BIO210Y5 Lecture Notes - Lecture 14: Medulla Oblongata, Epithelium, Vasculogenesis
Document Summary
Receives blood from right ventricle and pumps into left atrium. Tunica intima: includes endothelial lining and underlying layer of connective tissue containing elastic fibers. Tunica media: concentric sheets of smooth muscle tissue in a framework of loose connective tissue. Vasoconstriction: when the smooth muscles contract, the vessel decreases in diameter. Arteries: collagen fibers with scattered bands of elastic fibers. Veins: network of elastic fibers and bundles of smooth muscle cells. Capable of stretching and recoiling as heart beats. Muscular artery: distributed blood to skeletal muscle and internal organs. Thick tunica media which contains more smooth muscle cells. Arteriole: poorly defined tunica externa and tunica media consists of only 1-2 layers smooth muscle cells. Large vein: all three vessel wall layers present. Slender tunica media + thick tunic externa composed of elastic and collagen fibers. Medium-sized vein: 2 to 9 mm internal diameter. Tunic media is thin and contains smooth muscle cells and collagen fibers.
