Key Terms
Functions
Support, bind, protect, store energy, transport (blood/lymph), immune defense, temperature regulation
Two variables
Cell shape and number of layers.
Three components always present
1. Cells 2.
Blood
Liquid matrix (plasma); formed elements include erythrocytes (transport O2/CO2), leukocytes (immune defense), platelets
Lymph
Liquid matrix plus white blood cells; drains excess interstitial fluid back to blood; transports absorbed fats from inte
Two cell classes
Neurons and neuroglia.
Myelin sheath
Lipid layer that wraps some axons; acts as insulator; speeds up action potential transmission
Synapse
Gap between neurons (or between neuron and target); neurotransmitters carry the signal across
Five cardinal signs
1. Redness 2.
Sequence after injury
1. Chemical signals contain the injury 2.
Clotting (coagulation)
Fibrin network traps blood cells; seals wound edges 3. Scab forms as clot dries; reduces infection risk 4.
Angiogenesis
New blood vessels grow into the area; forms granulation tissue 6. Clot retracts, pulling wound edges together; then diss
Primary union
Wound edges close together; heal quickly; sutures help achieve this for deep wounds
Secondary union
Gaping wound; edges pulled together by wound contraction; slower; more scar formation