Anatomy & Physiology Tissue Review October 2012 General Characteristics of Epithelial Tissue General Characteristics of Epithelial Tissue Cells tightly packed together; very little intercellular space Therefore, avascular Free surface Basement membrane anchors to connective tissue below Regenerates readily, if close to nutrient source (if avascular, how does it get nourished?) Terms to understand Simple Stratified Cell shapes Microvilli Cilia Goblet cells Epithelium: identify by location Lines air sacs of lungs: Lines respiratory passages: Lines bladder & urinary passages: Lines mouth, throat, anal canal, vagina: Forms outer layer of skin: Lines digestive tract: Forms most glands: Epithelium: identify by function Protection Modified for excellent absorption Secretion Can distend, then return to original shape/layers Fabulous for diffusion Glandular epithelium EXOCRINE Has ducts to secrete product to free surface Sweat, oil, milk ENDOCRINE Ductless Empties product directly into bloodstream hormones Connective tissue (in general) Cells far apart from each other Intercellular space filled with FIBERS & MATRIX Vascular, with exceptions (dense regular & cartilage) Protects, connects, binds, supports Possible fibers in matrix 1. 2. 3. COLLAGEN: thick, white, tough, very strong ELASTIC: thin, yellow, stretchy RETICULAR: thin, delicate strands of collage; from delicate framework/web-like support Which connective tissue? Universal glue; contains all 3 fibers; waterygel matrix Hard matrix made of calcium salts Parallel bundles of collagen; tendons & ligaments Rubbery matrix; glassy appearance; connects ribs to breastplate Fluid matrix More connective tissues Thick, cushion; shock absorber; intervertebral disks Delicate framework supporting lymph nodes and bone marrow Strong; interwoven collagen fibers; vascular; dermis of skin Fat cells are dominant in this specialized areolar tissue Compare dense regular & dense irregular fibrous conn. REGULAR Parallel bundles of collagen, tightly packed Avascular Forms tendons & ligaments • • • • IRREGULAR Interwoven mesh of collagen fibers; lots more space Vascular Forms dermis of the skin More terms to understand Tendon Ligament Adipocyte Chondrocyte Osteocyte Fibroblast Neuron Muscle tissue: skeletal, cardiac, or smooth? Striated/banded Non-striated/banded Intercalated disks Spindle-shaped Multinucleate Uninucleate Heart Walls of hollow organs Moves the body Muscle and nervous tissue functions Muscle: contract to produce movement Nervous (1) irritability—can be stimulated (2) conductivity—can conduct an electrochemical impulse Inflammation—the 4 Cardinal Signs Edema---tissue swelling due to increased flow of tissue fluid to injury—why? Rubor— Calor— Dolor-- Tissue healing Which tissue regenerates the easiest? Which tissue will never regenerate? Which tissues are slow to regenerate? Which tissues will be replaced with scar tissue? Describe the general characteristics of connective tissue. How does connective tissue differ from other tissues as to relative amount of cells and intercellular substance? Describe the three types of fibers which might be found in connective tissue. Identify the connective tissue Composes tendons and ligaments Composes skeleton “glues” epithelium with basement membrane to other structures Fluid matrix Rubbery, smooth glassy matrix Composes the dermis of the skin Identify the connective tissue Areolar with large deposits of adipocytes Forms stroma of the liver, bone marrow Which cartilage: Framework of the ear Intervertebral disks Meniscus of knee Covers ends of long bones Loose (areolar) tissue, bone, cartilage, and blood are different types of connective tissue. Explain why their physical characteristics differ so much. What is the function of fibroblasts? Name the major types of cartilage. Describe their differences and similarities. Joints such as the elbow, shoulder, and knee contain considerable amounts of cartilage and fibrous connective tissue. How does this relate to the fact that joint injuries are often very slow to heal? A group of disorders called collagenous diseases are characterized by deterioration of connective tissues. Why would you expect such diseases to produce widely varying symptoms.