Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Seventh Edition Elaine N. Marieb Chapter 4 Skin and Body Membranes

Integumentary system Integumentary system clip Integ animation

Skin and Body Membranes Slide 4.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Function of body membranes  Line or cover body surfaces  Protect body surfaces  Lubricate body surfaces

Classification of Body Membranes Slide 4.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Epithelial membranes  Cutaneous membrane  Mucous membrane  Serous membrane  Connective tissue membranes

Cutaneous Membrane Slide 4.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cutaneous membrane = skin  A dry membrane  Outermost protective boundary  Superficial epidermis  Keratinized stratified squamous epithelium  (keratin-waterproofing protein found in hair & skin)  Underlying dermis  Mostly dense connective tissue

Mucous Membranes Slide 4.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Surface epithelium  Type depends on site  Underlying loose connective tissue (lamina propria)  Lines all body cavities that open to the exterior body surface  Often adapted for absorption or secretion Figure 4.1b

Serous Membranes Slide 4.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Surface simple squamous epithelium  Underlying areolar connective tissue  Lines open body cavities that are closed to the exterior of the body  Serous layers separated by serous fluid Figure 4.1c

Serous Membranes Slide 4.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Specific serous membranes  Peritoneum  Abdominal cavity  Pleura  Around the lungs  Pericardium  Around the heart Figure 4.1d

Connective Tissue Membrane Slide 4.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Synovial membrane  Connective tissue only  Lines fibrous capsules surrounding joints Figure 4.2

Integumentary System Slide 4.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Skin (cutaneous membrane)  Skin derivatives  Sweat glands  Oil glands  Hairs  Nails  skin, hair and nails skin, hair and nails

Skin Functions Slide 4.9a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Protects deeper tissues from:  Mechanical damage  Chemical damage  Bacterial damage  Thermal damage  Ultraviolet radiation  Desiccation  Aids in heat regulation  Aids in excretion of urea and uric acid  Synthesizes vitamin D

Skin Structure Skin Structure Slide 4.10a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Epidermis – outer layer  Stratified squamous epithelium  Often keratinized (hardened by keratin)  Dermis  Dense connective tissue

Skin Structure Slide 4.10b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Deep to dermis is the hypodermis  Not part of the skin  Anchors skin to underlying organs  Composed mostly of adipose tissue

Layer of Epidermis Slide 4.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Strata – layers  You do not need to know!

Melanin Slide 4.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pigment (melanin) produced by melanocytes  Color is yellow to brown to black  Melanocytes are mostly in the stratum basale  Amount of melanin produced depends upon genetics and exposure to sunlight

Dermis Slide 4.13a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Two layers  Papillary layer  Projections called dermal papillae  Pain receptors  Capillary loops  Reticular layer  Blood vessels  Glands  Nerve receptors

Skin Structure Slide 4.13b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.4

Normal Skin Color Determinants Slide 4.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Melanin  Yellow, brown or black pigments  Carotene  Orange-yellow pigment from some vegetables

 Hemoglobin  Red coloring from blood cells in dermis capillaries  Oxygen content determines red coloring

Appendages of the Skin Slide 4.15 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sebaceous glands (all over except palms and soles of feet)  Produce oil: Lubricant for skin; Kills bacteria  Ducts that empty into hair follicles  Glands activated at puberty  Acne – infection of sebaceous glands

Appendages of the Skin Slide 4.16 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sweat glands  Widely distributed in skin  Two types  Eccrine  Open via duct to pore on skin surface  Apocrine  Ducts empty into hair follicles

Sweat and Its Function Slide 4.17 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mostly water  Some metabolic waste (urea, uric acid)  Fatty acids and proteins (apocrine only)  dissipate excess heat  Excretes waste products  Acidic nature inhibits bacteria growth  Odor is from associated bacteria, not fluid!

Appendages of the Skin Slide 4.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Hair  Produced by hair bulb  hard keratinized epithelial cells  Melanocytes can provide pigment for color Figure 4.7c

Hair Anatomy Slide 4.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Central medulla  Cortex surrounds medulla  Cuticle on outside of cortex  Most heavily keratinized Figure 4.7b

Associated Hair Structures Slide 4.20 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Hair follicle  Dermal and epidermal sheath surround hair root  Arrector pili  Smooth muscle  Sebaceous gland  Sweat gland

Hair video clip – YouTube Hair video clip – YouTube Slide 4.20 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Hair follicles have a cycle of resting and growing that goes like this: 1. Rest: follicle has no hair growing in it. 2. Growth: The length of the hair reflects how long it has been growing, and the hair follicles from different parts of your body have different pre-programmed amounts of time that they will grow. So, for places with short hair, like eyelashes, the time for growing is short. For the hair on your head, however, the follicles grow for years. 3. Rest: Once the growth period ends, the hair stays in the follicle for a while. 4. Shedding: Eventually, the bottom of the hair loses its connection with the skin, and the hair falls out.

Appendages of Skin Slide 4.21 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Nails Nails  Scale-like modifications of epidermis  Heavily keratinized  Lack of pigment makes them colorless

Nail Structures Slide 4.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Free edge  Body  Root of nail  Heavily keratinized

Integumentary System ~support links Skin anatomy and definitions Appendages of skin Dermatology in movies Integumentary images

Athletes foot - caused by fungal infection Skin Homeostatic Imbalances Infections

Boils and carbuncles - caused by bacterial infection Cold sores - caused by virus

Slide 4.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Allergies Contact dermatitis- exposure cause allergic rx

Impetigo-bacterial infection Psoriasis - Cause unknown Triggered by trauma, infection, stress

Skin Homeostatic Imbalances Slide 4.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Burns  Tissue damage & cell death  Caused by heat, electricity, UV radiation, or chemicals  Associated dangers  Dehydration  Electrolyte imbalance  Circulatory shock

Body is divided into 11 areas for quick estimation of extent of burns

 Only epidermis is damaged  Skin is red and swollen Severity of Burns

2 nd degree burn Epidermis and upper dermis are damaged Skin is red with blisters

3 rd degree burn Destroys entire skin layer Burn is gray-white or black

Critical Burns Slide 4.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Burns are considered critical if:  >25% of body has 2nd degree burns  >10% of the body has 3rd degree burns  3rd degree burns of the face, hands, or feet

Skin Cancer Slide 4.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cancer – abnormal cell mass  Benign - Does not spread  Malignant - Metastasized (moves) to other parts of the body  Skin cancer - most common type of cancer

Basal Cell Carcinoma- Least malignant Most common Metastasizes to lymph nodes Early removal allows a good chance of cure

Malignant Melanoma Most deadly of skin cancers Cancer of melanocytes Metastasizes rapidly to lymph and blood vessels Detection uses ABCD rule

ABCD Rule Slide 4.32 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A = Asymmetry  Two sides of pigmented mole do not match  B = Border irregularity  Borders of mole are not smooth  C = Color  Different colors in pigmented area  D = Diameter  Spot is larger then 6 mm in diameter

Wrinkles ~ Take-home assessment Name:__________________ Date:________ 1.List all factors that might contribute to the skin deterioration with age. 2.Research retinoic acid for treatment of photo-aged skin. OR 3.Research damaging effects of sunlight on skin, describing differences in A and B types of UV rays relative to skin damage.