BODY TISSUES Epithelial Connective Muscle Nervous

Epithelial Tissues Tightly connected: covering body surfaces and lining body cavities Shapes vary: squamous, cuboidal, columnar Layers of cells: simple = one stratified = several

Connective Tissue Connects and supports body parts Cells scattered in matrix (protein fibers and ground substance) Loose, Dense, Specialized 1.Loose connective tissue: areolar and adipose – supports epithelium and body parts 2.Dense connective tissue: ligaments, tendons, dermis 3.Specialized: cartilage (chondrocytes), bone(osteocytes), blood (erythrocytes and leukocytes)

Muscle Tissue Skeletal (striated) Smooth Cardiac (in the heart) Muscle tissues form organs & organ systems

Nervous Tissue Communicates The neurons and neuroglia

Integumentary System: skin and its derivatives Functions: –Physical protection –Regulation of body temperature –Sensory reception –Immune system, Vitamin D Skin layers –Epidermis: stratified squamous epithelium; layers progress from living cells to dead (filled with keratin protein)

Dermis: tough, permanent connective tissue; has folds and ridges 1. Subcutaneous Layer: anchoring, fat storage 2. Melanin: pigment molecule produced by melanocytes in epidermis UV radiation: tanning, DNA damage  skin cancer

Hair Follicles Root & shaft of hairs –Root is living cells, shaft is dead tissue –Keratin on outside, melanin & air space inside Nails similar; living cells at cuticle filled with keratin Arrector pili muscle – stand on end Oil glands produce sebum, can plug up follicle – antibacterial Sweat glands secrete mixture of water, salts, acids, urea

–Part of homeostasis system – can modify body temperature, fluid loss –Homeostasis: dampens fluctuations around a set point – pH, temperature (fever, hypothermia) –Receptor, control center, and effectors –Biological clock and circadian rhythms