MSK_MT1_ILS1 (Histology of ConnTiss&Muscle) Flashcards
Epithelial Tissue
- continuous sheets of cells that line internal surfaces and cover the external surface of the body
- glands are derived from epithelium
Connective Tissue
supports, binds together, and protects tissues and organs.
It is composed of cells in an abundant extracellular matrix.
includes cartilage, bone, and blood.
Muscle Tissues
- cells that have the ability to contract.
- Uses the contractile proteins actin and myosin.
Nervous Tissues
- specialized for the rapid communication of information from one region of the body to another.
Connective Tissue Function
- Tissue for connecting, linking and holding other tissues.
- Contains cells and extracellular matrix of fibers and ground substance
- Function: structural support, defense, repair, storage (water, electrolytes, proteins, fat)
acts as a medium for exchange of nutrients and wastes between the blood and tissues, protects against microorganisms, repairs damaged tissues, and stores fat.
Embryonic Connective Tissue
Mesenchymal tissue is found only in embryos.
It consists of a gel-like amorphous matrix, a few scattered reticular fibers, star-shaped (stellate) fibroplasts, pale-staining mesenchymal cells
Mucous tissue (Wharton jelly) is a loose CT located in umbilical cord
Areolar / Loose Connective Tissue
- More ground substance and cells with few fibers
- Flexible and well vascularized
- Little tensile strength, not resistant to stress
- Lamina propria in the digestive tract
- More abundant than dense connective tissue
- space filler of deep skin
Dense Regular Connective Tissue
- Abundant collegen fibers arranged in parallel bundles with few cells/ECM
- strong/resistant to stress
- skin thick deep layer of dermis
- Found in tendons, ligaments, aponeuroses
Elastic Connective Tissue
- More elastin-based proteins than collagen
- Found in large arteries
Specialized Connective Tissue: Adipose Tissue
- Unilocular or white fat
- secrete hormones/cytokines (eg. leptin and adiponeptin; multilocular or brown fat)
- Adipocytes contain numerous mitochondria for metabolic generation of heat
- Flattened nucleus found around the rim of cytoplasm
- RARELY divides
Connective Tissue Components: Permanent Residents
- Fibroblasts: synthesize fibers, secrete ground substance
- Macrophages: protection and immunity
- Mast cells: inflammation, allergy
- Adipocytes: lipid storage
Connective Tissue Components: Transient Cells
- Plasma cells
- Leukocytes/ Lymphocytes
- Neutrophils and Eosinophils
Fibroblast
- Most abundant cells, Spindle-shaped
- Synthesize fibers (collagen, elastic fibers)
- Secrete ground substance
- Normally non-mitotic but can replicate
- Makes protein: contains rough ER and large Golgi complex
Macrophage
- Derived from blood monocytes
- MIGRATE into CT and stay (histiocytes)
- Phagocytic: contains lysosomes and residual bodies
- Exist as Kupffer cells in liver
- Initiate immune responses (present antigens to lymphocytes); secretehydrolyticenzymes(eg.collagenase);
- Can replicate
Mast Cell
Contain basophilic cytoplasmic granules that obscure the nucleus
- Granules contain histamine and heparin (involved in allergic reactions)