Inner layer (tunica intima): This layer is composed of endothelial cells and is in direct contact with the blood flow.
Middle layer (tunica media): Consists of smooth musclecells and elastic fibers, which allow the artery to expand and contract to accommodate changes in blood flow and pressure.
Arteries can be categorized into three main types based on their size and function:
Elastic arteries: These large arteries, such as the aorta, have a high proportion of elastic fibers in their walls, allowing them to stretch and recoil with each heartbeat, which helps propel blood forward.
Muscular arteries: Also known as distributing arteries, these medium-sized arteries have more smooth muscle in their walls and play a role in regulating blood flow to specific areas of the body.
Arterioles: These small arteries are involved in controlling blood flow into capillary beds and play a crucial role in regulating bloodpressure and distribution of blood flow within tissues.
Several diseases and conditions can affect the arteries, including:
Atherosclerosis: A condition characterized by the buildup of plaque (cholesterol, calcium, and other substances) in the arterial walls, leading to narrowing and reduced blood flow.
Hypertension: Also known as high bloodpressure, this condition can lead to damage to the arterial walls and increase the risk of heartdisease and stroke.
Peripheral artery disease (PAD): A condition in which the arteries that supply blood to the arms and legs become narrowed or blocked, leading to reduced blood flow and potential complications.
Study Tips for Arteries
When studying arteries, it's important to:
Understand the structure and function of each layer of the arterial wall.
Recognize the differences between elastic, muscular, and arteriolar arteries in terms of size, location, and function.
Be familiar with common arterial diseases and their impact on overall health.
Practice identifying the major arteries in the human body and their respective functions.
By understanding the role of arteries in the circulatory system and their significance in maintaining overall health, you can appreciate the importance of proper arterial function and the impact of arterial diseases.
Energy - A. Energy is involved in all physical and chemical processes. It is conserved, and can be transformed from one form to another and into work. At the atomic and nuclear levels energy is not continuous but exists in discrete amounts. Energy and mass are related through Einstein's equation E=mc 2 . B. The properties of atomic nuclei are responsible for energy-related phenomena such as radioactivity, fission and fusion. C. Changes in entropy and energy that accompany chemical reactions influence reaction paths. Chemical reactions result in the release or absorption of energy. D. The theory of electromagnetism explains that electricity and magnetism are closely related. Electric charges are the source of electric fields. Moving charges generate magnetic fields. E. Waves are the propagation of a disturbance. They transport energy and momentum but do not transport matter.
Relate temperature to the average molecular kinetic energy.