Tissues Groups of cells with a common structure

Tissues § Groups of cells with a common structure and function § Four primary types § Epithelium § Connective tissue § Muscle § Nervous Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Epithelial Tissues § Functions: protection, filtration, absorption, secretion § Location: § Line body cavities, cover body surfaces § Glandular epithelia § Exocrine glands: secretion to exterior via ducts § Endocrine glands: secretion directly into blood Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Epithelium Characteristics § Cells fit closely together § always one free surface § lower surface bound by “basement membrane” § Avascular (have no blood supply) § Regenerate easily if well nourished Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Epithelial Tissues: Classification § 1. Cell shape § Squamous: flattened cells § Cuboidal: cube shaped § Columnar: column shaped Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Epithelial Tissues: Classification § Number of cell layers § Simple – one layer § Stratified – more than one layer Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Epithelial Tissues: Attachments § Basement membrane § Structural support, attachment to tissue underneath § Made of secreted proteins Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Attachments: Junctions Between Cells §Tight junctions: nothing passes §Adhesion junctions: some movement between cells §Gap junctions: protein channels Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings. Figure 4. 2

Stratified Epithelium § Stratified squamous § Cells at the free edge are flattened § protective covering where friction is common § Locations § Skin § Mouth § Esophagus Figure 3. 18 e Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Connective Tissue Functions § Binds body tissues together § Supports the body § Provides protection Composed of cells and extracellular matrix: 1. Ground substance of water, proteins and sugars 2. Fibers Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

A. Fibrous Connective Tissue § Function: strength and flexibility § Fibers: collagen, elastic, reticular § Matrix: water, polysaccharides, proteins § Cells: fibroblasts, WBCs, fat cells Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

A. Fibrous Connective Tissue - 4 types § Loose (areolar): surrounds many organs, lines cavities around blood vessels § Dense: tendons, ligaments, deeper layers of skin Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

A. Fibrous Connective Tissue Elastic: surrounds stomach, bladder, maintains shape § Reticular: internal framework of soft organs (liver) and Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

B. Special Connective Tissues § Blood: fluid matrix of plasma; red blood cells, white blood cells, and platelets § Adipose tissue: fat cells; function in insulation, protection, and energy storage Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

B. Special Connective Tissue § Cartilage: no blood vessels, high collagen content § Bone: inorganic matrix with calcium salts for hardness Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Muscle Tissue: § Skeletal muscle § moves body parts § voluntary, multinucleated § Cardiac muscle § only in the heart § involuntary, single nuclei § Smooth muscle § surrounds hollow Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Nervous Tissue: Transmit Impulses § Neuron: specialized nervous system cell § Structure: cell body, dendrites, axon § Glial cells: support cells to neurons Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Tissue Repair § Regeneration § Replacement of destroyed tissue by the same kind of cells § Fibrosis § Repair by dense fibrous connective tissue (scar tissue) § Determination of method § Type of tissue damaged § Severity of the injury Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

The Language of Anatomy: Body Planes Figure 1. 6 Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Anatomical Position or Direction Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings. Figure 4. 9

Tissue Membranes: Line Body Cavities § Body surfaces, cavities are covered by tissue membranes § Composed of tissues (epithelium and connective)* 4 types Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

1. Serous Membranes reduce friction between organs § Lines interior body cavities § Serous layers separated by serous fluid Figure 4. 1 c Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Body Cavities Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings. Figure 4. 8

2. Mucous Membranes lubricate surfaces, capture debris § Epithelium (various types) plus loose connective tissue § Lines all body cavities that open to body’s exterior § absorption or secretion Figure 4. 1 b Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

3. Synovial Membrane lubricates joints § Connective tissue only § Lines fibrous capsules surrounding joints Figure 4. 2 Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

4. Cutaneous Membrane - skin Protective boundary § Epidermis § Keratinized stratified squamous epithelium § Dermis § dense connective tissue Figure 4. 1 a Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Review - Tissue Membranes: § Serous membrane: lines internal cavities § Mucous membrane: lines external cavities § Synovial membrane: lubricate joints § Cutaneous membrane: skin Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Organs and Organ Systems Perform Complex Functions § Organ systems § Groups of organs that perform a common function. § Digestive system: mouth, throat, stomach, intestines, liver § Lymphatic system: lymph nodes, tonsils, spleen Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Homeostasis § Maintenance constant internal conditions § Mechanisms § Negative feedback: deviations from normal detected and counteracted § Components: controlled variable, sensor, control center, effector Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Integumentary System Forms the external body covering § Protects deeper tissue from injury § Synthesizes vitamin D § Location of cutaneous nerve receptors § Aids in heat regulation § Aids in excretion of urea and uric acid Figure 1. 2 a Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Skin: Integumentary System Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings. Figure 4. 10

Appendages of the Skin § Sweat glands § Widely distributed in skin § Eccrine § Open via duct to pore on skin surface § Over entire body § Apocrine § Ducts empty into hair follicles § Axillary, pubic area Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Associated Hair Structures § Hair follicle § Dermal and epidermal sheath surround hair root § Arrector pilli § Smooth muscle § Sebaceous gland (oil) § Sweat gland Figure 4. 7 a Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Appendages of the Skin § Hair § Produced by hair bulb § Consists of hard keratinized epithelial cells § Melanocytes provide pigment for hair color Figure 4. 7 c Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Nail Structures § Free edge § Body § Root of nail § Cuticle proximal nail fold that projects onto the nail body Figure 4. 9 Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Melanin § Pigment (melanin) produced by melanocytes § Color is yellow to brown to black § Melanocytes are mostly in the stratum basale § Amount of melanin produced depends upon genetics and exposure to sunlight Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Skin Cancer Types § Basal cell carcinoma § Least malignant § Most common type § Arises from stratum basale § Squamous cell carcinoma § Arises from stratum spinosum § Metastasizes to lymph nodes § Early removal allows a good chance of cure Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

Skin Cancer Types § Malignant melanoma § Most deadly of skin cancers (50% mortality) § Cancer of melanocytes § Metastasizes rapidly to lymph and blood vessels § Detection uses ABCD rule Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.

ABCD Rule § A = Asymmetry § Two sides of pigmented mole do not match § B = Border irregularity § Borders of mole are not smooth § C = Color § Different colors in pigmented area § D = Diameter § Spot is larger then 6 mm in diameter Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings.