1. Chapter 5 The Integumentary System and Body Membranes Renita K Holmes msn rn Kaplan university

2. Integumentary system Unit 3 Activities Reading: Chapter 5
Discussion Questions
Pre-Quiz
Assignment
Post-Quiz

3. Integumentary system This system is called the integumentary system.
Integument is another name for the skin
The skin itself is the principal organ of the integumentary system.
The skin is the largest organ in the body
The skin is one of a group of anatomically simple but functionally important sheet-like structures called membranes.

4. The skin Membranes Cover and protect the body surface
Line body cavities
Cover the inner surfaces of the hollow organs such as the digestive, reproductive, and respiratory passageways.

5. The skin
Membranes
Some membranes anchor organs to each other or to bones
others cover the internal organs.
In certain areas of the body, membranes secrete lubricating fluids that reduce friction during organ movements such as the beating of the heart or lung expansion and contraction.
Membrane lubricants also decrease friction between bones in joints.

6. CLASSIFICATION OF BODY MEMBRANES
Classification of body membranes There are 2 main types of membranes
Epithelial membranes—composed of epithelial tissue and an underlying layer of connective tissue
Connective tissue membranes—composed largely of various types of connective tissue

7. Types of body membranes
Types of body membranes. A, Epithelial membranes, including cutaneous membrane (skin), serous membranes (parietal and visceral pleura and peritoneum), and mucous membranes.
B, Connective tissue membranes, including synovial membranes.

8. CLASSIFICATION OF BODY MEMBRANES
Epithelial membranes
Cutaneous membrane—the skin
Serous membranes—simple squamous epithelium on a connective tissue basement membrane
Types
Parietal—line walls of body cavities
Visceral—cover organs found in body cavities
Examples
Pleura—parietal and visceral layers line walls of thoracic cavity and cover the lungs
Peritoneum—parietal and visceral layers line walls of abdominal cavity and cover the organs in that cavity
Diseases
Pleurisy—inflammation of the serous membranes that line the chest cavity and cover the lungs
Peritonitis—inflammation of the serous membranes in the abdominal cavity that line the walls and cover the abdominal organs

9. Serous membrane
Serous Membrane
Line ventral body cavities (pleural, peritoneum, pericardium); transparent, thin, prevents friction

10. The skin The skin; covers the outer surface of the body.
Cutaneous Membrane
The skin; covers the outer surface of the body.
In contrast to serous or mucous membranes, the cutaneous membrane is thick, relatively waterproof, and usually dry.

11. CLASSIFICATION OF BODY MEMBRANES
Epithelial membranes (cont.)
Mucous membranes
Line body surfaces that open directly to the exterior
Produce mucus, a thick secretion that keeps the membranes soft and moist

12. Mucous membrane
Mucous Membrane
Mucous membranes are coated with the secretions of mucous glands.
They line most of the digestive and respiratory tracts and portions of the urinary and reproductive tracts.
Line passageways that communicate with exterior

13. CLASSIFICATION OF BODY MEMBRANES
Connective tissue membranes
Do not contain epithelial components
Produce a lubricant called synovial fluid
Examples are the synovial membranes in the spaces between joints and in the lining of bursal sacs

14. Synovial membrane
Synovial Membrane
Line join cavities (articulations) and produces the synovial fluid within the joint.
The synovial fluid lubricates the cartilages in the joint, distributes oxygen and nutrients, and cushions shocks at the joint.

15. THE SKIN Structure: two primary layers called epidermis and dermis
Outermost and thinnest primary layer of skin
Composed of several layers of stratified squamous epithelium
Stratum germinativum—innermost layer of cells that continually reproduce; new cells move toward the surface
As cells approach the surface, they are filled with a tough, waterproof protein called keratin; eventually cells flake off of body
Stratum corneum—outermost layer of keratin-filled cells

16. The skin
Skin pigment—produced by deepest epidermal layer; gives color to the skin
The brown pigment melanin is produced by specialized cells in deepest epidermal layer
Blisters—caused by breakdown of union between cells or primary layers of skin
Dermal-epidermal junction—specialized area between two primary skin layers

17. Microscopic view of the skin
Microscopic view of the skin. The epidermis, shown in longitudinal section, is raised at one corner to reveal the ridges in the dermis.

18. THE SKIN
Dermis
Deeper and thicker of the two primary skin layers; composed largely of connective tissue
Upper papillary layer of dermis characterized by parallel rows of tiny bumps called dermal papillae
Ridges and grooves in dermis form pattern unique to each individual
Basis of fingerprinting
Improves grip for tool use and walking

19. The skin
Deeper reticular layer of dermis filled with network of tough, interlacing, collagenous and stretchable elastic fibers
Number of elastic fibers decreases with age and contributes to wrinkle formation
Dermis also contains nerve endings, muscle fibers, hair follicles, sweat and sebaceous glands, and many blood vessels

20. THE SKIN Accessory structures of the skin Hair Lanugo
soft hair of fetus and newborn
Hair follicle
epidermal tubelike structure required for hair growth
Hair papilla
structure from which hair growth begins
Hair root
lies hidden in follicle
Hair shaft
visible part of hair
Arrector pili
specialized smooth muscle that produces “goose bumps” and causes hair to stand up straight

21. Hair follicle. Relationship of a hair follicle and related structures to the epidermal and dermal layers of the skin.

22. THE SKIN Accessory structures of the skin (cont.)
Receptors (Figure 5-2)
Specialized nerve endings—make it possible for skin to act as a sense organ
Meissner’s corpuscle—capable of detecting light touch
Pacinian corpuscle—capable of detecting pressure

24. THE SKIN Accessory structures of the skin (cont.) Nails (Figure 5-6)
Produced by epidermal cells over terminal ends of fingers and toes
Nail body—visible part of nail
Root—lies in a groove; hidden by cuticle
Lunula—crescent-shaped area nearest root
Nail bed may change color with change in blood flow

25. Structure of nails. Fingernail viewed from above.

26. Sagittal section of fingernail and associated structures

27. THE SKIN Accessory structures of the skin (cont.)
Skin glands—two types
Sweat, or sudoriferous, glands
Eccrine sweat glands
Most numerous, important, and wide-spread of the sweat glands
Produce perspiration or sweat, which flows out through pores on skin surface
Function throughout life and assist in body heat regulation
Apocrine sweat glands
Found primarily in axilla and around genitalia
Secrete a thicker secretion quite different from eccrine perspiration
Breakdown of secretion by skin bacteria produces odor

28. The skin Sebaceous glands Secrete oil or sebum for hair and skin
Level of secretion increases during adolescence
Amount of secretion is regulated by sex hormones
Sebum in sebaceous gland ducts may darken to form a blackhead

29. THE SKIN Functions of the skin
Protection—first line of defense against:
Infection by microbes
Ultraviolet rays from sun
Harmful chemicals
Cuts and tears

30. THE SKIN Functions of the skin (cont.) Temperature regulation
Skin can release almost 3000 calories of body heat per day
Mechanisms of temperature regulation
Regulation of sweat secretion
Regulation of blood flow close to the body surface
Sense organ activity
Skin functions as an enormous sense organ
Receptors serve as receivers for the body, keeping it informed of changes in its environment

31. The skin Skin Cancer The three most common types of skin cancer are
Squamous cell carcinoma,
Basal cell carcinoma
Malignant melanoma

32. The skin
Exposure to the sun’s ultraviolet (UV) radiation is thought to be the most important factor in causing the common skin cancers.
UV radiation damages the DNA in skin cells, causing the mistakes in mitosis that produce cancer.
Skin cells have a natural ability to repair UV damage to the DNA, but in some people, this inherent mechanism may not be able to deal with a massive amount of damage.

33. Squamous Cell Carcinoma
A common type of skin cancer, squamous cell carcinoma,is a slow-growing malignant tumor of the
epidermis.
Lesions begin as hard, raised nodules that are usually painless (Figure 5-7, A).
If not treated, squamous cell carcinomas will grow in size and eventually metastasize or spread

34. The skin
Squamous Cell Carcinoma

35. Basal Cell Carcinoma
The most common type of skin cancer,
Usually appears on the upper face
Originating in cells at the base of the epidermis,
Much less likely to metastasize
It often appears first as a small, raised lesion that erodes in the center to form a bleeding, crusted crater

36. The skin
Basal Cell Carcinoma

37. The skin
Melanoma
Malignant melanoma is the most serious form of skin cancer.
This type of cancer sometimes develops from a benign or noncancerous pigmented mole, and then transforms into a dark, spreading cancerous lesion

38. The skin
Malignant Melanoma

39. The skin
Kaposi sarcoma is a rare form of skin cancer frequently associated with AIDS and other immune deficiencies.

40. The skin Warning Signs of Malignant Melanoma ABCD Rule Asymmetry
Benign moles are usually symmetrical; their halves are mirror images of each other.
Melanoma lesions are asymmetrical or lopsided.
Border
Benign moles are outlined by a distinct border, but malignant melanomal lesions are often
irregular or indistinct in shape.
Color
Benign moles may be any shade of brown but are relatively evenly colored; melanoma lesions
tend to be unevenly colored, exhibiting a mixture of shades or colors.
Diameter
By the time a melanoma lesion exhibits characteristics A, B, and C, it also is probably larger
than 6 mm (14 inch).

41. THE SKIN
Burns
Treatment and recovery or survival depend on total area involved and severity or depth of the burn
Body surface area is estimated using the “rule of nines” (Figure 5-8) in adults
Body is divided into 11 areas of 9% each
Additional 1% located around genitals

42. The “rule of nines.” Dividing the body into 11 areas of 9% each helps to estimate the amount of skin surface burned in an adult.

43. THE SKIN Burns (cont.) Classification of burns
First-degree (partial-thickness) burns—only the surface layers of epidermis involved
Second-degree (partial-thickness) burns—involve the deep epidermal layers and always cause injury to the upper layers of the dermis
Third-degree (full-thickness) burns—characterized by complete destruction of the epidermis and dermis
May involve underlying muscle and bone
Lesion is insensitive to pain because of destruction of nerve endings immediately after injury—intense pain is soon experienced
Risk of infection is increased

44. questions
Questions?