BIO10004 Anatomy and Physiology Vessels - Arteries 2021 PDF

Department of Health Sciences and Biostatistics Anatomy and Physiology Bio10004-2021 OVERVIEW OF VESSELS AND CARDIOVASCULAR SYSTEM Vessels - Arteries Dr. Greg Davis Copyright notice Learning objectives By the end of this lecture y...

Department of Health Sciences and Biostatistics Anatomy and Physiology Bio10004-2021 OVERVIEW OF VESSELS AND CARDIOVASCULAR SYSTEM Vessels - Arteries Dr. Greg Davis Copyright notice Learning objectives By the end of this lecture you will be able to: ▪Understand the functions of the arteries ▪Understand the types of arteries and their functions ▪Know the parts of the aorta ▪Count the main branches of the aortic arch what they supply ▪Count the main branches of the abdominal aorta what they supply ▪Understand the clinical definition of hypertension and aneurysm Functions of the arteries Arteries carry blood away from the heart. Pulmonary arteries transport deoxygenated blood (blood that has a low oxygen content) from the right ventricle to the lungs. Systemic arteries transport oxygenated blood from the left ventricle to the body.  Types of arteries There are three main types of arteries: Elastic arteries Muscular arteries Arterioles are those nearest the heart (aorta and pulmonary arteries) that contain much more elastic tissue in the tunica media than muscular arteries. This feature of the elastic arteries allows them to maintain a relatively constant pressure gradient despite the constant pumping action of the heart.  Types and functions of arteries There are three main types of arteries: Elastic arteries Muscular arteries Arterioles  Types and functions of arteries There are three main types of arteries: Elastic arteries are those nearest the heart (aorta and pulmonary arteries) that contain much more elastic tissue in the tunica media than muscular arteries. This feature of the elastic arteries allows them to maintain a relatively constant pressure gradient despite the constant pumping action of the heart.  Types and functions of arteries There are three main types of arteries: Muscular arteries: are medium-sized artery that draws blood from an elastic artery and branches into small arteries and arterioles. Their walls contain larger number of smooth muscles, allowing them to contract (vasoconstriction) and expand (vasodilation) depending on peripheral blood demand.  Types and functions of arteries There are three main types of arteries: Arterioles: are considered as the primary resistance vessels as they distribute blood flow into capillary beds. Arterioles provide approximately 80% of the total resistance to blood flow through the body The constriction of arterioles increases resistance, which causes a decrease in blood flow to downstream capillaries and a larger increase in blood pressure. Dilation of arterioles causes a decrease in resistance, increasing blood flow to downstream capillaries, and a smaller decrease in blood pressure Elastic arteries Aorta 1. Ascending aorta 2. Aortic arch 3. Descending - Thoracic aorta 4. Abdominal aorta The aortic arch is the section of the aorta between the ascending and descending aorta. Main branches supply head, neck and Aortic arch upper limb 1. brachiocephalic trunk ▪ Right common carotid artery ▪ Right Internal carotid artery ▪ Right External carotid artery ▪ Right subclavian artery ▪ Right Vertebral artery 2. Left common carotid artery ▪ left Internal carotid artery ▪ left External carotid artery 3. Left subclavian artery ▪ left Vertebral artery Abdominal aorta It is a continuation of the thoracic aorta. It begins at the diaphragm, and runs down to the point where it ends by splitting into: Two common iliac arteries The abdominal aorta supplies oxygenated blood to all of the abdominal and pelvic organs and the legs. Single (unpaired) o Coeliac artery (trunk): supplies the liver, stomach, spleen, the superior duodenum and the superior pancreas. o Superior mesenteric artery: supplies the distal duodenum, jejuno-ileum, ascending colon and part of the transverse colon. o Inferior mesenteric artery: It supplies the large intestine from the end of the transverse colon to the rectum. Paired o Suprarenal arteries: supply adrenal glands. o Renal arteries: supply the kidneys. o Gonadal arteries: male gonadal artery (testicular artery) and females gonadal artery (ovarian artery). End with Two common iliac arteries  Hypertension Hypertension, also known as high blood pressure, is a condition in which the blood vessels have persistently raised pressure. Blood pressure is created by the force of blood pushing against the walls of blood vessels (arteries) as it is pumped by the heart. The higher the pressure, the harder the heart has to pump. Hypertension is a serious medical condition and can increase the risk of heart, brain, kidney and other diseases. It is a major cause of premature death worldwide, with upwards of 1 in 4 men and 1 in 5 women – over a billion people – having the condition. Abdominal aortic aneurysm An abdominal aortic aneurysm occurs when a lower portion of the aorta becomes weakened and bulges. A ruptured aneurysm can cause massive internal bleeding, which is usually fatal. Around 8 out of 10 people with a rupture either die before they reach hospital or don't survive surgery. The most common symptom of a ruptured aortic aneurysm is sudden and severe pain in the abdomen  Summary Arteries carries blood away from the heart There are three types of arteries: elastic, muscular and arterioles The aorta divided into parts ascending, arch, descending (thoracic and abdominal) There are three branches from the aortic arch There are two types of branches from the abdominal aorta: single and paired Hypertension and aneurysm are vascular conditions with high risk