Body Tissues & Membranes

1. Tissues are groups of cells similar in structure and function Body Tissues & Membranes

2. the 3 primary germ layers • Ectoderm • Endoderm • Mesoderm • These give rise to all the basic tissues of the body

3. The four types of tissues. • Epithelial • Connective • Muscle • Nerve

4. Describe the characteristics & functions of epithelial tissue. LT#1 • Forms continuous sheets over the body surface & most of the bodies inner cavities • Protects the body from drying out, injury, bacterial exposure • Inside specialized - cilia sweeps impurities from GI tract, secretes mucus to protect from acids, microvilli in kidneys increases absorption • Replaces lost cells by cell division (regenerative)

5. Tissue cell shapes 101 • Simple • Stratified = layering

6. Tissue cell shapes 101 • Squamous, cuboidal, or columnar-cell shape

7. Name the major types of epithelial tissues, relate each one to an organ. LT#2 • simplesquamous • simplecuboidal • simple columnar • pseudostratified columnar • stratifiedsquamous • stratifiedcuboidal • stratified columnar • transitional

8. Visual

9. simple squamous (flattened) • Single layer of flattened cells with disc-shaped nuclei and sparse cytoplasm • Functions: • Diffusion and filtration • Provides a slick, friction-reducing lining in lymphatic and cardiovascular systems

10. Simple squamous

11. Simple cuboidal • Single layer of cubelike cells with large, spherical central nuclei • Found in the liver – make insulin & glucagon • Also found on surface of ovaries, duct linings of glands, lining tubules of kidneys • Function in secretion and absorption

12. Simple cuboidal

13. Simple columnar • Single layer of tall cells with oval nuclei; many contain cilia • Goblet cells are often found in this layer • Function in absorption and secretion • Non-ciliated type line digestive tract and gallbladder • Ciliated type line small bronchi, uterine tubes, and some regions of the uterus • Cilia help move substances through internal passageways

14. Simple columnar

15. Simple columnar with goblet cells (secrete mucus)

16. Pseudostratified Columnar • Single layer of cells with different heights; some do not reach the free surface • Nuclei are seen at different levels • Found in lungs and nasal cavities • Also found in linings of repro sys tubes • Function in secretion and propulsion of mucus & sex cells

17. Pseudostratified Columnar

18. Stratified Squamous • Thick membrane composed of several layers of cells • Function in protection of underlying areas subjected to abrasion • Forms the external part of the skin’s epidermis (keratinized cells), and linings of the esophagus, mouth, and vagina (nonkeratinized cells)

19. Stratified squamous

20. Stratified squamous from esophagus

21. Stratified squamous from skin

22. Stratified cuboidal • Quite rare in the body • Found in some sweat and mammary glands

23. Stratified cuboidal

24. Stratified columnar • Limited distribution in the body • Found in the pharynx, male urethra, and lining some glandular ducts, salivary ducts

25. Stratified columnar

26. Transitional • Several cell layers, basal cells are cuboidal, surface cells are dome shaped • Stretches to permit the distension of the urinary bladder • Lines the urinary bladder, ureters, and part of the urethra

27. Transitional

28. Transitional collapsed & distended

29. glandular epithelium and how it is classified • A gland is one or more cells that makes and secretes an aqueous fluid • Classified by: • -Site of product release – endocrine or exocrine • -Relative number of cells forming the gland – unicellular or multicellular

30. Glandular epithelium

31. 22) What is an endocrine gland, what do they secrete and how do they do it? 23) What is an exocrine gland, what do they secrete and how do they do it? 24) Give the major types of connective tissue and some examples. 25) What are the general functions of connective tissue? 26) What are the common characteristics of connective tissue? 27) What are the three major structural elements of connective tissue? 28) What type of cells do you find in connective tissue and where would you find them? 29) What are the two types of loose connective tissue proper given and what characterizes them? 30) What are the two types of dense connective tissue proper given and what characterizes them?

32. 31) Describe the three different types of cartilage: what they are made of, their functions and where you would find them? • Hyaline cartilage • Elastic cartilage • Fibrocartilage cartilage

33. 1. Hyaline Cartilage • Looks like jelly – does not heal and usually is cut out when injured with hope of gaining muscle to compensate for the loss • Chondrocytes lie in lacunae (a small space containing an osteocyte in bone or chondrocyte in cartilage) • Supports, reinforces, cushions, and resists compression

34. Hyaline cartilage • Forms the costal cartilage • Found in embryonic skeleton, the end of long bones, nose, trachea, and larynx

35. 2. Elastic Cartilage • Similar to hyaline cartilage but with more elastic fibers • Maintains shape and structure while allowing flexibility • Supports external ear (pinna) and the epiglottis

36. Elastic cartilage has “little eyes”

37. 3. Fibrocartilage cartilage • Matrix similar to hyaline cartilage but less firm with thick collagen fibers • Provides tensile strength and absorbs compression shock • Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint

38. Fibrocartilage

39. 32) Give the characteristics and functions of osseous tissue. • Hard, calcified matrix with collagen fibers found in bone • Osteocytes are found in lacunae and are well vascularized

40. Osseous Tissue

41. Osseous Tissue cont’d • Supports, protects, and provides levers for muscular action • Stores calcium, minerals, and fat • Marrow inside bones is the site of hematopoiesis • Bones will change shape with pressure: braces/jawbone, tight shoes/bunions, hammer toe

42. Bone marrow: 2 kinds • Red marrow – site of hematopoiesis • Yellow marrow – fat (this is why you make soup from bones)

43. hematopoietic bone marrow of flat bones  vertebrae, sternum, ribs, iliac. It represents 4-6% of body weight. The fatty degeneration of red bone marrow (RBM) (25%) into yellow bone marrow (YBM) (75%) is completed around age 21 years.

44. Red marrow C  hematopoietic tissue forming new blood cells.

45. Yellow marrow

46. 33) Give the characteristics and functions of blood. • Red(carry O2, CO2) and white cells (defense) in a fluid matrix (plasma) • Contained within blood vessels • Functions in the transport of respiratory gases, nutrients, and wastes

47. Blood

48. 34) Describe and give the functions of nervous tissue? Where is it found? • Branched neurons with long cellular processes and support cells • Transmits electrical signals from sensory receptors to effectors (using ions) • Found in the brain, spinal cord, and peripheral nerves

49. Nervous Tissue: unique shape carries signals (like wire) but uses ions – not electricity

50. 35) Describe and give the functions of the three types of muscle tissue. • Skeletal • Cardiac • Smooth