connective tissue

connective tissue

1. SUBMITTED BY K.GOPALASATHEESKUMAR M.PHARM.PHARMACOLOGY [email protected] 1 SUBJECT: DRUG DESIGN AND MOLECULAR PHARMACOLOGY CONNECTIVE TISSUE [email protected] 2/25/2017

2. INTRODUCTION COMPOSITION OF CONNECTIVE TISSUE TYPES OF CONNECTIVE TISSUE FUNCTIONS OF CONNECTIVE TISSUE HISTOPATHOLOGY STAINING OF CONNECTIVE TISSUE REFERENCES CONTENTS 2 [email protected] 2/25/2017

3. 2/25/2017 [email protected] 3 INTRODUCTION

4. 2/25/2017 [email protected] 4

5. 2/25/2017 [email protected] 5 TYPES

6. Tissues Types of tissues Epithelial tissue : protection, secretion, and absorption C onnective tissue: support, bind, and protect organs Muscle tissue: contraction N ervous tissue : information to other cells CONNECTIVE TISSUE Connects, supports, binds, or separates different types of tissues and organs in the body Develops from the mesoderm Found in b/w other tissues everywhere in the body, including nervous system INTRODUCTION 6 [email protected] 2/25/2017

7. COMPOSITION 7 [email protected] 2/25/2017

8. FIBROBLASTS MACROPHAGES MAST CELLS PLASMA CELLS LEUKOCYTES ADIPOCYTES (FAT CELLS ) MIXTURE OF CELLS 8 [email protected] 2/25/2017

9. FIBROBLASTS Most common cells in connective tissue . Their nuclei are ovoid or spindle shaped and can be large or small in size depending on their stage of cellular activity. S ynthesis ECM and collagen MACROPHAGES Highly phagocytic cells that are derived from blood monocytes. With conventional staining, macrophages are very difficult to identify unless they show visible ingested material inside their cytoplasm. 2/25/2017 [email protected] 9

10. MAST CELLS Bone marrow origin and are distributed chiefly around small blood vessels. They are oval to round in shape, with a centrally placed nucleus . PLASMA CELLS Derived from B lymphocyts They are oval shaped and have the ability to secrete antibodies that are antigen specific . 2/25/2017 [email protected] 10

11. LEUKOCYTES White blood cells, are considered the transient cells of connective tissue. They migrate from the blood vessels into connective tissue by the process of diapedesis . ADIPOCYTES Arise from undifferentiated mesenchymal cells of connective tissue. They gradually accumulate cytoplasmic fat, which results in a significant flattening of the nucleus in the periphery of the cell. 2/25/2017 [email protected] 11

12. Ground substance is a clear, viscous substance with a high water content, but with very little morphologic structure . When stained with basic dyes (periodic acid-Schiff [PAS]), it appears amorphous, it appears as a clear space . Its major component is G lycosaminoglycans (GAGs), which are long, un-branched chains of polysaccharides with repeating disaccharide units. Most GAGs are covalently bonded to a large central protein to form larger molecules called proteoglycans . GROUND SUBSTANCE 12 [email protected] 2/25/2017

13. FIBERS 13 [email protected] 2/25/2017

14. Collagen COLLAGEN FIBERS are the most common and widespread fibers in connective tissue. 25-35% of body The collagen molecule ( tropo -collagen) is a product of the fibroblast. Each collagen molecule is 300 nm in length and consists of three polypeptide amino acid chains. Elastic Elastic fibers have a very resilient nature (stretch and recoil), which is important in areas like the lungs, aorta, and skin. They are composed of two proteins, elastin and fibrillin , and do not have a banding pattern. Reticular RETICULAR FIBERS are small-diameter fibers. Supporting mesh in soft tissues( liver,bone marrow and lymphatic system) 2/25/2017 [email protected] 14

15. TYPES OF CONNECTIVE TISSUE 15 [email protected] 2/25/2017

16. CONNECTIVE TISSUE 16 [email protected] 2/25/2017

17. CONNECTIVE TISSUE PROPER 17 [email protected] 2/25/2017

18. CONNECTIVE TISSUE PROPER 18 [email protected] 2/25/2017

19. Dense irregular connective tissue is a cushion like tissue, which provides great strength against pressure-induced stresses on structures or organs. “Dense” refers to the high abundance of collagen fibers (but fewer cells) compared to loose connective tissue. “Irregular” indicates that the orientation of the fiber bundles is in many different directions (or randomly oriented bundles). Contains mostly collagen fibers with a lesser number of other fibers such as elastic fibers. The skin has a thick layer of dense irregular connective tissue, with fibers arranged in various directions to resist stretching forces in any direction. It is prominent in the dermis of the skin, mammary glands , and capsules of many organs. Function - provide strength. DENSE IRREGULAR CT 19 [email protected] 2/25/2017

20. This type of tissue is composed of coarse collagen bundles that is densely packed and oriented into parallel cylinders . Long , thin fibroblasts are found among the fiber bundles and are oriented in the same direction as the fibers . The nuclei of the fibroblasts are visible, but the cytoplasm is not easily seen . The thick bundles of collagen fibers fill the intercellular spaces. Dense regular connective tissue provides resistance to traction forces in tendons and ligaments . Function = provide strong attachment between various structures DENSE REGULAR CT 20 [email protected] 2/25/2017

21. Loose connective tissue is also called areolar connective tissue. This type of connective tissue has abundant ground substance, with many connective tissue cells and relatively few fibers . It is richly vascularized , flexible , and not highly resistant to stress . The lamina propria of the digestive tract is an extreme example of loose connective tissue. This tissue lies immediately beneath the thin epithelium of the gut, which is one place where the body’s defense mechanisms initially attack bacteria and pathogens . Therefore , plasma cells, mast cells, leukocytes, and fibroblasts are common in this area. Loose connective tissue is characterized by loosely arranged, woven connective fibers , abundant ground substance , and tissue fluid , which contains the rich array of connective tissue cells. LOOSE CONNECTIVE TISSUE 21 [email protected] 2/25/2017

22. SPECIALIZED CONNECTIVE TISSUES 22 [email protected] 2/25/2017

23. Specialized Connective Tissues 23 [email protected] 2/25/2017

24. Adipose tissue is a special form of connective tissue and has a rich neurovascular supply. Adipocytes (fat cells) are scattered within a loose collagenous supporting tissue in this unilocular adipose tissue . Each adipose cell contains a single large drop of lipid ; it has a thin rim of cytoplasm around the lipid , and its flattened nucleus is located in the periphery of the cell. Adipocytes are the primary site for storage of energy, and lipid deposition and mobilization are regulated by hormonal factors (steroids, insulin, thyroid hormone, etc.). Adipocytes also play a role in the synthesis of some hormones such as leptin . During childhood , the adipocyte numbers may increase depending on nutrition and other factors, but in adulthood, adipocyte numbers normally remain constant. ADIPOSE CONNECTIVE TISSUE 24 [email protected] 2/25/2017

25. Reticular tissue is a specialized loose connective tissue that provides a delicate supporting framework for many highly cellular organs, such as endocrine glands, lymphoid organs, the spleen, and the liver. They are arranged in a net like framework to support parenchymal cells, in this example, pancreatic cells . The inset drawing represents the organization of reticular fibers and pancreatic cells . These fibers consist of collagen type III, which forms a mesh like network that supports the liver cells and holds these cells together. There is a sinusoid running between the reticular fibers, which appears as empty space here. RETICULAR CONNECTIVE TISSUE 25 [email protected] 2/25/2017

26. Elastic connective tissue consists predominately of elastic material, and this allows distension and recoil of the structure. This tissue can be found in some vertebral ligaments , arterial walls , and in the bronchial tree . Thick bundles of elastic lamellae are arranged in parallel wavy sheets, with the smooth muscle cells and collagen fibers insinuated between alternating lamellae. The elastic fibers are formed by elastin and fibrillin micro-fibrils . Elastic connective tissue is able to recoil after stretching. This property in large arteries helps to moderate the extremes of pressure associated with the cardiac cycle . Abnormal expression of the fibrillin (FBN1) gene is associated with abnormal elastic tissue disease. ELASTIC CONNECTIVE TISSUE 26 [email protected] 2/25/2017

27. EMBRYONIC CONNECTIVE TISSUES 27 [email protected] 2/25/2017

28. EMBRYONIC CONNECTIVE TISSUES 24 [email protected] 2/25/2017

29. Mesenchyme ( mesenchymal connective tissue) is found in the developing structures in the embryo . It contains scattered reticular fibers and mesenchymal cells, which have irregular , star or spindle shapes and pale-stained cytoplasm. These cells exhibit cytoplasmic processes, which often give the cells a stellate appearance. Mesenchymal cells are relatively unspecialized and are capable of differentiating into different cell types in mature tissue cells, such as cartilages, bones , and muscles . These blood cells contain a nucleus in each cell . T his is the characteristic of their immature state ( a nucleated red blood cells are characteristic of the mature state and are found in adult tissues). Interestingly enough, some vertebrates , such as frogs and chickens, have nucleated red blood cells in the adult state. MESENCHYMAL CONNECTIVE TISSUE 29 [email protected] 2/25/2017

30. An example of mucous connective tissue that has an abundance of a jellylike matrix with some fine aggregates of collagen fibers and stellate-shaped fibroblasts is shown. It is found in the umbilical cord and sub dermal connective tissue of the embryo . Mucous tissue is a major constituent of the umbilical cord , where it is referred to as Wharton jelly . In this example, the viscous ground substance has been stained with a special stain to reveal jelly like mucin , which contains hyaluronic acid and glycoproteins . Collagen fibers and large stellate-shaped fibroblasts (not mesenchymal cells ) predominate in the mucous tissue. MUCOUS CONNECTIVE TISSUE 30 [email protected] 2/25/2017

31. SUPPORTIVE CONNECTIVE TISSUE 31 [email protected] 2/25/2017

32. Bone cells (osteocytes) are surrounded by a matrix of collagen fibres strengthened by inorganic salts, especially calcium and phosphate . This provides bones with their characteristic strength and rigidity. BONE 32 [email protected] 2/25/2017

33. 33 [email protected] 2/25/2017

34. TYPES OF BONE 34 [email protected] 2/25/2017

35. Found on ends of long bone Contains bony bars and plates called trabeculae separated by irregular spaces Blood cells are made within the red marrow found in the spongy bone SPONGY BONE 35 [email protected] 2/25/2017

36. COMPACT BONE Found in the outer portion of long bones Consists of many cylindrical-shaped units called osteon 36 [email protected] 2/25/2017

37. Cartilage has a flexible rubbery matrix. It is found in organs like, External ear Tip of the nose or The “Adam’s apple” (thyroid cartilage of the larynx). CARTILAGE 37 [email protected] 2/25/2017

38. TYPES OF CARTILAGE 38 [email protected] 2/25/2017

39. Hyaline Cartilage Elastic Cartilage Fibrocartilage Hyaline cartilage is named for its clear, glassy microscopic appearance. surrounded by a sheath of dense irregular connective tissue. locations : end of a rib to the breastbone, around the larynx, the fetal skeleton. Functions : Eases joint movements; holds airway open during respiration; moves vocal cords during speech , growth zones of long bones of children. Elastic cartilage is named for its conspicuous elastic fibers. surrounded by a sheath of dense irregular connective tissue. locations : External ear; epiglottis Functions : Provides flexible, elastic support. Fibrocartilage for its coarse, readily visible bundles of collagen. locations: Pubic- symphysis , spinal column; menisci, or pads of shock-absorbing cartilage, knee joint. Functions: Resists compression and absorbs shock in some joints. TYPES OF CARTILAGE 39 [email protected] 2/25/2017

40. FLUID CONNECTIVE TISSUE 40 [email protected] 2/25/2017

41. BLOOD Connective tissue composed of cells suspended in liquid matrix called plasma Red blood cells (erythrocytes) – carries oxygen White blood cells (leukocytes) – fights infection Platelets – fragment of giant cells found in bone marrow 41 [email protected] 2/25/2017

42. Type Connective Tissue Cells Main Locations Main Functions Dense irregular connective tissue Predominantly fibroblasts; other connective tissue cells occasionally present Dermis of the skin, capsules of many organs   Resists stress from all directions; protects organs Dense regular connective tissue Predominantly fibroblasts; other connective tissue cells occasionally present Tendons, ligaments Provides resistance to traction forces Loose connective tissue Fibroblasts, macrophages, adipocytes, mast cells, plasma cells, leukocytes Lamina propria of gastrointestinal tract; around the nerves and vessels (in adventitia layer) Provides protection, suspension, and support; conduit for vessels and nerves; environment for immune defense function Adipose connective tissue Predominantly adipocytes (fat cells); fibroblasts and other connective tissue cells occasionally present Hypodermis of the skin, mammary glands, and around many organs Provides energy storage, insulation; cushioning of organs; hormone secretion Types of connective tissue 42 [email protected] 2/25/2017

43. Reticular connective tissue Fibroblasts, reticular cells, hepatocytes, smooth muscle cells, Schwann cells depending on the location Liver, pancreas, lymph nodes, spleen, and bone marrow Provides supportive framework for hematopoietic and parenchymal organs Elastic connective tissue Predominantly fibroblasts or smooth muscle cells; other connective tissue cells occasionally present Vertebral ligaments, walls of the large arteries Provides flexible support for the tissue; reduces pressure on the walls of the Arteries Mesenchymal connective tissue Mesenchymal cells Embryonic mesoderm Gives rise to all connective tissue types Mucous connective tissue Spindle-shaped fibroblasts Umbilical cord, subdermal layer of the fetus, dental pulp of the developing teeth, nucleus pulposus of the disk Provides cushion to protect the blood vessels in the umbilical cord. 43 [email protected] 2/25/2017

44. Providing a medium for oxygen and nutrients to diffuse from capillaries to cells. Wraps around and cushions and protects organs Stores nutrients Internal support for organs As tendon and ligaments, it protects joints and attaches muscles to bone and each other Runs through organ capsules and in deep layers of skin giving strength FUNCTIONS OF CONNECTIVE TISSUE 44 [email protected] 2/25/2017

45. Fibroblasts are responsible for synthesis of various fibers and extracellular matrix components, such as collagen, elastic, and reticular fibers. Macrophages contain many lysosomes and are involved in the removal of cell debris and the ingestion of foreign substances ; they also aid in antigen presentation to the immune system. Adipocytes function to store neutral fats for energy or production of heat and are involved in hormone secretion. Mast cells contain many granules, indirectly participate in allergic reactions, and act against microbial invasion. Plasma cells are derived from B lymphocytes and are responsible for the production of antibodies in the immune response. Lymphocytes participate in the immune response and protect against foreign invasion. Neutrophils are the first line of defense against bacterial invasion. Eosinophils have anti-parasitic activity and moderate allergic reactions. Basophils have a (primary) function similar to mast cells; they mediate hypersensitivity reactions. FUNCTIONS OF THE CELLS IN CONNECTIVE TISSUE 45 [email protected] 2/25/2017

46. 2/25/2017 [email protected] 46 HISTOPATHOLOGY

47. 1 in 10 people have a connective tissue disorder Congenital disease – Marfan syndrome Ehlers- Danlos syndrome Myxomatous degeneration – Pathological weakness Mixed connective tissue disease – Autoimmune disease Systemic lupus erythematosus (SLE) Scurvy – Vit -C – collagen synthesis PATHOLOGICAL TERMS Urticaria : An itchy skin eruption Pruritis : Itching of the skin Cirrhosis : An abnormal liver condition Jaundice : Yellow staining of the skin Coagulopathy : A disorder that prevents the normal clotting process Necrosis : Irreversible cell changes that occur as a result of cell death CONNECTIVE TISSUE DISORDER 47 [email protected] 2/25/2017

48. Van Gieson’s stain- staining of collagen and other connective tissue Masson’s trichrome stain- distinguishing cells from surrounding connective tissue Mallory’s trichrome stain- examining the collagen of connective tissue Aniline blue stain Eosin- stain of blood cells Reticulin stain- visualize reticular fiber STAINING OF CONNECTIVE TISSUE 48 [email protected] 2/25/2017

49. Human Anatomy second edition by Kenneth S. Saladin, “ H istology: the study of tissues”. Anatomy& Physiology in Health and Illness 12th Edition by Ross and Wilson, “ The cells, tissues and organization of the body ”. Fundamentals of histology by GP Verma , “Connective tissue”. Anatomy& Physiology for nurses by Inderbir Singh, “General connective tissue” Human anatomy & Physiology by Biology-about.com, “Connective tissue Types and examples”. Biology Encyclopedia by Biologyreference.com, “Connective tissue”. REFERENCES 49 [email protected] 2/25/2017

50. THANK YOU 50 [email protected] 2/25/2017