Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
65 Cards in this Set
- Front
- Back
|
Arteries |
(Elastic and contractile, walls are thick) Carry blood away from heart |
|
|
Arterioles |
Smaller in diameter; important in regulation of blood pressure; delivers blood to capillaries |
|
|
Capillaries |
Microscopic vessels that connect arterioles to venules; permits exchange of gas nutrients and waste between blood and tissues; critical for homeostasis, main site of cardiovascular activity |
|
|
Venules |
Small veins formed from the union of capillaries; they collect capillary blood and leads to veins |
|
|
Veins |
Carry blood to heart |
|
|
Tunica externa (tunica adventitia) |
(Thickest) Elastic and collagen fibers; stabilize and anchor blood vessels in surrounding tissue; top layer of vein |
|
|
Tunica media (middle) |
Collagen fibers, elastic and smooth muscle fibers (external elastic membrane) middle layer of vein |
|
|
Tunica interna (tunica intima - inner) |
Endothelium and basement membrane (internal elastic membrane) thinner than arteries; bottom layer of vein |
|
|
Artery walls are _____ than veins |
Thicker |
|
|
Artery tunica media contains more _____&_____ than veins do |
Smooth muscle and elastic fibers |
|
|
What do artery walls do when they aren't being opposed by blood pressure? |
Recoil |
|
|
Veins contain valves to prevent____? |
Backflow of blood |
|
|
Elastic arteries (conducting arteries) |
Nearest the heart, largest diameter, help propel blood from heart when ventricles are relaxing, helps maintain blood pressure |
|
|
Muscular arteries (distributing arteries) |
Medium-sized arteries, greater vasoconstriction and vasodilation, distribute blood to body, pressure points to reduce bleeding |
|
|
Arteriosclerosis |
Thickening and toughening of arterial walls |
|
|
Focal calcification |
Calcium salts deposited in tunica media, limbs and genital organs |
|
|
Atherosclerosis |
Formation of lipid deposits in tunica media |
|
|
Arteriosclerosis factors |
Lipid levels, cholesterol, smoking, hypertension, high LDL, diabetes, obesity, stress |
|
|
Arteriosclerosis results |
Plaque formation and can lead to blood clots |
|
|
Vasoconstriction |
Deceased blood flow, increased blood pressure |
|
|
Vasodilation |
Increased blood flow, decreased blood pressure |
|
|
What are the 3 types of capillaries |
Continuous, fenestrated, and sinusoid |
|
|
Continuous capillaries |
Endothelium complete, found in all tissues except cartilage and epithelia, permit diffusion of water, small solutes, lipid soluble materials, prevent loss of blood and plasma protein |
|
|
Fenestrated capillaries |
Pore-containing capillaries, allow rapid exchange of water and solute between blood plasma and IF |
|
|
Sinusoid capillaries |
Capillaries with gaps between cells, permits free exchange of large solutes and water between blood and IF |
|
|
Capillary beds |
Interconnected = 1 arteriole connected to dozens of capillaries |
|
|
Capillary exchange |
Movement of substances between blood plasma and interstial fluid |
|
|
Diffusion |
Movement of a substance down its concentration gradient (high to low) |
|
|
Transcytosis |
Substances enter endothelium by endocytosis, move across cell and leave by exocytosis |
|
|
Bulk flow |
Passive process where large numbers of ions, molecules or particles move together in the same direction (high pressure to low pressure) |
|
|
Filtration |
Pressure-driven movement of fluid and solutes from capillaries into interstitial fluid |
|
|
Reabsorbtion |
Pressure-driven movement from interstitial fluid into blood capillaries |
|
|
Venuos valves |
Venous bp is low and can't overcome force of gravity, valves prevent blood backflow in veins, push blood to heart to improve venous return |
|
|
Venous return |
Volume of blood flowing back to the heart |
|
|
Skeletal muscle pump |
Standing/rest proximal valve closet to heart and distal valve are open; blood flows toward heart (leg muscle contraction compresses vein which pushes blood through proximal valve, distal valve closes, after muscle relaxation proximal valve closes and distal vein opens |
|
|
Respiratory pump |
Alternating compression and decompression of veins during respiration |
|
|
What happens if venous vein malfunctions (stretch/weaken)? |
Blood pools in veins and vessel distends |
|
|
2 types of venous valve malfunction |
Varicose veins and hemorrhoids |
|
|
Edema |
Filtration greatly exceeds reabsorbtion |
|
|
Blood flow |
Volume of blood that flows through any tissue in a given period of time |
|
|
Cardiac output (co) |
Co= hr x sv |
|
|
What determines capillary blood flow? |
Pressure (P) and resistance (R) |
|
|
What must the heart do to keep blood flowing? |
Generate pressure to overcome resistance to blood flow in circuits |
|
|
Flow is proportional to___? |
Pressure |
|
|
Flow is inversely proportional to___? |
Resistance |
|
|
Higher blood viscosity from? |
Dehydration or polycythemia |
|
|
Lower blood Viscosity from? |
Anemia or hemorrhage |
|
|
Mabp |
Perfusion pressure in organs |
|
|
Hypotension |
BP is to low |
|
|
What are the 3 major mechanisms for control of bp? |
Autoregulation, neural mechanism, and endocrine mechanism |
|
|
Autoregulation |
Ability of tissue to adjust blood flow to match metabolic needs in localized area |
|
|
Neural mechanism |
Cardiovascular centers found in medulla oblongota |
|
|
Baroreceptor reflex |
Pressure-sensitive sensory receptors in carotid arteries |
|
|
Chemoreceptor reflexes |
Monitor chemical composition of blood |
|
|
Endocrine mechanism |
Hormones that increase bp, provides short term and long term regulation of cardiovascular performance |
|
|
Epinephrine and norepinephrine |
Stimulate cardiac output and peripheral vasoconstriction |
|
|
Epo |
Increase in rbc's leads to increase in bp |
|
|
Antidiuretic hormone (ADH) |
Increase blood volume |
|
|
Angiotension 2 |
Responds to decreased pressure at kidneys |
|
|
Atrial natriuretic peptide (ANP) |
Produced by cardiac muscle cells in right atrium wall in response to excessive stretching during diastole |
|
|
Histamine |
Causes vasodilation of arterioles |
|
|
What is cardiac output at rest? |
5.8liters/min |
|
|
Maximum level of cardiac output during heavy exercise is ____? |
20-25L/min |
|
|
Shock |
Failure of cardiovascular center to deliver enough oxygen and nutrients to meet metabolic needs of cells/tissues |
|
|
In a capillary bed the bands of smooth muscle at the entrance to each capillary is called a |
Precapillary sphincter |
