What is the endothelium? part of the tunica externa in arteries ample squamous epithelium that is in contact with the blood the internal elastic membrane that has fenestrae concentric \"holey\" (laminae) of elastic connective tissue interspersed between smooth muscle layers of the tunica media Blood vessels of the large arteries and veins that are greater than 1mm in diameter are called the lamina propria anastomoses fenestrae metarterioles vasavasorum sinusoids Select all of the following that are TRUE of muscular arteries. largest diameter arteries subclavian artery is an example the tunica media has more smooth muscle than elastic fibers they are also referred to as distributing arteries they contain both the internal elastic membrane and the external elastic membrane proportionately, has the thickest tunica media of ail vessels common iliac artery is an example Find the correct statement regarding our capillaries. capillaries that have tight junctions between endothelial cells, making them less permeable to large molecules than other capillary types are referred to as sinusoidal capillaries or discontinuous capillaries continuous capillaries are found in the endocrine glands where large molecules cross the capillary walls fenestrated capillaries are the most common type of capillaries the distal portion of the metarteriole that has no smooth muscle is called a thoroughfare channel Select all of the TRUE statements regarding our blood vessels. arterioles can be called our \"resistance vessels\" because this is where blood encounters its creates! decline in blood pressure b a venous anastomosis is where two or more veins dram an area in common there are about 10 billion capillaries. yet only about 5% of our blood is in them at any one time venules have only the tunica internal and the tunica external, they have NO tunica media about 40% of the blood is in veins at any given time capillaries are known as blood reservoirs for extra blood veins of the appendages that are greater than 2 mm in diameter have valves made of fold in the intima and are similar to shape and function of the semilunar valves compared to their companion arteries, veins have a very thick tunica intima which contains an internal elastic membrane, a thin tunica mod a with no external elastic membrane and a vety tunica adventitia (externa) Solution 1. Endothelium is: b. simple squamous cells that is in contact with the blood 2. Vasa vasorum 3. Tunica media has more smooth muscles than elastic fibers They are also called distributing artery 4. The distal portion of the metarteriole that has no smooth muscle is called a thoroughfare channel.