Download 6c Important Tissue Concepts

Highlights of Tissue Types Overview
Epithelial Tissue
•Found as linings, coverings, and glands
•Functions: protection, absorption, filtration, secretion
•Poorly vascularized; always has an apical edge and a basement membrane
•Named based on layering (simple/stratified/pseudo-stratified) and shape (squamous, cuboidal, columnar/transitional)
•Includes endocrine and exocrine glands
Connective Tissue
•Found everywhere in the body; most abundant
•Functions: binding, support, protection, respiratory gas carriers
•Mostly well vascularized
•Cells include: erythrocytes, leukocytes, osteocytes, fibroblasts, mast cells, chondrocytes, adipocytes/signet cells
•Extracellular matrix: ground substance (glycoproteins and glycoasminoglycans) and fibers (collagen, keratin, elastin,
reticular)
•Includes: 3 types of cartilage: hyaline (ribs, larynx, nose), elastic (ear), fibrcartilage (intervertebral discs); loose (areolar) and
dense connective (tendons, ligaments; also in reticular layer of dermis) tissue; blood, bone, adipose, and reticular tissue.
Muscle Tissue
• Contractile tissue made of bundles muscle fibers (cells); ATP drive proteins actin and mysosin to cause shortening of cell
-Striated (skeletal) muscle: voluntary, striated, multinucleate, cylindrical; muscles that connect bones together
-Smooth muscle: involuntary, not striated, single nuclei, spindle-shaped; in GI tract, blood vessel walls
-Cardiac muscle: involuntary, striated,single nuclei, cylindrical but branched at intervertebral disks; heart muscle
Nervous Tissue
• Neurons (long filaments (axons) extending from cell bodies with “spiky” dendrites; in brain, spinal cord, peripheral nerves to
and from organs and skin; rapid and focused communication (both incoming and outgoing messages)
Tissue Repair, Growth, and Aging
•Types of repair: Regeneration vs. fibrosis
•Steps of repair: 1. Inflammation, 2. Vascularization, 3. Regeneration
•Epithelial and fibrous connective regenerate well, skeletal/cardiac muscle and nervous tissue very little or none
•The body systems that arise from embryonic germ layers: endoderm (GI tract, lungs), mesoderm (muscles & bones),
ectoderm (nervous and skin)
•How tissues change with age