Question Answer
Arteries Transport blood away from the heart. Carry O2 rich blood in the systemic circuit. Carry O2 poor blood in the pulmonary circuit & umbilical arteries.
Anastomosis Union of 2 blood vessels. Ex. The 2 vertebral arteries fuse into the basilar artery.
Capillaries Location of gas and nutrient exchange between vessels & tissues.
Veins Transport blood towards the heart. Carry O2 poor blood in the systemic circuit. Carry O2 rich blood in the pulmonary circuit & umbilical vein.
Vessel Tunics Lumen, Tunica intima, Tunica media, Tunica externa
Lumen inner space of the vessel
Tunica intima Innermost layer. Simple squamous endothelium. Touches blood directly. Most intimate.
Tunica media Circularly arranged smooth muscle fibers. Location of vasodilation & vasoconstriction.
Tunica externa Outermost layer. Collagen & elastic fibers.
Comparison of Vessel Structures Arteries-Thickest tunica media. No valves. Capillaries-Only tunica intima. Allow rapid gas exchange. Veins-Thickest tunica externa. Smaller tunica media than arteries. Valves.
Blood flow Heart, Elastic artery, Muscular artery, Arteriole, Capillary, Venule, Medium vein, Large vein, Heart.
Elastic Arteries Largest Arteries. "Conducting arteries." Between heart & muscular arteries. High elastin sat_flash_1 allows arteries to stretch & dampen surges & reduce bp resulting from contraction of heart. Aorta & its major branches-Brachiocephalic trunk, etc.
Aortic Branches -exs of elastic arteries. 3 branch directly from aorta. Brachiocephalic trunk-right common carotid art-right external & internal carotid arts. -right subclavian art-right vertebral & internal thoracic. Left common carotid artery-left external & internal carotids. Left subclavian-vertebral & internal thoracic.
Muscular Arteries "Distributing arteries"-body organs & tissues. Thick tunica media. Actively changes diameter of lumen to regulate amt of blood flow to the tissues. Most of named arteries in lab. exs. brachial, coronary, inferior mesenteric arteries, etc.
Arterioles Smallest arteries. Lead to the capillary beds. Diameter regulated by: Local tissue factors. Sympathetic nervous system. Vasoconstriction & vasodilation.
Capillaries Functional units of cardiovascular sys. Gas/nutrient/waste exchange between blood & tissues. Smallest vessels. Endothelium only. tunica intima. Simple squamous epithelium. 3 types: Continuous, fenestrated, sinusoid.
Capillary bed Network of capillaries that run throughout body tissues. Flow control: precapillary sphincter. Bypass: thoroughfare channel.
Continuous Capillaries Most common. Muscle, skin, thymus, lungs, & the CNS.
Fenestrated Have pores. Small intestine, most endocrine glands, kidneys.
Sinusoid Bone marrow (RBCs born-get into blood stream), spleen, liver (RBCs die-leave blood stream). Look messed up.
Venules Smallest veins. Primary location of diapedesis (WBCs leaving blood stream). Venules join to form veins.
Veins Return blood to the heart. Act as blood reservoir. Walls thinner than artery walls. Low blood pressure. Most contain valves-prevent backflow of blood. Skeletal muscle contractions help pump blood toward the heart.
Hepatic Portal System For digestion/absorption of nutrients. Know where blood drains from. Hepatic portal vein-liver. Gastric & gastro-omental-superior stomach. Splenic-spleen. Inferior & superior mesenteric-intestines.
Varicose Veins Dysfunctional valves lead to blood pooling in the superficial limb veins. Genetic predisposition, aging, or strain that inhibits venous return. Strains-obesity, pregnancy, or continuous standing.
Hemorrhoids Varicose veins of the anorectal region. caused by increased intraabdominal pressure. Bowel movement, childbirth.
Fetal Circulation (Part 1) Umbilical cord-2 arteries become medial umbilical ligaments after birth. 1 umbilical vein becomes round ligament of liver or ligamentum teres. Ductus venosus-diverts blood from liver. Becomes ligamenum venosum after birth. Directly to inferior vena cava.
Fetal Circulation (Part 2) Foramen Ovale-diverts blood from r atrium to left. Bypasses immature lungs. Becomes fossa ovalis. Ductus arteriosus-diverts blood from pulmonary trunk to aortic arch bypassing immature lungs. Becomes ligamentum arteriosum.
Patent Ductus Arteriosis Ductus arteriosus stays open after birth. If untreated, PDA can lead to right ventricle failure. Treated w/ prostaglandin-inhibitors or surgery.
Blood Pressure Sphygmomanometer. Systolic/diastolic. Average=120/80 (specifically refers to brachial artery)-lower further from heart. Hypertenstion=high blood pressure (140/90)
Atherosclerosis (Part 1) Linked to over 50% of all deaths in U.S. Progressive disease of the elastic & muscular arteries. Aorta & coronary arteries most affected. Atheroma (fatty plaque)-thickening of the tunica intima. Narrowing of arterial lumen.
Atherosclerosis (Part 2) Risk factors: genetics, sex, age, smoking, hypertension. Treatments: angioplasty, stents, coronary bypass surgery. Best=Prevention! healthy diet-watch cholesterol. dont smoke. monitor bp.
Abdominal Aortic Aneurism (Like vericose veins. BP makes worse-explode & bleed out. Most common in abdomen). Localized dilation of a blood vessel, specifically arteries. Most often caused by atherosclerosis. May be detected through abdominal palpation, x-ray, or ultrasound. Treated w/ artificial vascular prosthesis or stents inserted through the femoral artery.
Cerebrovascular Accident Stroke. Caused by blockage of a brain blood vessel. Thrombus-blood clot that forms w/i the brain blood vessel. Embolus-clot that formed in another blood vessel that migrates to the brain. Can lead to death of brain tissue.