Presentation is loading. Please wait.

Presentation is loading. Please wait.

Tissues and tissue types

Similar presentations

Presentation on theme: "Tissues and tissue types"— Presentation transcript:

1 Tissues and tissue types
Tissues are: Collections of specialized cells and cell products organized to perform a limited number of functions Histology = study of tissues The four tissue types are: Epithelial Connective Muscular Nervous

2 Epithelial tissue Includes glands and epithelium Is avascular
Glands are secretory Is avascular Forms a protective barrier that regulates permeability Cells may show polarity

3 Functions of epithelium
Physical protection Control permeability Provide sensation Produce specialized secretions

4 Specializations of epithelium
Perform secretory functions Perform transport functions Maintain physical integrity Ciliated epithelia move materials across their surface

5 The Polarity of Epithelial Cells

6 Maintaining the integrity of epithelium
Cells attach via cell adhesion molecules (CAM) Cells attach at specialized cell junctions Tight junctions Desmosomes Gap junctions

7 Intercellular connections

8 Structure of typical epithelium
Basal lamina attaches to underlying surface Lamina lucida Lamina densa Germinative cells replace short-lived epithelial cells

9 Classification of epithelia
Number of cell layers Simple Stratified Shape of apical surface cells Squamous Cuboidal Columnar

10 Squamous Epithelia

11 Cuboidal Epithelia

12 Cuboidal Epithelia

13 Transitional Epithelium

14 Columnar Epithelia

15 Columnar Epithelia

16 Columnar Epithelia


18 Glandular epithelia Exocrine glands Endocrine glands
Secrete through ducts onto the surface of the gland Endocrine glands Release hormones into surrounding fluid

19 Glandular secretions can be:
Merocrine (product released through exocytosis) Apocrine (involves the loss of both product and cytoplasm) Holocrine (destroys the cell)

20 Mechanisms of Glandular Secretion

21 Glands Unicellular Multicellular Individual secretory cells
Organs containing glandular epithelium Classified according to structure

22 A Structural Classification of Exocrine Glands

23 Connective tissue functions:
Establishing a structural framework Transporting fluids and dissolved materials Protecting delicate organs Supporting, surrounding and interconnecting tissues Storing energy reserves Defending the body from microorganisms

24 A Classification of Connective Tissues

25 Connective tissues contain
Specialized cells Matrix Composed of extracellular protein fibers and a ground substance

26 Connective tissue proper
Contains varied cell populations Contains various fiber types A syrupy ground substance

27 Fluid connective tissue
Contains a distinctive cell population Watery ground substance with dissolved proteins Two types Blood Lymph

28 Supporting connective tissues
Less diverse cell population Dense ground substance Closely packed fibers Two types Cartilage Bone

29 Connective tissue proper
Contains fibers, a viscous ground substance, and a varied cell population Fibroblasts Macrophage Adipocytes Mesenchymal cells Melanocytes Mast cells Lymphocytes Microphages

30 Connective tissue proper
Three types of fiber Collagen fibers Reticular fibers Elastic fibers

31 Connective tissue proper
Classified as loose or dense Loose Embryonic mesenchyme, mucous connective tissues Areolar tissue Adipose tissue Reticular tissue Dense Dense regular CT Dense irregular CT


33 The Cells and Fibers of Connective Tissue Proper

34 Connective Tissue in Embryos

35 Adipose and Reticular Tissues

36 Dense Connective Tissues

37 Dense Connective Tissues

38 Dense Connective Tissues

39 Fluid connective tissues
Distinctive collections of cells in a fluid matrix Blood Formed elements and plasma Red blood cells, white blood cells and platelets Arteries carry blood away, veins carry to the heart Capillaries allow diffusion into the interstitial fluid Lymph Interstitial fluid entering the lymphatic vessels

40 Formed Elements of the Blood

41 Supporting connective tissues
Cartilage and bone support the rest of the body Cartilage Grows via interstitial and appositional growth Matrix is a firm gel containing chondroitin sulfate Cells called chondrocytes Cells found in lacunae Perichondrium separates cartilage from surrounding tissues Three types: hyaline, elastic and fibrocartilage

42 The Perichondrium and Types of Cartilage

43 The Perichondrium and Types of Cartilage

44 The Perichondrium and Types of Cartilage

45 Bone, or osseus tissue Has osteocytes Little ground substance
Depend on diffusion through canaliculi for nutrients Little ground substance Dense mineralized matrix Surrounded by periosteum

46 Bone

47 Membranes are simple organs
Form a barrier Composed of epithelium and connective tissue Four types Cutaneous Synovial Serous Mucous

48 Membranes

49 Mucous membranes Line cavities that communicate with the exterior
Contain lamina propria

50 Serous membranes Line sealed internal cavities Form transudate

51 Cutaneous membrane Synovial membrane Covers the body surface
Incomplete lining within joint cavities


53 Organs and systems are interconnected
Network of connective tissue proper consisting of Superficial fascia Deep fascia Subserous fascia

54 The Fasciae

55 Muscle tissue Specialized for contraction Three types Skeletal Cardiac

56 Muscle Tissue

57 Muscle Tissue

58 Muscle Tissue

59 Skeletal muscle Cells are multinucleate Striated voluntary muscle
Divides via satellite cells

60 Cardiac muscle Cardiocytes occur only in the heart
Striated involuntary muscle Relies on pacemaker cells for regular contraction

61 Smooth muscle tissue Non-striated involuntary muscle
Can divide and regenerate

62 Neural tissue Conducts electrical impulses
Conveys information from one area to another

63 Neural tissue cells Neurons Neuroglia Transmit information
Support neural tissue Help supply nutrients to neurons

64 Neural Tissue

65 Neural anatomy Cell body Dendrites Axon (nerve fiber)
Carries information to other neurons

66 Inflammation and regeneration
Injured tissues respond in coordinated fashion Homeostasis restored by inflammation and regeneration

67 Inflammatory response
Isolates injured area Damaged cells, tissue components and dangerous microorganisms removed Infection avoided Regeneration restores normal function

68 An Introduction to Inflammation

69 Aging and tissue repair
Change with age Repair and maintenance less efficient Structure altered Chemical composition altered

70 Aging and cancer incidence
Incidence of cancer increases with age 70-80% of all cases due to exposure to chemicals or environmental factors

71 Changes in a Tissue under Stress

Download ppt "Tissues and tissue types"

Similar presentations

Ads by Google