ANAT 309 Lecture Notes - Lecture 3: Exocytosis, Serous Fluid, Keratin
Document Summary
Epithelium range in layers, and function in protection, secretion, absorption. All body surfaces and body cavities [except articular cartilage] are covered by epithelium. All epithelia are continuously renewed to replace dead cells. Blood vessels rarely invade the epithelium [except in the cochlea of the inner ear]. Ectoderm, mesoderm, and endoderm all give rise to epithelium. Ectoderm gives rise to the oral and nasal mucosae, the cornea, skin, and glands. Mesoderm gives rise to the kidneys, reproductive tracts, blood vessels, and cavities. Endoderm gives rise to the liver, pancreas, and the respiratory and intestinal tracts. Simple squamous epithelium is single-layered, flat, and plate-like. This type of epithelium is found in areas of absorption such as the lungs, in blood vessels, and the heart; they also line the body cavities of the body. This type of epithelium is found in areas of absorption such as the ovaries; they also line the secretory and excretory ducts of the kidney tubules and many glands.