TISSUES 4 Major Types
1. EPITHELIAL TISSUE Linings of organs. 3 Types: SQUAMOUS – thin CUBOIDAL – “cube” or square shaped COLUMNAR – rectangular These 3 may be SIMPLE (one layer) or STRATIFIED (more than one layer).
2. MUSCLE TISSUE 3 Types: SKELETAL CARDIAC SMOOTH Attached to skeleton Voluntary movement of the body Striated, un-branched fibers and multinucleated cells CARDIAC Makes up the heart, only. Involuntary movement Striated, branched fibers and multinucleated cells (sometimes) SMOOTH In or surrounding internal organs and blood vessels. Non-striated, non-branched, and single nucleus in cells
MUSCLE TYPE SKELETAL CARDIAC SMOOTH CONTROL Voluntary Involuntary STRIATIONS Present None NUMBER OF NUCLEI PER FIBER Many Peripheral One or Two Peripheral One Central BRANCHING Unbranched Branched SPEED OF CONTRACTION Most Rapid Intermediate Slowest
Cardiac Muscle
Smooth Muscle
3. CONNECTIVE TISSUE 1) Loose (Areolar) Connective –Holds organs in place and attaches epithelial tissue to other underlying tissues. It also surrounds the blood vessels and nerves Adipose Tissue A type of loose connective. Fat storage Cells are called ADIPOCYTES 2) Dense Connective – Tendons and ligaments
3) Cartilage - CHONDROCYTES (cells) sit in space called LACUNA and secrete a surrounding matrix. 4) Bone – Contains OSTEOCYTES (cells) which form LAMELLAE (rings) surrounding HAVERSIAN CANALS (paths for blood and nerves). CANALICULI – Extensions of cells to communicate with blood vessels, nerves and each other. Osteocytes also lie in lacuna.
Cartilage
Bone
5) Vascular - RBC's, WBC's, and platelets in plasma. Erythrocytes (RBC’s)- Contain the iron based protein HEMOGLOBIN which carries gases (Oxygen, Carbon Dioxide, Carbon Monoxide) Hemoglobin also gives the cell its red coloration. Leukocytes (WBC’s)- Fight infection by engulfing pathogens. Also create antibodies. Thrombocytes (Platelets)- Involved in blood clotting
Blood
Blood
4. NERVOUS TISSUE Nerve cells are called NEURONS. DENDRITES receive impulses, CYTONS are the main cell bodies, and AXONS transmit the impulse along. NEUROTRANSMITTERS are chemicals that jump across the SYNAPSE from the axon of one neuron to the dendrite of the next, transmitting the message. Na+ (outside) and K+ (inside) are responsible for the electrical conduction of an impulse. As the impulse moves down the neuron, the Sodium and Potassium switch places, then return back to their original spots by active transport.
Nerve Cells
Na/K Pump Animation http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html