular artery. - These arteries anastomose (connect) with each other, providing collateral circulation. - The blood supply to the scalp is important for maintaining the health and vitality of the hair follicles. - The scalp also has an extensive venous network that allows for efficient drainage.

Nerve Supply to the Scalp - The scalp is innervated by branches of the trigeminal nerve (cranial nerve V) and the cervical nerves. - The trigeminal nerve supplies the anterior and middle parts of the scalp. - The occipital nerve, a branch of the cervical plexus, supplies the posterior part of the scalp. - The nerve supply to the scalp is responsible for sensation, including pain, touch, and temperature. - The scalp also has a rich sensory innervation, making it highly sensitive.

Functions of the Scalp - The scalp serves as a protective covering for the skull, providing cushioning and insulation. - It helps regulate body temperature by preventing heat loss from the head. - The scalp plays a role in the expression of emotions through facial expressions. - Hair on the scalp provides physical protection from UV radiation and trauma. - The scalp is an important aesthetic feature and can impact self-image and confidence.

Scalp Disorders - Scalp disorders include dandruff, scalp psoriasis, seborrheic dermatitis, and scalp folliculitis. - Dandruff is characterised by flaky skin on the scalp, often caused by an overgrowth of a yeast-like fungus. - Scalp psoriasis presents as red, scaly patches on the scalp, often accompanied by itching. - Seborrheic dermatitis is a chronic inflammatory condition that causes redness, itching, and flaking of the scalp. - Scalp folliculitis is an infection of the hair follicles, resulting in pustules or small abscesses on the scalp.