Highlights of Tissue Types Overview


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