Tissues 1

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

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

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

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

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

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Cuboidal Epithelia 11

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Cuboidal Epithelia Figure 4.4b 13

Transitional Epithelium Figure 4.4c 14

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Columnar Epithelia Figure 4.5a 16

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Columnar Epithelia Figure 4.5b 18

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Columnar Epithelia Figure 4.5c 20

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

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Part 2 23

Connective Tissues 24

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

A Classification of Adult Connective Tissues 26

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

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

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

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

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2) Cells  Fibroblast most abundant Synthesis of fibers and ground substance  Macrophage Phagocytic capacity Components of the connective tissue 33

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

The Cells and Fibers of Connective Tissue Proper 35

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

Connective tissue proper Dense  Dense regular  Dense irregular  Elastic  Poor blood supply 37

Connective Tissue in Embryos 38

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Dense Connective Tissues Figure 4.12a 43

Dense Connective Tissues Figure 4.12b 44

Dense Connective Tissues Figure 4.12c 45

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

Bone 50

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

Formed Elements of the Blood 60

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Specialized for contraction Three types  Skeletal  Cardiac  Smooth Muscle tissue 62

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

Muscle Tissue - Skeletal 64

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

Muscle Tissue - Cardiac 67

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

Muscle Tissue - Smooth 70

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