Lecture notes for Wednesday January 23, 2002
Outline
• Epithelial tissue
• Connective tissue
Tissues
• A tissue is a group of similar cells with a common function
• Histology (hist = tissue)
• Pathology (patho = disease)
• Biopsy
4 principle tissue types
• Epithelial (protect/cover)
• Connective (support)
• Muscle (movement)
• Nervous (control)
Epithelium
• Epi = upon/on/above
• See Table 4.1 in Tortora (both books)
Location
• Any FREE surface
• Glands
Functions
• Protection
• Absorption
• Secretion
• Glandular
• Sensory
Structure
• Closely packed cells
• Very little ECF
• No blood vessels
• Some nerve fibers
• APICAL surface
• BASAL surface
• Always underlined with connective tissue
• Anchored to conn. tiss. by BASEMENT MEMBRANE
Classification
• Cell shapes:
Squamous / cuboidal / columnar
• Arrangement of layers:
Simple / stratified / pseudostratified
Glandular Epithelium
• Function = secretion
• Gland = 1 or more specialized epith. cells that produce & release a certain fluid
Exocrine Glands
• Always secrete substances to the surface of the tissue
E.G.:
• Sweat glands
• Salivary glands
• Goblets cells
Endocrine Glands
• Endo = inside
• Secrete HORMONES into blood vessels
• E.G. thyroid; pituitary; adrenal glands
Connective Tissue
Functions
• Connects one type of tissue to another
• Support
• Protection
• Insulation
• See Table 4.2 (both books)
Location
• Always underlines epithelium
• Forms DERMIS, FAT, BLOOD, LYMPH, BONE and CARTILAGE
Structure
• Cells
• Matrix
• Highly vascular
• Never found on a free surface
Cells
• Fibroblasts
• Macrophages
• Plasma cells
• Mast cells
• Adipocytes
Matrix
• Ground substance
• Collagen fibers (white)
• Elastic fibers (yellow)
• Reticular fibers