Connective Tissues: Types, Functions, and Elements

1. Connective Tissue Tissues

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. glandular epithelium & how is it 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

5. Glandular epithelium – made up of cells that produce secretions

6. endocrine glands, what they secrete & how do they do it • Ductless glands that produce hormones • Secretions include amino acids, proteins, glycoproteins, and steroids • “Stuff” goes directly into blood

7. exocrine glands, what they secrete & how do they do it • More numerous than endocrine glands • Secrete their products onto body surfaces (skin) or into body cavities • Examples include mucous, sweat, oil, and salivary glands • The only important unicellular gland is the goblet cell • “stuff” goes through ducts • Sebum from sebaceous gland secretes acid mantle on skin surface to kill bacteria

8. the major types of connective tissue & some examples • Found throughout the body • Connective tissue proper, cartilage, bone, & blood • All arise from the same stem cell

9. Endoderm becomes gastrointestinal tract, respiratory tract, endocrine glands and organs • Mesoderm becomes bones, cartilage, blood, muscles • Ectoderm becomes the nervous system and skin

10. the general functions of connective tissue • Binding and support, protection, insulation, and transportation

11. the common characteristics of connective tissue • Mesenchyme as their common tissue of origin • Varying degrees of vascularity • Nonliving extracellular matrix, consisting of ground substance and fibers • Collagen is the main protein of ct

12. the major structural elements of connective tissue • Ground substance – unstructured material that fills the space between cells • Fibers – collagen (fibrous), elastic (elastin), or reticular (fibrous)

13. types of cells you find in connective tissue & where you find them • Fibroblasts • Chondroblasts • Osteoblasts • Hematopoietic stem cells • Found in mesenchyme, derived from mesenchymal stem cells

15. Fibroblast

16. Chondroblast

17. Osteoblast

18. Hematopoietic stem cells

20. the two types of loose connective tissue proper given & what characterizes them • Areolarconnective tissue • Gel-like matrix with all three connective tissue fibers • Fibroblasts, macrophages, mast cells, and some white blood cells • Wraps and cushions organs • Widely distributed throughout the body

21. Areolar connective tissue (loose)

22. Loose connective Tissue Proper • Adipose connective tissue • Matrix similar to areolar connective tissue with closely packed adipocytes • Reserves food stores, insulates against heat loss, and supports and protects • Found under skin, around kidneys, within abdomen, and in breasts • Local fat deposits serve nutrient needs of highly active organs

23. Adipose connective tissue (loose)

24. the two types of dense connective tissue proper & what characterizes them • Regular • Parallel collagen fibers with a few elastic fibers • Major cell type is fibroblasts • Attaches muscles to bone or to other muscles, and bone to bone • Found in tendons, ligaments, and aponeuroses

25. Dense Regular (tendons)

26. Dense connective tissue proper • Irregular • Irregularly arranged collagen fibers with some elastic fibers • Major cell type is fibroblasts • Withstands tension in many directions providing structural strength • Found in the dermis, submucosa of the digestive tract, and fibrous organ capsules

27. Dense irregular (fibrous dermis)

28. the 3 different types of cartilage: what they are made of, their functions & where you would find them • Hyaline cartilage • Elastic cartilage • Fibrocartilage cartilage

29. 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

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

31. 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

32. Elastic cartilage has “little eyes”

33. 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

34. Fibrocartilage

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

36. Osseous Tissue

37. 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

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

39. 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.

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

41. Yellow marrow

42. the characteristics & 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

43. Blood