1. CHAPTER 30 TISSUES IN HUMANS

2. TISSUE - a group or mass of similar cells working together to perform certain common functions There are 4 major types of tissue

3. 4 TYPES OF TISSUES Epithelial Connective Muscle Nervous

4. Epithelial Tissue General Characteristics: 1) covers all body surfaces both inside and out. 2) Main glandular tissue. 3) Usually has no vascular tissue - blood supply -4) Cells reproduce rapidly (rapid healing). 5) Cells tightly packed together Functions: Protection, secretion, absorption, excretion, sensory perception

5. Five Specific types of epithelial tissue ( grouped by cell shape and # layers) SIMPLE SQUAMOUS. SIMPLE CUBOIDAL SIMPLE COLUMNAR STRATIFIED SQUAMOUS PSEUDOSTRATIFIED COLUMNAR

6. SIMPLE SQUAMOUS - single layer (simple) of very thin, flattened cells (squamous). Function: diffusion and filtration. found in air sacs of lungs, walls of capillaries.

7. SIMPLE CUBOIDAL - single layer, cube- shaped cells. Function: Secretion and absorption. Found: Lining of kidney tubules, ducts of glands, covering surface of ovaries

8. SIMPLE COLUMNAR - single layer, elongated cells with their nuclei in about the same position in each cell (usually near the basement membrane). Protection, secretion, absorption. Found in the lining of digestive tract - contains scatter goblet cells functioning in the secretion of mucus - some columnar cells (involved in absorption) have tiny finger-like processes from their free surface called microvilli (increases surface area)

9. STRATIFIED SQUAMOUS - muli-layered, squamous cells. Thicker tissue. Functions in protection. Found lining body cavities like the mouth and outer layer of skin

10. PSEUDOSTRATIFIED COLUMNAR - appear "stratified" but really a single layer with nuclei at various levels giving the appearance of layered cells. Usually ciliated (tiny, hair-like projections for sweeping materials along a surface). Contains goblet cells. - Function: secretion and cilia-aided movement - Location: lining air passages like the trachea and tubes of the reproductive system

12. CONNECTIVE TISSUE General Characteristics: --Binds structures together -Provides support, protection, framework, fills space, stores fat, produces blood cells, fights infection, and helps repair tissue. -Made up of a ground substance (fluid, semi- solid) non cellular material called matrix

13. Main types of fibers: ( Dense)-collagenous fibers - thick, made of protein collagen, major structural protein in the body, appear in long parallel bundles. Strong, flexible, but not very elastic,. (bones, ligaments, tendons) - (Loose)elastic fibers –allows organs to expand; supports skin and internal organs

14. ADIPOSE TISSUE - aka FAT, beneath skin, around kidneys and eyeballs, abdominal membranes. Function: Protective cushion, insulation to preserve body heat, stores energy, cells are called adipocytes

15. . CARTILAGE (all cartilage cells are called chondrocytes) rigid material made of structural proteins Found in : sketelon of sharks, at end of long bones and nose.ear;

16. BONE TISSUE –. Rigid due to calcium salts. contain cells called osteocytes Contain marrow where blood cells are made BLOOD– made of plasma matrix with white and red cells and platlets ; function to transport nutrients and waste

17. MUSCLE TISSUE composed of muscle fibers actin and myosin A. Skeletal - skeletal muscles - voluntary (striated) multinucleated - atttached to bone for movement B. Smooth - in hollow organs, stomach - involuntary; non striated C. Cardiac - wall of the heart; striated; intercalated discs

19. NERVE TISSUE- contain cells called neurons NEURON – made of dendrites, cell body and an axon Found in brain, spinal cord, nerves 1) dendrite- conduct signals toward cell body 2) AXON- AWAY