Unformatted text preview: Chapter 6 The Integumentary System Epidermis and dermis Hypodermis Skin thickness Skin color Functions of the skin Hair and nails Cutaneous glands Overview of the Skin Largest organ of the body Epidermis What type of tissue and cells? Contains 5 layers Dermis Hypodermis Thickness of skin varies, normally 12mm Cell Types and Layers of the Epidermis Stratum Corneum Stratum Lucidum Thin translucent zone seen only in thick skin Cells have no nucleus or organelles Keratinocytes are packed with eleidin Stratum Granulosum Produces lipidfilled vesicles that release a glycolipid to waterproof the skin Stratum Spinosum Several layers of keratinocytes Contains dendritic cells Macrophages from bone marrow migrating to the epidermis Helps protect body against invading pathogens Stratum Basale Single layer of cuboidal or columnar cells Keratinocytes are present Where most mitosis occurs Melanocytes principle nonkeratinocytes The Dermis Thickness = 0.6mm 3mm Composition Layers Dermal papillae are upward extensions of the dermis into the epidermis forming the ridges of fingerprints Papillary layer Reticular Layers of the Dermis Hypodermis Known as subcutaneous tissue or superficial fascia Has more adipose than dermis Functions Hypodermic injections Skin Colors (Pigmentation) Hemoglobin Carotene Visible through dermal collagen fibers Concentrated in stratum corneum and subcutaneous fat Pigment synthesis stimulated by UV radiation from sunlight produces yellow, brown, black, and reddish hues Melanin Abnormal Skin Colors Cyanosis blue Erythema redness Jaundice yellowing of skin Pallor pale lack of blood flow Albinism lack of melanin Hematoma bruised visible clotted blood Functions of the Skin Barrier Vitamin D synthesis Sensory functions Thermoregulation Psychological and social functions Structure of Hair Follicles Hair bulb Hair root Piloerector muscle Functions of Hair Body hair Scalp hair Beard, pubic, and axillary Guard hair and eyelashes Eyebrows Cutaneous Glands Sweat glands
Merocrine Apocrine Ceruminous glands Sebaceous glands Mammary glands Sweat Glands (apocrine) Ceruminous Glands Found only in external ear canal Secretion combines with sebum to produce earwax Waterproof keeps eardrum flexible Bitterness repel mites and other pests Sebaceous Glands Mammary Glands Breasts of both sexes rarely contain glands Secondary sexual characteristic of females Mammary glandular tissue found only during lactation and pregnancy Diseases of the Skin Most vulnerable organ to injury and disease Skin cancer Induced by UV rays of the sun Who does this most commonly effect? Basal cell carcinoma Squamous cell carcinoma Malignant melanoma ABCD Burns What are some causes of burns? Why do burns cause death? Degrees of burns Treatment 1st degree effects only the epidermis 2nd degree epidermis and part of dermis effected 3rd degree epidermis, dermis, and more is destroyed Skin Grafts Graft options
Autograft Isograft Temporary graft options Homograft (allograft) Heterograft (xenofraft) Amnion from an afterbirth Artificial skin from silicone and collagen ...
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- Spring '08
- Ceruminous glands, glands mammary glands