Angiology • Angiology: The study of the anatomy, physiology and related diseases of blood vessels. Anatomy of an Artery • Tunica Adventitia/Externa: Anchors artery along its proper course (connective tissue). • Tunica Musculosa/Media: Smooth Muscle controls blood pressure. • Tunica Intima/Interna: Essentially composed of a single layer of endothelial cells. Anatomy of an Artery ANATOMY OF AN ARTERY Capillary Beds Figure 19.4a Capillary Beds Figure 19.4b Typical Artery and Vein Atherosclerosis and Arteriosclerosis • Atherosclerosis - the process through which cholesterol plaques form on the arterial walls. • Arteriosclerosis - The process through which cholesterol plaques become infiltrated with calcium resulting in hardening of the arteries. Pathophysiology • • • • • • • • • • • • • • • • • 1. Vascular irritants irritate the tunica interna of the blood vessel. Vascular Irritants: a. Smoking b. Alcohol c. Fried foods d. Chemical produced during stress e. Caffeine f. Physical trauma g. Normal wear and tear (aging) (anti-oxidant vitamins improve circulation) h. Environmental toxins I. Homocysteine: intermediate chemical substance in the metabolism of the amino acid cysteine that is a strong vascular irritant. Folic acid, vitamin B12 and vitamin B6 will prevent the build up of homocysteine in the blood. Homocysteine Folic B12 B6 Acid Cysteine Methionine Normal Artery VS Atherosclerotic Artery Protrusion of Tunica Musculosa Cells Into the Arterial Lumen • 2. Tunica intima cells die and cells from the tunica musculosa protrude through into the lumen (hole) Pathophysiological Progression of Atherosclerosis Macrophages • 3. Macrophages (a type of white blood cell) infiltrate the smooth muscle cells with oxidized LDL cholesterol. As the smooth muscle cells become infiltrated with cholesterol, they die and form a cholesterol plaque resulting in atherosclerosis. Infiltration of LDL Cholesterol Into the Arterial Wall Foam Cell Arteriosclerosis • 4. A calcification of the cholesterol plaque leads to hardening of the arteries resulting in arteriosclerosis Collateral Circulation • Alternate routes of blood flow developed primarily within the arterial system which help to compensate for atherosclerosis and arteriosclerosis in the body. Collateral circulation develops with time and exercise. Hypercholesterolemia • Hypercholesterolemia is a term describing high serum concentrations of cholesterol. The serum concentrations of cholesterol which have been used to diagnose hypercholesterolemia have been reduced since 1980. In 1980 a serum cholesterol concentration of 220 mg of blood would have been diagnostic of hypercholesterolemia. In 1984 the level was reduced to 200mg, and in 1986 it was again reduced to 180mg. Types of Cholesterol • Exogenous Cholesterol: dietary cholesterol • Endogenous Cholesterol: the amount of cholesterol produced daily by the liver Variables Affecting Serum Cholesterol • 1. Genetics • • • • 2. Diet (+/- cholesterol level 15%) a. Saturated fat increases serum cholesterol levels b. Unsaturated fat decreases serum cholesterol levels c. Fiber decreases cholesterol levels • • • 3. Sex a. Males -------> testosterone increases cholesterol b. Females -----> estrogen decreases cholesterol • • • 4. Thyroid Function a. Hyperactive thyroid - decreases serum cholesterol levels b. Hypoactive thyroid - increases serum cholesterol levels • 5. Diabetes increases cholesterol • • • 6. Liver Function a. the liver produces endogenous cholesterol b. the liver produces the lipoproteins High Density Lipoproteins • High Density Lipoproteins/ HDL’s (Good) • • cholesterol Tissues --------------> Liver Low Density Lipoproteins • Low Density Lipoproteins/ LDL’s (Bad) • • cholesterol Liver -----------------> Tissues Lipoprotein Profile • The lipoprotein profile provides a health care practitioner with the ratio of LDL cholesterol (Bad) to HDL cholesterol (Good) and translates this ratio into a percentage risk factor for developing cardiovascular disease for the patient. Most progressive nutritionists believe that a LDL to HDL ratio of 4 : 1 is optimal. Major Arteries Major Arteries Aortic Arch • The aortic arch has three major branches: • • • Right Brachiocephalic Artery Left Common Carotid Left Subclavian Aorta Arch and It’s Major Branches Aorta and Its Superior Branches • Aorta is largest artery of the body – ascending aorta • 2 coronary arteries supply myocardium – arch of aorta -- branches to the arms & head • brachiocephalic trunk branches into right common carotid and right subclavian • left subclavian & left carotid arise independently – thoracic aorta supplies branches to pericardium, esophagus, bronchi, diaphragm, intercostal & chest muscles, mammary gland, skin, vertebrae and spinal cord Coronary Circulation • Right & left coronary arteries branch to supply heart muscle – anterior & posterior interventricular aa. Thoracic Aorta • Artery • Rt/Left Anterior/Posterior Intercostal Arteries • Supplies • Supplies blood to the anterior and posterior aspects of the ribs, intercostal muscles and associated tissues • Supplies blood to the superior surface of the diaphragm • Rt/Left Phrenic Arteries Abdominal Aorta • Artery • Rt/Left Inferior Phrenic Artery • Supplies • Supplies blood to the inferior surface of the diaphragm Abdominal Aorta and Its Branches • Supplies abdominal & pelvic viscera & lower extremities – – – – celiac aa. supplies liver, stomach, spleen & pancreas superior & inferior mesenteric aa. supply intestines renal aa supply kidneys gonadal aa. supply ovaries and testes • Splits into common iliac aa at 4th lumbar vertebrae – external iliac aa supply lower extremity – internal iliac aa supply pelvic viscera Visceral Branches off Abdominal Aorta • Celiac artery is first branch inferior to diaphragm – left gastric artery, splenic artery, common hepatic artery • Superior mesenteric artery lies in mesentery – pancreaticoduodenal, jejunal, ileocolic, ascending & middle colic aa. • Inferior mesenteric artery – descending colon, sigmoid colon & rectal aa Celiac Trunk • Celiac Trunk: • Artery • • • Common Hepatic Artery • Supplies blood to the liver • Left Gastric Artery • Supplies blood to the stomach • Splenic Artery • Supplies blood to the spleen Supplies Celiac Trunk Visceral Branches of the Abdominal Aorta • Arteries • Superior Mesenteric Artery • Rt/left Suprarenal Arteries • Rt/left Renal Arteries • Inferior Mesenteric Artery • Rt/left Gonadal Arteries • Supplies • Supplies blood to the small intestine • Supplies blood to the rt/left suprarenal (adrenal) glands • Supplies blood to the rt/left kidneys • Supplies blood to the large intestine • Supplies blood to gonads • (ovaries/testes) Arteries of the Abdomen Liver (cut) Inferior vena cava Celiac trunk Hepatic artery proper Common hepatic artery Right gastric artery Gallbladder Gastroduodenal artery Right gastroepiploic artery Duodenum Abdominal aorta (b) Diaphragm Esophagus Left gastric artery Left gastroepiploic artery Splenic artery Spleen Stomach Pancreas (major portion lies posterior to stomach) Superior mesenteric artery Figure 19.23b Arteries of the Abdomen Opening for inferior vena cava Hiatus (opening) for esophagus Celiac trunk Diaphragm Inferior phrenic artery Middle suprarenal artery Renal artery Kidney Superior mesenteric artery Lumbar arteries Abdominal aorta Median sacral artery Gonadal (testicular or ovarian) artery Inferior mesenteric artery Common iliac artery Ureter (c) Figure 19.23c Arteries of the Abdomen Celiac trunk Middle colic artery Right colic artery Ileocolic artery Ascending colon Ileum Superior rectal artery Cecum Appendix Transverse colon Superior mesenteric artery Intestinal arteries Left colic artery Inferior mesenteric artery Aorta Sigmoidal arteries Descending colon Left common iliac artery Sigmoid colon Rectum (d) Figure 19.23d Arteries of the Abdominal Cavity Arteries of the Abdominal Cavity Arteries of the Right Upper Extremity Peripheral Arteries: Upper Extremities • Artery • Supplies • Right Brachiocephalic Artery • Supplies blood to the right subclavian artery • Rt/Left Subclavian Arteries • Supplies blood to the clavicles and surrounding soft tissue • Rt/left Axillary Arteries • Supplies blood to the axillary regions • Rt/left Brachial Arteries • Supplies blood to the rt/left humerus, biceps muscles, and surrounding soft tissue • Rt/left Radial Arteries • Supplies blood to the lateral aspects of the rt/left forearms • Rt/left Ulnar Arteries • Supplies blood to the medical aspects of the rt/left forearms • Rt/left Deep Palmar Arch • Supplies blood to the digital arteries • Rt/left Digital Arteries • Supplies blood to the digits (fingers) of the rt/left hands Arteries of the Lower Extremities Peripheral Arteries Lower Extremities Artery • • Rt/left Common Iliac Arteries Rt/left Internal Iliac Arteries • Rt/left External Iliac Arteries • Rt/left Femoral Arteries • Rt/left Popliteal Arteries Supplies • Supplies blood to the rt/left internal and external iliac arteries • Supplies blood to the pelvic muscles and organs • Supplies blood to the external structures of the pelvis (hip, etc.) and femoral arteries • Supplies blood to the femur, thigh muscles and skin over the thigh • Supplies blood to the rt/left knees and surrounding soft tissues Arteries of the Lower Leg • Artery • Supplies • Rt/left Posterior Tibial Arteries • Supplies blood to the rt/left calf muscles (soleus/gastrocnemius) • Rt/left Anterior Tibial Arteries • Supplies blood to the rt/left tibialis anterior muscles and the soft tissue of the anterior aspects of the legs • Rt/left Peroneal Arteries • Supplies blood to the rt/left peroneal muscle groups and the soft tissue of the lateral aspects of the legs • Rt/left Deep Plantar Archers • Supplies blood to the digital arteries of the rt/left feet • Rt/left Digital Arteries • Supplies blood to the digits (toes) of the rt/left feet Blood Supply to the Brain The Circle of Willis • The brain is supplied with blood by a vascular network referred to as the Circle of Willis. The right and left vertebral arteries originate at the right and left subclavian arteries respectively, and travel cephalad towards the brain through the transverse foramen of the cervical vertebrae. At the base of the brain, the right and left vertebral arteries converge to form the basilar artery. The basilar artery divides at the base of the brain to form a right and left posterior communicating artery. These arteries form the posterior loop of the Circle of Willis. • The right carotid artery arises from the right brachiocephalic artery and travels cephalad towards the brain along the right side of the neck. The left common carotid artery arises from the aortic arch and travels cephalad towards the brain along the left side of the neck. The right and left common carotid arteries will each divide into an external and internal carotid artery. The right and left external carotids will supply the structures of the head and face, while the right and left internal carotid arteries will supply the brain. When the right and left internal carotid arteries reach the base of the brain, they give rise to a respective right and left anterior communicating artery. The right and left anterior communicating arteries form the anterior loop of the Circle of Willis. When the anterior and posterior loops join, they form a complete circle at the base of the brain known as the Circle of Willis. The Circle of Willis provides all parts of the brain with a constant, and uniform blood supply Blood Supply to the Brain: Carotid and Vertebral Arteries Angiogram of Carotid and Vertebral Arteries Circle of Willis Circle of Willis Vertebral Arteries Taveling Through the Transverse Foramen of the Cervical Vertebrae Three Dimensional Axial CT Scan of the Cervical Spine Closing of a Vertebral Artery As The Head/Cervical Spine is Rotated Palpated Pulse Figure 19.11 Pulse Points The Major Veins Major Veins Drainage of Blood From the Head and Brain • Rt/left External Jugular Veins • Rt/left Internal Jugular Veins Drain blood from the structures of the head and face Drain blood from the brain Veins of the Head and Brain Drainage of Blood From the Upper Extremities • Rt./Left Brachial Veins Drain blood from the rt/left humeri, the biceps and surrounding soft tissues • Rt./Left Axillary Veins Drains blood from the axillary region • Rt./Left Subclavian Veins • Rt./Left Brachiocephalic Veins Drains blood from the rt./left clavicles and surrounding soft tissues Receives blood from the rt./left internal jugular veins, and the rt./left subclavian veins. The rt./left brachiocephalic veins eventually drain into the superior vena cava. The superior vena cava drains blood into the right atrium of the heart. Veins of the Right Upper Extremity Drainage of Blood From the Internal Organs • Rt./Left Anterior/Posterior Intercostal Veins • Rt./Left Superior Phrenic Veins • • • • • Rt./Left Inferior Phrenic Veins Gastric Veins Hepatic Veins Superior Mesenteric Vein Rt./Left Suprarenal Veins • Drain blood from the anterior/posterior aspects of the ribs, intercostal muscles and associated soft tissues • Drains blood from the superior surface of the diaphragm • Drains blood from the inferior surface of the diaphragm • Drains blood from the stomach • Drain blood from the liver • Drains blood from the small intestine • Drain blood from the rt./left suprarenal glands Veins of the Abdominal Cavity Drainage of Blood From the Internal Organs (continued) • Rt./Left Renal Veins • Inferior Mesenteric Vein • Rt./Left Gonadal Veins • Drain blood from the rt./left kidneys • Drains blood from the large intestine • Drain blood from the gonads (ovaries/testes) Veins of the Abdominal Cavity Drainage of Blood From the Lower Extremities • Rt./Left Great Saphenous Vein • Rt./Left Small Saphenous Vein • Rt./Left Posterior Tibial Veins • Rt./Left Popliteal Veins • Drain blood from the medial aspects of the rt./left legs and thighs • Drain blood from the lateral aspects of the rt./left legs • Drains blood from the posterior aspects of the rt./left legs and calf muscles (soleus/gastrocnemeus) • Drains blood from the rt./left knee joints and surrounding soft tissues Drainage of Blood From the Lower Extremities • Rt./Left Femoral Veins • Rt./Left External Iliac Veins • Rt./Left Internal Iliac Veins • ***All of the blood drained from the internal organs, lower extremities and hepatic portal circulation eventually drains into the inferior vena cava which in turn empties into the right atrium of the heart • Drain blood from the rt./left femurs, thigh muscles and surrounding tissues • Drains blood from the rt./left legs • Drain blood from the pelvic organs and muscles Veins of the Right Lower Extremity Hepatic Portal Circulation • The hepatic portal circulation is designed to divert blood from the digestive system to the liver before it (and the nutrients it carries) enters the general circulation. The hepatic portal vein is formed from the joining of the superior mesenteric vein and splenic vein. The hepatic portal circulatory route is referred to as a “portal” system because the blood contained within it travels from one capillary bed to another. Hepatic Portal Circulation Factors Assisting the Return of Venous Blood Back to the Heart • Skeletal muscle contraction and one way valves in the veins • Respiratory movements (Diaphragmatic) • Decreasing surface area of venous blood vessel Skeletal Muscles and Valves of the Veins