Blood Vessels I Flashcards
These are large arteries that allow rapid blood flow and their elastic laminae help to smooth out pressure differences with distance from the heart, what are they called?
Conducting arteries
The medium arteries have a slower blood flow and the flow can be controlled by regulatory factors such as chemical or neural input to regulate flow to various organs, what are they called?
Distributing arteries
What composes the tunic intima?
Endothelium, basal lamina, and sub endothelial layer of loose connective tissue that may contain an occasional smooth muscle cell
What composes the tunic media?
Smooth muscle and variable amounts of elastic fibers, lamellae, reticular fibers, and proteoglycans.
In arteries what is an internal elastic lamina?
It borders the media and it is a fenestrated layer of elastin
What types of vessels have an external elastic lamina?
Larger vessels.
In capillaries and postcapillary venues what replaces the media?
Pericytes
What is the tunica adventitia?
The outermost layer is composed of fibroblasts and longitudinally oriented type I collagen and elastic fibers
What is a vasa vasorum? When is it present? In what vessel is it the most extensive?
“vessels of the vessel” Larger blood vessels have a vasa vasorum in the adventitia and a portion of the media that provides nutrients via small vessels to the vessel wall. Veins have a more extensive vas vasorum b/c of the low nutrient and oxygen content of venous blood.
What does the intima function to do?
Forms a permeable or smipermeable barrier
What does the media function to do?
Controls the diameter and blood pressure and movement
What does the adventicia function to do?
Provides physical support, attaches vessels to tissue and carries vessels and nerves.
What is the endocardium of the hear homologous to?
The intima of blood vessels. It lines the atria and ventricles. It is composed of an endothelium and a sub endothelial layer of connective tissue.
What is the myocardium homologous to?
The media of blood vessels. It is the thickest layer of the heart wall and composed of cardiac muscle.
What is the epicardium homologous to?
The adventitia of blood vessels. It forms the surface of the heart and is anatomically defined as the visceral layer of the pericardium. The epicardium is composed of a mesothelium and the subepicardial layer of loos connective tissue that contains nerves, adipose tissue, and coronary blood vessels.
