TISSUES

Tissues definition and classification, function & location of of epithelium tissues, connective tissues, muscular tissues, nervous tissue etc.. it is usefull for the diploma in pharmacy students , bachelor of pharmacy students and doctor of pharmacy students

1. Tissue level of organization Tissue s

2. Tissue The tissues of the body consist of large numbers of cells and they are classified according to the size, shape and functions of these cells.

3. Classification of Tissues There are four main types of tissue, each of which has sub divisions. They are: 1.Epithelial tissue or epithelium 2.Connective tissue 3.Muscle tissue 4.Nervous tissue .

4. Epithelial tissue provides a covering ( skin, the linings of the various passages inside the body ). Connective tissue supports other tissues and binds them together (bone, blood, and lymph tissues).

5. Muscle tissue includes striated (also called voluntary) muscles that move the skeleton, and smooth muscle, such as the muscles that surround the stomach. Nerve tissue is made up of nerve cells (neurons) and is used to carry "messages" to and from various parts of the body.

6. 1. Epithelial Tissue Epithelial tissue, commonly referred to as epithelium is made up of one or more layers of cells that covers or lines the external and internal surfaces of various body parts. It consists of variously shaped cells closely arranged in one or more layers.

7. Epithelial tissue This group of tissues is found covering the body and lining cavities and tubes . It is also present in glands . Functions of Epithelium tissues • P rotection of underlying structures from, dehydration , chemical and mechanical damage • S ecretion • Absorption

8. The cells are very closely packed and the intercellular substance , called the matrix . The cells usually lie on a basement membrane . Epithelial tissue may be: • simple : a single layer of cells • stratified : several layers of cells.

9. Simple E pithelium Simple epithelium consists of a single layer of identical cells and is divided into four types. It is usually found on absorptive or secretory surfaces , the single layer enhances these processes. The types are named according to the shape of the cells, which differs according to their functions. The more active the tissue, the taller are the cells.

10. Classification of epithelium tissues Epithelium tissues are classified in to Two types 1.Si m p l e E pith e lium Squamous Cuboidal C o l um n a r Ciliated Pseudostratified Glandular 2.Compound epithelium

11. 1.Squamous (pavement) epithelium This is composed of a single layer of flattened cells. The cells fit closely together like flat stones, forming a thin and very smooth membrane .

12. Squamous (pavement) epithelium This epithelium occurs in the walls of blood vessels, air sacs of the lungs where oxygen and carbon dioxide are exchanged,lymph vessels, wall of Bowman’s capsule, loops of the nephrons of Kidneys .

13. Functions of squamous epithelium Exchange of gases. Filtration in Bowman’s Capsule. Exchange of materials in blood capillaries and tissue fluid

14. Diffusion takes place freely through this thin, smooth, inactive lining of the following structures : Heart Blood vessels Lymph vessels where it is also known as Endothelium alveoli of the lungs

15. 2.Cuboidal (cubical) epithelium Cuboidal cells epithelium are single-layered cells that are shaped like a cuboid.

16. Cuboidal (cubical) epithelium These are found in small collecting ducts of kidneys, pancreas, and salivary glands Cuboidal epithelium is actively involved in secretion, absorption and excretion

17. Functions of cuboidal epithelium The main function of the cuboidal cell epithelium is to help in absorption, excretion, and secretion.

18. 3.Columnar E pithelium This is formed by a single layer of cells, rectangular in shape , on a basement membrane.

19. It is found lining the organs of the alimentary tract and consists of a mixture of cells. Some absorb the products of digestion and others secrete mucus. Mucus is a thick sticky substance secreted by modified columnar cells called goblet cells .

20. 4.Ciliated epithelium This is formed by columnar cells each of which has many fine , hair-like processes, called cilia. The cilia consist of microtubules inside the plasma membrane that extends from the free border (luminal border) of the columnar cells. .

21. Ciliated epithelium The wave-like movement of many cilia propels the contents of the tubes, which they line in one direction only

22. Ciliated epithelium is found lining the uterine tubes and most of the respiratory passages. In the uterine tubes the cilia propel ova towards the uterus and in the respiratory passages they propel mucus towards the throat.

23. Functions of Ciliated Epithelium It is responsible for passing of ovum through fallopian tube. In respiratory tract, it helps in expelling the mucus and particles tr a pped in it, towa r ds the ph a r y n x.

24. Stratified E pithelia Stratified epithelia consist of several layers of cells of various shapes . The superficial layers grow up from below. Basement membranes are usually absent. The main function of stratified epithelium is to protect underlying structures from mechanical wear and ear . There are two main types: stratified squamous and transitional

25. Stratified squamous epithelium This is composed of a number of layers of cells of different shapes representing newly formed and mature cells. In the deepest layers the cells are mainly columnar.as they grow towards the surface, they become flattened and are then shed.

26. Stratified epithelium

27. Non- keratinised stratified epithelium. This is found on wet surfaces that may be subjected to wear and tear but are protected from drying . e.g . the conjunctiva of the eyes , the lining of the mouth, the pharynx, the esophagus and vagina .

28. Keratinized stratified epithelium This is found on dry surfaces that are subjected to wear and tear, i.e. skin, hair and nails. The surface layer consists of dead epithelial cells to which the protein keratin has been added.

29. This forms a tough, relatively waterproof protective layer that prevents drying of the underlying live cells. The surface layer of skin is rubbed off and is replaced from below

30. Transitional epithelium This is composed of several layers of pear-shaped cells and is found lining the urinary bladder . It allows for stretching as the bladder fills. Urinary bladder .

31. Connective tissue Connective tissue is the most abundant tissue in the body . The cells forming the connective tissues are more widely separated from each other than those forming the epithelium , and intercellular substance (matrix) is present in considerably larger amounts.

32. There may or may not be fibres present in the matrix, which may be of a semisolid jelly-like consistency or dense and rigid , depending upon the position and function of the tissue.

33. 2. MuscularTissue Muscle: an organ composed of one of three types of muscle tissue (skeletal, cardiac or smooth) , specialized for contraction to produce voluntary or involuntary movement

34. Muscular Tissue

35. Muscular Tissue A group of cells (fibers) specialized to produce motion in response to muscle action potentials by its qualities of contractility, extensibility, elasticity and excitability

36. Properties of Muscular Tissue 1. Excitability : an ability of muscle to generate impulse.

37. Contractility: it is either shortening or development of tension or both. Isotonic Contraction-contraction in which tension remains same whereas changes occurs in the length of muscle fiber. E.g. flexion of arm Isometric Contraction-contraction in which length of muscle fibers remain same and tension is increased. E.g. holding book by hand, pulling any heavy object

38. Muscle Tone- the muscle fibers always maintain a state of slight contraction with certain degree of vigor and tension. This is a state of partial contraction of muscles. It is achieved by the contraction of a few muscle fibres at a time. Extensibility - an ability of muscle fibers to stretch without being damaged Elasticity- an ability of muscle fibers to return to its original length and shape after contraction or extension

39. F u n cti o ns o f M u s c u l a r ti s su e : Through sustained contraction or alternating contraction & relaxation, muscular tissue has four functions: 1. Producing Body Movements- movements of the whole body such as walking and running, and localized movements such as holding pen, nodding head, rely on integrated functioning of bones, joints and skeletal muscles

40. Stabilizing Body Positions- Skeletal muscle contractions stabilize joints and help maintain body positions such as sitting & standing Storing and moving substances within body- sustained contractions of sphincters temporarily stores food in stomach and urine in urinary bladder. Cardiac muscle contractions pump blood through blood vessels of the body. -cont.

41. Smooth muscles contractions move food and substances such as bile, enzymes through g.i.t., push gametes through passageway of reproductive system, propel urine through urinary system. Skeletal muscle contractions promote the flow of lymph and helps the return of blood to heart. 4.Generating heat- As muscular tissue contracts, it produces heat, by thermogenesis. Heat generated by muscle is used to maintain normal body temp.

42. Types of Muscular Tissue M u sc l e Stria t io n s Con t ro l Nerve Supp ly Skeletal Present Voluntary Somat i c Cardi a c Present Involuntary Autonomic S m oo th Absent Involuntary Autonomic

43. Cells of connective tissue Connective tissue, excluding blood (Ch. 4), is found in all organs supporting the specialized tissue. The different types of cell involved include: fibroblasts fat cells macrophages leukocytes mast cells.

44. COMPOSITION OF CONNECTIVE TISSUE Collagen Fibers: Large fibers made of the protein collagen and are typically the most abundant fibers. Promote tissue flexibility. Elastic Fibers: Intermediate fibers made of the protein elastin. Branching fibers that allow for stretch and recoil Reticular Fibers: Small delicate, branched fibers that have same chemical composition of collagen. Forms structural framework for organs such as spleen and lymph nodes.

45. C L A SSIFI CA TIO N O F CONNE C TIVE TISSUE Loose connective tissue : Areolar connective tissue Adipose connective tissue Reticular connective tissue Dense connective tissue: Dense regular connective tissue Dense irregular connective tissue Elastic connective tissue

46. CLASSIFICATION OF CONNECTIVE TISSUE Cartilage: Hyaline cartilage Fibro cartilage Elastic cartilage Bone tissue Liquid connective tissue Blood tissue Lymph

47. Loose connective tissue Areolar Connective tissue: They forms a loose network in intracellular material . It consists of collagen, elastic fibers, reticular fibers and several kinds of cells. Location: Below the skin, fill space between muscles, supports blood vessels and nerves in alimentary canal. Functions: It gives strength, elasticity and support to tissue.

48. Areolar Connective tissue:

49. ADIPOSE CONNECTIVE TISSUE It consists of adipocytes which stores fat. Lo c ati o n: It is p r esent in s u bcut a n e ous la y e r deep in the skin, around the heart and kidneys Functions : Prevents heat loose from body. Act as reservoir of energy. It give shape to the limbs and body. It protects underlying organ from injury.

50. ADIPOSE CONNECTIVE TISSUE

51. RETICULAR CONNECTIVE TISSUE It contains reticular fibers and reticular cells. Location: It is present in the supporting framework of liver, spleen, lymph nodes, red bone marrow and it is also found around blood vessels and muscles. Functions: It binds together smooth muscle tissue cells, filters and removes microbes in the lymph node.

52. RETICULAR CONNECTIVE TISSUE

53. DENSE CONNECTIVE TISSUE In this tissue, fibers are densely packed. The fiber content is higher. Cell content is lower as compared to loose connective tissue.

54. DENSE REGULAR CONNECTIVE TISSUE Bundles of collagen fibers are arranged in parallel patterns to provide strength to tissue. Fibroblast are appear in rows between the fibers. It is tough in nature. Location: It forms tendons (attach muscle bone) and ligaments(attach bone to bone). Functions: It provides strong attachment to structure.

55. DENSE REGULAR CONNECTIVE TISSUE

56. DENSE IRREGULAR CONNECTIVE TISSUE It contains collagen fibers which are irregular arranged and a few fibroblasts are appear in rows between the fibers. Location: It present in dermis layer of skin, membrane capsules around kidneys, liver, testes and lymph node, heart valves. Functions: It provides strength to different organs.

57. DENSE IRREGULAR CONNECTIVE TISSUE

58. ELASTIC CONNECTIVE TISSUE It consists of freely branching elastic fibers. Fibroblast are present in space between fibers. It is yellowish in colour. Location: It is present in tissues , walls of elastic arteries, trachea, bronchial tubes and vocal cords. Functions : It allows stretching of various organs.

59. ELASTIC CONNECTIVE TISSUE

60. CA R TILAGE It con s i st of network of closely packed collagen fibers and elastic fibers. The ce l l s o f mat u re ca rti la g e ca ll e d as chondrocytes.

61. HYALINE CARTILAGE It is bluish white in color. It consists of fine collagen fibers and many chondrocytes. Location: It is present at the end of long bones, anterior ends of ribs, nose and parts of larynx, trachea, bronchi, bronchial tubes. Function: It provides small surface for movement at joints, flexibility and support.

62. HYALINE CARTILAGE

63. FIBRO CARTILAGE It is strongest form of cartilage. The chondrocytes are scattered among the bundle collagen fibers within the extracellular matrix. Location: It is present in inter-verteblar disc. Functions: It covers and protects bony structures of body.

64. FIBRO CARTILAGE

65. ELASTIC CARTILAGE The chondrocytes are located within a threadlike network of elastic fibers within extracellular matrix. Location: It is present in pinna of ear and top of larynx. Functions: It provides strength and elasticity and maintain the shape of certain organs such as the external ear.

66. ELASTIC CARTILAGE

67. 4. Nervous Tissue The human body is composed of approximately 200 distinctly different types of cells. These cells are organized into four basic tissues that in turn, are assembled to form organs.

68. Nervous tissue consists of two kinds of nerve cells: Neurons are the basic structural unit of the nervous system. Each cell consists of the following parts; the cell body contains the nucleus and other cellular organelles.

69. The dendrites are typically short, slender extensions of the cell body that receive stimuli. The axon is typically a long, slender extension of the cell body that sends stimuli.

70. The axon branches are, typically, smaller extensions of the axon. Neuroglia , or glial cells , provides support functions for the neurons, such as insulation or anchoring neurons to blood vessels.

71. N e u r on

72. References: Presentation on Introduction To Human Anatomy & Physiology, By Mr. Abhay Shripad Joshi. Human Anatomy and Physiology-I, By Dr. Mahesh Prasad, Dr. Antesh Kumar Jha, Mr. Ritesh Kumar Srivastav, Nirali Prakashan, As per PCI Syllabus. Page No. 1.23 to 1.28. www.google.com.

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