ABOUT CONNECTIVE TISSUE ……….

1. ABOUT CONNECTIVE TISSUE……….

2. 2 Histology TERMS: • PARENCHYMA: Epithelial Components of an Organ ( consists of that tissue which conducts the specific function of the organ and which usually comprises the bulk of the organ) STROMA: Supporting Framework of Connective Tissue ……Everything else….This Supports and Cushions the parenchyma.

4. Parenchyma / Stroma:  The parenchyma of an organ consists of that tissue which conducts the specific function of the organ and which usually comprises the bulk of the organ.  Stroma is everything else --

5. Parenchyma/Stroma • The parenchyma of the kidney is epithelial tissue (renal tubules and corpuscles).  The blood vessels, nerves, and supporting connective tissue of the kidney comprise the stroma. • The parenchyma of the spleen is connective tissue (mostly lymphocytes and other blood cells).  The supporting fibrous connective tissue of the spleen comprises the stroma. • The parenchyma of the heart is muscle tissue (cardiac muscle cells).  The nerves, intrinsic blood vessels, and connective tissue of the heart comprise the stroma. • The parenchyma of the brain is nervous tissue (nerve cells and glia).  The blood vessels within the brain and the connective tissue associated with these blood vessels are stroma.

6. Connective Tissue • Widely spaced cells separated by fibers and ground substance (Matrix) • Most abundant and variable tissue type

7. What is MATRIX?

8. Maintaining the Integrity is as GLUE IS IMPORTANT IN THIS MANNER… And So THE MATRIX is Very IMPORTANT in CONNECTIVE TISSUE • MATRIX IS LIKE …..GLUE….

10. Connective Tissue Matrix • Matrix = Fibers + ground substance • 3 Types of fibers occur in connective tissue: collagen, reticular and elastic • Fibroblasts form all 3 of these by secreting protein subunits • Ground Substance = clear, colorless, viscous fluid that fills the spaces between fibers. Its density slows the spread of pathogens. • Composed of glycoproteins and proteoglycans.

11. Connective Tissue Ground Substance • Gelatinous material between cells • absorbs compressive forces • Consists of 3 classes of large molecules • glycosaminoglycans – chondroitin sulfate • disaccharides that attract sodium and hold water • role in regulating water and electrolyte balance • Proteoglycan (bottlebrush-shaped molecule) • create bonds with cells or extracellular macromolecules • adhesive glycoproteins • protein-carbohydrate complexes bind cell membrane to collagen outside the cells

12. Glycosaminoglycans (GAGs) • These are important components of connective tissues. • Long unbranched polysaccharides consisting of a repeating disaccharide unit. • Examples of GAGs : Chrondroitin Sulfate and hyaluronic acid …remember the cement?.

13. Hyauluronic Acid

14. Chondroitin Sulfate

15. Functions of Connective Tissue • connects organs • Support • protection (physical AND immune) • stores energy and produces heat • movement and transport of materials

16. Binding of Organs • Tendons bind muscles to bone • Ligaments bind one bone to another • Fat holds the kidneys and eyes in place • Fibrous tissue binds the skin to underlying muscle

17. Support • Bones support the body • Cartilage supports the ears, nose trachea and bronchi

18. Physical Protection • Easy to see how BONEs. The skeleton, ribs, cranium protect the visceral organs such as brain, lungs and heart.

19. Immune Protection • BLOOD…a connective tissue also…protects us ( the immune cell portion of the blood by attacking foreign invaders such as pathogens) • Connective tissue other than blood i.e. areola tissue produces immune cells such as the MAST cell.

20. Movement • Bones act as levers for body movement • Cartilage involved in movement of vocal cords and ease joint movement

21. Storage • Adipose tissue (fat) is the body’s major energy reserve. • Bone is a reservoir of Calcium and phosphorous. These minerals are needed for many bioreactions one being muscle contraction.

22. Heat Production • Brown Adipose Tissue.- This is a phenomenon used mostly in infants. They do not have the ability to shiver. BAT can generate heat production by “uncoupling ATP’.

23. Transport • Blood: The red blood cells in particular, for oxygen and plasma for nutrients, wastes and hormones. And plasma can be crediting for transporting the red blood cells!

24. Connective Tissue Subgroups: • 1. Connective Tissue Proper • 2. Fluid Connective Tissue • 3. Supporting Connective Tissue

25. Connective Tissue Proper • loose connective tissue (areolar, reticular and adipose tissue) b) dense connective tissues ( regular and irregular forms)

26. Fluid connective Tissues • Those that have cells suspended in watery matrix ( lymph and blood (only 2) Formed Elements of Blood: Erythrocytes = red blood cells Leukocytes = white blood cells Platelets = cell fragments

27. A couple of SUFFIXES - • Cyte- means cell • Blast- means maker or creater

28. Supporting Connective Tissue • Differ from connective tissue proper in having a less diverse cell population • Having a matrix containing much MORE DENSELY PACKED FIBERS • These Protect soft tissues from damage. • You guessed it; BONE and Cartilage! • IMPORTANT: Matrix of Cartilage-is a gel characteristics vary w/ type of fiber ( there are 3) • Matrix of BONE is calcified…makes it rigid.

29. What is Mesenchyme? • The part of the embryonic mesoderm, consisting of loosely packed, unspecialized cells set in a gelatinous ground substance, from which connective tissue,bone, cartilage, and the circulatory and lymphatic systems develop .

31. Cells of Connective Tissue • Fibroblasts produce fibers and ground substance • Macrophages phagocytize foreign material and activate immune system • arise from monocytes (WBCs) • Neutrophils wander in search of bacteria • Plasma cells synthesize antibodies • arise from WBCs • Mast cells secrete • heparin inhibits clotting • histamine that dilates blood vessels • Adipocytes store triglycerides

32. Fibroblasts • Permanent Residents of connective tissue • They are the most abundant cells • Primary function is to maintain structural INTEGRITY by continuously secreting components of the MATRIX, primarily ground substance and FIBERS. • Ex. Of components made by fibroblasts: GAGs, collagen, elastic and reticular fibers, and glycoproteins.

33. Fibers of Connective Tissue • Collagen fibers (white fibers) • tough, stretch resistant, yet flexible • tendons, ligaments and deep layer of the skin • Reticular fibers • thin, collagen fibers coated with glycoprotein • framework in spleen and lymph nodes • Elastic fibers (yellow fibers) • thin branching fibers of elastin protein • stretch and recoil like rubberband (elasticity) • skin, lungs and arteries stretch and recoil

34. Fibrous Connective Tissue Types • Loose connective tissue • gel-like ground substance between cells • types • areolar • reticular • adipose • Dense connective tissue • fibers fill spaces between cells • types vary in fiber orientation • dense regular connective tissue • dense irregular connective tissue

35. Adipocytes •  Brown fat is more typical in infants, being replaced gradually by white fat as we age.  In both cell types fat droplets enlarge to push nuclei and cytoplasm to the periphery. Since alcohol used during tissue preparations dissolve these lipids from the cells they appear in most specimens as circular, empty cells.

36. Embryonic Connective Tissue:Mesenchyme • Irregularly shaped cells • In semifluid ground substance with reticular fibers • Gives rise to all other types of connective tissue Diane Olin, 2009

37. Loose Connective Tissues • Loosely woven fibers throughout tissues • Types of loose connective tissue • areolar connective tissue • adipose tissue • reticular tissue Diane Olin, 2009

38. Areolar Connective Tissue • Cell types = fibroblasts, plasma cells, macrophages, mast cells and a few white blood cells • All 3 types of fibers present • Gelatinous ground substance • Location:Subcutaneous Skin Layer • Thin filling between body parts • Reservoir for water and salts • Wraps nerves, muscles, blood vessels Diane Olin, 2009

39. Areolar Connective Tissue • Black = elastic fibers, • Pink = collagen fibers • Nuclei are mostly fibroblasts Diane Olin, 2009

41. Reticular Tissue • LOCATION: liver, spleen, lymph nodes. • FUNCTION: structural maze support and slows down blood fluids so cells can perform their metabolic functions. ( MAKE UP THE STROMA of ORGANS!!! • RETICULAR FIBERS

42. Adipose Tissue • Peripheral nuclei due to large fat storage droplet • Deeper layer of skin, organ padding, yellow marrow • Reduces heat loss, energy storage, protection • Brown fat found in infants has more blood vessels and mitochondria and responsible for heat generation Diane Olin, 2009

43. Dense Connective Tissue • More fibers present but fewer cells • Types of dense connective tissue • dense regular connective tissue • dense irregular connective tissue • elastic connective tissue Diane Olin, 2009

46. Cartilage • The matrix is a gel-like substance that gives the cartilage shape along with flexability • Combining matrix components with one or more types of fibers produces a variety of 3 types of cartilage: elastic, hyauline and fibercartilage.

48. Connective Tissues is Composed of : • Cells and Matrix • Fibers of Collagen and / or Elastin • May or may not have a PERICHONDRIUM (surrounding covering that secretes matrix)

49. TROPONIN I : Protein that prevent vacualarization in cartilage This protein is being used to treat CANCER Tumors need to vascularize; Troponin -1 could prevent vascularization of metatases.

50. Showing the Vascularization of a Tumor