Physiology I- Cardiology/ Blood Exam 3 study Flashcards

Question

What is erythropoeisis?

Answer 1

Formation of RBC

Answer 2

Liver and Spleen

Answer 3

Long bones ( tibia and femur)

Answer 4

Flat bones (vertebrae, pelvis, sternum, ribs)

Answer 5

Pluripotent stem cell

Answer 6

Pro erythroblasts and erythroblasts. The hemaglobin concentration will gradually increase, and the nucleus will become smaller and finally disapears (reticulocytes)

Answer 7

Iron ( for Hb synthesis) Vitamin B12 and folic acid ( synthesis for DNA for cell division) Erythropoietin (34 kDa glycoprotien, produced in kidney and upregulated by low O2 tension in tissues)

Answer 8

An increased number of erythrocytes ( seen at high altitudes, and in erythropoietin doping) - When hematocrit increases so does blood viscosity. Increased viscosity makes it difficult for the heart to pump polycythemia blood. Therefore polycythemia causes a heavy workload for the heart and can lead to failure. Particularly if the cardiac muscle is not healthy.

Answer 9

Macrophages, and occurs in liver, spleen, and bone marrow.

Answer 10

Conditions where the capacity of blood to transport O2 is reduced. Causes: Blood loss (hemorrhage), RBC destruction ( hemolysis), Decreased RBC production (erythroid hypoplasia) Symptoms: Pale MM, Depression, Lethargy, Weakness, Exercise intolerance, Jaundice (icterus if Bilirubin concentration is \> 2mg/dL), Splenomegaly, Recombancy, seizures, syncope, coma. \* Could be low Hematocrit ( abnormally few RBCs in each deciliter blood) or Low MCH and or MCHC: abnormally low hemoglobin concentration in each RBC. Cardiac increase must be increased above normal to deliver normal O2 to tissues each minute. Necessity to increase cardiac output also imposes increased workload on heart and can lead to failure in diseased heart.

Answer 11

Morphology ( erythrocytes in micro, macro, and normocytic) Hb content ( in erythrocytes in hypo, hyper, normochromic) Regeneration (ability of bone marrow in regenerative and non regenerative)

Answer 12

Mean corpuscular volume (MCV) If increased macrocytic anemia, if decreased microcytic anemia. Mean corpuscular hemoglobin (MCH) If increased hyperchrome, if decreasd hypochrome Mean corpuscular hemoglobin concentration (MCHC) avg # of hemaglobin within erythrocytes

Answer 13

Regenerative anemia will have increased #'s of circulating reticulocutes which indicates increased bone marrow erythropoiesis Causes: hemorrhage ( gastric ulcer, trauma, hemostasis defect, parisitism) Hemolysis: - Intrinsic defects ( mostly congenital: hemoglobin defects, sickle cell, membrane deformation, enzyme deficiencies) Extrinsic defects ( mostly acquired): chemicals ( methemoglobin formation, denaturation of Hb), Parisitism (bartonella, babesia, mycoplasm, rikettsia), immune mediated ( hemolytic anemia of newborn)

Answer 14

Non- Regenerative: low number of reticulocytes, no increased erythropoiesis Function of bone marrow impaired: FELV, Chemo, Congenital Extramarrow diseases: Chronic renal failure, liver disease, B12 deficiency, Iron deficiency.

Answer 15

Piglets grow rapidly in first few weeks, in modern rearing they dont get access to soil/ other iron sources. Iron pool is only sufficient for first few days. Must be supplemented with Iron to help piglets thrive. Given within first 2 weeks of life. Those who got it sooner increased in body mass quicker.

Answer 16

WBC Big nucleus (sometimes segmented), with many organelles No hemoglobin Function is immune response, and perform at sites of inflammation, infection ect.

Answer 17

Transport of fluid, protiens, fat, pathogens and antigens. Big lymph vessels are surrounded by smooth muscle cells, and have endothelial valves which enable lymph to move in one direction. - recovered lymph makes its way to the thoracic duct and then to the blood.

Answer 18

Megakaryocytes

Answer 19

Innate: Immediate destruction ( phagocytosis) and alert immune system. - Cell mediated: macrophages, granulocytes, dendritic cells. Adaptive immunity: Creates memory, delayed/ acts later - Cell mediated: T lymphocytes ( Helper T cells and Cytotoxic T cells)

Answer 20

Granulocytes are the Neutrophils, Eosinophils, and Basophils. Each have specific functions/ triggers but in general they engage in phagocytosis.

Answer 21

Agranulocytes include lymphocytes and monocytes. Lymphocytes will become B lymphocytes, T lymphocytes, or natural killer cells. Monocytes will become tissue specific macrophages ( which have Toll like receptors) and participate in phagocytosis and cytokine release.

Answer 22

Contraction of injured vessel, formation of platelet plug, and coagulation of blood.

Answer 23

Inhibits activation of blood platelets.

Answer 24

ADP and TXA2 ( thromboxane A2)

Answer 25

All factors participating in the cascade are present in the blood. Occurs when blood comes into contact with collagen fibers or with surfaces other from endothelium (this also occurs inside a test tube

Answer 26

Triggered by a tissue factor (tissue thromboplastin, factor III) that is not present in the blood but is released from surrounding tissues upon tissue damage

Answer 27

Fibrinolysis is slow process and begins right after clot formation Plasmin is an active proteolytic enzyme that will slowly dissolve clot.

Answer 28

Hemophillia: congenital deficiency of coag factors VIII (Hemophillia A) and IX (hemophilla B) Vitamin K: Required by liver for synthesis of coag factors. Warfarin ( present in rat posion): inhibits action of Vitamin K and because of that reduces concentration of several clotting factors. Acetylsalicylic acid (asprin) inhibits synthesis of thromboxane X2 so it inhibits formation of platelet plugs Many anticoagulants are Ca++ chelators ( edta, citrate)

Answer 29

Glycosphingolipids ( and the difference is just one additional compound at the end of the chain. )

Answer 30

Universal donors are type O blood because they dont have A or B antigens. They cannot receive blood with A or B antigens however. AB blood type can receive blood from anyone.

Answer 31

Anaphylaxis, hemolytic anemia, agglutination, destruction of RBC

Answer 32

RhD allel is mutated in 15 % of population (deletion). Generation of antibodies against Rh+ patients. This is extremely dangerous when transfusing blood from an incompatible donor. Pregnant women who are Rh- and have a fetus that is Rh+ can pass antibodies through placenta and can cause hemolytic anemia in the fetus, first pregnancy is normally unproblematic though.

Answer 33

Hemolytic disease of newborn. During pregnancy Aa- mares can be immunized by Aa+ fetuses during pregnancy. Upon second antigen contact the mother will have IgGs against Aa+ RBC of the fetus. After birth IgGs will be taken up by foal from colostrum and this will go to blood stream and cause hemolytic anemia in the foal.

Answer 34

FALSE Positive cross match = do not transfuse with that unit.

Answer 35

The portion of the ventricle that is infarcted remains depolarized at all times, and cannot return to resting membrane potential.

Answer 36

The major and broad components of the cardiovascular system consists of Heart blood vessels and blood. This helps to transport blood, O2 to brain and other organs. These “tubes”/ vessels also transport blood / CO2 to the lungs to be oxygenated, and carries waste for appropriate disposal.

Answer 37

Mitral Valve, Aortic Valve,Tricuspid Valve, Pulmonary Valve: Their job is to keep blood flowing in one direction/ prevent back flow.

Answer 38

Central circulation: specifically coronary arteries

Answer 39

◦ Pulmonary circulation: Blood vessels of lungs, including pulmonary arteries and veins. ◦ Systemic circulation: The blood vessels between the aorta and venae cavae are collectively called systemic circulation. ◦ Central circulation: The heart and pulmonary circulation

Answer 40

Systolic aortic pressure: Aortic blood pressure at peak after aorta is distended with blood from left ventricular contraction. (Approximately 120 mmHg) Diastolic pressure: Minimal value or aortic BP before next cardiac ejection ( blood continues to flow between ejection into downstream arteries, this cause aortic pressure to decrease) (Approximately: 80 mmHG)

Answer 41

* Systemic Perfusion Pressure: mean aortic pressure - mean venae Cavae pressure = systemic perfusion pressure * Pulmonary Perfusion pressure: pulmonary artery blood pressure - mean pressure in pulmonary veins= Pulmonary Perfusion pressure * Perfusion pressure for systemic circulation is much greater than the perfusion pressure for pulmonary circulation. Systemic = high pressure, high resistance Pulmonary circulation = low pressure, low resistance.

Answer 42

◦ Splachnic portal system: Directs blood flow to the abdominal GI organs including, stomach spleen, small and large intestines, pancreas, and liver. ◦ Renal portal system: blood from caudal vein to kidneys via two renal portal veins. ◦ Hypothalmic- hypophyseal portal system: System of blood vessels in the microcirculation at the back of the brain.

Answer 43

* Plasma is the liquid, cell - free part of blood that has been treated with anticoagulants. ( contains clotting factors) * Serum: is the liquid part of blood after coagulation, therefore devoid of clotting factors.

Answer 44

The mean quantity of hemoglobin in each RBC. (Normal is: 21-26 pga)

Answer 45

The mean quantity of hemoglobin in each Deciliter of packed RBCs. (Normal is: 32-36 g/dL)

Answer 46

Percent by volume of RBC in blood. (Normal is 35-57%)

Answer 47

Most of CO2 becomes hydrated to form bicarbonate (HCO3-) or combines with hemoglobin or plasma proteins to form carbamino compounds. Only small portion of CO2 in blood is carried in dissolved form.

Answer 48

Bulk transportation is the transport of blood through the heart and blood vessels. The source of energy for bulk flow is its perfusion pressure. Perfusion pressure is the pressure difference that causes blood to flow through blood vessels. • Transmural pressure (distending pressure) is pressure difference between blood pressure inside vessel and fluid pressure in tissue immediately outside vessel. ◦ Equations: ‣ Perfusion Pressure = P[inlet] - P[outlet] ‣ Transmural Pressure = P[inside] - P[outside]

Answer 49

Diffusion is the slow transport of nutrients and wastes from an area of high concentration to low concentration. It is a major mode of transport that occurs at capillaries, and every metabolically active cell in the body must be close to a capillary carrying blood via bulk flow.

Answer 50

◦ The SA node is in the right atrial wall, near where the venae cavae enter the right atrium. SA nodes spontaneously depolarize most quickly to threshold. In resting dog the ventricular rate from SA node cells is 80-90 BPM. Each heartbeat is initiated by a spontaneous action potentials in one of the pacemaker cells of the SA node. ◦ AV Node and bundle of his is in the interventricular septum. The only route of propogation of action potentials is from the atria to the ventricles. Slow conduction of action potentials which creates delay between atrial and ventricular contractions. AV node also exhibits spontaneous pacemaker activity.

Answer 51

twin properties of slow conduction of action potentials and an ability to conduct action potentials in only one direction. Occurs in damaged heart cells.

Answer 52

◦ Pre-potential: K+ channels close and open Na+ channels, Na+ slowly influxes in. ◦ Depolarization: (atria contraction) Ca2+ channel opens and there is a rapid influx of CA2+. ◦ Repolarization: Open of K+ channel which allows outflow of K+

Answer 53

◦ Phase 0: Sodium channels are open due to depolarization threshold. Causing rapid depolarization ◦ Phase 1: Na+ channels inactivate which causes Na+ permeability to decrease quickly. Membrane begins to repolarize. ◦ Phase 2: Subsequently, some types of K+ channels close so K+ permeability decreases. In addition many gated Ca2+ channels open so Ca2+ permeability increases. These actions keep the cell membrane in the depolarized state for 200ms which causes the prolonged plateau of depolarization. (Ca2+ entering cell triggers more Ca2+ to be released from the sarcoplasmic reticulum. ◦ Phase 3 and 4: K+ channels reopen and Ca2+ channels close, which causes the cell to repolarize (Phase 3) and eventually return to its stable negative resting potential (phase 4)

Answer 54

◦ With each pump cycle a Na+,K+ exchanger transfers three Na+ out of a cell and 2 K+ cells into a cell. This imbalance creates a small negative resting membrane potential. ◦ There are also many K+ leakage channels and very few open Na+ channels, so their is a greater tendency for positive K+ to exit the cell then for positive Na+ to enter. This charge imbalance is the main contributor to the normal, negative resting membrane potential. ◦ In resting cardiac cells the membrane Ca2+ channels are closed so Ca2+ permeability is low and extracellular Ca2+ is prevented from entering cardiac cells.

Answer 55

◦ Cardiac muscle cells are electrically linked to one another with specialized gap junctions allowing ionic currents to flow into neighboring cells and initiate action potentials. Cardiac cells form a functional syncytium. Skeletal Muscles are electrically isolated from one another ◦ Action potential lasts 100x longer than in skeletal muscle. Cardiac: 200-250 ms. Skeletal: 1-2 ms. Cardiac muscle cells also has long refractory period.

Answer 56

◦ They activate B-adrenergic receptors on the cell membranes of pacemaker cells and leads to elevated HR. ◦ In cardiac muscle cells: B adrenergic receptors lead to taller (more positive) plateau, Shorter duration of action potentials, and quicker, stronger, and shorter duration contractions.

Answer 57

◦ Acetylcholine activates muscarinic cholinergic receptors on the cell membranes of pacemaker cells which decrease heart rate. ◦ Does the opposite of above and exert strong anti-sympathetic influences on all the atrial cells. (Not ventricular because very few ventricular cells receive direct parasympathetic innervation).

Answer 58

◦ Parasympathetic neurons exert indirect effect on ventricular muscles. Parasympathetic neurons release their acetylcholine onto sympathetic neuron terminals. This inhibits release of norepinephrine, and weakens the effects of sympathetic activation on ventricular cells.

Answer 59

Overlapping control- varies based on activity/ behavior. Stressed/ animals exerting = more sympathetic nerve activity S leeping or resting/ non exerting = more parasympathetic nerve activity. Walking or doing minimal exertion will be at the intrinsic rate/ have equal parasympathetic and sympathetic influence or if they have an absence of both.

Answer 60

◦ Characteristic: ‣ Extreme: Sinus arrest. SA node completely fails to form action potentials. Auxilary pace maker function fo AV node keeps ventricles beating at very low rate. ‣ Less Extreme: Sluggish depolarization of SA node pacemaker cells, abnormally low intrinsic HR. Usually exhibit bradycardia and insufficient increase in HR during exercise. ◦ Treatment: Atropine (cholinergic muscarinic antagonist drug), Isoproterenol ( B-adrenergic agonist drug), Artificial cardiac pacemaker.

Answer 61

Dependent on the type but would say usually some sort of Beta1adrenergic antagonist and/ or some sort of muscurinic agonist/ chollinergic substance

Answer 62

◦ Characteristic: Each tiny region of ventricular wall contracts and relaxes at random in response to action potentials that propagate randomly and continuous throughout ventricles. Synonymous with sudden cardiac death. ◦ Treatment: Only treatment is electrical defib

Answer 63

◦ Characteristics: ‣ 1st degree: AV node transmits all action potentials but slowly. Calm dog transmits even slower. ‣ 2nd degree: AV node transmits some action potentials. Some Action potentials pass. ‣ 3rd degree: Complete block of AV node. No action potentials pass from atria to ventricles ◦ Treatment: ‣ Must be treated if resulting ventricular rate is too low or to maintain adequate blood flow to body, ‣ Atropine (cholinergic muscarinic antagonist drug), Isoproterenol ( B-adrenergic agonist drug), Artificial pacemaker- applied to ventricles . ◦ Causes: Cardiac trauma, toxins, viral/bacterial infection, ischemia, congenital heart defects, cardiac fibrosis, inadvertent damage of AV node during surgical repair of a ventricular septal defect.

Answer 64

Examples: quinidine, lidocaine, procaine Act by binding to some of the voltage-gated Na+ channels (fast Na+ channels) in cardiac muscle cells and preventing them from opening, which counteracts membrane depolarization and action potential formation.

Answer 65

Example: Digitalis Inhibits the Na+,K+ pump in cell membranes. Increase cardiac contractility. Keeps resting membrane potential less negative as normal, cardiac cells do not repolarize fully at end of action potential. Acts on CNS and causes increase PNS tone. Allow more Ca2+ to accumulate inside cardiac cells, which increases strength of cardiac contraction.

Answer 66

Examples: verapamil, diltiazem, and nifedipine Bind to L- type (slow) Ca2+ channels and prevent them from opening, this decreases the entry of Ca2+ into cardiac muscle cells during action potential. This lowers the plateau ( membrane potential less positive) and lengthen the action potential (Slower opening of K+ channels. Also decrease strength of cardiac contractions.

Answer 67

Example: propranolol Bind to some of the b-adrenergic receptors on cardiac cells and prevent their activation by norepinephrine from sympathetic nerves or by circulating epinephrine and norepinephrine from the adrenal medulla. A. Decreasing heart rate; B. Lengthening refractory period; C. Slowing conduction of action potentials, especially through the AV node. D. Reverse sympathetic-induced increases in cardiac contractility.

Answer 68

Positive wave. Action potential moves from right to left, right being negative, left being positive so you will see positive wave

Answer 69

Measures voltage differences from right fore limb, left hind limb, and left forelimb and compares with the average voltage of the other leads.

Answer 70

Atrial Depolarization

Answer 71

Intraventricular septum depolarization, ventricular depolarization, depolarization of ventricular base

Answer 72

Depolarization that spreads from left to right across the interventricular septum. This is the small voltage difference between left and right forelimb, with left forelimb being slightly negative compared to right.

Answer 73

Corresponds to repolarization of both ventricles. Not predictable. In normal dogs it follows same direction of depolarization (from inside out), creating negative T wave.

Answer 74

◦ Vertical calibration: The standardized vertical calibration on an ECG is that 10 mm (two major division) equals 1 millivolt (mV).

Answer 75

Time between start of atrial depolarization (start of P wave) and start of ventricular depolarization (QRS complex)

Answer 76

Time it takes for the ventricles to depolarize, once the Cardiac AP emerges from AV node/ AV bundle ( Normal: \<0.1 sec)

Answer 77

Beginning of ventricular depolarization to the end of ventricular repolarization. This approximates the duration of an AP in ventricular tissue (Normal: ~ 0.2 secs)

Answer 78

Time between atrial depolarization/ contraction and the next atrial depolarization/ contractions. Can be used to determine atrial rate.

Answer 79

Time between ventricular depolarization/ contractions and the next ventricular depolarization/contraction. Can be used to determine ventricular rate. ‣ Usually Atrial rate = ventricular rate.

Answer 80

◦ less consistent pathways followed by cardiac depolarization in atria and ventricles of large animals lead to variability with small animals ◦ ECG not useful in detecting structural cardiac abnormalities in large animals. ◦ There is consistency in basic sequence of electrical events in hearts of normal animals large and small, so ECG is useful in large animals for detecting/ categorizing cardiac arrhythmias. ◦ Lead / electrode placement that yields clearly discernible complexes is sufficient.

Answer 81

Blood pressure decreases as it flows through systemic circulation. Pressure will be greatest in aorta (98 mm Hg) and least in the venacavae (~ 3 mm Hg)

Answer 82

The blood pressure of static circulation when the heart is not pumping blood ( ~7 mm Hg)

Answer 83

◦ Mean aortic blood pressure is determined by two, and only two, factors. Cardiac output and TPR or Total peripheral resistance (systemic vascular resistance) Mean aortic pressure = CO x TPR

Answer 84

Cardiac output is increased and is redistributed from brain, splanchnic, and other muscles and is redistributed to skeletal muscles.

Answer 85

Vascular resistance. Specifically arteriolar resistance

Answer 86

This is because the resistance must be divided over the total surface area and the surface area will be larger in a capillary network, hence a lower resistance overall.

Answer 87

a single capillary has more resistance then a single arteriole.

Answer 88

Resistance= change in pressure/ blood flow Flow = change in pressure/ resistance

Answer 89

FALSE: It is vasodialation that can increase bloodflow to brain

Answer 90

cardiac output is normal. But the blood pressure is elevated because of excessively constricted systemic arterioles, which increases TPR above normal. Naturally occurring hypertension is rare in veterinary species.

Answer 91

The arteriole pressure is reduced in these conditions, not elevated because of decreased cardiac output. TPR is actually increased above normal because the body constricts the arterioles in the kidneys, splanchnic circulation, and resting skeletal muscle. The vasoconstriction in these organs minimizes the fall in arterial pressure. However over time the blood pressure will decrease, and this is usually due to severe hemorrhage and decreased blood volume. ( Hypovolemia from decrease of fluid (severe dehydration) or blood volume ( hemorrhage)

Answer 92

Cardiac output is elevated. TPR is decreased ( arterioles in exercising skeletal muscle dilates which increases skeletal muscle blood flow).

Answer 93

The greatest pressure decrease occurs as blood flows through arterioles; that is because, the resistance to blood flow is greater in the arterioles than in any other segment of the systemic circulation.

Answer 94

The change in the volume within a vessel or a chamber divided by the associated change in distending (transmural) pressure Compliance=ΔVolume ÷ Δtransmural Pressure

Answer 95

Veins are about 20 times more compliant than arteries: Veins thus function as the major blood volume reservoirs of the body. Arteries function as pressure reservoirs. Arteries are tough vessels with low compliance. Arteries accommodate a large increase in pressure during a cardiac ejection and then sustain the pressure high enough between cardiac ejections to provide a continuous flow of blood through the systemic circulation.

Answer 96

◦ Systolic: The pressures in the aorta and pulmonary artery during each cardiac ejection. ◦ Diastolic: The minimal pressures in the aorta and pulmonary artery before each new cardiac ejection. ◦ Pulse Pressure: The amplitude of the pressure pulsations in an artery.

Answer 97

◦ Increase in stroke volume increases pulse pressure (larger ejections, larger pulses) (also increase MAP/ Cardiac output ◦ Decrease in Heart rate increases pulse pressure (longer time between ejections, more blood runs out of aorta) also decreases MAP and cardiac output. ◦ Increase stroke volume + decrease in heart rate = greatly increased pulse pressures. Unchanged MAP and unchanged cardiac output. Ex: athlete, strong slow pulse at rest.

Answer 98

Decrease in arterial compliance = increase of pulse pressure with unchanged MAP.

Answer 99

PDA = elevated aortic systolic pressure, decreased aortic diastolic pressure ( because of the two pathways from the PDA) and this greatly increases aortic pulse pressures.

Answer 100

Blood flows back into heart, Decrease in diastolic pressure, increase in systolic pressure, increase in pulse pressure. Heart working harder.

Answer 101

◦ Aorta/ Large arteries: ‣ are elastic and low compliant vessels. ‣ Aorta: Wall thickness: 2 mm, Inside Diameter: 25 mm ‣ Artery: Wall thickness: 1mm, Inside diameter: 4mm

Answer 102

◦ Arterioles: ‣ Adjust blood flow to an organ. Small arteries are called muscular vessels, and have relatively thick walls with less elastic tissue and predominance of smooth muscle. Muscular vessels vary the total peripheral resistance and direct blood flow toward or away from particular organs/ organ regions. ‣ Wall thickness: 20 um, Inside diameter: 30 um

Answer 103

‣ Are where fluid exchange takes place. Smallest vessels are usually 0.5 mm long. Walls are especially adapted for exchange functions. Sometimes called microcirculation or exchange vessels. Have single layer of epithelial cells, form network, each cell of a tissue is within 100um of a capillary. Not all capillaries of a tissue carry blood flow at all times, pre-capillary sphincters can reduce or stop blood flow in individual capillaries. At max metabolic rate, arterioles become maximally dilated, and blood flows through all the capillaries all the time. ‣ Wall thickness: 1 um. Inside Diameter: 8um

Answer 104

enules/ veins: ‣ Veins are compliant vessels and are reservoir vessels. Venules and veins are larger than capillaries but capillaries have thicker walls. Primary role of veins is to serve as reservoir vessel. Veins are very complaint and can accommodate substantial changes in blood volume without much change in venous pressure. ‣ Venule: Wall thickness: 2 um, Inside diameter: 20 um ‣ Vein: Wall thicknessL 0.5 um, Inside diameter: 5 um

Answer 105

◦ Continuous: ‣ Most widespread in body. Lipid soluble substances readily diffuse. Pores diameter is typically 4 nm. Can permit passage of water, ions, glucose and amino acids. No plasma proteins/ blood cells. Main route for delivery of plasma proteins to interstitial fluid us transcytosis. This is very slow compared to passage of small lipid insoluble substances through capillary pores and extremely slow compared to the diffusion of lipid soluble substances through endothelial cells. Can be found in fat, muscles, and nervous system. ◦ Sinusoidal/ Discontinuous: ‣ have clefts between capillary endothelial cells which are typically longer than 100 nm width. Plasma proteins (like albumin and globulin can pass through clefts. Found in liver, spleen, and bone marrow. Allows liver to transport newly synthesized proteins to enter blood and allows toxins bound to plasma proteins to get into liver and be detoxified. ◦ Fenestrated capillaries: ‣ have holes/ perforations through (not between) endothelial cells. These perforations are usually 50-80 nm in diameter, and are found in places where large amounts of fluid and solutes must pass in or out of capillaries ( like gi, endocrine glands, and kidneys)

Answer 106

◦ During exercise the arterioles dilate and more of them remain open. Areolar vasodilation speeds the delivery of O2 and increases diffusion rate by increasing the area available for diffusion, decreasing the distance between each exercising muscle cell and the nearest open capillaries, and the driving force for the diffusion of O2 and metabolic substrates are increased.

Answer 107

Actual rate of water movement across capillaries is affected by both the magnitude of the imbalence between hydrostatic and oncotic forces and by the permeability of the capillary wall to water.

Answer 108

◦ Semipermeable membrane ◦ Difference in total concentration of the impermeable solutes on the two sides of the membrane.

Answer 109

Hydrostatic pressure is greater on inside (18 mm Hg) then on outside (- 7 mm Hg), creating a difference of 25 mm Hg. This difference drives filtration.

Answer 110

◦ Since there is a small net filtration between net hydrostatic and osmotic pressure of water reabsorption it allows for excess interstitial fluid and plasma proteins to be removed from the interstitial space via lymph flow.

Answer 111

◦ Excessive filtration of fluid out of capillaries. ◦ Depressed removal of excess interstitial fluid by lymph system.

Answer 112

◦ Increase in venous BP ◦ hypoproteinemia ◦ Physical Injury/ Allergic reaction to antigen challenge

Answer 113

◦ Application of too tight dressing on extremity. ◦ Severe pulmonic stenosis (can be caused by HW disease) ◦ Failure of right ventricle: cause increase in systemic venous pressure ◦ Failure of left ventricle: cause pulmonary edema.

Answer 114

◦ Decrease plasma protein production in liver ◦ Plasma protein loss from kidney diseases ◦ Severe burns

Answer 115

``` Impairment by inflammation of nodal tissue or neoplasia/tumors growing within nodes Parasitical diseases (microfilarie lodge in lymph nodes and obstruct outflow) ```

Answer 116

Act within an organ or tissue and do not rely on an external influence. Histamine: acts on the arteriolar smooth muscle to relax it. Dilation of the arterioles decrease arteriolar resistance and therefore increases blood flow to the tissues), Exercise (increases metabolic rate in skeletal muscle)

Answer 117

Act from outside organ/ tissue, through nerves or hormones to alter arteriolar resistance. (Include nerve and hormones)

Answer 118

First there us a release of metabolic products which are vasodialators ( ex: K+, CO2, adenosine, lactic acid) Then this triggers a decrease in the O2 concentration and an increase in concentration of vasodialators. Next you will have a decrease in precapilary sphincter tone, and vasodialation will occur. Because of the decrease in precapillary sphincter tone you will have an increase in the number of open capillaries. Vasodialation will cause an decrease in arteriolar resistance . The increase in number of open capillaries and a decrease in diffusion difference. Because of the decreased in arteriolar resistance you will have an increase in blood flow, these three things will lead to an increased supply of O2 and an increase in the washout of vasodialators.

Answer 119

A high level of oxygen, for example, causes dilation of pulmonary vessels, whereas the effect in systemic vessels is vasoconstriction.

Answer 120

During the period when mechanical compression restricts blood flow, metabolism continues in the compressed tissue, metabolic products accumulate, and the local concentration of oxygen decreases. These metabolic effects cause dilation of the arterioles and a decrease in arteriolar resistance. Then the mechanical obstruction to flow is removed, blood flow increases above normal until the “oxygen debt” is repaid and the excess metabolic products have been removed from the compressed tissue.

Answer 121

Same as reactive hyperemia but also Other mechanisms also contribute to autoregulation. However, metabolic control plays a major role in the autoregulation of blood flow, particularly in the critical tissues of a body (brain, coronary vessels, and exercising skeletal muscle) Regardless of the status of arterioles, mechanical compression can reduce blood flow to a tissue.

Answer 122

◦ Long-term mechanical pressure causes a prolonged period of subnormal blood flow (ischemia), which can lead to reversible tissue damage, then irreversible tissue damage, and eventually to cell death (necrosis). ◦ Mechanical compression during ventricular systole reduces the blood flow to left but not right coronary blood vessels.

Answer 123

◦ Pulmonary vessels are susceptible to narrowing under the influence of mechanical compression. ◦ An abnormal elevation in airway pressure can compress pulmonary blood vessels, which could happen when a tracheal tube is attached to a source of elevated pressure. An increase in airway pressure exerts a compressing force on the pulmonary blood vessels.

Answer 124

Associated with the closure of the AV valves (the mitral and tricuspid valves).

Answer 125

S2 (Second heart sound): Associated with closure of the aortic valve on the left side of the heart and the pulmonic valve on the right side of the heart.

Answer 126

3. S3 (Third heart sound): In early diastole, the rush of blood into the ventricles can create sufficient turbulence to vibrate the ventricular walls and create this sound.

Answer 127

If audible, occurs at the very end of diastole, as atrial systole causes a sudden rush of blood into the ventricle

Answer 128

Mitral/ Tricuspid regurgitation/ incompetence ( the large pressure difference between ventricle and atrium causes rapid/ backward flow through partially closed valve. present in 8% of dogs over 5 years old) Ventricular septal defect (hole/ cleft in interventricular septum) Pulmonic/ Aortic stenosis (common congenital defect, valve fails to open widely enough)

Answer 129

THIS TYPE IS RARE Tricuspid/ Mitral stenosis - atroventricular valve fails to open widely enough, filling of ventricle occurs through a stenotic valve, which creates turbulent flow and diastolic murmur. Mitral is common among humans with calcification of mitral valve from rheumatic heart disease. Tricuspid is not common as congenital defect but can occur with heavy infestion in right heart which can create a functional stenosis. Aortic/ Pulmonic regurgitation ( insufficiency) - Aortic/ pulmonary valve does not close tightly during diastole, turbulent flow of blood regurgitates from aorta to ventricle. Aortic regurg common in horses not dogs. Pulmonic regurg is not common.

Answer 130

PDA: Persistence after birth of the opening between the aorta and pulmonary artery. Sometimes called machinery murmur because it sounds like rumble of machinery. Common in young dogs, more prevelant in females. Arteriovenous fistulae: Abnormal openings between peripheral arteries and peripheral veins. Carries turbulent blood flow during both systole and diastole. Is audible at body surface close to point of fistula

Answer 131

Abnormally high/ low blood flow to a region of the body Abnormally high or low blood pressure in a region of the body Cardiac hypertrophy (enlargement of cardiac muscle)

Answer 132

Increased volume work of Left ventricle and thus left ventricle hypertrophy. Also causes an increase left atrial pressure which leads to an increase in pulmonary venous pressure and the onset of pulmonary edema. Consequences are usually more noticable during exercise then at rest.

Answer 133

Increased left atrial pressure which leads to increased left atrial size and an increase of pulmonary venous pressure. The increase of left atrial size leads to afib, while the increase of pulmonary venous pressure leads to pulmonary edema. Right ventricular hypertrophy occurs. Animals with greatly elevated left atrial pressures uusually die of the effects of pulmonary edema before they have a chance to develop right ventricular hypertrophy

Answer 134

Increased volume work of Left ventricle and increased pulmonary artery pressure. The increase volume work of left ventricle leads to left ventricular hypertrophy, while an increase in pulmonary artery pressure increases the pressure work of Right ventricle which will then lead to right ventricular hypertrophy as well. PDA causes exercise intolerance. Surgical repair in a young animal leads to rapid reveral of all these abnormalities

Answer 135

A patient with aortic stenosis may be able to function normally at rest but characteristically exhibits exercise intolerance.

Answer 136

Left ventricular hypertrophy; pulmonary edema may develop.

Answer 137

Moderate left ventricular hypertrophy; pronounced right ventricular hypertrophy; possible pulmonary edema; probable exercise intolerance.

Answer 138

Pronounced right ventricular hypertrophy.

Answer 139

Left ventricle

Answer 140

Because of the high amount of pressure work done by the left ventricle compared with the right ventricle, the left ventricle normally develops much heavier and thicker muscle walls than the right ventricle.

Answer 141

Because the systolic pressure generated is about five times higher in the left ventricle than in the right, the external work done by the left ventricle is approximately five times greater than the external work done by the right ventricle.

Answer 142

Veins are compliant vessels and are reservoir vessels: • Venules and veins are larger than capillaries, but have thicker walls. • The primary role of veins is to serve as reservoir vessels. • Veins are very compliant and can accommodate substantial changes in blood volume without much change in venous pressure. - contain some elastic tissue and some smooth muscle

Answer 143

Capillaries are where the fluid exchange takes place: Capillaries are the smallest vessels, being about 8 mm in diameter and about 0.5 mm long. Walls of capillaries are especially well adapted for their exchange function. Capillaries are sometimes called microcirculation or exchange vessels. They have a single layer of endothelial cells. Capillaries form network. In most tissues, each cell of a tissue is within 100 mm of a capillary. However, not all the capillaries of a tissue carry blood flow at all times. Contraction of precapillary sphincters can reduce or stop the flow of blood in individual capillaries. At maximal metabolic rate, arterioles become maximally dilated, and blood flows through all the capillaries all the time. - capillaries have no smooth muscle or elastic tissue.

Answer 144

Arterioles adjust blood flow to an organ: Small arteries are called muscular vessels. They have relatively thick walls with less elastic tissue and a predominance of smooth muscle. The muscular vessels vary the total peripheral resistance and direct blood flow toward or away from particular organs or regions within an organ. - contains the most muscle

Answer 145

Aorta and large arteries are elastic and low compliant vessels: Aorta and large arteries are called elastic vessels. They have a large amount of elastic material along with smooth muscle. However, They have low compliance. Elasticity denotes dispensability and an ability to return to the original shape after the distending force or pressure is removed. Compliance is a measure of how much force or pressure is required to achieve distention. Therefore, there is no contradiction in saying that the arteries are both elastic and stiff.

Answer 146

TRUE. Atrial cells also have shorter refractory periods, and can preform more action potentials per minuter then ventricular cells.

Answer 147

AP moves from right to left Right side is negative, left side is postive so you will see a positive wave between the two

Answer 148

Lead I: Voltage in left forelimb compared to right forelimb Lead II: Voltage in left hind limb compared to right forelimb Lead III: voltage in the left hind limb compared to the left forelimb. aVr: Measures voltage from right forelimb electrode compared to all other leads aVl: Measures voltage from left forelimb electrode compared to all other leads aVf: Measures voltage from left hindlimb compared to all other leads.

Physiology I- Cardiology/ Blood Exam 3 study Flashcards

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