BODY TISSUES
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Transcript of BODY TISSUES
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