Skin and the Integumentary System Chapter 6 Skin and the Integumentary System

 Types of Membranes A. Serous membranes CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Types of Membranes A. Serous membranes 1. Line thorax and abdomen and cover organs within cavities. 2. Epithelium and loose connective tissue 3. Secrete serous fluid

1. Line cavities and openings that lead to the outside of the body CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. B. Mucous membranes 1. Line cavities and openings that lead to the outside of the body a. Oral and nasal cavities b. Openings of the digestive reproductive, respiratory, and urinary systems. 2. Epithelium and connective tissue with specialized cells 3. Secrete mucus

1. Line the joint cavities. CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. C. Synovial membranes 1. Line the joint cavities. 2. Connective tissues and secrete lubricating synovial fluid. D. Cutaneous membranes 1. Skin

A. The skin is the largest organ CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Skin and Its Tissues A. The skin is the largest organ B. Responsible for: 1. Maintaining homeostasis through temp. regulation 2. Protects underlying tissues 3. Prevents water loss 4. Houses sensory receptors 5. Synthesizes chemicals 6. Excretes wastes

C. Layers 1. Epidermis 2. Dermis 3. Subcutaneous layer CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. C. Layers 1. Epidermis 2. Dermis 3. Subcutaneous layer

a. Stratified squamous epithelium b. Lacks blood vessels CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1. Epidermis a. Stratified squamous epithelium b. Lacks blood vessels c. Reproducing cells in the stratum basale at the base of the epidermis contains dermal blood vessels.

d. Keratinization – dead cells push to the surface and harden CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. d. Keratinization – dead cells push to the surface and harden e. Layers Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale Basement membrane

f. Function g. Melanocytes CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. f. Function 1. Protects against water loss, injury, chemicals, and microorganisms. g. Melanocytes 1. Deep in the epidermis and underlying dermis 2. Pigment, melanin protects deeper cells ultraviolet rays. 3. Pass melanin to nearby cells by cytocrine secretion.

CopyrightThe McGraw-Hill Companies, Inc CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. h. Skin Color 1. Genetic differences result from differing amounts of melanin and the size of melanin granules 2. Sunlight causes darkening of skin as melanin production increases

CopyrightThe McGraw-Hill Companies, Inc CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2. Dermis a. Binds epidermis to underlying tissues b. Connective tissue with collagen and elastic fibers within a gel-like ground substance. c. Blood vessels carry nutrients to upper layers of skin and help regulate temperature. d. Contains nerve fibers, sensory fibers, hair follicles, sebaceous glands, and sweat glands.

3. Subcutaneous Layer (Hypodermis) CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3. Subcutaneous Layer (Hypodermis) a. Loose connective tissue and insulating adipose tissue. b. Binds skin to underlying organs and contains blood vessels.

1. Hair Follicles Accessory Organs of the Skin CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. Accessory Organs of the Skin 1. Hair Follicles a. Nearly all regions of the skin. b. Individual hairs develop at the base of the hair follicle when the lower epidermis dips down into the dermis. c. Keratinization forms the hair shaft.

CopyrightThe McGraw-Hill Companies, Inc CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Attach to each hair follicle. Cause goose bumps. e. Hair color CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. d. Arrector pili muscle Attach to each hair follicle. Cause goose bumps. e. Hair color 1. Melanin from melanocytes is responsible for most hair colors 2. Red hair contains the pigment, trichosiderin.

2. Sebaceous Glands (holocrine glands) CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2. Sebaceous Glands (holocrine glands) Associated with hair follicles Secrete sebum to waterproof and moisturize hair shafts.

3. Nails a. Protective coverings on ends of fingers and toes. CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3. Nails a. Protective coverings on ends of fingers and toes. Consist of stratified squamous epithelial cells Lunula - most actively growing region of the nail root. c. Keratinization

4. Sweat Glands (Sudoriferous glands) CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display. 4. Sweat Glands (Sudoriferous glands) Eccrine respond to body temperature Apocrine respond to body temperature, stress, and sexual arousal. c. Ceruminous glands secrete wax in the ear canal. d. Mammary glands secrete milk.

 Regulation of Body Temperature CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Regulation of Body Temperature A. Vital to maintaining metabolic reactions. B. Hypothalamus controls regulation. C. Active cells, such as those of the heart and skeletal muscle, produce heat. D. Excessive heat - dilation of dermal blood vessels and sweating. E. Excessive cooling - constricting dermal blood vessels, inactivating sweat glands, and shivering.

 Healing of Wounds and Burns CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Healing of Wounds and Burns Inflammation - blood vessels dilate and become permeable Cause tissues to become red and swollen Superficial cuts are filled in by reproducing epithelial cells. Deeper cuts are closed off by clots, covered by scabs, and eventually filled in by fibroblasts. 1. Blood vessels extend into the area, injured tissues are replaced, and the scab falls off

Burns First Degree Epidermis only Second Degree Epidermis and dermis Third Degree Destroys epidermis, dermis, and accessory organs

Common Skin Disorders

Acne Vulgaris These include blackheads, whiteheads (comedones), the larger papules (pimples) and later, pustules and large cysts.

Birthmarks Hemangioma – many blood vessels in one area

Skin Cancer From Epithelial cells Squamous cell carcinoma Basal cell carcinoma From Melanocytes Cutaneous melanomas

Squamous Cell Carcinoma

Basal Cell Carcinoma

Malignant Melanoma

Uncommon Skin Disorders

Blue Man http://www.msnbc.msn.com/id/21134540/vp/22534645#22534645 http://www.msnbc.msn.com/id/21134540/vp/22534645#32774369

Hypertrichosis Werewolf Disease http://abcnews.go.com/Video/playerIndex?id=2261198

Harlequin Ichthyosis http://www.telegraph.co.uk/telegraph/template/ver1-0/templates/fragments/telegraphTv/singlePlayer.html?titleId=1459170187&playerId=1494875123

Ehlers-Danlos Syndrome Stretchy skin syndrome http://www.youtube.com/watch?v=g0PlwgJ2q6o

Tree man http://abcnews.go.com/Video/playerIndex?id=5558922