skin and appendages of skin dr iram tassaduq the integument the integument is the body’s most the...

31

Upload: curtis-weaver

Post on 17-Dec-2015

228 views

Category:

Documents


2 download

TRANSCRIPT

Page 1: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive
Page 2: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

SKIN AND APPENDAGES OF SKIN

Dr Iram Tassaduq

Page 3: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

THE INTEGUMENT•The integument is the body’s most

massive organ.• It is composed of skin that covers

the entire body, together with certain accessory organs which are derivatives of the skin, such as nails, hair, sweat and sebaceous glands.

Page 4: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

ESSENTIAL FUNCTIONS

• Acts as a barrier• Provides immunologic information• Participates in homeostasis• Conveys sensory information• Performs endocrine functions• Functions in excretion

Page 5: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

LAYERS OF SKIN

Page 6: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive
Page 7: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

1. STRATUM BASALE/ STRATUM GERMINATIVUM

• Single layer of cells• Cuboidal / Columnar cells• Closely spaced nuclei• Basophilic cytoplasm• Contains melanin• Cell junctions• Contains stem cells• Provides epidermal cell renewal

Page 8: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

2. STRATUM SPINOSUM

• Several cells thick• Larger cells• Cytoplasmic processes or spines

• Desmosomes• Prickle cells• Flattening of cells towards surface

Page 9: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

3. STRATUM GRANULOSUM

•Most superficial layer of nonkeratinized portion of epidermis

•One to three cell layers thick

•Keratohyalin granules

Page 10: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

4. STRATUM LUCIDUM

• A subdivision of stratum corneum

• Normally well seen in thick skin

• Refractile appearance• Stains poorly• Eosinophilic cells

Page 11: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

5. STRATUM CORNEUM• Cells are flattened, desiccated, anucleated

• Most differentiated cells in the skin

• Filled almost entirely with keratin filaments

• Thick plasma membrane• Water barrier in epidermis• Variation in the thickness of layer

Page 12: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive
Page 13: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

• Dermis varies from 0.2 to 4 mm in thickness

• Composed of dense, irregularly arranged C.T.

• Contains three types of C.T. fibres plus fibroblasts and macrophages

• Two layers can be distinguished

• Junction between dermis and epidermis

Page 14: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

LAYERS OF DERMIS

1. THE PAPILLARY LAYER• Consists of loose C.T.• Thickness of collagen fibres• Contains type I and type III collagen• Irregular network of elastic fibres• Dermal papillae and ridges• Blood vessels• Nerve processes

Page 15: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

THE RETICULAR LAYER

• Always considerably thicker and less cellular than the papillary layer (although its thickness varies)

• Characterized by thick irregular bundles of mostly type I collagen and by coarse elastic fibres

• Langer’s lines

Page 16: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

THIN HAIRY SKIN THICK NONHAIRY SKIN

Page 17: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

FLEXOR OR JOINT LINES• Major markings found in the

vicinity of synovial joints where the skin is attached strongly to underlying deep fascia.

• Prominent on the flexor surfaces of palms, soles and digits.

• Skin lines don't necessarily coincide with the underlying joint line.

Page 18: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

PAPILLARY/EPIDERMAL/FRICTON/RIDGES

• A friction ridge is a raised portion of the epidermis on the fingers and toes, the palm of the hand or the sole of the foot.

Page 19: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

WRINKILE LINES• Caused by contraction of underlying

muscles, present perpendicular to their axis of shortening.

• On face, they are known as lines of facial expression, aging makes them permanent due to loss of skin elasticity.

Page 20: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

BLOOD SUPPLY OF SKIN• The dermis contains horizontally arranged superficial and deep plexuses, which are interconnected via communicating vessels oriented perpendicular to the skin surface.

Page 21: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

INNERVATION OF SKIN

Page 22: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

APPENDAGES OF SKIN

•Nails

•Hair follicles•Sweat glands •Sebaceous glands

Page 23: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive
Page 24: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

HAIR• Hairs are elastic keratinized threads that develop from epidermis

• Has free shaft and root embedded in skin• Length: 1 mm. to 5 feet• Humans: hair covers entire body except: palm, sole, region of anal & urogenital apertures

Page 25: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

Hair Bulb

Page 26: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

NAILS

•The nails are horny plates that form a protective covering on the dorsal surface of the terminal phalanges of the fingers and toes

Page 27: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

SWEAT GLANDS(SUDIFEROUS GLANDS

• widely distributed on body• Sweat – is a blood filtrate

• 99% water with some salts• Contains traces of metabolic wastes

•Vital for thermoregulation

• Also influence water and ion balance

Page 28: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive
Page 29: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

SEBACOUS GLANDS

• One to several sebaceous glands always connect with a hair

• A gland usually is located in the angle between the follicle and its muscle

• Its short duct empties into the follicle at a level three-fourths of the way up.

Page 30: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive

• Occur over entire body• Except palms and soles

• Secrete sebum – an oily substance• Simple alveolar glands • Most are associated with a hair

follicle

• Functions of sebum• Collects dirt; softens and

lubricates

SEBACOUS GLANDS

Page 31: SKIN AND APPENDAGES OF SKIN Dr Iram Tassaduq THE INTEGUMENT The integument is the body’s most The integument is the body’s most massive organ. massive