cariovascular system Flashcards
functions
distribution of oxygen, nutrients, and thermoregulation (maintain a stable temp and distrubute
4 types of vessels
arteries, veins, lymphatic vessels and capillaries
arteries
carry oxygenated blood away from the heart to the bodies tissues
veins
carry deoxygenated blood back to the heart from capillary beds, there are some exceptions
3 tunics (coats) of circulatory vessels
-tunica intima: thin endothelial lining, simple squamous; inner layer
-tunica media: middle smooth muscle layer
-tunica adventitia: outer CT coat, common, on the outside
thick layer of smooth muscle (tunica medina) is associated with
an artery
thin layer of smooth muscle (tunica medina) is associated with
a vein
what are the three types of arteries:
- large elastic
- medium muscular
- small arteries and arterioles
arteries:
large elastic
many elastic layers allow expansion when the heart contracts.
ex. aorta and its arch branches
arteries
medium muscular
ability to vasoconstruct regulates blood flow to different parts of the body as required, distributes; have smooth muscle; ANS
arteries
small arteries and arterioles
narrow lumina and thick muscular
-ex. found everywhere
veins
have thinner walls compared to companion arteries due to lower blood pressure in the venous system; variable and frequent anastomoses are present
smallest veins and venules
form plexus
medium veins in limbs
have two mechanisms that encourage blood flow back to heart
-valves: permit blood flow toward the heart, stops blood from dropping further
-muscolovenous pump: next to large muscles, contract and squeeze veins
large veins
wide bundles of longitudinal smooth muscle and a well-d tunica and adventitia developed. ex SVS and IVC
capillaries
simple endothelial tubes: connection between arterial venous sides of circulation. between soft tissues, lymp beds
capillaries arranged in network:
capillary beds between arterioles and venules
function of capillaries
follow the exchange of O2 nutrients and other cellular materials with surrounding tissues.
arteriovenous anastromeses (AV)
shunts permit blood to bypass the capillaries, numerous in the skin, conserve body heat. close themselves
what are the two types of capillaries
continuous and sinusoidal
capillaries
continuous
most common type, formed of tight junctions (desmosomes), small molecules are forced to pass between capillaries at intracellular clefts between membranes, found everywhere
capillaries
sinusoidal
rare, wider and leaky capillaries that allow the transfer of molecules that are larger
-present in the lymph system
what are the major vascular systems
pulmonary, systemic, azygous, and hepatic
pulmonary circulation
carries deoxygenated blood from the heart to the respiratory surfaces for oxygenation and back into the heart for distribution to the body.
-right ventricle-pulmonary trunk (arteries)-lungs-pulmonary veins-left atrium
systemic circulation
takes oxygenated blood to body tissues-deoxygenated blood with CO2 to heart-back to lungs
-associated with the left side of the heart and has higher pressure
-associated with all arteries in the body except those that travel to the lungs for oxygenated purposes and veins
arteries arise from the aorta: 4 parts
-ascending aorta
-aortic arch
-descending thorax and abdominal aorta
4 parts of aorta
ascending aorta
right and left coronary arteries (supply the heart)
4 parts of aorta
aortic arch
arteries to the head, neck, and upper limbs
4 parts of aorta
descending thorax and abdominal aorta
arteries to the thorax, abdomen, pelvis, and lower limbs
systemic circulation
takes deox blood to the heart by 3 major veins
-superior vena cava
-inferior vena cava
-coronary sinus
systemic circulation; 3 major veins
SVC
drains the head and upper limbs
systemic circulation; 3 major veins
IVC
drains the thorax, abdomen, and lower limbs
systemic circulation; 3 major veins
coronary sinus
drains the wall of the heart
what is the function of azygous venous systems
drains blood from the thoracic wall and some thoracic viscera into the SVC and includes 3 unpaired vessels
what are the three unpaired vessels in the azygous systems
-azygous: right side
-hemiazygos: left side
-accessory hemiazygos vein: left side
describe the right side azygous system
intercostal vein-azygous vein-SVC
describe the left side azygous system
intercostal vein-hemiazygos vein-azygous- SVC
what is the function of the hepatic portal venous system
relays digestive products from the stomach and intestines, and red blood cell products to the liver for processing
hepatic venous system
-hepatic portal vein
deoxy nutrient rich blood is drained into this vein to reach the liver for processing, detoxification and storage
hepatic venous system
-processed blood is conveyed into the
systemic venous circuit by the hepatic veins that drain into the IVC
hepatic venous system is formed by
superior mesenteric, splenic, and inferior mesenteric veins
-join to form the hepatic portal vein
what are vascular anastomoses
neighboring vessels connect with one another; plexus like
what is the importance of anastomeses
if one artery is blocked, blood can circumvate the blockage and still maintain competency with the tissue in question
around joints: help oxygenated blood to continue to flow to the tissue even if it is flexed/ extended
varicose veins
abnormally weak and dilated veins as a result of lost elasticity.
-have less normal caliber and incompentent valves with cusps that do not meet or have been destroyed by inflammation
-most often seen in legs
-poor circulation, valves, and veins open.
-comes with age
hemorrids
varicosities of the anal veins. the pooling in these veins is caused by the straining associated with childbirth or bowel movements. this straining raises the intraabdominal pressure, preventing the draining of the blood
-common with age, painful
atherosclerosis
-atheroma: small, patchy thickenings that intrude into the vessel lumen and can prevent backflow if a passing clot becomes lodged.
- in the coronary arteries
beginning stage of atherosclerosis
the fatty plaques force the vessel walls to grow outward, until the vessel cannot accomodate any further
-the vessels will grow less elastic and more brittle over time and plaque accumulates
blood
- accounts for 8% of body mass
specialized form of CT in which blood cells are suspended in plasma
composition of blood
blood plasma: the suspension fluid contains nutrients, proteins, sugars, amino acids, 90% water
elements of blood cells
-erythrocytes: red blood cells, contain oxygen, no nucleus
-leukocytes: white blood cells
-platelets: clotting cells
