Tissues 1 Tissues and tissue types l Tissues

Tissues 1

Tissues and tissue types l Tissues are: ¡Group of cells similar in structure an function ¡Tissues are organized into organs ¡Histology = study of tissues l The four tissue types are: ¡Epithelial ¡Connective ¡Muscular ¡Nervous 2

Functions of epithelium l Physical protection l Secretion l Sensory perception l Absorption l Filtration l Excretion 3

Epithelial tissue l Includes glands and epithelium ¡Glands are secretory l Avascular l Polarity l Regeneration l Cellularity l Supported by connective tissue ¡Attached to a basement membrane 4

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Specializations of epithelium ¡Ciliated ¡Microvilli ¡Stereocilia ¡Flagella 6

Classification of epithelia l Number of cell layers ¡Simple ¡Stratified l Shape of apical surface cells ¡Squamous ¡Cuboidal ¡Columnar 7

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Cuboidal Epithelia 11

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Cuboidal Epithelia 13 Figure 4. 4 b

Transitional Epithelium 14 Figure 4. 4 c

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Columnar Epithelia 16 Figure 4. 5 a

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Columnar Epithelia 18 Figure 4. 5 b

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Columnar Epithelia 20 Figure 4. 5 c

Glandular epithelia l Epithelium that secrete substances l Exocrine glands ¡Secrete through ducts onto the surface of the gland l Endocrine glands ¡Release hormones into surrounding fluid. Ductless glands. 21

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Part 2 23

Connective Tissues 24

Connective tissue functions and classification: l Protects l Supports l Bind tissues together l Classification: l Embryonic ¡Mesenchyme ¡Loose connective tissue, mucous l Adult 25

A Classification of Adult Connective Tissues 26

Connective tissues characteristics l No free surface l Vascular ¡Scanty in tendons ¡Except cartilage l Supports the body l Maintain body form 27

Components of the connective tissue 1)Extracellular matrix ¡Ground substance l. Amorphous l. Binds cells to fibers l. Colorless l. Homogeneous l. Liquid, semisolid, gel-like, or hard 28

Matrix l Fibers ¡Collagen (white) l. Most abundant l. Brings flexibility and strength to the tissue l. Thicker one ¡Elastic (yellow) l. Brings elasticity to the tissues l. Can stretch and recoil 29

Fibers l Reticular ¡Thinnest one ¡Found in smooth muscle and framework of the organs ¡Brings flexibility to organs that need changes in volume 30

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Components of the connective tissue 2) Cells ¡Fibroblast lmost abundant l. Synthesis of fibers and ground substance ¡Macrophage l. Phagocytic capacity 33

Components of the connective tissue ¡Adipocytes l. Closely packed l. Signet ring cell l. Nucleus eccentric and flat l. Mesenchymal cells ¡Mast cells l. Releases histamin l. Responsible for allergic reactions ¡Lymphocytes, etc 34

The Cells and Fibers of Connective Tissue Proper 35

Connective tissue proper l Classified as loose or dense l Loose l Areolar tissue l Adipose tissue l Reticular tissue l Rich blood supply 36

Connective tissue proper l Dense ¡Dense regular ¡Dense irregular ¡Elastic ¡Poor blood supply 37

Connective Tissue in Embryos 38

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Dense Connective Tissues 43 Figure 4. 12 a

Dense Connective Tissues 44 Figure 4. 12 b

Dense Connective Tissues 45 Figure 4. 12 c

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Bone, or osseous tissue l Has osteocytes and osteoblasts l Lacuna l Little ground substance l Dense mineralized matrix l Richly Vascularized 49

Bone 50

Part 3 51

Supporting connective tissues: Cartilage ¡Cells called chondrocytes or chondroblasts ¡Cells found in lacunae ¡Firm matrix ¡Avascular ¡Three types: hyaline, elastic, fibrocartilage 52

Types of Cartilage 53

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Types of Cartilage 55

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Types of Cartilage 57

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Fluid connective tissues • Blood – Red blood cells, white blood cells and platelets – Plasma is the fluid matrix 59

Formed Elements of the Blood 60

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Muscle tissue l Specialized for contraction l Three types ¡Skeletal ¡Cardiac ¡Smooth 62

Skeletal muscle l Cells are multinucleate, long, cylindrical l Presence of striation l Voluntary muscle 63

Muscle Tissue - Skeletal 64

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Cardiac muscle l Cells: ¡Long, ¡ 1 or 2 nucleus ¡Branching cells l Intercalated discs l Presence of striation l Involuntary muscle 66

Muscle Tissue - Cardiac 67

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Smooth muscle tissue l Cells ¡Fusiform ¡One central nucleus l Non-striated l Involuntary muscle l Forms the wall of hollow organs 69

Muscle Tissue - Smooth 70

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