TISSUES AND MEMBRANES.power point presentation

tissues and membrane

1. Insta | husain.z.kmu

2. Objectives At the end of the session the students will be able. Define tissues List name of different tissues in human body Explain different functions of tissues. Discuss classification of body membranes.

3. Tissues “A tissue is an group of similar cells that together carry out a specific function”. organizational level intermediate between cells and a complete organism. The study of tissue is known as histology.

4. STRUCTURAL ORGANIZATION Life is characterized by hierarchical orders of organization Atoms Molecules Organelles Cells Tissues Organs Organ systems Organism (Population) (Community) (Ecosystem) Insta | husain.z.kmu

5. STRUCTURAL ORGANIZATION The cell is the lowest level of organization that can live independently as an organism Insta | husain.z.kmu

6. STRUCTURAL ORGANIZATION In multicellular organisms, specialized cells are grouped into tissues A tissue is a group of cells similar in structure and performing a common function Organs are comprised of combinations of various tissues Organ systems include multiple organs working together Insta | husain.z.kmu

7. TYPES OF TISSUES

8. TISSUE TYPES Four major tissue types Epithelial tissue Connective tissue Muscle tissue Nervous tissue Insta | husain.z.kmu

9. 1. EPITHELIAL TISSUE Sheets of cells covering body surfaces or lining body cavities and also founds in glands. Form boundaries between different environments e.g., Epidermis of skin separates inside and outside of body e.g., Epithelium lining urinary bladder separates underlying cells from urine

10. EPITHELIAL TISSUE Many diverse functions Protection of underlying structure Absorption Filtration Excretion Secretion Sensory reception

11. EPITHELIUM CHARACTERISTICS Cells are closely packed Intercellular matrix is minimal Lies on basement membrane. Regeneration Rapid cell division at basal surface Insta | husain.z.kmu

12. CLASSIFICATION OF EPITHELIA Cell layers Simple epithelia Single cell layer Facilitates absorption and filtration Stratified epithelia Two or more cell layers Common in high-abrasion areas e.g., Skin surface, mouth Insta | husain.z.kmu

13. CLASSIFICATION OF EPITHELIA Cell shape All epithelia have six sides Cells vary in height Three common shapes Squamous cells Cuboidal cells Columnar cells Insta | husain.z.kmu

14. CLASSIFICATION OF EPITHELIA Cell layers & cell shape Two names First name indicates cell layers Second name indicates cell shape e.g., Simple squamous epithelium e.g., Stratified cuboidal epithelium

15. SIMPLE SQUAMOUS EPITHELIUM Flattened Sparse cytoplasm Resemble tiled floor from top Resemble fried egg from side Thin and permeable Found where exchange is important e.g., Filtration in kidneys e.g., Rapid diffusion in lungs, capillaries Insta | husain.z.kmu

16. SIMPLE SQUAMOUS EPITHELIUM Two have special names reflecting their location Endothelium Inner lining of the heart, blood vessels, and lymphatic vessels Capillaries are exclusively endothelium Mesothelium Found in serous membranes lining the ventral body cavity and covering its organs Insta | husain.z.kmu

17. SIMPLE CUBOIDAL EPITHELIUM Forms the walls of the smallest ducts of glands and of many kidney tubules Insta | husain.z.kmu

18. SIMPLE COLUMNAR EPITHELIUM Mainly associated with absorption & secretion Lines digestive tract (stomach  rectum) Microvilli on apical surface of absorptive cells Mucus-secreting goblet cells May possess cilia Insta | husain.z.kmu

19. PSEUDOSTRATIFIED COLUMNAR EPITHELIUM Single layer of cells All cells rest on basement membrane Cells vary in height Only tallest cells reach free (apical) surface Gives false appearance of multiple layers Secretes or absorbs substances May possess cilia May possess goblet cells Insta | husain.z.kmu

20. STRATIFIED EPITHELIA Possess two or more cell layers Regenerate from below Basal cells divide and push apically (“upward”) More durable than simple epithelia Protection is major role

21. STRATIFIED SQUAMOUS EPITHELIUM Most widespread of stratified epithelia Found in areas subjected to wear and tear External part of skin, extending into body openings directly continuous with skin Free surface cells are squamous Cells in deeper layers are cuboidal or columnar Insta | husain.z.kmu

22. STRATIFIED SQUAMOUS EPITHELIUM Outer layer of skin is keratinized Cells filled with resinous protein keratin Protective role Insta | husain.z.kmu

23. STRATIFIED CUBOIDAL OR COLUMNAR EPITHELIUM Both are rather rare in the body Cuboidal Present in ducts of some larger glands e.g., Sweat glands, mammary glands Typically two layers of cuboidal cells Columnar Only apical layer is columnar Limited distribution e.g., Pharynx, ♂ urethra, line some glandular ducts Also present at transition areas or junctions between two other types of epithelia

24. TRANSITIONAL EPITHELIUM Forms lining of hollow urinary organs Bladder and ureters Basal layer cuboidal or columnar 6 cell layers when empty Thins to 3 layers when distended with urine Allows more urine to be stored or transported Insta | husain.z.kmu

25. 2. CONNECTIVE TISSUE

26. 2. CONNECTIVE TISSUE Found everywhere in the body Most abundant tissue in the body Cells are most widely separated Intercellular matrix is present in larg amount Fibers present in the matrix Have good blood supply.

27. CONNECTIVE TISSUE Major functions Binding and support Protection Insulation Transportation Which of these functions are accomplished by bone and cartilage? Fat? Blood ?

28. Types Four main classes Connective tissue proper Cartilage Bone tissue Blood

29. CONNECTIVE TISSUE Proper Common Characteristics Common origin All connective tissues arise from mesenchyme (an embryonic tissue) Degrees of vascularity Avascular poorly vascular highly vascular Extracellular matrix Largely composed of non-living extracellular matrix Insta | husain.z.kmu

30. CONNECTIVE TISSUE Proper Three main structural elements Ground substance Fibers Cells Ground substance + fibers = matrix

31. GROUND SUBSTANCE Unstructured material filling space between cells Contains fibers Composed of Interstitial (tissue) fluid Cell adhesion proteins “Glue” attaching cells to matrix elements Proteoglycans Large, negatively charged polysaccharides e.g., Hyaluronic acid, etc. Traps H 2 O Holds fluid  facilitates diffusion of dissolved substances between blood capillaries and cells Insta | husain.z.kmu

32. FIBERS Three types of fibers provide support Collagen fibers “White” fibers Strongest and most abundant Tensile strength > steel Elastic fibers “Yellow fibers” Long, thin, branching fibers Contain the protein elastin Can stretch and recoil Reticular fibers Fine collagenous fibers Networks surround and support soft tissue of organs Insta | husain.z.kmu

33. CELLS Each major class of connective tissue is derived from a fundamental cell type ( _____-blast ) Fibroblast  connective tissue proper Hematopoietic stem cell  blood Chondroblast  cartilage Osteoblast  bone ___-blasts ultimately derived from mesenchyme Insta | husain.z.kmu

34. CELLS Connective tissue is a home for many other cell types Fat cells Leukocytes Macrophages Mast cells

35. CELLS Mast cells Cluster along blood vessels Detect foreign substances e.g., microorganisms Release secretory granules to initiate local inflammatory response Macrophages Descended from monocytes Relatively large phagocytic cells “Eat” foreign material Mobile or fixed

36. TYPES OF CONNECTIVE TISSUE Embryonic Connective Tissue: Mesenchyme Star-shaped mesenchymal cells Fluid ground substance Arises early in embryonic development Differentiates into all other connective tissues Insta | husain.z.kmu

37. TYPES OF CONNECTIVE TISSUE A. Connective Tissue Proper Two subclasses Loose connective tissue Areolar Adipose Reticular Dense connective tissue Dense regular Dense irregular Elastic

38. TYPES OF CONNECTIVE TISSUE Loose Connective Tissue: Areolar Functions Supporting and binding other tissues Fibers Holding body fluids Ground substance Defending against infection Leukocytes Macrophages Storing nutrients Fat cells Insta | husain.z.kmu

39. TYPES OF CONNECTIVE TISSUE Loose Connective Tissue: Areolar Fibroblasts predominate Numerous macrophages Fat cells singly or in small clusters Occasional mast cells Other cell types also sparsely present Insta | husain.z.kmu

40. TYPES OF CONNECTIVE TISSUE Loose Connective Tissue: Adipose (Fat) Tissue Similar to areolar tissue in structure and function Greater nutrient-storing ability Adipocytes predominate Adipose cells / fat cells 90% of tissue’s mass Cells packed tight Nucleus and thin crescent of cytoplasm visible on periphery Insta | husain.z.kmu

41. TYPES OF CONNECTIVE TISSUE Loose Connective Tissue: Adipose (Fat) Tissue Richly vascularized High metabolic activity ~18% of average person’s body mass Insulates & absorbs shocks May develop almost anywhere e.g., Subcutaneous tissue e.g., Surrounding kidneys Insta | husain.z.kmu

42. TYPES OF CONNECTIVE TISSUE Loose Connective Tissue: Adipose (Fat) Tissue “White fat” has just been described “Brown fat” is a variant found only in infants Found between shoulder blades, anterior abdominal wall, and anterolateral neck Nutrient stores consumed to generate heat Insta | husain.z.kmu

43. TYPES OF CONNECTIVE TISSUE Loose Connective Tissue: Reticular Present in lymph nodes, spleen, bone marrow Resembles areolar tissue Only fibers present are reticular fibers Forms framework supporting many free blood cells e.g., Lymphocytes Insta | husain.z.kmu

44. TYPES OF CONNECTIVE TISSUE Dense connective tissues Dense Regular Connective Tissue Fibers are predominant element a.k.a. “Fibrous connective tissues” Contain closely packed bundles of collagen fibers Run together, parallel to direction of pull Great resistance to tension exerted in a single direction Insta | husain.z.kmu

45. TYPES OF CONNECTIVE TISSUE Dense Regular Connective Tissue Forms tendons Attach muscles to bones or muscles Forms ligaments Bind bones together at joints More elastic fibers than tendons Insta | husain.z.kmu

46. TYPES OF CONNECTIVE TISSUE Dense Irregular Collagenous Connective Tissue Same structural elements as dense regular Bundles of collagen fibers Thicker Arranged irregularly (run in >1 plane) Withstands tension from many directions Found in dermis of skin fibrous joint capsules, fibrous coverings of some organs (e.g., testes, kidneys, etc.) Insta | husain.z.kmu

47. TYPES OF CONNECTIVE TISSUE Dense Irregular Elastic Connective Tissue Similar to dense irregular collagenous Contains abundant elastic fibers Found in wall of elastic arteries Insta | husain.z.kmu

48. TYPES OF CONNECTIVE TISSUE B. Cartilage Tough and flexible Withstands both tension and compression Intermediate between dense connective tissue and bone Lacks nerve fibers Avascular Large amount of tissue fluid Up to 80% water Chondroblasts are predominant cell type Produce new matrix Insta | husain.z.kmu

49. TYPES OF CONNECTIVE TISSUE Cartilage Three varieties Hyaline cartilage Elastic cartilage Fibrocartilage Insta | husain.z.kmu

50. TYPES OF CONNECTIVE TISSUE Hyaline Cartilage Most abundant type of cartilage Covers ends of long bones “Articular cartilage” Forms epiphyseal plate Allows growth in long bones Supports tip of nose, connects ribs to sternum, supports respiratory system passages Large numbers of collagen fibers Not apparent in matrix Chondrocytes only 1 – 10% of volume Insta | husain.z.kmu

51. TYPES OF CONNECTIVE TISSUE Elastic Cartilage Nearly identical to hyaline cartilage Many more elastin fibers Supports external ear, epiglottis Insta | husain.z.kmu

52. TYPES OF CONNECTIVE TISSUE Fibrocartilage Structural intermediate between hyaline cartilage and dense regular connective tissue Rows of chondrocytes alternate with rows of thick collagen fibers Compressible, resists tension Often found where hyaline cartilage meets a true tendon or ligament Intervertebral disks, spongy cartilages of the knee Insta | husain.z.kmu

53. TYPES OF CONNECTIVE TISSUE C. Bone (Osseous Tissue) Matrix similar to cartilage More abundant collagen fibers Inorganic calcium salts Rocklike hardness Ability to support & protect Insta | husain.z.kmu

54. TYPES OF CONNECTIVE TISSUE Bone (Osseous Tissue) Osteoblasts produce organic portion of matrix Bone salts then deposited on & between fibers Osteoblasts  osteocytes Vascular Insta | husain.z.kmu

55. TYPES OF CONNECTIVE TISSUE Blood Very atypical connective tissue Does NOT connect things Provides NO mechanical support Why is it considered connective tissue? Derived from mesenchyme Insta | husain.z.kmu

56. TYPES OF CONNECTIVE TISSUE Blood Various types of cells Blood plasma is fluid matrix Plasma proteins are “fibers” Various functions Transportation Protection Insta | husain.z.kmu

57. 3. NERVOUS TISSUE Main component of the nervous system Brain, spinal cord, and nerves Regulates and controls body functions Two main cell types Neurons Generate and conduct nerve impulses Supporting cells Non-conducting cells that support, insulate, and protect neurons Insta | husain.z.kmu

58. 4. MUSCLE TISSUE Highly cellular Well vascularized Responsible for most types of body movement Possess myofilaments Actin and myosin Three types Skeletal muscle Cardiac muscle Smooth muscle

59. a. SKELETAL MUSCLE Skeletal muscle cells a.k.a., “Muscle fibers” Long, cylindrical cells Multinucleate Striated Voluntary Insta | husain.z.kmu

60. SKELETAL MUSCLE Forms organs called skeletal muscles Packaged by sheets of connective tissue Attached to bones of skeleton Contract to pull on bones or skin Movement results Insta | husain.z.kmu

61. b. CARDIAC MUSCLE Found only in the wall of the heart Contractions propel blood through blood vessels Cardiac muscle cells “Myocytes” Striated Uninucleate Branching Involuntary Insta | husain.z.kmu

62. c. SMOOTH MUSCLE Found mainly in walls of hollow organs e.g., Intestines, esophagus, blood vessels, etc. Contractions squeeze substances through these organs No visible striations Smooth muscle cells Spindle shaped Uninucleate Involuntary Insta | husain.z.kmu

63. Body Membranes Insta | husain.z.kmu

64. Skin and Body Membranes Function of body membranes Line or cover body surfaces Protect body surfaces Lubricate body surfaces Form protective sheets around organs

65. Classification of Body Membranes Epithelial membranes Cutaneous membrane Mucous membrane Serous membrane Connective tissue membranes

66. Cutaneous Membrane Cutaneous membrane = skin A dry membrane Outermost protective boundary Superficial epidermis Keratinized stratified squamous epithelium Underlying dermis Mostly dense connective tissue

67. Mucous Membranes 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

68. Serous Membranes Surface: simple squamous epithelium Underlying: areolar connective tissue Lines open body cavities that are closed to the exterior of the body Serous membranes occur in pairs separated by serous fluid Visceral layer covers the outside of the organ Parietal layer lines a portion of the wall of body cavity Figure 4.1c

69. Serous Membranes Specific serous membranes Peritoneum Abdominal cavity Pleura Around the lungs Pericardium Around the heart Figure 4.1d

70. Connective Tissue Membrane Synovial membrane Connective tissue only Lines fibrous capsules surrounding joints

71. Thank you