Transcript body tissues - De Anza College

BODY TISSUES
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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
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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
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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