Tissue and Membranes ST110 Concorde Career College

1. Tissue and MembranesST110Concorde Career College

2. INTRODUCTION • Tissue: group of similar cells that perform a common function • Matrix: nonliving intercellular material • Histology: The study of the structure, composition and functions of tissues

3. Four Major Types of Human Tissue • Epithelial • Connective • Muscle • Nervous

4. EPITHELIAL TISSUE • Types • Epithelium is divided into two types: • Membranous (covering or lining) epithelium • Glandular epithelium

5. Epithelial tissue • Locations • Membranous epithelium: covers the body and some of its parts and lines the serous cavities; blood and lymphatic vessels; and respiratory, digestive, and genitourinary tracts • Glandular epithelium: secretory units of endocrine and exocrine glands • Along with connective are bound together by a basement membrane.

6. Epithelial Tissues • Functions include: • Protection • Skin • Excretion and Secretion • endocrine glands • Mucous glands • Kidneys • Sweat glands • Diffusion • Alveolar wall • Cleaning • Intestinal tract (Ciliated) • Absorption • Intestinal tract • Kidneys • Sensation • Skin • Tongue

7. EPITHELIAL TISSUE (cont.) • Generalizations about epithelial tissue • Limited amount of matrix material • Membranous type attached to a basement membrane • Avascular • Cells are in closely packed together, with many desmosomes and tight junctions • Capable of reproduction

8. EPITHELIAL TISSUE: MEMBRANOUS • Classification of epithelial tissue • Membranous (covering or lining) epithelium • Classification based on cell shape • Squamous • Cuboidal • Columnar • Transitional • Pseudostratified columnar

9. EPITHELIAL TISSUE: MEMBRANOUS • Epithelial and Connective tissue are bound together by basement membrane

11. EPITHELIAL TISSUE Classification based on layers of cells: Simple epithelium • Simple squamous epithelium • One-cell layer of flat cells • Permeable to many substances • Examples: Alveoli of the lungs and lining of blood vessels • Simple cuboidal epithelium • One-cell layer of cells that are as tall as they are wide • Found in many glands and ducts (secretion & absorption)

12. Simple squamous • Found in the lining of the heart, blood and lymphatic vessels, body cavities, and alveoli of the lungs.

13. Simple cuboidal

14. EPITHELIAL TISSUE (cont.) • Classifications based on layers of cells (cont.) • Simple columnar epithelium • Single layer of tall, column-shaped cells • Cells often modified for certain functions such as goblet cells (secretion), cilia (movement), microvilli (absorption) • Often lines hollow visceral structures • Pseudostratified columnar epithelium • Columnar cells of differing heights • All cells rest on basement membrane but may not reach the free surface above • Cell nuclei at odd and irregular levels • Found lining air passages and segments of male reproductive system • Motile cilia and mucus are important modifications

15. Simple columnar

16. Pseudostratified columnar

17. Cilia • Hair-like extensions of cells in the respiratory tract and female reproductive system.

18. EPITHELIAL TISSUE (cont.) Classifications based on layers of cells (cont.) • Stratified epithelium • Keratinized stratified squamous epithelium • Multiple layers of flat, squamous cells • Cells filled with keratin • Covering outer skin on body surface • Nonkeratinized stratified squamous epithelium • Lining vagina, mouth, and esophagus • Free surface is moist • Primary function is protection • Stratified cuboidal epithelium • Two or more rows of cells are typical • Basement membrane is indistinct • Located in sweat gland ducts and pharynx

19. Keratinized stratified squamous • Found in covering outer skin on body surface.

20. Nonkeratinized stratified squamous • Found in lining of vagina, mouth and esophagus.

21. Stratified cuboidal

22. EPITHELIAL TISSUE (cont.) Classifications based on layers of cells (cont.) • Stratified columnar epithelium • Multiple layers of columnar cells • Only most superficial cells are typical in shape • Rare • Located in segments of male urethra and near anus • Transitional epithelium • Located in lining of hollow viscera subjected to stress (e.g., urinary bladder) • Often 10 or more layers thick • Protects organ walls from tearing • Has varying shapes and is capable of stretching (found in urinary bladder)

24. EPITHELIAL TISSUE: GLANDULAR EPITHELIUM • Glandular epithelium • Glands are usually composed of simple cuboidal cells • Specialized for secretory activity • Exocrine glands: discharge secretions into ducts • Simple exocrine glands- only has one duct leading to the surface • Compound exocrine glands- only has two or more ducts leading to the surface • Endocrine glands: “ductless” glands; discharge secretions directly into blood or interstitial fluid • Goblet cells- glandular epithelial cells that secrete mucous to lubricate the intestinal wall

25. EPITHELIAL TISSUE: GLANDULAR EPITHELIUM (cont.) • Structural classification of exocrine glands • Multicellular exocrine glands are classified by the shape of their ducts and the complexity of their duct system • Shapes include tubular and alveolar • Simple exocrine glands: only one duct leads to the surface • Compound exocrine glands: have two or more ducts

27. EPITHELIAL TISSUE: GLANDULAR EPITHELIUM (cont.) • Functional classification of exocrine glands (Figure 5-12) • Apocrine glands • Secretory products collect near apex of cell and are secreted by pinching off the distended end • Secretion process results in some damage to cell wall and some loss of cytoplasm • Mammary glands are good examples • Holocrine glands • Secretion products, when released, cause rupture and death of the cell • Sebaceous glands are holocrine • Merocrine glands • Secrete directly through cell membrane • Secretion proceeds with no damage to cell wall and no loss of cytoplasm • Most numerous gland type Mast= cell that produces heparin and histamine

29. CONNECTIVE TISSUE • Has large amounts of intracellular matrix • Most varied and abundant tissue in the body • Functions, characteristics, and types • General function: • Support – holds organ together • Bind together tissues • Mechanical framework (skeleton) • General characteristics • ECM predominates in most connective tissues and determines its physical characteristics • Consists of fluid, gel, or solid matrix, with or without extracellular fibers (collagenous, reticular, and elastic) and proteoglycans or other compounds that thicken and hold together the tissue

30. CONNECTIVE TISSUE • Types • Three subgroups: • Loose connective Tissue • Dense Connective Tissue • Specialized Connective Tissue

31. CONNECTIVE TISSUE (cont.) • Loose Connective Tissue • Areolar • Adipose • Reticular • Dense Connective Tissue • Fibrous • Elastic • Specialized Connective Tissue • Bone • Compact bone • Cancellous bone • Cartilage • Hyaline • Fibrocartilage • Elastic • Blood

32. Loose areolar connective tissue

33. CONNECTION TISSUE cont. • Areolar connective tissue • One of the most widely distributed of all tissues • Intercellular substance is prominent and consists of collagenous and elastic fibers loosely interwoven and embedded in soft viscous ground substance • Several kinds of cells present, notably fibroblasts and macrophages, also mast cells, plasma cells, fat cells, and some white blood cells • Function: stretchy, flexible connection

34. Areolar connective tissue

35. CONNECTION TISSUE (cont.) • Adipose tissue • Similar to loose connective tissue but contains mainly fat cells • Functions: protection, insulation, support, and food reserve • Reticular tissue • Forms framework of spleen, lymph nodes, and bone marrow • Consists of network of branching reticular fibers with reticular cells overlying them • Functions: defense against microorganisms and other injurious substances; reticular meshwork filters out injurious particles and reticular cells phagocytose them

36. Adipose tissue

37. Reticular tissue

38. Dense CONNECTIVE TISSUE • Dense Connective Tissue • Matrix consists mainly of densely packed fibers and relatively few fibroblast cells • Irregular: fibers intertwine irregularly to form a thick mat • Regular: bundles of fibers are arranged in regular parallel rows • Fibrous(Collagenous): mostly collagenous fibers in ECM • Elastic: mostly elastic fibers in ECM

39. Dense connective tissue

40. Dense fibrous connective tissue

41. Fibrous elastic dense connective tissue

42. Dense CONNeCTIVETISSUE (cont.) • Locations: structures that need great tensile strength, such as tendons and ligaments; also dermis and the outer capsule of the kidney and spleen • Function: furnishes flexible connections that are strong or stretchy

43. DAY 2 Membranes and Wound Healing

44. Specialized CONNECTIVE TISSUE: BONE TISSUE • Bone tissue • Uniquely hard and strong connective tissue type • Cells (osteocytes) embedded in a calcified matrix • Inorganic component of matrix accounts for 65% of total bone tissue • Functions • Support • Protection • Point of attachment for muscles • Reservoir for minerals • Supports blood-forming tissue • Provide movement

45. Specialized CONNECTIVE TISSUE:BONE TISSUE (cont.) • Compact bone • Osteon (Haversian system) • Structural unity of bone • Spaces for osteocytes called lacunae • Matrix present in concentric rings called lamellae • Canaliculi are canals that join lacunae with the central Haversiancanal (communication passageway) • Cell types • Osteocyte: mature, inactive bone cell • Osteoblast: active bone-forming cell • Osteoclast: bone-destroying cell

47. Compact bone tissue

48. Specialized CONNECTIVE TISSUE: BONE TISSUE (cont.) • Cancellous bone made up of trabeculae • Trabeculae: thin beams of bone • Supports red bone marrow • Myeloid tissue: a type of reticular tissue • Produces blood cells • Called spongy bone because of its spongelikeappearance • Endochondrial ossification- the conversion of cartilage to bone • Periosteum- membrane that surrounds bone