1. Tissues II Ch. 4

2. Connective Tissue

3. Matrix Extracellular substances in which connective tissue cells are imbedded. – Support, strength, elasticity Hyaluronic acid: lubricates joints, maintains shape (eyeball) Chondroitin sulfate: support, adhesion of cartilage, bone, heart valves, cornea, umbilical cord

4. Matrix Collagen fibers: cartilage, tendons, ligaments (inelastic) Reticular fibers: support fat, nerves, muscle, and blood vessels (collagen, glycoproteins) Elastic fibers: elastin protein, skin and blood vessels

5. Connective Tissue (CT) 4 classes of connective tissue 1.Connective Tissue Proper 2.Cartilage 3.Bone 4.Blood Most abundant and widely distributed of the 4 tissue types in body, amount in particular organs varies

6. Functions of Connective Tissue 1.Binding and support Ex. bone, connective tissue proper 2.Protection Ex. bone, connective tissue proper 3.Insulation Ex. connective tissue proper 4.Transportation Ex. blood 5.Stores energy Ex. Connective tissue proper

7. Characteristics of Connective Tissue All connective tissues arise from mesenchyme Cells widely scattered within extracellular matrix (except adipose tissue) Most of CT is non-living extracellular matrix Most highly vascularized (except cartilage)

8. Extracellular Matrix of Connective Tissue Consists of A. Ground substance - material in space around cells; largely consists of proteins & fluid B. Fibers 1.Collagen fibers - Made of collagen (a fibrous protein), most abundant/strongest 2.Elastic fibers - Made of elastin (a rubber-like protein) thin, branching 3.Reticular fibers - Made of collagen, thin branching

9. 1.Macrophages – “eat” foreign molecules 1.Fibroblast – secrete fibers until they mature into fibrocytes 1.Leukocytes (WBC)– immune response Connective Tissue Cell Types 4. Mast cells – inflammatory response 5. Adipocyte – fat cell

10. Cells maturity has different names – blast means forming => these are immature, actively mitotic cells that secrete ground substance and fibers for that particular matrix – cyte indicates a blast cell that has become a mature, less active cell Macrophages - phagocytize and break-down foreign materials (macrophages are mature) Leukocytes or white blood cells - involved in immune response Mast cells- involved in inflammatory response Adipocyte - fat cells- store nutrients

12. Connective Tissue (CT) 4 classes of connective tissue 1.Connective Tissue Proper 2.Cartilage 3.Bone 4.Blood

13. 1. Connective Tissue (CT) Proper A.Loose CT 1.Areolar Loose CT 2.Adipose Loose CT 3.Reticular Loose CT B.Dense CT 1.Dense regular CT 2.Dense irregular CT 3.Dense elastic CT

14. A. Loose Connective Tissue

15. edema Other Function- soak up fluid that would cause edema, underlies most epithelial tissue, abundant.

17. LCT: Adipose Adipocytes - store fat, nucleus displaced to the side SUPPORTS AND PROTECTS ORGANS, STORES FAT, INSULATES White fat = stores nutrients Brown fat = lost of mitochondria to make heat instead of ATP – Babies

18. STROMA (“MATTRESS”)- internal framework support reticular fibroblasts and others (white blood cells, mast cells, macrophages)

19. B. Dense (Fibrous) Connective Tissue

21. DCT: Dense Regular Little ground substance, mainly thick wavy collagen fibers running in parallel - very strong and provides resistance to pulling (in the direction the fibers run) – few elastic fibers Fibroblasts are the cells - constantly making collagen fibers FORM TENDONS, LIGAMENTS, AND APONEUROSES

22. Dense Regular Connective Tissue Makes up: a.Ligaments - attach bone to bone, more elastin a.Tendons - attach muscle to bone, cord-like a.Aponeuroses – sheet-like; attach muscle to muscle or bone a.Fascia - “plastic wrap” for muscles

24. fibroblasts between elastic fibers, Allows tissue to recoil after stretching -walls of large arteries, walls of bronchial tubes and lungs, ligaments attaching vertebra together

25. 2. Cartilage A.Characteristics 1.Matrix – gel-like (up to 80% water) 2.Avascular Nutrients from blood vessels in perichondrium Dense irregular CT membrane 3.Cells called chondroblasts secrete matrix (immature), mature into chondrocytes (in lacunae) 4.Can withstand tension and compression At what developmental stage would the chondroblasts stop secreting matrix?

26. 2. Cartilage B.Types 1.Hyaline cartilage 2.Elastic cartilage 3.Fibrocartilage

29. LC2 SHOCK ABSORBER

30. 3. Bone A.Characteristics 1.Matrix Calcium salts Collagen fibers 2.Vascularized 1.Cells called osteoblasts- secrete matrix (immature), mature into osteocytes (1 per lacuna)

31. 3. Bone B. Types 1. Compact Bone Osteon (Haversion System) – fundamental unit -Lamella – (bone calcium salt ring) -Lacuna – space containing the osteocyte -Central (Haversion) Canal- blood, lymph, nerves -Volkmann’s Canal – transverse canals -Canaliculi – microscopic canals between lacunae 2.Spongy Bone – Trabeculae (thin lattice plates)

33. 4. Blood A.Characteristics 1.Matrix – plasma (90% water) 2.Cell types – i.Red blood cells (erythrocytes) – no nucleus, O 2 and CO 2 transport If there is no nucleus what cellular process is not functional? ii.White blood cells (leukocytes) - nucleated, 5 types 1.Neutrophils 2.Lymphocytes 3.Monocytes 4.Eosinophils 5.Basophils iii.Platelets (thrombocytes) – blood clotting

35. Muscle Tissue -Contractile Tissue 3 Types: 1. Skeletal 2. Cardiac 3. Smooth

36. Thin and thick myofilaments give banded look, many mitochondria Sarcolemma – plasma membrane Sarcoplasm - cytoplasm

37. Involuntary, specialized gap junctions called intercalated discs

38. INVOLUNTARY CONTROL

39. Nervous Tissue

40. Cell types: 1.Nerve cell = neuron generate and transmit electrical impulses a.Dendrites – receives and responds b.Axon – transmits impulse 2.Supporting cells: do not conduct impulses Stimulus

41. LC3

42. Membranes Made up of different tissues put together to form a specialized function

44. Membranes 4 types – Cutaneous – skin IS AN ORGAN SYSTEM! Outer layer is stratified squamous epithelium that is keratinized (called epidermis) and underlying dermis (dense irregular connective tissue)

45. Membranes 4 types 1.Cutaneous - skin 2.Serous - lining ventral body cavity and organs 1.simple squamous epithelium (called mesothelium) and underlying layer of areolar loose connective tissue

46. Membranes 4 types 1.Cutaneous - skin 2.Serous - lining ventral body cavity and organs 3.Mucous - line body cavities open to exterior 1.stratified squamous or simple columnar epithelia and underlying layer of areolar loose connective tissue

47. Membranes 4 types 1.Cutaneous - skin 2.Serous - lining ventral body cavity and organs 3.Mucous - line body cavities open to exterior 4.Synovial - line joint cavities Loose areolar connective tissue and adipose

48. Membranes 1.Cutaneous – ET and CT 1.Serous – ET and CT 1.Mucous – ET and CT 1.Synovial – CT and CT LC4