Introduction of Skin and fascia Dr. Navneet Kumar Professor (Anatomy)

Introduction of structures met in dissection Skin Superficial fascia Artery, Vein ,Nerve Deep fascia Muscles Bones joints Dr. Navneet Kumar Professor (Anatomy

Dr. Navneet Kumar Professor (Anatomy

Objectives Introduction to Skin. Fascia. - Superficial Fascia - Deep Fascia. Dr. Navneet Kumar Professor (Anatomy

Dr. Navneet Kumar Professor (Anatomy

Skin Structure of skin. Functions of skin. Appendages of skin. Dr. Navneet Kumar Professor (Anatomy

Structure of the skin Dermis Epidermis Keratinized stratified squamous epithelium devoid of blood vessels Dermis Connective tissue containing (bl. v. lymph v., sensory nerve endings, smooth m, hair follicles, sweat and sebaceous glands) In its deep part the collagen bundles are arranged in parallel rows Dr. Navneet Kumar Professor (Anatomy

Skin Layers of skin Epidermis Dermis Five type of layers Two type of layers Junction Dermal papilla Epidermal peg (rete pegs) Dr. Navneet Kumar Professor (Anatomy

5.Stratum corneum-non nucleated keratinized dead cells Skin…. Epidermis - 1. Stratum basale Single layer of columnar cells 2. Stratum spinosum Several layers of polyhedral cells, spine like process, tonofilament 3.Stratum granulosum Keratohyline granules 4. Stratum lucidum Homogeneous keratin, fusiform cells 5.Stratum corneum-non nucleated keratinized dead cells Dr. Navneet Kumar Professor (Anatomy)

Reticular layer Collagen fibre Skin….. Dermis Papillary layer Tactile papilla Vascular papilla Collagen fibre Reticular layer Collagen fibre Sweat glands Sebaceous glands Hairs Dr. Navneet Kumar Professor (Anatomy)

Thick skin Thin skin -No hairs Devoid of Stratum lucidum Skin…… Dr. Navneet Kumar Professor (Anatomy)

epidermis dermis

Functions of the Skin 1-Protection  abrasion, invasion, water loss, UV protection 2-Vitamin D synthesis  epidermal keratinocytes when exposed to UV light  helps maintain health of skeleton by increasing absorption of Ca2+ 3-Sensation  receptors for heat, cold, touch, pressure, vibration and pain Dr. Navneet Kumar Professor (Anatomy

 thermo receptors and sweat glands 4- Thermoregulation  thermo receptors and sweat glands  hypothalamus controls cutaneous arteries and sweat glands to retain or dissipate heat 5- Psychological and social functions  appearance and social acceptance  facial expression and nonverbal communication Dr. Navneet Kumar Professor (Anatomy

The appendages of the skin Nails Hairs Sebaceous glands Sweat glands Dr. Navneet Kumar Professor (Anatomy)

Dr. Navneet Kumar Professor (Anatomy

Collection of connective tissue Fascia Collection of connective tissue Superficial fascia Deep fascia Dr. Navneet Kumar Professor (Anatomy

Superficial fascia Superficial fascia: Functions: Loose, mixture of adipose and loose areolar tissues. It unites the skin to the underlying structures. It is dense in some places as scalp, palm of hand and sole of foot and contains collagen bundles It is thin in the eyelids, auricle, scrotum, penis and clitoris (devoid of adipose tissue). Functions: Facilitates movement of skin over underlying structures. Passage for cutaneous vessels, nerves… Protects the body against heat loss. Dr. Navneet Kumar Professor (Anatomy)

Superficial fascia

Superficial Fascia -Eyelids -Pinna -Penis Site with more fat - Breast Site with Very less fat -Eyelids -Pinna -Penis Site with more fat - Breast - Abdomen -Gluteal region Dr. Navneet Kumar Professor (Anatomy)

Deep fascia It is more dense than superficial fascia Collagenous bundles are more compact and more regularly arranged It is usually present in the form of membranes Dr. Navneet Kumar Professor (Anatomy)

Examples of deep fascia A. Investing fascia Covers the surfaces of muscles In the neck: it forms well-defined layers, bounds fascial spaces so limits spread of infection or determine the path of infection In the abdomen: it is thin In the limbs: forms a definite sheath around the muscles Dr. Navneet Kumar Professor (Anatomy)

B. Inter muscular septa Examples of deep fascia……….. lie between muscles dividing the limb into compartments Dr. Navneet Kumar Professor (Anatomy

C. Retinacula Examples of deep fascia……….. Localized thickening of deep fascia around joints, hold the tendons in place, prevent bowstringing of tendon Dr. Navneet Kumar Professor (Anatomy)

Examples of deep fascia……….. Fibrous sheath - eg. Carotid sheath Axillary sheath Fibrous capsule -eg Parotid capsule Ligaments Dr. Navneet Kumar Professor (Anatomy)

Absence of deep fascia Face Breast Penis Anterior abdominal wall Dr. Navneet Kumar Professor (Anatomy)