Skin Lecture Notes PDF

Anatomy Department Level 1 - Semester 1 Module: General Lecture: Skin  2 Learning Outcomes: Recognize the skin structure. Identify Different function of...

Anatomy Department Level 1 - Semester 1 Module: General Lecture: Skin  2 Learning Outcomes: Recognize the skin structure. Identify Different function of the skin. Detect the layers of the fascia. Identify Function of the superficial fascia. Recognize the deep fascia modifications in certain areas Dr Nagy Abd Al Hady  The Skin (Integument) I- Definition of the Skin The Skin is the external surface of the body It is the largest organ: surface area around 2 m2 II- Characters of the Skin The skin consists of three layers  Epidermis ❑ (Outer layer). ❑ Avascular. ❑ epithelial layer Dermis ❑ (inner layer) ❑ Vascular connective tissue Hypodermis ❑ Subcutaneous tissue ❑ Fatty connective tissue The Skin appendages  1- Nails: ❑plates on the tip of fingers and toes Formed of: ▪ Root of the nail ▪ Body of the nail ▪ Nail folds: ▪ Nail bed: 2- Hairs Structure: It consists of root and shaft Hairs: present over the whole body except: Lips , soles, palms, glans penis and clitoris 3- Sebaceous gland: ❑ Lie in the dermis. ❑ secretes oily material (sebum) which lubricates the hair and theskin ❑ They are abundant in the scalp and face. ❑ Absent in the palms of the hands and soles of the feet. 4- Sweat glands: ❑ Each gland consists of a single tube ❑ Function: sweat secretion, and control of body temperature. ❑ present over the surface of the body except: Lips , nails, glans penis and clitoris  III- Functions of the Skin 1. Protection of the underlying soft tissues from external damage. 2.Barrier against microorganisms, water loss and ultraviolet rays. 3. It contains sense receptors & sensory nerves. 4. Control body temperature. 5.Activation of vitamin “D” by the action of ultraviolet rays.  Fascia Definition of Fascia Fascia is the tissue that lies immediately deep to the skin. Layers of Fascia It consists of two layers; superficial and deep Skin Superficial Fascia Deep Fascia Muscles Superficial Fascia Superficial Fascia fills hollows and rounds off irregularities  Deep Fascia Special modifications of deep fasciae in certain sites of the body: ❑ Investing fascia : Special modifications of deep fasciae in certain sites of the body: ❑ Inter-muscular septa: Special modifications of deep fasciae in certain sites of the body: ❑ Retinacula: Retinacula Special modifications of deep fasciae in certain sites of the body: ❑ Sheaths for large vessels (carotid sheath) Special modifications of deep fasciae in certain sites of the body: ❑Aponeurosis: (Palmar aponeurosis & Plantar aponeurosis)