Skin & Fascia Anatomy PDF

Anatomy of The Skin Dr.Sayed Jahin Lecturer of anatomy and embryology Anatomy Integument (Skin) Structure of the skin: - The skin consists of three layers: - 1. Epidermis: Avascular superficial epithelial layer 2. Dermis: Vascular deep c...

Anatomy of The Skin Dr.Sayed Jahin Lecturer of anatomy and embryology Anatomy Integument (Skin) Structure of the skin: - The skin consists of three layers: - 1. Epidermis: Avascular superficial epithelial layer 2. Dermis: Vascular deep connective tissue layer 3. Subcutaneous tissue: (hypodermis) is made of fat and connective tissue. http://www.siumed.edu/~dking2/intro/IN001b.htm 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. 6. Absorption of substances applied to it such as cream. The skin has 4 appendages: A. Nails C. Sebaceous glands B. Hairs D. Sweat glands pg. 1 Anatomy Pigmentation of the skin: - The color of the skin is determined by the presence of melanin pigment which protects the deep layers from damage by ultraviolet rays. 1. Hair D is tr ib utio: n - Hair covers most of the body surface exceptsome areas such as palms of the hands and soles of the feet. Structure of hair: - The hair consists of a root and a shaft: 1. Root of the hair: the lower part, embedded in the skin. 2. Shaft of the hair: the upper part, projecting from the surface of the skin. https://rootsandrituals.co.uk/the-science/ 2. Sebaceous glands Distribution: - Lie in the dermis of the skin near the surface. - They are abundant in the scalp and face around the orifices of the mouth, ear and nose. - They are absent in the palms of the hands and soles of the feet. F unc tio n:The secretion of sebum (oily waxy substance), which lubricates the hair and the skin. pg. 2 Anatomy 3. Sweat glands Each gland consists of a single tube (with no alveoli) which is coiled in its deep part. Absent in red margin of lips, nail bed, glans penis and clitoris. Function: sweat secretion, and control of body temperature. https://images.app.goo.gl/uizz5o9HfG6Pr36PA 4. Nails - A nail is a flattened horny plate on the dorsal surface of the tips of the fingers and toes. Root of the nailis the part embedded in the skin. Body of the nailis the exposed part of the nail and has a free distal border. Nail folds: folds of skin surrounding and overlapping nails. Nail bed: deep to the root of the nail, responsible for formation and growth of the nail. https://images.app.goo.gl/VHW76Y71UgUCoDcu6 pg. 3 Anatomy Fascia D e finitio n: - Fascia is a collection of connective tissue that lies between the skin and the underlying muscles and bones. - Types: superficial and deep fascia. Superficial fascia https://www.ddgpodcast.com/blog/fascial-magic Character: Mixture of loose areolar and fatty tissue that unite the skin to the underlying deep fascia. It is thinnest and have no fatty tissue over the penis, scrotum, and in the external ear. Func tio ns : Acts as a bad conductor to heat so keeping the body temperature constant. Fills up the hollows and rounds off the irregularities at the surface of the body. Facilitates the movement of the skin over the underlying structures. Deep fascia Cha ra c te rs : It is membranous layer of connective tissue that invests the muscles and other deep structures. Denser than superficial fascia and lies deep to it. Special modifications of deep fasciae in certain sites of the body: Investing fascia covers and surrounds the surface of muscles. Inter-muscular septa: lie in between muscles Retinacula: are localized transverse thickenings of deep fascia around the wrist and ankle joints to hold the long tendons in place. Sheaths for big neurovascular bundles: examples are femoral sheath and carotid sheath. Aponeurosis: thickened parts of deep fascia; in the palm of the h(Paanldmar aponeurosis)a nd the sole of the foot (planter aponeurosis). pg. 4 Anatomy Cut section in the thigh pg. 5