CV Flashcards

Question

arteries and arterioles

Answer 1

arteries: walls that are both stiff and springy (pressure reservoir) thick smooth muscle layer and large amount of elastic and fibrous connective tissue branch into smaller arterioles that mainly contain vascular smooth muscle,

Answer 2

arteries, arterioles, capillaries, venules, veins they all contain inner layer of thin endothelial cells and can be wrapped in a combination of elastic tissue, smooth muscle, or fibrous tissue.

Answer 3

smallest vessels in the cardiovascular system, where the majority of exchange between the blood and interstitial space occurs. single thin endothelial layer surrounded by basal lamina (extracellular matrix) gases can normally passively diffuse across the endothelial cells linked by interendothelial junctions that also aid in the transport of small solutes and water some cells contain fenestrations, membrane-lined conduits running through them to allow the transport capilleries often surrounded by pericytes (BBB)

Answer 4

continous capillary: most common, thicker endothelial cells that do not contain fenestrations only allow passage of water and small ions fenestrated capillary: thin endotheial cells that have fenestrations. small molecular passage discontinuous capillary: lack a basal membrane, have large open fenstrations as weel as gaps between the endothelial cells

Answer 5

transcellular transport: diffusion or osmosis across the endothelial cell membrane. gases, small lipid molecules, water (aquaporin channels) paracellular transport: diffusion through interendothelial junctions, pores, or fenestrations (water, small water-soluble, and small polar molecules) transcytosis: the combination of endocytosis, vesicular transport, and exocytosis that transports macromolecules across endothelial cells

Answer 6

veins are more numerous and have a lager volume, thinner walls and less muscle tissue in comparision to arteries making the venous circulation the volume resvoir of the circulatory system

Answer 7

the formation of new blood vessels not really seen in adult unless wound healing, endurance training, inflammation, tumor growth, and in the endometrium during the menstrual cycle. promoters and inhibitors angiogenesis is a necessary part of the process in the progression of cancer

Answer 8

ventricular contraction creates the force necessary to propel blood through the CV system ventricular contraction pushes the blood into elastic arteries, causing them to stretch. ventricular relaxation: elastic recoil in the arteries maintains driving pressure during ventricular ventricualr diastole aorta and larger arteries sustain driving pressure during ventricular diasotle

Answer 9

highest in the aorta and decreases through the circuit aortic pressure highest during ventricular contraction (systole): Systolic pressure (120 mm Hg) and lowest during ventricular relaxation (diastole) diastolic pressure 80mm Hg the difference between the systolic and diastolic pressure is known as the pulse pressure. in the aorta PP= 120-80 = 40 mmhg

Answer 10

is not simply the average of the systolic and diastolic pressures (100 mm hg) because equal amounts of time is not spent in systole and diastole cardiac cycle 800ms: 250 ms ventricular systole and 550ms ventricular diastole MAP= diastolic pressure + 1/3 (pulse pressure) = 80 mm HG + 1/3 (120-80 mm Hg) = 93 mm Hg

Answer 11

hypotension represents when the blood pressure falls too low (<90/60) this can cause the driving force for blood flow to be inadequate to overcome the opposition by gravity. hypertension: represents when the blood pressure is elevated ( >140/90) high pressure on the vessel walls can casue them to become weakned or even rupture if this occurs in the brain it is called a cerebral hemorrhage and can cause stroke

Answer 12

used to measure blood pressure a) cuff pressure >120 mm Hg when the cuff is inflated so it stops arterial blood flow, no sound can be heard through a stethoscope placed over the brachial artery b) cuff pressure b/w 80-120 mm Hg korotkoff sounds are created by pulsatile blood flow through the compressed artery C) Cuff pressure <80 mm Hg blood flow is silent when the artery is no longer compressed

Answer 13

is the driving force for blood flow balance between blood flow into the arteries and blood flow out of the arteries mean arterial pressure = cardiac output x peripheral resistance if cardiac output increases and peripheral resistance does not change, then blood is pumped into the arteries faster than it is removed from the arteries, inc volume in arteries= inc arteiral blood pressure

Answer 14

small changes in blood volume occur from ingestion of food and liquids primarily resolved by kidneys decrease in blood volume requires an integrated response from the kidneys (urination) and the cardiovascular system (decrease cardiac output or vasodilation) and ingestion of fluid fast response is CV slow response is kidneys increased blood volume leads to increased blood pressure

Answer 15

contributes >60% of total resitance to flow in CV system is influenced by both local and systemic control mechanisms that alter the vascular smooth muscle changing the radius of vessels and greatly influencing resistance: 1) Local control of anterior resistance matches tissue blood flow to the metabolic needs of the tissue. -in the heart and skeletal muscle, these local controls often take precedence over reflex control by the CNS sympathetic reflexes mediated by the CNS maintain mean arterial pressure and govern blood distribution for certain homesotatic needs such as temperature regulation hormones- particularly those that regulate salt and water exertion by the kindeys, influence blood pressure by acting directly on the arterioles and by altering autonomic reflex control

Answer 16

some vascular smooth muscle has the ability to regulate its own state of contraction, known as myogenic autoregulation. an inc in blood pressure causes the vascular smooth muscle in the wall of the arteriole to stretch, which causes the smooth muscle to stretch, leading to vasoconstriction

Answer 17

local control cell signaling of blood flow is important in allowing individual tissues to regulate their own blood supplies. they affect blood flow to the tissue they are released from the target tissue.

Answer 18

the main determinant of resistance in the majority of arterioles primarily sympathetic neurons innervate arterioles and tonically control anterior diameter through activation or deactivation of alpha-1 adrenergic receptors (lead to vasoconstriction). norepinephrine is released from them when inc of sympathetic if decreased, then there decrease of nonepinephrine there is a secondary mechanism involving epinephrine from the adrenal medulla in response to sympathetic activation. is has a low affininty to alpha receptors and high affinity to beta-2 adrenergic receptors, which lead to vasodilation. more alpha then beta in muscles and more beta than alpha in Gi tract

Answer 19

Tachycardia is sympathetic bradycardia is parasympathetic

Answer 20

the primary reflex pathway for homeostatic control of mean arterial pressure is the baroreceptor reflex baroreceptors are tonically active (sensory neurons), stretch-sensitive mechanoreceptors that are situated on the aorta and on the carotid artery. when there is an inc of blood pressure, the baroreceptors sense the stretch in the artery walls and increase their firing rate. decrease blood pressure decrease firing rate cardiac vascular control center will cause the appropriate response: inc in MAP there would be dec in cardiac output and dec peripheral resitance, so dec in sympathetic output (less NE) and inc in parasympathetic there will dec in MAP inc in sympatheric output (more NE) and dec in parasympathetic output and inc in peripheral resistance and inc in cardiac output

Answer 21

Every morning when you stand up out of bed, your baroreceptor reflex is highly engaged cardiac output falls from 5L/min to 3L/min within 2 heartbeats, baroreceptors increases CO and peripheral resistance to increase MAP extended bed rest leads to dec in blood volume, when you finally stand up baroreceptor dont work to return Map due to blood loss

Answer 22

peripheral chemoreceptors located on aoritc arch and cartid artery sense alterations in blood-gas concentrartions O and CO2 send info back to the control center which results in autonomic output to return blood gas level to normal the hypothalamus is capable of altering cardiovascular function in repsonse to emotional stress some individuals faint in response to sudden emotional distress, sight of blood, acute pain, and needle insertion results in a large inc of parasympathetic output and reduction in sympathetic output both these combine to a large fall to MAP

Answer 23

bulk flow is the mass movement of fluid as the result of hydrostatic or osmotic pressure gradients. is bulk flow is resulting in fluid moving in the capillaries, its absorption and osmotic pressure If bulk flow is resulting in the movement of fluid out of the capillaries, it is filtration and hyrdostatic pressure.

Answer 24

osmotic pressure steady in the capillary and exceeds the interstial space osmotic pressure hydrostatic pressure decreases as blood travels through the capillaries due to the resistance encountered and exceeds interstitial hydrostatic pressure. at the arterial end, hydrostatic pressure exceeds osmotic pressure, causing filtration at the venous end, osmotic pressure exceeds hydrostatic pressure and there is absorption. overall there is net filtration resulting in loss of 3L of fluid per day

Answer 25

lymphatic vessels assist the CV system with returning fluid and proteins lost through the capillaries. single endothelial cell layer contain large interendothelial junctions

Answer 26

the initial lymphatic segment has the interstitial hydrostatic pressure higher than inside the lymphatic, causing the microvalves to open and fluid to flow in as it fills up with fluid the lymphatic hydrostatic pressure exceeds interstitial, the microvalves close and secondary valves open collecting lymphatics contain smooth muscle that actively contract to propel fluid

Answer 27

disorders of the heart and blood vessels, such as heart attacks and strokes, play a role in over 1/3 of the deaths in U.S risk factors for CV disease include: uncontrolled risk factors: age, sex, family history of early CVD, genetics controlled risk factors: cigarette smoking, obesity, sedentary lifestyle combo of both: diabetes, hyperlipdemia

Answer 28

albumins: liver, function: contributes to colloid osmotic pressure of plasma, carries for various substances globulins: liver and lymphoid tissue, function: clotting factors, enzymes, antibodies, carriers for various substances fibrinogen: liver, function: forms fibrin threads essential to blood clotting transferrin: liver and other tissues function: iron transport

Answer 29

connective tissue with cellular elements suspended in the extensive fluid matrix 7-8% total body mass 70ml/kg female 80 for male

Answer 30

production of blood cells 75%white blood cells 25% red blood cells (long life span0

Answer 31

they are released from one cell and affect the growth/activity of another cell they guide in hematopoiesis. erythropoiesis: RBC production leukopoiesis: production of WBC thrombopoiesis: platelelt production

Answer 32

most abundant life span is about 4 months non nucleated functions 1) carrying O2 from the lungs to the tissues 2)carrying CO2 from the tissues to the lungs 3) buffering of acid and bses

Answer 33

it is a 02 transport protein structure is 4 protein chains, centered around a heme group, most common is 2 alpha and 2 beta each heme group consists of a porphyrin ring with a iron atom in the center 70% of iron in the body found in the heme group

Answer 34

defend against infection 2 major groups 1) Granulocytes: contain cytoplasmic granules, lifespan <12 hours neutrophil: most abundant, contain granules with enzymes capable of digesting foreign material (phagocytosis) eosinophil: granules contain major basic protein, which is toxic to parasites, important in response to virus basophil: least common, contain histamine, helps in allergic reaction 2) non-granule contiang lymphocytes and monocytes lymphocytes: two types T-lympocytes and B lymphocytes T cells: 70-80% of all lymphocytes and responsible for cell mediated immunity does not involved with antibodies. B cells: responsible for humoral immunity, make antibodies to antigens monocytes: spend life in peripheral tissues developing into macrophages, which serve two purposes 1) phagocytosis of pathogens or cellular debris 2) Present antigens to lymphocytes.

Answer 35

nucleus-free fragments, A single megakaryocyte can produce thousands of platelets. 10 day life span contain 2 special types of granules dense core granules alpha granules essential for hemostasis, the process which keeps blood within a damaged vessel

Answer 36

the prevention of bleeding 1) Vasoconstriction: contributes to hemostasis by closing the vessel and preventing blood flow to the damaged region. can be triggered by direct injury to smooth muscle brings down the pressure within the vessel so a secure mechanical seal can be applied in the form of a clot 2) platelet plug formation: inactivated platelets do not adhere to themselves or to the intact endothelial cells that line the vessel. platelets contain cell surface receptors (integrins) a breach of the endothelium exposes integrins to collagen, fibronectin, and laminin, which are all part of the subendothelial layer, causing platelets to bind The binding of integrins causes platelets to release the contents of their granules