Classification of Body Membranes: Epithelial, Serous, and Connective Tissue Membranes

1. Chapter 4 Skin and Body Membranes

2. BODY MEMBRANES • _________________________cover surfaces,line body cavities and forms protective-sometimes lubricating –sheets around organs

3. I.Classification of Body Membranes • A) EPITHELIAL MEMBRANES • Covering and lining membranes • All have an underlying sheet of connective tissue

4. 1) Cutaneous Membranes= skin • Superficial epidermis is____________________________________ • Underlying dermis is mostly dense(fibrous) connective tissue.The superficial tissue is exposed to air and is a ________________________________ Composed of keratinizing stratified squamous epithelial Dry membrane

5. 2) Mucous Membranes-made of varying types(w/sites) of epithelial tissue resting on a loose connective tissue called ____________________ and lines all cavities that open to the exterior(hallow organs of respiratory tract,digestive,urinary and reproductive… • Mucosa refers to location,not cellular makeup….But most mucosa are stratified squamous (mouth and esophagus) epithelium or simple columnar (rest of digestive tract)----all wet and bathed in secretions) -in urine w/urinary mucosa Lamina propria

6. Epithelium of mucosae is adapted for absorption or secretion/most secrete mucous ,but not all

7. 3)Serous membranes(serosa)- • Has a layer of simple squamous epithelium on a thin layer of ________________________________ • Serosa are closed to the exterior (except for dorsal body cavities and joint cavities) Areolar connective tissue

8. Occur in pairs…The __________________lines a specific portion of the ventral body cavity • Parietal layer folds in itself to form ________________-covers outside of the organs in that cavity • THINK of balloon analogy! • Serous layers separated by___________________-secreted by both membranes Parietal layer Serous fluid Visceral layer

9. Serous fluid allows organs to slide against ea. Other and cavity w/o friction, even though membranes are very close to each other

10. SEROUS NAMES RELATED TO LOCATION peritoneum • ______________________covers abdominal cavity • ____________________-surrounds lungs • _______________________surrounds heart pleural pericardium

13. Connective Tissue membranes/synovial membranes • Composed of ______________________and has NO epithelial cells-line capsules surrounding joints • Line small sacs of connective tissue called bursae and the tubelike tendon sheath----all cushioning organs against each other and tendon across bone-no epithelial tissue Soft areolar connective tissue

15. II.The Integumentary Sysyem(skin)-cutaneous membrane • The Integumentary System(skin)-cutaneous membrane • functions –most importantly protective….against mechanical damage,chemical damage, • bacterial damage, • UV effects,thermal effects and dessication(drying out) • ---also aids in controlling body heat • ---aids in excretion of urea and uric acid • ----synthesizes Vitamin D-modified cholesterol molecules convert to Vitamin D w/sunlight

16. The uppermost layer is full of _____________-and is cornified or hardened-help prevent water loss • Capillaries and sweat glands work on thermal control • ____________sense touch,pressure,temperature and pain keratin Cutaneous sensory receptors

18. Structure of skin • Epidermis-stratified squamous epithelial capable of keratinizing(hardening) • _________-underneath-mostly dense connective tissue • Epidermis and dermis strongly connected-fairly tear resistant-,but some abuse can cause them to separate—interstitial fluid comes between layers making a _____________ • _____________(hypodermis)is below dermis and mostly adipose----not actually considered part of skin,but attaches skin to organs beneath---works as “shock absorber” and insulates from extreme temperatures-also resposible for “curves” Subcutaneous tissue dermis blister

19. 1)Epidermis- strata • has 5 layers or _______________.From inside out they are stratum basale,spinosum,granulosum,lucidum and corneum • avascular • most cells are ______________________________which make keratin keratinocytes

20. Stratum basale-closest to dermis and connected along a wavy borderline.Contains epidermal cells that that get the most nourishment by diffusion from dermis;constant cell division-MILLIONS OF NEW CELLS DAILY(also called stratum germanitivum),daughter cells pushed upward • Stratum Spinosum and stratum granulosum become flatter and increasingly full of keratin

21. When the previous cells die,they form the clear _________________________________-not in all skin regions-only where skin is hairless and extra thick-ie.palms and soles;it secretes a water repellent glycolipid into extracellular space;distant from blood supply,so little nutrients-doomed cells Stratum lucidum

22. OUTERMOST Stratum corneum—20-30 cells layers thick and is ¾ of epidermal thickness;cornified,shinglelike dad cells,filled w/ keratin--tough protein-protects lower cells;dandruff sloughs off from here/very protective • Shed 18kg(~40 lbs.) dandruff in a lifetime-food source for dust mites • We have a totally new epidermis every 25-45 days • ___________________pigment that ranges in color from yellow to brown to black produced by melanocytes(in stratum basale).When skin is exposed to sun,this stimulates these cells to make more of the pigment---THUS tanning melanin

23. Melanin accumulates in membrane bound granules called __________________.They move to the end of the melanocytes and taken up by keratinocytes .THERE,melanin froms a pigment umbrella over superficial side of nuclei-shielding DNA from UV • _______________and moles are where melanin are concentrated in one spot melanosomes freckles

24. Melanin affects production of leathery skin and depress immune system-may contribute to herpes simplex and cold sores-more likely after tanning • Epidermal dendritic cells –scattered in epidermis –alert and activate immune system to react to bacterial invasion @ epidermal-dermal junction • Merkel cells- associated w/sensory nerve endings and act as touch receptors

26. 2)dermis-‘hide Dermal papillae Papillary layer • strong,stretchy • dense fibrous connective tissue • ___________________upper dermal region;______________-peglike projections from superior-indent into epidermis- surface-many containing capillary loops-thus nutrients;some have pain receptors-___________________ or touch receptors-_________________________________ Free-nerve endings Meissner’s corpuscles

29. Has whorled rings on soles and palms,increasing friction and gripping ability-papillary patterns----genetically determined…..sweat pores provide for fingerprints

30. Reticular layer • 2)___________________________(lamellae corpuscles)-deepest skin layer w/blood vessels,sweat and oil glands and _______________________________deep pressure receptors;phagocytes act here at reticular layer • Collagen and elastic fibers found in dermis.collagen gives toughness and attract water for hydration.Elasisic fibers give elasticity that declines w/age • Many blood vessels help w/ body temp.homeostasis.skin is red when hot due to engorging of blood Pacinian corpuscles

31. ___________________________________ happen in bedridden patients not turned regularly-pressure restricts blood supply and redness when pressure is released • Rich nerve supply • Read about Botox-p.118 Decubitus ulcers

35. C-Skin Color-3 pigments: • 1-melanin in epidermis • 2-carotene in stratum corneum and subcutaneous tissue-orange/yellow • 3-O2-rich hemoglobin in dermis • ----varying amounts of thr above create the numerous skin colors.Which is showing up more in Caucasians?_________________________ • ________________________hemoglobin is poorly oxygenated---can happen during heart failure and severe bleeding hemoglobin cyanosis

36. What else affects skin color?: • Emotions and various disease states: • ___________________-redness-blushing,hypertension,inflammation,allergy • ___________________-blanching-pale—fear,anger also anemia,low blood pressure,impaired blood flow • ___________________-yellowness-liver disorder • ____________-sites wher blood has escaped and clotted in tissue spaces;can happen w/disese or vitamin C deficiency • _________________-clotted blood mass jaundice pallor erythema hematomas bruises

37. D.Appendages of the Skin Cutaneous glands • 1-__________________________________-exocrine glands-release secretions to skin’s surface via ducts***formed by cells of stratum basale and push into deeper into dermis ,mostly • a)Sebaceous glands-oil glands-excepts on palms and soles—some open into hair follicle and some to surface • ________________-is product-clump of oil and cells;keeps skin moist and prevents hair from drying out/also kills some bacteria/more active during adolescence sebum

38. ______________(sudoriferous glands)-many in the skin-2 types: 1)eccrine glands-all over body and make sweat(mostly water,NaCl,vitamin C and tarces of metabolic wastes(ammonia, urea,uric acid and lactic acid.It is acidic and inhibits bacteria….sweat comes through a poer(not same as facial pores);helps regulate temp.(37 C Sweat glands

39. Apocrine glands • 2)_____________________________-mostly at axillary and genital areas;ducts empty into hair follicles;contains fatty acids and proteins—giving milky/yellowish color.It is odorless,but that changes whe bacteria use it as food:function at onset of puberty regulated by androgens(male sex hormones)----have been connected to sexual foreplay

42. Hair follice 3-Hair and Hair Follicles • . • 1)Hairs –millions-/minor protective function-filter and cushion) made by hair follicles and is flexible epithelial structure;root in ________________and shaft protrudes It is formed by mitosis of stratum basale epithelial cells in matrix(growth zone-of hair bulb)-become keratinized and die as pushed forward---mostly hair contains protein • Hair has central core called a medulla surrounded by a cortex.This is covered by a cuticle(most keratinized region)-gives strength • Frizz-cuticle worn away/split-ends • Hair pigments made by melanocytes in hair bulb

43. Variety of shapes and sizes(eyebrows v. head then skin hair).If shaft is flat and ribbonlike-hair curly or kinky.If shaft is round-straight or coarse hair • oval shape yields smooth,silky and wavy hair • Hair all over except soles,palms,nipples and lips • Fastest growing tissue in body • Have hormonal control

44. 2) hair follicles-contain inner epidermal sheath that forms hair/outer dermal sheath is actually connective tissue/papilla yield blood supply to matrix in hair bulb • ______________________________smooth muscle that raise hair in response to temp Errector pilli

45. Free edge Nail matrix • 3) Nails-scalelike product of dermis(corresponds to hoof or claw) • Each nail has a _______________,a body(visible and a root(imbedded in skin) • Nail folds of skin become cuticle at proximal end • Nail bed in stratum basale and inner ____________________,responsible for growth-cells become keratinized and die • Part appears pink due to vascularization in dermis • ___________________ appears white lunule

47. E.Homeostatic imbalances of skin1000’s of different skin ailments • 1) Infections and Allergies • ___________________________-fungal,itchy red ,peeling skin(tinea pedis) • Boils and Carbuncles-inflammation of hair follicles and sebaceous glands—often dorsal neck.Carbuncles are caused by bacteria-esp. Staphylococcus aureus Athlete’s foot

48. _____________________-small fluid filled(fever blisters)-itch and sting –caused by a herpes simplex virus-can be activated from dormancy from emotions,fever,UV light-usually around lips or oral mucosa • _____________________________-itchy,red,swelling and turns into blisters-exposure to chemicals like poison ivy Cold sores Contact dermatitis

49. ___________________-pink,water-filled raised lesions around nose and mouth;w/yellow crust;caused by Staphylococcus/common in children • _____________________-chronic overproduction of cells w/ red epidermal lesions—probably autoimmune/triggered often by trauma,infection,hormone changes or stress impetigo psoriasis

50. 2-burns-tissue damage and cell death caused intense heat,electricity,UV light or certain chemicals---This can have a domino effect on several organ systems • destroys cells • Life threatening from 1) loss of fluids as they seep from burned surface-dehydrating and fluid imbalance-could shut down kidneys and cause circulatory shock