2Blood Vessels Vascular system: A closed transport system where blood circulates through the blood vesselsArteries:Blood enters from the heart into the circulatory system from these and moves into the …Arterioles:Smaller branches off the arteries which feed into the..Capillaries:Contained within the tissues and branch out becoming smaller and smaller. The only connection between arteries and veins. Serves the needs of the body’s cells by exchanging blood between tissue cells and blood.Venules:Smaller branches off the veins. Drain from the capillaries and enter into the …Veins:Empty blood from the circulatory system back into the heart.
3Blood Vessels Blood Vessel Walls: Contain three layers/walls called “Tunics”Tunica Intima:Lines the interior of the vessels and is a thin layer of endothelial tissue on top of a thin layer of loose connective tissue. It has a slick surface to decrease friction as blood flows through it.Tunica Media:Bulky middle “coat” made of smooth muscle and elastic tissue. The smooth muscle is controlled by the Sympathetic NS and is active in changing the diameter of the vessels and in bringing BP up or downTunica Externa:Outermost layer made up of fibrous connective tissue. It functions to support and protect the vessels.
4Artery Walls and Functions Much thicker than veinsMust be able to expand as the blood is forced into them and then recoil as the blood moves out.Walls must be strong and stretchy in order to accomplish these goals
5Vein Walls and Function Thinner walls located further from the heartPressure in veins is continually lowThey contain valves which prevent backflowVeins are modified to make sure the blood returning to the heart is the same amount as blood being pumped out of the heart.
6Skeletal Muscle Activity and Venous Return The action of muscle movement enhances venous return by contracting and relaxing causing the blood in the veins to move towards the heart.
7Respiratory PumpWhen we inhale pressure in the thorax decreases causing the veins near the heart to expand and fill with blood.
8Major Arteries and Systemic Circulation Aorta:Largest artery of the body.Parts of the aorta are named for their location and/or shapeAscending Aorta: curves upward from the left ventricle and when it arches to the left it becomes the aortic arch.Right and Left Coronary Arteries:Only branches of the ascending aorta and serve the heart.
9Major Arteries and Systemic Circulation Aortic Arch:Brachiocephalic Artery: first branch of the aortic arch which splits into…Right common carotid artery: serves the brain, skin and muscles of the neckRight Subclavian Artery: serves part of the brain and right armLeft Common carotid Artery: second branch off the aortic arch which splits into …Left internal carotid: serves the brainLeft External carotid: serves the skin and muscles of the head and neck.
10Major Arteries and Systemic Circulation Left Subclavian Artery: third branch of aortic archVertebral Artery: serves part of the brainAxillary Artery: serves the axillaBrachial Artery: serves the armRadial and Ulnar arteries: serves the forearm
11Major Arteries and Systemic Circulation Thoracic Aorta: moves downward through the thorax following the spineIntercostal arteries: 10 pairs serving the ribsBronchial arteries: serve bronchioles of lungsEsophageal Arteries: serve esophagusPhrenic arteries: serve diaphragm
12Major Arteries and Systemic Circulation Abdominal Aorta: moves through diaphragm into the abdominopelvic cavity.Celiac Trunk:Left gastric artery: supplies the stomachSplenic Artery: serve the spleenCommon hepatic artery: serves part of colonSuperior Mesentrick artery: supplies most of the smaller intestine and the first part of the large.Renal Arteries: serve the kidneysGonadal Arteries:Ovarian: serve ovaries in femalesTesticular: serve testes in males
13Major Arteries and Systemic Circulation Lumbar arteries: pairs of arteries which serve the muscles of the abdomen and trunk.Inferior mesentric artery: serves second half of the large intestine.Common Iliac Arteries: final branches of the abdominal aorta.Internal iliac artery: supplies pelvic organsExternal iliac artery: enters the thigh and becomes…Femoral artery: serves thigh and becomes …Popliteal artery: splits into …Anterior and Posterior tibial arteries: supply leg and footDorsalis Pedis artery: supplies bottom of foot
14Major veins of Systemic circulation Superior Vena cava: veins coming from the head and armpitsRadial & Ulnar Veins: deep veins draining the forearm and they come together to form the:Brachial Vein: drains the armAxillary vein: drains the axillary regionCephalic Vein: superficial drainage of the lateral arm & empties into the axillary veinBasilic Vein: Superficial vein drains the medial aspect of the arm and empties into the brachial veinMedial Cubital vein: the joining of the cephalic and basilic veins. Major site of blood draws
15Major veins of Systemic circulation Subclavian vein: receives blood from the axillary vein, skin and muscles of head through the jugular vein.Vertebral vein: drains posterior headInternal Jugular vein: drains dural sinuses of brainBrachiocephalic veins: right and left drain from the subclavian, vertebral and internal jugular veins. The join to form the …Superior vena cava: where blood enters the heart
16Major veins of Systemic circulation Azygos vein: single vein draining the thorax and enters into the superior vena cavaInferior Vena cava: veins draining from the lower bodyAnterior and Posterior tibial veins: drain the calf and foot.Peroneal vein: drains the calf and footPopliteal vein: posterior tibial vein that becomesFemoral vein: drains the thigh and becomes theExternal Iliac vein: where blood drains from the pelvis
17Major veins of Systemic circulation Great Saphenous vein: longest veins in the body. Receives drainage from the leg. Begins at the foot and goes to the thigh.Common iliac vein: right and left are formed by the external and internal iliac veins and drain the pelvisRight gonadal vein: drain the right ovary and right testicleLeft gonadal vein: drain the left ovary and left testicle.
18Major veins of Systemic circulation Renal Veins: drain the kidneysHepatic portal vein: single vein which drains the digestive tract organsHepatic veins: drain the liver
19Arterial Supply of the Brain The brain is supplied by two pairs of arteriesInternal carotid:Run through the neck and enter the skull through the temporal bone and then divide into the…Anterior and Middle cerebral arteries: supply most of cerebrumVertebral artery:Paired arteries running upward from the subclavian arteries at the base of the neck. In the skull they join to form the …Basilar arteries: serve the brain stem and cerebellum. At the base of the cerebellum they divide into the …Posterior Cerebral Arteries: supply the posterior cerebrum
20Circle Of WillisThe circle of Willis is where the anterior and posterior blood supplies unite by small communicating arterial branches.They form a complete circle around the base of the brain of connecting blood vessels.
21Hepatic Portal Circulation Veins of hepatic circulation drain the digestive system, the spleen and pancreas and deliver blood to the liver through…Hepatic portal vein: blood contained here contains large amounts of nutrients and ensures that the liver processes these nutrients before entering systemic circulation.Inferior mesentric vein: drains part of the large intestine and drains into the …Splenic vein: drains the spleen, pancreas and left side of the stomach
22Hepatic Portal Circulation Superior Mesentric vein: joins with the splenic vein to form the hepatic portal veinLeft gastric vein: drains the right side of the stomach directly into the hepatic portal vein.
23Fetal CirculationIn the fetus the lungs and digestive system are not functioning so all nutrients and gas exchange go through the placenta.Umbilical cord: contains three blood vesselsUmbilical vein: one vein carries blood rich in nutrients and oxygen to the fetusUmbilical arteries: two arteries carrying carbon dioxide and debris from the fetus to the placentaDuctus Venousus: bypass for blood to go towards the heart and bypass the liver which is non functioning.
24Fetal LungsIn the fetus the lungs are non-functional and are collapsed.Shunts: there are two shunts which make sure the lungs are bypassed.Foramen Ovale: blood entering the right atrium is shunted directly to the left atrium through this opening in the internal septum. It closes after birthDuctus Arteriosus: short vessel connecting the aorta and pulmonary trunk. At birth it collapses and becomes the …Ligamentum Arteriosum: fibrous tissue completing the circulatory system of an adult.