The Integumentary System

1. The Integumentary System I. The Integumentary System - Epidermis, Dermis, Hypodermis Major functions of the skin 1. Protection – 2. Regulation of body temperature – 3. Sensation – 4. Excretion of waste – 5. Vitamin D Production - when exposed to , helps with the absorption of calcium (bone growth).

2. II. Hypodermis A. Lies to the skin, but is not apart of the layers of skin. B. Attached to underlying bone & muscle. C. Supplied with blood & nerve. D. Composed of 1. 2. E. Stores half of your body fat. 1. 2.

3. The Skin Made up of two parts. 1. – structure & strength 2. – prevent water loss & abrasion

4. II. Dermis A. Composed of that contain a large supply 1. Dense collagenous connective tissue. 2. B. – fibers are arranged in a parallel direction for greater resistance to stretching. 1. – cut across the tensions lines, more scare tissue. 2. (striae) – overstretching of the dermis. C. Holds the accessory organs of the integumentary system.

5. D. Divided into areas 1. Papillary region a. upper part of dermis, contains . b. the lower part of the , removal of wastes, and temperature regulation. c. – projections upward 1 the connection between the 2 areas. d. – extended papillae into the epidermis & effects the contour to form friction ridges, help the hand & foot grasp by increasing friction.

6. 2. - Deeper thicker area. a. Composed of dense irregular tissue. b. Strengthens, extensibility, & elasticity by using protein fibers, elastic, collagenous fibers. c. Wrinkles that accompany & are a result of a change in the production or quality of these protein.

7. III. Epidermis – 40-56 days for cells to be replaced •Region of stratified squamous epithelium that is continuously replaced. •Water Proof. •Protective wrap around the body. A. Layers(strata) of the Epidermis. 1. deepest 1 layer of columnar cells lots of nourishment 2. multiple layer of cuboidal cells Nuclei are pyknosis state of death 3. 3-5 layers of partially flatten cells that contain granule, granules contain protein (keratin) 4. - present only in the thick skin of the palms and soles. 3-4 rows of flatten dead transparent “ghost” cells 5. - Most superficial layer 25-50 rows of flatten, dead cells - Wear & Tear Joined by desmosomes, that eventually breaks off and the skin falls off.

8. The Epidermis

9. B. Problems 1. 2. 3.

10. C. Skin color of the epidermis 1. Determined by melanocytes a. Cells that lie between cells on the stratum basale and produce melanin (pigment). b. The golgi apparatus packages the melanin in vesicles called melanosomes. c. The packages move out of the cells to neighboring cells and between them.

11. d. All humans have the about the same amount of melanocyte, what causes differences in skin color? e. Amount of melanin produced, causes of skin color UV light triggers melanocyte to produce melanin - tan f. What benefit is provided by the production of melanin? g. Protects the body from harmful UV light.

12. d. Disorders of skin pigments • – lack of pigment • – bluish skin pigment • – disorders of blood vessels at birth.

13. IV. Accessory Organs Organs located within the dermis. Provide a role in protection, communication, & excretion A. Hair 1. Parts of hair a. – extends through the epidermis. b. – below the epidermis c. – base of root d. – hard outer part e. – soft inner part f. – outermost covering

14. 2. Cycles of hair a. b. ex eyelashes - grows for days, rests for days. scalp – grows for years & rest for .

15. B. - Oil glands (sebum) -Occasionally they can be blocked by dirt or dead cells. - Become plugged or swollen – blackhead C. Sweat Glands - Function through out life, watery substance - Sudoriferous - - During puberty in response to sex hormones Proteins, which promote the growth of bacteria, which produce odoriferous materials (armpits, & groin) D. Receptors -

16. Accessory Organs

17. Nails E. Nails - flap of stratum corneum that overlies the proximal edge of the nail active stratum basale - nail matrix light color crescent - sign of calcium deficiency

18. V. Homeostasis - Temperature Regulation Good health - 37C +/- 1C Proper function of enzymes Movement of molecules Chemical reactions • Integumentary System helps to Maintain Body Temperature Hot Receptors in the skin external temperature which relay’s information to the brain. Brain Sweat glands to secretion Blood vessels dilate or relax which blood flow to the skin Carries heat to the skin which is removed from the body by evaporation. Breathe to exhale heat Heart beats to move more blood to the skin to remove heat faster.

19. Cold Goose bumps, arrector muscles contract Skeletal muscle slightly Blood vessels slightly volume of warm blood to the skin, therefore reducing heat lose by the skin

20. Temperature Regulation

21. B. Skin Repair Skin damage Bleeding - increase blood flow to damage area. 1. Remove 2. Promote - clotting, scabs, temporary barrier. a. minor cut - are produced and migrate there. b. Major - large number of are present - scar ( )

22. Skin Repair –new cells are the same as the ones lost. – new tissue develops leaving a scar and has los some function. – do not divide after growth stops, but can grow if there is an injury. – little or no dividing ability. - fibers to stop the bleeding – a dried clot – revascularize area under the scab (small wounds). – (large wounds)

23. Skin Repair

24. VI. Skin Disease A. - Pimples B. - Bacteria infection of a hair follicle - abscess Can spread to other tissue if not treated with antibiotics. C. - Metabolic disease because it effects a metabolic balance that the cells must maintain. Fatal - 50% or more is burned 3 types – epidermis ( week to heal) - epidermis & dermis ( weeks to heal) - completely damage in the epidermis, dermis, & hypodermis, including all accessory organs. Cannot regenerate itself - grafting.

25. Burns, Partial & full –thickness burns

26. D. - Fungus - athletes foot, jock itch. E. - Virus F. - Disease from the formation of a groups of cells with NO function. - (non invasive) freckles, moles - - cancer G. - Virus - Contagious -Reoccurring outbreaks

27. H. - Shingles -Similar to herpes -forms from chicken pox -common in people over 50 - along a nerve usually in trunk region I. -Congenital disease - 3% - 4% -Small round skin elevation that are covered with flaky skin - Flare Ups J. - Infestation of parasites - lice, tick, crabs, spiders, insects K. - Inflammation of the dermis - redness, swelling, vesicles - secondary infections - bacteria

28. L. Skin Cancer Too may overwhelm the function of melanin resulting in sunburn or mutation in which may lead to skin cancer. • carcinoma– invasive cancer. • Common in fair skin individuals. • Lesions that grow rapidly ½ cm per week. • Red hard nodules break opening after forming. • Treated by surgical removal or X-ray radiation.

29. b. carcinoma • Tumors arise from the cells from the layer. • Grows slowly 1 -2 cm/yr. • Red waxy nodules in the skin. • May cause lesion in organs under the skin if left untreated. • Excision is the treatment.

30. c. - Most life threatening. Tumor arises from melanocyte in the basal layer. May appear to be discolored, tender, or a small nodule. Starts as a small mole that bleeds easily to injury. Spreads quickly to nearby lymphs nodes then vital organs 4,000 die each year Since 1973 there has been an average of a - 4% increase in cases per year 30,000 new cases a year Treatment is only effective if the cancer is detected early - widespread X-ray radiation

31. Malignant Melanoma

32. IX. Determining Your Skin Surface Area [(height in inches x weight in lbs)/3131].5 Average is 2m2 Your answer X 10.7639104 ft2 Source: Mosteller 1987