Exam 3 Flashcards

Question

Aged RBCs

Answer 1

are removed from the blood in sinuses of the spleen and are degraded

Answer 2

Erythropoiesis refers to the formation of erythrocytes, and leukopoiesis to the formation of leukocytes

Answer 3

HP give rise to blood cells originate in the yolk sac of the human embryo and then migrate to the liver of the fetus. The stem cells then migrate to the bone marrow. These processes occur in two classes of tissues after birth, myeloid and lymphoid.

Answer 4

is the red bone marrow of the long bones, sternum, pelvis, bodies of the vertebrae

Answer 5

includes the lymph nodes, tonsils, spleen, and thymus

Answer 6

all of the different types of blood cells

Answer 7

The production of red blood cells and synthesis of hemoglobin depends on the supply of iron, Vitamin B12, folic acid

Answer 8

Anemia, leukemia, sickle cell disease

Answer 9

Inherited blood disorder that affects red blood cells

Answer 10

mostly hemoglobin* S, an abnormal type of hemoglobin

Answer 11

sickle-shaped (crescent shaped) and have difficulty passing through small blood vessels

Answer 12

the disease causing anemia, jaundice and the formation of pigment gallstones

Answer 13

painful episodes (crises), which can last from hours to days. These crises can affect the bones of the back, the long bones, and the chest

Answer 14

Attacks of abdominal pain, Bone pain, Breathlessness, Delayed growth and puberty, Fatigue, Fever, Jaundice, Paleness, Rapid heart rate, Ulcers on the lower leg

Answer 15

They should take supplements of folic acid. Antibiotics and vaccines are given to prevent bacterial infections

Answer 16

Is the main substance of the red blood cell

Answer 17

carry oxygen from the air in our lungs to all parts of the body

Answer 18

hemoglobin A, are soft and round and can squeeze through tiny blood tubes (vessels).

Answer 19

for about 120 days before new ones replace them

Answer 20

Hemoglobin S and hemoglobin C

Answer 21

Is cancer of the blood cells

Answer 22

in the bone marrow, the soft tissue inside most bones

Answer 23

blood cells are made

Answer 24

to make a lot of abnormal white blood cells, called leukemia cells

Answer 25

They don't do the work of normal white blood cells, they grow faster than normal cells, and they don't stop growing when they should

Answer 26

acute or chronic, lymphocytic, myelogenous

Answer 27

white blood cells called lymphocytes

Answer 28

large numbers of mature white blood cells (lymphocytes)

Answer 29

white blood cells called myelocytes

Answer 30

large numbers of immature and mature white blood cells (myelocytes).

Answer 31

Fever and night sweats, Headache, Bleeding easily, Bone or joint pain, Swollen lymph nodes in the armpit, neck, getting a lot of infections, Weakness, Losing weight

Answer 32

chemotherapy, interferon-alpha (INFa) therapy, radiation therapy, stem cell transplantation (SCT)

Answer 33

Chemotherapy - to kill leukemia cells using strong anti-cancer drugs

Answer 34

Interferon-alpha (INFa) therapy - to slow the reproduction of leukemia cells and promote the immune system's anti-leukemia activity

Answer 35

Radiation therapy - to kill cancer cells by exposure to high-energy radiation.

Answer 36

Stem cell transplantation - to enable treatment with high doses of chemotherapy and radiation therapy.

Answer 37

arteries, capillaries, veins

Answer 38

Carry blood away from the heart

Answer 39

elastic arteries, muscular (distributing) arteries, arterioles

Answer 40

the largest arteries, High elastin, Diameters range from 2.5 cm to 1 cm (aorta and its major branches)

Answer 41

conducting arteries

Answer 42

smallest arteries

Answer 43

Carry blood toward the heart

Answer 44

blood from capillaries toward the heart

Answer 45

is much lower than in arteries

Answer 46

Smallest veins, diameters from 8-100 µm

Answer 47

Smallest venules, venules join to form veins

Answer 48

is the thickest tunic in veins

Answer 49

have valves

Answer 50

muscle press the veins and push the blood toward heart

Answer 51

surgical procedure connecting blood vessels together

Answer 52

small blood vessels that supply the walls of larger blood vessels

Answer 53

Smallest blood vessels, the site of exchange of molecules between blood and tissue fluid

Answer 54

from 8–10 µm

Answer 55

through single file

Answer 56

Network of capillaries running through tissues

Answer 57

Blood-brain barrier Highly selective, only vital substances pass through. Not a barrier against O2, CO2 and some anesthetics

Answer 58

Wide, leaky capillaries found in spleen, liver

Answer 59

After flowing through the body, blood enters the heart at the right atrium

Answer 60

From the right atrium, it passes through the right atrioventricular valve and into the right ventricle

Answer 61

When the right ventricle contracts, it ejects the blood out of the heart through the pulmonary valve and into the pulmonary artery to the lungs

Answer 62

After passing through the lungs, removing CO2 and picking up oxygen (O2), the blood returns through the pulmonary vein to the left atrium

Answer 63

From here the blood enters the left ventricle through the left atrioventricular valve

Answer 64

When the left ventricle contracts, blood is ejected through the aortic valve into the aorta and out to the body

Answer 65

the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart. The term is contrasted with pulmonary circulation.

Answer 66

Oxygenated blood from the lungs leaves the left heart through the aorta, from where it is distributed to the body's organs and tissues, which absorb the oxygen, through a complex network of arteries, arterioles, and capillaries

Answer 67

The deoxygenated blood is then collected by venules, from where it flows first into veins, and then into the inferior and superior venae cavae, which return it to the right heart, completing the systemic cycle

Answer 68

The blood is then re-oxygenated through the pulmonary circulation before returning again to the systemic circulation

Answer 69

is the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart. The term is contrasted with systemic circulation

Answer 70

Oxygen-depleted blood from the body leaves the right heart through the pulmonary arteries, which carry it to the lungs, where red blood cells release carbon dioxide and pick up oxygen during respiration

Answer 71

The oxygenated blood then leaves the lungs through the pulmonary veins, which return it to the left heart, completing the pulmonary cycle

Answer 72

The blood is then distributed to the body through the systemic circulation before returning again to the pulmonary circulation

Answer 73

deliver oxygenated blood to the tissues, are thick-walled with extensive elastic tissue and smooth muscle, are under high pressure

Answer 74

The blood volume contained in the arteries

Answer 75

the smallest branches of the arteries, the site of highest resistance in the cardiovascular system

Answer 76

a smooth muscle wall that is extensively innervated by autonomic nerve fibers

Answer 77

is regulated by the autonomic nervous system (ANS)

Answer 78

arterioles of the skin, splanchnic, and renal circulations

Answer 79

arterioles of skeletal muscle

Answer 80

consist of a single layer of endothelial cells surrounded by basal lamina, are thin-walled, are the site of exchange of nutrients, water and gases

Answer 81

are formed from merged capillaries

Answer 82

progressively merge to from larger veins, are thin-walled, are under low pressure, contain the highest proportion of the blood in the cardiovascular system, have alpha 1-adrenergic receptors

Answer 83

largest vein, returns blood to the heart

Answer 84

The blood volume contained in the veins

Answer 85

is directly proportional to blood flow and inversely proportional to the cross-sectional area at any level of the cardiovascular system.

Answer 86

drives blood flow

Answer 87

high pressure to low pressure

Answer 88

is inversely proportional to the resistance of the blood vessels

Answer 89

is directly proportional to the viscosity of the blood and to the length of the vessel

Answer 90

Describes the distensibility of blood vessels Is inversely related to elastance. The greater the amount of elastic tissue in a blood vessel, the higher the elastance, and the lower the compliance Is directly proportional to volume and inversely proportional to pressure Describes how volume changes in response to a change in pressure Is much greater for veins than for arteries. As a result, more blood volume is contained in the veins (unstressed volume) than in the arteries (stressed volume).

Answer 91

produce changes in unstressed volume. For example, a decrease in venous capacitance decreases unstressed volume increases stressed volume by shifting blood from the veins to the arteries.

Answer 92

with age, as a person ages, the arteries become stiffer and less distensible

Answer 93

Aorta, 100 mm Hg Arterioles, 50 mm Hg Capillaries, 20 mm Hg Vena cava, 4 mm Hg

Answer 94

Is a force exerted by circulating blood on the walls of blood vessels is not constant during a cardiac cycle. It is pulsatile

Answer 95

Is the highest arterial pressure during a cardiac cycle Is measured after the heart contracts (systole) and blood is ejected into the arterial system

Answer 96

Is the lowest arterial pressure during a cardiac cycle. Is measured when the heart relaxed (diastole) and blood is returning to the heart via the veins

Answer 97

Is the difference between the systolic and diastolic pressures

Answer 98

stroke volume

Answer 99

systolic pressure increases because of the relatively low capacitance of the arteries.

Answer 100

the pulse pressure increases to the same extent as the systolic pressure

Answer 101

increases in pulse pressure

Answer 102

Can be calculated approximately as diastolic pressure plus one-third of pulse pressure

Answer 103

Is very low, The veins have a high capacitance and therefore, can hold large volumes of blood at low pressure

Answer 104

Is even lower than venous pressure

Answer 105

the pulmonary wedge pressure. A catheter, inserted into the smallest branches of the pulmonary artery, makes almost direct contact with the pulmonary capillaries. The measured pulmonary capillary pressure is approximately equal to the left atrial pressure

Answer 106

Primary or essential hypertension is of unknown etiology. Secondary hypertension

Answer 107

Primary hypertension: increased total peripheral vascular resistance (TPR) by inducing vasoconstriction or to increased cardiac output (CO), or both

Answer 108

the pathophysiology of hypertension, both can increase CO and TPR

Answer 109

defect in or inhibition of the Na+/K+ pump or because of increased permeability to the Na+

Answer 110

which makes the cell more sensitive to sympathetic stimulation

Answer 111

the increased sensitivity

Answer 112

prostaglandin, bradykinin

Answer 113

Can be caused by conditions that affect your kidneys, arteries, heart or endocrine system. Secondary hypertension can also occur during pregnancy, disorders of the adrenal gland, thyroid and parathyroid problems

Answer 114

a condition caused by an overproduction of cortisol

Answer 115

too much aldosterone

Answer 116

a rare tumor that causes over secretion of hormones like adrenaline and NA

Answer 117

polycystic kidney disease, kidney tumor, kidney failure, or a narrow or blocked main artery supplying the kidney

Answer 118

corticosteroids (anti-inflammatory drugs like prednisone) leads to increased systolic, diastolic pressures and increases arterial resistance. Nonsteriodal anti-inflammatory drugs (motrin, aleve), weight loss drugs (such as meridia), salt and water retention, sympathetic activity, loss of renal vasodilation

Answer 119

a birth defect in which the aorta is narrowed

Answer 120

a condition related to pregnancy, endothelial dysfunction in the maternal blood vessels

Answer 121

Usually asymptomatic, Headache, Fatigue, Shortness of breath, Dizziness, Convulsion, Changes in vision (Blurred vision, Double vision), Nausea, Vomiting, Anxiety, Increased sweating, Nose bleeds, Tinnitus - ringing or buzzing in ears, Heart palpitations, General feeling of unwellness, Increased urination frequency, flushed face, Pale skin

Answer 122

Angiotensin-converting enzyme (ACE) inhibitors: Captopril, Ramipril Angiotensin II receptor blockers (ARBs): Valsartan Diuretics: Thiazide diuretics such as hydrochlorothiazide Calcium channel blockers: Felodipine, Benidipine Beta-adrenergic blocking agents: Propranolol

Answer 123

the wave of depolarization that spreads from the SA node throughout the atria, and is usually 0.08 to 0.1 seconds (80-100 ms) in duration (atrial depolarization)

Answer 124

atrial repolarization, which is buried in the QRS complex

Answer 125

The period of time from the onset of the P wave to the beginning of the QRS complex, which normally ranges from 0.12 to 0.20 seconds in duration

Answer 126

the time between the onset of atrial depolarization and the onset of ventricular depolarization.

Answer 127

0.2 sec, there is an AV conduction block

Answer 128

The duration of the QRS complex is normally 0.06 to 0.1 seconds. This relatively short duration indicates that ventricular depolarization normally occurs very rapidly

Answer 129

0.1 sec, conduction is impaired within the ventricles. This can occur with bundle branch blocks or whenever a ventricular foci (abnormal pacemaker site) becomes the pacemaker driving the ventricle

Answer 130

abnormal pacemaker sites within the heart (outside of the SA node) that display automaticity

Answer 131

impulses being conducted over slower pathways within the heart, thereby increasing the time for depolarization and the duration of the QRS complex

Answer 132

Is the segment from the end of the S wave to the beginning of the T wave

Answer 133

the period when the ventricles completely are depolarized

Answer 134

ventricular ischemia or hypoxia because under those conditions, the ST segment can become either depressed or elevated

Answer 135

ventricular repolarization and is longer in duration than depolarization (i.e., conduction of the repolarization wave is slower than the wave of depolarization).

Answer 136

Sometimes a small positive U wave may be seen. This wave represents the last remnants of ventricular repolarization

Answer 137

underlying pathology or conditions affecting repolarization

Answer 138

Is the interval from the beginning of the Q wave to the end of the T wave.

Answer 139

the time for both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential. Represents the entire period of depolarization and repolarization of the ventricles

Answer 140

0.2 to 0.4 seconds depending upon heart rate

Answer 141

ventricular action potentials shorten in duration, which decreases the Q-T interval Because prolonged Q-T intervals can be diagnostic for susceptibility to certain types of tachyarrhythmias.

Answer 142

resting membrane potentials of about -90mV. This value approaches the K+ equilibrium potential

Answer 143

long duration, especially in Purkinje fibers, where they last 300 msec

Answer 144

Is the upstroke of the action potential Is caused by a transient increase in Na+ conductance. This increase results in an inward Na+ current that depolarizes the membrane At the peak of the action potential, the membrane potential approaches the Na+ equilibrium potential

Answer 145

Is a brief period of initial repolarization Initial repolarization is caused by an outward current, in part because of the movement of K+ ions (favored by both chemical and electrical gradients) out of the cell and in part because of a decrease in Na+ conductance

Answer 146

Is the plateau of the action potential Is caused by a transient increase in Ca2+ conductance, which results in an inward Ca2+ current, and by an increase in K+ conductance. During phase 2, outward and inward currents are approximately equal, so the membrane potential is stable at the plateau level

Answer 147

Is repolarization. During phase 3, Ca2+ conductance decreases, and K+ conductance increases and therefore predominates. The high K+ conductance results in a large outward K+ current (Ik) which hyperpolarizes the membrane back toward the K+ equilibrium potential

Answer 148

Is the resting membrane potential. Is a period during which inward and outward current (Ik1) are equal and the membrane potential approaches the K= equilibrium potential

Answer 149

Is normally the pacemaker of the heart Has an unstable resting potential

Answer 150

Is upstroke of the action potential Is caused by an increase in Ca2+ conductance. This increase causes an inward Ca2+ current that drives the membrane potential toward the Ca+ equilibrium potential. The ionic basis for phase 0 in SA node is different from that in the ventricles, atria and Purkinje fibers (where it is result of an inward Na+ current.)

Answer 151

Are not present in the SA node action potential

Answer 152

Is repolarization Is caused by an increase in K+ conductance. This increase results in an outward K+ current that causes repolarization of the membrane potential

Answer 153

Is slow depolarization. Accounts for the pacemaker activity of the SA node (automaticity). Is caused by an increase in Na+ conductance, which results in an inward Na+ current called If (slow depolarization, produced by the opening of Na+ channels and an inward Na+ current called If). (“f” which stands for funny)

Answer 154

Upstroke of the action potential in the AV node is the result of an inward Ca+ current (as in the SA node)

Answer 155

Reflects the time required for excitation to spread throughout cardiac tissue.

Answer 156

on the size of the inward current during the upstroke of the action potential. The larger the inward current the higher the conduction velocity.

Answer 157

is the fastest in the purkinje system

Answer 158

the AV node, allowing time for ventricular filling before ventricular contraction. If conduction velocity through the AV node is increased, ventricular filling may be compromised.

Answer 159

Is the ability of cardiac cells to initiate action potentials in response to inward, depolarizing current

Answer 160

the recovery of channels that carry the inward currents for the upstroke of the action potential.

Answer 161

over the course of the action potential. These changes in excitability are described by refractory periods

Answer 162

No action potential can be initiated (absolute means absolutely no stimulus is large enough to generate another action potential)

Answer 163

ERP is slightly longer than (effective means that a conducted action potential cannot be generated)

Answer 164

Action potential can be elicited but more than the usual inward current is required.

Answer 165

end of the absolute refractory period and continues until the cell membrane has repolarized to about -70mV

Answer 166

to generate a second action potential (which is an abnormal configuration and shortened plateau phase)

Answer 167

produces changes in heart rate

Answer 168

decreases heart rate by decreasing the firing rate of the SA node.

Answer 169

increases heart rate by increasing the firing rate of the SA node

Answer 170

Produce changes in conduction velocity, primarily in the AV node.

Answer 171

conduction velocity through the AV node, slowing the conduction of action potentials from the atria to the ventricles and increasing the PR interval.

Answer 172

increases conduction velocity through the AV node, speeding the conduction of action potentials from the atria to the ventricles and decreasing the PR interval

Answer 173

decreases force of contraction, a positive inotropic effect increases force of contraction

Answer 174

50 to 99 times a minute

Answer 175

It results from abnormalities in impulse formation or in impulse conduction, Disturbances in the formation of impulses lead to change in the sinus rhythm

Answer 176

If sinus frequency rises above 100/min (exercise, psychic excitation, fever, rise of 10 beats/min

Answer 177

If it drops below 50-60/min. In both cases the rhythm is regular

Answer 178

A rhythm disturbance that arises in the atria

Answer 179

highly variable, with a range of 100-250 beats per minute (bpm). The atrial rhythm is usually regular

Answer 180

It results from a rapid sequence of ectopic ventricular impulses. Beginning with ES

Answer 181

Ventricular filling and cardiac output decrease and ventricular fibrillation can even ensue, that is a high frequency uncoordinated twitching of the myocardium

Answer 182

the failure to eject blood can be just as dangerous as cardiac arrest. With a rate between 120 and 250 beats per minute

Answer 183

atrial or nodal extrasystole (ES). Abnormal or ectopic (heterotopic) impulses may arise in the atria (atrial), in the AV node (nodal) or in the ventricle (ventricular).

Answer 184

transmitted to the ventricle, which thus thrown out of its sinus rhythm: supraventricular arrhythmia due to atrial or nodal extrasystole (ES).

Answer 185

deformed but the QRS complex is normal.

Answer 186

atria is retrograde; the P wave is thus negative and is either masked by the QRS wave or appears shortly after it. Because in supraventricular extrasystole the sinus nodes often also depolarize.

Answer 187

Ventricular premature complexes (VPCs) are ectopic impulses originating from an area distal to the His Purkinje system

Answer 188

most common ventricular arrhythmia, in this case the QRS complex of the ES is deformed

Answer 189

automaticity, reentry

Answer 190

This is the development of a new site of depolarization in nonnodal ventricular tissue, which can lead to a VPC

Answer 191

electrolyte abnormalities or ischemic myocardium.

Answer 192

Reentry typically occurs when slow-conducting tissue (eg, infarcted myocardium) is present adjacent to normal tissue

Answer 193

damaged myocardium, as in the case of a healed MI

Answer 194

Ischemia, Certain medicines such as digoxin, which increases heart contraction, Myocarditis, Cardiomyopathy hypertrophic or dilated, Hypoxia, Hypercapnia (CO2 poisoning), Mitral valve prolapse, Smoking, Alcohol, Drugs such as cocaine, Caffeine, Magnesium and potassium deficiency, Calcium excess, Thyroid problems, Heart attack

Answer 195

Chest pain, Faint feeling, Fatigue, Hyperventilation (after exercise)

Answer 196

ventricular tachycardia (VT), which is a rapid heartbeat, because there is an extra electrical impulse, causing an extra ventricular contraction.

Answer 197

Restoring the balance of magnesium, calcium and potassium within the body

Answer 198

Sodium channel blockers. Class I agents are grouped by what effect they have on the Na+ channel, and what effect they have on cardiac action potentials. Lidocaine, Phenytoin

Answer 199

Beta blockers. They act by blocking the effects of catecholamines at the β1-adrenergic receptors, thereby decreasing sympathetic activity on the heart. They decrease conduction through the AV node. Class II agents include atenolol, propranolol, and metoprolol

Answer 200

Block the potassium channels, thereby prolonging repolarization. Since these agents do not affect the sodium channel, conduction velocity is not decreased. Sotalol

Answer 201

Calcium channel blockers. They decrease conduction through the AV node, and shorten phase two (the plateau) of the cardiac action potential. They thus reduce the contractility of the heart, so may be inappropriate in heart failure. However, in contrast to beta blockers, they allow the body to retain adrenergic control of heart rate and contractility. Class IV agents include verapamil and diltiazem

Answer 202

PR interval in the normal heart, this time is 0.12 to 0.20 second in duration, damage to AV node causes slowing of impulse conduction and is reflected by changes in the PR interval

Answer 203

PR interval exceeds 0.20 second

Answer 204

Occurs when the AV node is damaged so severely that only one out of every two, three, or four atrial electrical waves can pass through to the ventricles. ECG: P waves without associated QRS waves

Answer 205

none of the atrial waves can pass through the AV node to the ventricles. Result is bradycardia

Answer 206

The action potential (AP) spreads from the cell membrane into the T tubules

Answer 207

During the plateau of AP, Ca2+ conductance is increased and Ca2+ enters the cell from extracellular fluid (inward Ca2+ current).

Answer 208

This Ca2+ entry triggers the release of even Ca2+ from the SR (Ca2+ induced Ca2+ release).

Answer 209

As a result of this Ca2+ release, intracellular (Ca2+) increases

Answer 210

Ca2+ binds to troponin C, and tropomyosin is moved out of the way, removing the inhibition of action and myosin binding

Answer 211

Actin and myosin binds, the thick and thin filaments slide past each other, and the myocardial cell contracts

Answer 212

Relaxation occurs when Ca2+ is reaccumulated by the SR by an active Ca2+-ATPase pump

Answer 213

Is the intrinsic ability of the cardiac muscle to develop force at a given muscle length. It is also called inotropism. Is related to the intracellular Ca2+ concentration.

Answer 214

the ejection fraction (stroke volume/end-diastolic volume), which is normally 0.55 (55%).

Answer 215

an increase in contractility

Answer 216

a decrease in contractility

Answer 217

Increased heart rate, sympathetic stimulation, cardiac glycoides (digitalis)

Answer 218

More AP occur per unit time, more Ca2+ enters the myocardial cells during the AP plateaus, more Ca2+ is released from the SR, and greater tension is produced during contraction.

Answer 219

Increases the inward Ca2+ current during the plateau of each cardiac action potential. It increases the activity of the Ca2+ pump of the SR as a result more Ca2+ is accumulated by the SR and thus more Ca2+ is available for release in subsequent beats.

Answer 220

Parasympathetic (Ach) via muscarinic receptors: decrease the force of concentration in the atria by decreasing the inward Ca2+ current during the plateau of the cardiac action potential

Answer 221

Preload, afterload, sarcomere length, velocity of contraction at a fixed muscle length

Answer 222

is equivalent to end-diastolic volume, which is related to right atrial pressure. When venous return increases, end-diastolic volume increases and stretches or lengthens the ventricular muscle fibers

Answer 223

is equivalent to aortic pressure. Increases in aortic pressure cause an increase in afterload on the left ventricle

Answer 224

is equivalent to pulmonary artery pressure

Answer 225

cause an increase in afterload on the right ventricle.

Answer 226

the maximum number of cross-bridges that can form between actin and myosin. the maximum tension, or force of contraction.

Answer 227

is maximal when the afterload is zero, is decreased by increases in afterload.

Answer 228

the increases in stroke volume and cardiac output that occur in response to an increase in venous return or end-diastolic volume

Answer 229

on the length-tension relationship in the ventricle. Increases in end-diastolic volume cause an increase in ventricular fiber length, which produces an increase in developed tension.

Answer 230

that matches cardiac output to venous return. The greater the venous return, the greater the cardiac output.

Answer 231

upward (increased contractility) or downward (decreased contractility).

Answer 232

increase in cardiac output for any level of right atrial pressure or end-diastolic volume

Answer 233

decrease in cardiac output for any level of right atrial pressure or end-diastolic volume

Answer 234

Isovolumetric ventricular contraction, Ventricular systole, Early ventricular diastole, Late ventricular diastole (ventricular filling)

Answer 235

Also called early ventricular systole. This begins with the ventricles depolarizing (QRS complex) then contracting. The left ventricle is filled with blood from the left atrium and its volume is about 140 ml (end-diastolic volume). Ventricular pressure is low because the ventricular muscle is relaxed.

Answer 236

the ventricle contracts and ventricular pressure increases. The mitral valve closes when left ventricular pressure is greater than left atrial pressure. Because all valves are closed, no blood can be ejected from the ventricle (isovolumetric).

Answer 237

Also called ejection period. The aortic valve opens at point 2 when pressure in the left ventricle exceeds pressure in the aorta. Blood is ejected into the aorta, and ventricular volume decreases. The volume that is ejected in this phase is the stroke volume. The volume remaining in the left ventricle at point 3 is end-systolic volume

Answer 238

Also called isovolumetric relaxation phase. At point 3, the ventricle relaxes. When ventricular pressure decreases to less than aortic pressure, the aortic valve closes. Because all of the valves are closed again, ventricular volume is constant (isovolumetric) during this phase.

Answer 239

Once left ventricular pressure decreases to less than left atrial pressure, the mitral (AV) valve opens and filling of the ventricle begins. During this phase, ventricular volume increases to about 140 ml (the end-diastolic volume)

Answer 240

increased preload, increased afterload, increased contractility

Answer 241

refers to an increase in end-diastolic volume and is the result of increased venous return.

Answer 242

an increase in stroke volume based on the Frank-Starling relationship.

Answer 243

is reflected in increased width of the pressure-volume loop.

Answer 244

refers to an increase in aortic pressure. The ventricle must eject blood against a higher pressure, resulting in a decrease in stroke volume.

Answer 245

is reflected in decreased width of the pressure-volume loop. results in an increase in end-systolic volume.

Answer 246

The ventricle develops greater tension than usual during systole, causing an increase in stroke volume. The increase in SV results in a decrease in end-systolic volume.

Answer 247

is the volume ejected from the ventricle on each beat. Stroke volume= End-diastolic volume - End-systolic volume

Answer 248

Cardiac output (CO) is the amount of blood each ventricle can pump in one minute CO= Stroke volume x Heart rate

Answer 249

Cerebral=15%, Coronary=5%, Renal=25%, Gastrointestinal=25%, Skeletal muscle=25%, Skin=5%

Answer 250

Is the fraction of the end-diastolic volume ejected in each stroke volume. Is related to contractility. Is normally 0.55, or 55%. EF = Stroke volume/End-diastolic volume

Answer 251

Is directly related to the amount of tension developed by the ventricles

Answer 252

Increased afterload (increased aortic pressure), Increased size of the heart, Increased contractility, Increased heart rate

Answer 253

CA (Cardiac output) = O2 consumption/O2 pulmonary vein-O2 pulmonary artery

Answer 254

is a slowly developing process and produces no sound. However, when they close, the vanes of the valves and the surrounding fluid vibrate under the influence of sudden pressure differences, producing sounds that travel in all directions through the chest.

Answer 255

is produced (indirectly) by the closure of the AV valves; it is of low pitch and of relatively long duration

Answer 256

is produced (indirectly) by the closing of the aortic and pulmonary semilunar valves; this is of high pitch and of relatively smaller duration.

Answer 257

sometimes occurs in the middle of diastole. This is caused by blood flowing with rumbling motion into the almost filled ventricles; it is difficult to hear with a stethoscope.

Answer 258

is patchy intimal plaques (atheromas) in medium and large arteries; the plaques contain lipids, inflammatory cells, smooth muscle cells, and connective tissue

Answer 259

the arteries get blocked by fats and cholesterol

Answer 260

all large and medium-sized arteries, including the coronary, carotid, and cerebral arteries, the aorta, its branches, and major arteries of the extremities

Answer 261

Dyslipidemia, diabetes, cigarette smoking, family history, sedentary lifestyle, obesity, and hypertension

Answer 262

atherosclerotic plaque, which contains lipids (intracellular and extracellular cholesterol and phospholipids), inflammatory cells (eg, macrophages, T cells), smooth muscle cells, connective tissue (eg, collagen, elastic fibers), thrombi, Ca++ deposits.

Answer 263

Shortness of breath, Tightening pain in the chest

Answer 264

Strokes, Damage of muscles, body organs and blood vessels, Deficiency of blood supply due to obstruction (angina)

Answer 265

are abnormal heart rhythms in which the atria are out of sync with the ventricles.

Answer 266

the atria beat regularly and faster than the ventricles.

Answer 267

the heart beat is completely irregular. The atrial muscles contract very quickly and irregularly; the ventricles beat irregularly but not as fast as the atria.

Answer 268

blood that is not completely pumped out can pool and form a clot. In atrial flutter, the heart beat is usually very fast but steady. The atria beat faster than the ventricles.

Answer 269

people with various types of heart disease. Atrial fibrillation may also result from an inflammation of the heart's covering (pericarditis), chest trauma or surgery, pulmonary disease, and certain medications

Answer 270

many types of heart disease, stress and anxiety, caffeine, alcohol, tobacco, diet pills, open heart surgery

Answer 271

are generated by turbulent flow of blood, which may occur inside or outside the heart. Murmurs may be physiological (benign) or pathological (abnormal).

Answer 272

Stenosis restricting the opening of a heart valve, causing turbulence as blood flows through it Valve insufficiency (or regurgitation) allows backflow of blood when the incompetent valve is supposed to be closed.

Answer 273

There are three standard leads, usually designated as I, II and III. They are bipolar (i.e., they detect a change in electric potential between two points) and detect the electrical potential change in the frontal plane

Answer 274

is between the right arm and left arm electrodes, the left arm being positive

Answer 275

is between the right arm and left leg electrodes, the left leg being positive

Answer 276

is between the left arm and left leg electrodes, the left leg again being positive

Answer 277

Fourth intercostal space to the right of the sternum

Answer 278

Fourth intercostal space to the Left of the sternum

Answer 279

Directly between leads V2 and V4

Answer 280

Fifth intercostal space at midclavicular line

Answer 281

Level with V4 at left anterior axillary line

Answer 282

Level with V5 at left midaxillary line (Directly under the midpoint of the armpit)

Answer 283

V1 & V2, V3 & V4, V5 & V6

Answer 284

Right Ventricle, Septum/Lateral Left Ventricle, Anterior/Lateral Left Ventricle

Answer 285

The blood supply to certain areas of the myocardium is obstructed. The muscle tissue at the center of the infarct dies off

Answer 286

plaque builds up in the walls of your coronary arteries. This plaque is made up of cholesterol and other cells. A heart attack can occur

Answer 287

Stress, Male gender, Diabetes, Family history of coronary artery disease (genetic or hereditary factors), High blood pressure, Smoking, Unhealthy cholesterol levels especially high LDL ("bad") cholesterol and low HDL ("good") cholesterol, chronic kidney disease

Answer 288

chest pain (angina pectoris), Sweating, Anxiety, Cough, Fainting, Dizziness, Nausea or vomiting, Palpitations (feeling like your heart is beating too fast), Dyspnea

Answer 289

Feeling the pain in only one part of your body, or it may move from your chest to your arms, shoulder, neck, teeth, jaw, belly area, or back

Answer 290

A tight band around the chest, Bad indigestion, something heavy sitting on your chest, Squeezing or heavy pressure, The pain usually lasts longer than 20 minutes. Rest and a medicine do not completely relieve the pain of a heart attack. Symptoms may also go away and come back

Answer 291

Clinical history of ischaemic type chest pain lasting for more than 20 minutes

Answer 292

Changes in serial ECG tracings

Answer 293

Rise and fall of serum cardiac biomarkers such as creatine kinase -MB fraction and troponin T and I and myoglobin, Lactate dehydrogenase as they are more specific for myocardial injury. (The cardiac troponins T and I which are released within 4–6 hours of an attack of MI and remain elevated for up to 2 weeks)

Answer 294

If there is a high positive R, there is also a Larger negative Q waves, ST segment elevation or depression, or coronary intervention are diagnostic of MI

Answer 295

A MI is a medical emergency which requires immediate medical attention. Oxygen, aspirin, and nitroglycerin.

Answer 296

is inflammation of the inside lining of the heart chambers and heart valves (endocardium)

Answer 297

of a blood infection. Bacteria or other infectious substance can enter the bloodstream during certain medical procedures, including dental procedures, and travel to the heart, where it can settle on damaged heart valves. The bacteria can grow and may form infected clots that break off and travel to the brain, lungs, kidneys, or spleen

Answer 298

Artificial heart valves, congenital heart disease (atrial septal defect, patent ductus arteriosus), Heart valve problems (such as mitral insufficiency), History of rheumatic heart disease

Answer 299

Abnormal urine color, Chills (common), Excessive sweating (common), Fatigue, Fever (common), Joint pain, Muscle aches and pains, Night sweats, Nail abnormalities (splinter hemorrhages under the nails), Paleness

Answer 300

Blood culture and sensitivity (to detect bacteria), Chest x-ray, Complete blood count (may show mild anemia), Echocardiogram (ultrasound of the heart), Erythrocyte sedimentation rate (ESR), Transesophageal echocardiogram

Answer 301

Long-term, high-dose antibiotic treatment is needed to get rid of the bacteria. Treatment is usually given for 4-6 weeks, depending on the specific type of bacteria. Blood tests will help your doctor choose the best antibiotic. Surgery may be needed to replace damage heart valves.

Answer 302

is a heart valve disorder that involves the mitral valve. Stenosis refers to a condition in which the valve does not open fully, restricting blood flow

Answer 303

the valve area becomes smaller, less blood flows to the body. The upper heart chamber swells as pressure builds up. Blood may flow back into the lungs. Fluid then collects in the lung tissue (pulmonary edema), making it hard to breathe, Rheumatic fever, Congenital mitral stenosis

Answer 304

May begin with an episode of: Atrial fibrillation, Chest discomfort (rare): Increases with activity, decreases with rest. Radiates to the arm, neck, jaw, or other areas. Tight, crushing, pressure. Cough possibly bloody (hemoptysis), Difficulty breathing during or after exercise or when lying flat; may wake up with difficulty breathing, Fatigue, becoming tired easily, Bronchitis, Palpitations, Swelling of feet or ankles

Answer 305

Atrial fibrillation and atrial flutter, Blood clots to the brain (stroke), intestines, kidneys, or other areas, Heart failure, Pulmonary edema, Pulmonary hypertension

Answer 306

There is atrial fibrillation. No P waves are visible. The rhythm is irregularly irregular (random). With severe pulmonary hypertension, right ventricular hypertrophy can be seen

Answer 307

Cardiac Glycosides: These agents alter the electrophysiologic mechanisms responsible for arrhythmia, Digoxin (Lanoxin). Diuretics, β-blockers, Ca2+ channel blockers, Anticoagulants, balloon valvotomy, surgical commissurotomy, valve replacement

Answer 308

i.e., slowing the heart rate by decreasing conduction of electrical impulses through the AV node, making it a commonly used antiarrhythmic agent in controlling the heart rate during atrial fibrillation or atrial flutter.

Answer 309

i.e., increasing the force of heart contraction via inhibition of the Na+/K+ ATPase pump

Answer 310

is a long-term disorder in which the heart's mitral valve does not close properly, causing blood to flow backward (leak) into the upper heart chamber when the left lower heart chamber contracts. The condition is progressive, which means it gradually gets worse.

Answer 311

Mitral valve prolapse, Congenital, Atherosclerosis, Endocarditis, Heart tumors, High blood pressure, Marfan syndrome, Untreated syphilis

Answer 312

Cough, Fatigue, Palpitations (related to atrial fibrillation), Shortness of breath during activity and when lying down, Urination, excessive at night, enlarged liver

Answer 313

The choice of treatment depends on the symptoms present and the condition and function of the heart. antihypertensive drugs and vasodilators

Answer 314

reduce the risk of infective endocarditis in patients with mitral valve prolapse who are having dental work.

Answer 315

prevent clot formation in patients with atrial fibrillation.

Answer 316

may be used to strengthen the heartbeat, along with diuretics to remove excess fluid in the lungs

Answer 317

Fast mechanism: neural, (baroreceptor) Slow mechanism: hormonal (renin-angiotensin-aldosterone)

Answer 318

includes fast, neural mechanisms. is a negative feedback system that is responsible for the minute-to-minute regulation of arterial pressure.

Answer 319

stretch receptors located within the walls of the carotid sinus near the bifurcation of the common carotid arteries.

Answer 320

A decrease in arterial pressure decreases stretch on the walls of the carotid sinus. Because the baroreceptors are most sensitive to changes in arterial pressure, rapidly decreasing arterial pressure produces the greatest response. Additional baroreceptors in the aortic arch respond to increases, but not to decreases, in arterial pressure.

Answer 321

Decreased stretch decreases the firing rate of the carotid sinus nerve cranial nerve IX, which carries information to the vasomotor center in the brain stem.

Answer 322

The set point for mean arterial pressure in the vasomotor center is about 100 mm Hg. Therefore, if mean arterial pressure is less than 100 mm Hg, a series of autonomic responses is coordinated by the vasomotor center. These changes will attempt to increase blood pressure toward normal.

Answer 323

The responses of the vasomotor center to a decrease in mean arterial blood pressure are coordinated to increase the arterial pressure to 100 mm Hg. The responses are decreased parasympathetic (vagal) outflow to the heart and increased sympathetic outflow to the heart and blood vessels

Answer 324

Increases heart rate, Increases contractility and stroke volume, Increases vasoconstriction of arterioles, Increases vasoconstriction of veins

Answer 325

response to acute blood loss

Answer 326

is a slow, hormonal mechanism, Regulation by adjustment of blood volume, Renin is an enzyme.

Answer 327

is inactive

Answer 328

is physiologically active, is degraded by angiotensinase

Answer 329

response of the RAA system to acute blood loss.

Answer 330

Cerebral ischemia, Chemoreceptors in the carotid and aortic bodies, Vasaopressin (antidiuretic hormone), Atrial natriuretic peptide (ANP)

Answer 331

Pco2 pressure increases in brain tissue

Answer 332

Chemoreceptors in the vasomotor center respond by increasing sympathetic outflow to the heart and blood vessels

Answer 333

Constriction of arterioles causes intense peripheral vasoconstriction and increased TPR.

Answer 334

Blood flow to other organs (kidneys) is significantly reduced in an attempt to preserve blood flow to the brain

Answer 335

The Cushing reaction in an example of the response to cerebral ischemia. Increases intracranial pressure cause compression of the cerebral blood vessels, leading to cerebral ischemia and increased cerebral Pco2.

Answer 336

The vasomotor center directs an increase in sympathetic outflow to the heart and blood vessels, which causes a profound increase in arterial pressure.

Answer 337

are located near the bifurcation of the common carotid arteries and along the aortic arch

Answer 338

very high rates of O2 consumption and are very sensitive to decreases in the partial pressure of oxygen (Po2)

Answer 339

Po2 activate vasomotor centers that produce vasoconstriction, an increase in TPR, and an increase in arterial pressure.

Answer 340

Too little water in blood -> detected by hypothalamus -> more ADH secreted into blood by pituitary gland -> kidneys absorb less water from blood -> less urine produced -> blood water level back to normal

Answer 341

Too much water in blood -> detected by hypothalamus -> less ADH secreted into blood by pituitary gland -> kidneys absorb more water from blood -> lots of dilute urine produced -> blood water level back to normal

Answer 342

ANP binds to a specific set of receptors. Receptor-agonist binding causes a reduction in blood volume and therefore a reduction in cardiac output and systemic blood pressure.

Answer 343

renin secretion, thereby inhibiting the renin-angiotensin system, Reduces aldosterone secretion by the adrenal cortex, Relaxes vascular smooth muscle in arterioles and venules.

Answer 344

At the junction of the arterioles and capillaries is a smooth muscle band called the precapillary sphincter.

Answer 345

do not have smooth muscle; they consist of a single layer of endothelial cells surrounded by a basement membrane.

Answer 346

between the endothelial cells allow passage of water-soluble substances. The clefts represent a very small fraction of the surface area (<0.1%).

Answer 347

Blood flow through the capillaries is regulated by contraction and relaxation of the arterioles and the precapillary sphincters.

Answer 348

Normally, filtration of fluid out of the capillaries is slightly greater than absorption of fluid into the capillaries. The excess filtered fluid is returned to the circulation via the lymph. Lymph also returns any filtered protein to the circulation.

Answer 349

one-way flap valves permit interstitial to enter, but not leave, the lymph vessels. Flow through larger lymphatic vessels is also unidirectional, and is aided by one-way valves and skeletal muscle contraction.

Answer 350

occurs when the volume of interstitial fluid exceeds the capacity of the lymphatic to return it to the circulation. Can be caused by excess filtration or blocked lymphatics

Answer 351

Lipid-soluble substances (o2 and CO2)

Answer 352

cross via the water-filled clefts between the endothelial cells. include water, Glucose, and amino acid. Proteins molecules are too large to pass freely through the clefts.

Answer 353

In the brain, the clefts between endothelial cells are exceptionally tight (blood-brain barrier).

Answer 354

In the liver and intestine, the clefts are exceptionally wide and allow passage of protein. These capillaries are called sinusoids.

Answer 355

can cross by pinocytosis

Answer 356

It maintains constancy of ECF volume and of osmolality by balancing intake and excretion of Na+ and water

Answer 357

constancy of extracellular K+ concentration and of blood and cellular PH by adjusting excretion of H+ and HCO3-

Answer 358

nutrients (e.g., glucose, amino acids) and excretes end products of metabolism (urea, uric acid)

Answer 359

metabolic functions (arginine formation, gluconeogenesis, peptide hydrolysis)

Answer 360

of hormones (angiotensin II, erythropoietin, prostaglandins)

Answer 361

Whence the greater part of this ultrafiltrate is transported across the tubule wall and reenters the blood

Answer 362

The fraction that is not reabsorbed remains in the tubules and appears in the terminal urine

Answer 363

Some urinary solvents enter the nephron lumen from tubule cells by secretion.

Answer 364

A nephron consists of a glomerulus and renal tubule.

Answer 365

The glomerulus is a glomerular capillary network, which emerges from an afferent arteriole

Answer 366

Renal tubule comprises the following segments: Proximal tubule, Loop of Henle (thin descending limb, a thin ascending and a thick ascending limb), Distal tubule, Collecting ducts

Answer 367

Blood enters each kidney via renal artery, which branches into interlobar a., arcuate a. and cortical radial.

Answer 368

The smallest arteries subdivide into first set of arterioles, the afferent arterioles. The afferent arterioles deliver blood to the first capillary network, the glomerular capillaries.

Answer 369

Then blood leaves the glomerular capillaries, via a second set of arterioles, the efferent arterioles, which deliver blood to a second capillary network, the peritubular capillaries.

Answer 370

The peritubular capillaries surround the nephrons. Solutes and water are reabsorbed into the peritubular capillaries and a few solutes are secreted from the peritubular capillaries. Blood from the peritubular capillaries flows into small veins and then into the renal vein.

Answer 371

In the juxtamedullary nephrons, the peritubular capillaries have a specialization called the vasa recta. Vasa recta serve as osmotic exchangers for the production of concentrated urine.

Answer 372

60% of body weight

Answer 373

in newborns and adult males and lowest in adult females and in adults with a large amount of adipose tissue.

Answer 374

¼ of the ECF.

Answer 375

¾ of the ECF.

Answer 376

TBW is 60% of body weight, ICF is 40% of body weight, ECF is 20% of body weight

Answer 377

The glomerular capillaries have large pores in their walls, and the layer of Bowman’s capsule in contact with the glomerulus has filtration slits. Water, together with dissolved solutes (but not proteins) can thus pass from the blood plasma to the inside of the capsule and the nephron tubules

Answer 378

The volume of this filtrate produced by both kidneys per minute

Answer 379

The fluid that enters the glomerular capsule is called ultrafiltrate

Answer 380

this modest net filtration pressure produces an extraordinarily large volume of filtrate

Answer 381

115 ml per min in woman and 125 ml per min in men. It 180 L per day

Answer 382

Measurement of GFR-clearance of inulin, Inulin is filtered, but not reabsorbed or secreted by the renal tubules. GFR= U inulin V/ P inulin. U=Urine concentration of inulin (mg/ml). P=Plasma concentration of inulin (mg/ml)

Answer 383

Na+-glucose cotransport in the proximal tubule reabsorbs glucose from tubular fluid into the blood. There are a limited number of Na+-glucose carriers

Answer 384

At plasma glucose concentrations less than 250 mg/dl, all of the filtered glucose can be reabsorbed because plenty of carriers are available; in this range, the line for reabsorption is the same as that for filtration

Answer 385

At plasma glucose concentration greater than 350 mg/dl, the carriers are saturated. Therefore, increases in plasma concentration above350 mg/dl do not result in increased rates of reabsorption. The reabsorptive rate at which the carriers are saturated is the transport maximum ™

Answer 386

At plasma concentrations less than 250 mg/dl, all of the filtered glucose is reabsorbed and excretion is zero. Threshold is approximately 250mg/dl

Answer 387

At plasma concentrations greater than 350 mg/dl, reabsorption is saturated ™. Therefore, as the plasma concentration increases, the additional filtered glucose cannot be reabsorbed and is excretes in the urine.

Answer 388

glomerular capillaries; therefore, the Na+ in the tubular fluid of Bowman’s space equals that in plasma

Answer 389

entire nephron, and very little is excreted in urine <1% of the filtered load

Answer 390

reabsorb 2/3, or 67%, of the filtered Na+ and H2O, more than any other part of the nephron, is the site of glumerulo-tubular balance, The reabsorption of Na+ and H2O in the proximal tubule are exactly proportional

Answer 391

reabsorbs Na+ and H2O with HCO3-, glucose, amino acids, phosphate, and lactate

Answer 392

cotransport with glucose, AAs, phosphate, and lactate. These cotransport processes account for the reabsorption of all of the filtered glucose and AAs

Answer 393

counter transport via Na+-H+ exchange, which is linked directly to the reabsorption of filtered HCO3-

Answer 394

Filtered glucose, amino acids, and HCO3- have already been completely removed from the tubular fluid by reabsorption in the early proximal tubule In the middle and late proximal tubules, Na+ is reabsorbed with Cl-

Answer 395

reabsorbs 25% of the filtered Na+. contains a Na+-K+-2Cl- cotransporter in the luminal membrane. is impermeable to water. NaCl is reabsorbed without water. As a result, tubular fluid Na+ and tubular fluid osmolarity decrease to less than their concentrations in plasma This segment, therefore, is called the diluting segment

Answer 396

together reabsorb 8% of the filtered Na+.

Answer 397

reabsorbs NaCl by a Na+-Cl- cotransporter. is impermeable to water. is called the cortical diluting segment

Answer 398

Most of the body’s K+ is located in the ICF A shift of K+ out of cells causes hyperkalemia A shift of K+ into cells causes hypokalemia

Answer 399

K+ is filtered, reabsorbed, and secreted by the nephron K+ balance is achieved when urinary excretion of K+ exactly equals intake of K+ in the diet K+ excretion can vary widely from 1% to 110% of the filtered load, depending on dietary K+ intake, aldosterone levels, and acid-base status

Answer 400

Filtration occurs freely across the glomerular capillaries

Answer 401

reabsorbs 67% of the filtered K+ along with Na+ and H2O

Answer 402

reabsorbs 20% of the filtered K+ Reabsorption involves the Na+-K+-2Cl- cotransporter in the luminal membrane of cells in the thick ascending limb

Answer 403

either reabsorb or secrete K+, depending on dietary K+ intake.

Answer 404

occurs in the principal cell is variable and accounts for the wide range of urinary K+ excretion depends on factors such as dietary K+, aldosterone levels, acid-base status, and urine flow rate.

Answer 405

A diet high in K+ increases K+ secretion, and a diet low in K+ decreases K+ secretion, the alpha-intercalated cells are stimulated to reabsorb K+ by the H+, K+-ATPase

Answer 406

intracellular K+ increases so than the driving force for K+ secretion also increases

Answer 407

intracellular K+ decreases so that the driving force for K+ secretion decreases

Answer 408

increases K+ secretion. The mechanism involves increased Na+ entry into the cells across the luminal membrane and increased pumping of Na+ out of the cells by the Na+-K+ pump.

Answer 409

Stimulation of the Na+-K+ pump simultaneously increases K+ uptake into the principal cells, increasing the intracellular K+ concentration and the driving force for K+ secretion. Aldosterone also increases the number of luminal membrane K+ channels

Answer 410

Effectively, H+ and K+ exchange for each other across the basolateral cell membrane

Answer 411

decreases K+ secretion. The blood contains excess H+; therefore, H+ enters the cell across the basolateral membrane and K+ leaves the cell. As a result, the intracellular K+ concentration and the driving force for K+ secretion decrease

Answer 412

increases K+ secretion. The blood contains too little H+; therefore, H+ leaves the cell across the basolateral membrane and K+ enters the cell. As a result, the intracellular K+ concentration and driving force for K+ secretion increase.

Answer 413

have two cell types, Principal cells, alpha Intercalated cells

Answer 414

reabsorb Na+ and H2O secrete K+ Aldosterone increases Na+ reabsorption and increases K+ secretion

Answer 415

increases H2O permeability by directing the in secretion of H2O channels in the luminal membrane. In the absence of ADH, the principal cells are virtually impermeable to water

Answer 416

secrete H+ by a H+ adenosine triphosphatase (ATP ase), which is stimulated by aldosterone reabsorb K+ by a H+, K+-ATPase.

Answer 417

oFifty percent of the filtered urea is reabsorbed passively in the proximal tubule. Rest are impermeable ADH increases the urea permeability of the inner medullary collecting ducts

Answer 418

Eighty-five percent of the filtered phosphate is reabsorbed in the proximal tubule by Na+-phosphate cotransport. 15% of the filtered load is excreted in urine

Answer 419

inhibits phosphate reabsorption in the proximal tubule by activating adenylate cyclase, PTH causes phosphaturia and increased urinary cAMP

Answer 420

Sixty percent of the plasma Ca+ is filtered across the glomerular capillaries

Answer 421

Together, the proximal tubule and thick ascending limb reabsorb more than 90% of the filtered Ca+ by passive processes that are coupled to Na+ reabsorption

Answer 422

Together, the distal tubule and collecting duct reabsorb 8% of the filtered Ca+ by an active process

Answer 423

increases Ca+ reabsorption by activating adenylate cyclase in the distal tubule

Answer 424

is reabsorbed in the proximal tubule, thick ascending limb of the loop of Henle, and distal tubule

Answer 425

In the thick ascending limb, Mg2+ and Ca+ compete for reabsorption; therefore, hypercalcemia causes an increase in Mg2+ excretion (by inhibiting Mg+ reabsorption).

Answer 426

ADH attaches to a V2 receptor and activates a cascade through a Gs protein, adenylyl cyclase, cAMP and protein kinase A to cause the insertion of aquaporin 2 into the apical membrane

Answer 427

H2O moves through aquaporin 2 in response to an osmotic gradient and thence through aquaporins 3 and 4 in the basolateral membrane

Answer 428

is also called hyperosmotic urine, in which urine osmolarity> blood osmolarity is produced when circulating ADH levels are high (e.g., water deprivation, hemorrhage, SIADH)

Answer 429

is the gradient of osmolarity from the cortex (300mOsm/L to the papilla (1200mOsm/L), and is composed primarily of NaCl and urea

Answer 430

by countercurrent multiplication and urea recycling

Answer 431

by countercurrent exchange in the vasa recta

Answer 432

The osmolarity of the glomerular filtrate is identical to that of plasma (300mOsm/L) Two-thirds of the filtered H2O is reabsorbed isosmotically (with Na+, Cl-, HCO3-. Glucose, AAs, ) in the proximal tubule TF/P osm= 1.0 throughout the proximal tubule because H2O is reabsorbed isosmotically with solute.

Answer 433

is called the diluting segment reabsorbs NaCl by the Na+-K+-2Cl- cotransporter is impermeable to H2O. Therefore, H2O is not reabsorbed with NaCl, and the tubular fluid becomes dilute The fluid that leaves the thick ascending limb has an osmolarity of 100 mOsm/L and TF/P osm<1.0 as a result of the dilution process

Answer 434

is called the cortical diluting segment like the thick ascending limb, the early distal tubule reabsorbs NaCl but is impermeable to water. Consequently, tubular fluid is further diluted

Answer 435

ADH increases the H2O permeability of the principal cells of the late distal tubule

Answer 436

H2O is reabsorbed from the tubule until the osmolarity of distal tubular fluid equals that of the surrounding interstitial fluid in the renal cortex (300mOsm/L)

Answer 437

TF/Posm=1.0 at the end of the distal tubule because osmotic equilibration occurs in the presence of ADH.

Answer 438

as in the late distal tubule, ADH increases the H2O permeability of the principal cells of the collecting ducts

Answer 439

As tubular fluid flows through the collecting ducts, it passes through the corticopapillary gradient (regions of increasingly higher osmolarity), which was previously established by counter recurrent multiplication and urea recycling

Answer 440

H2O is reabsorbed from the collecting ducts until the osmolarity of tubular fluid equals that the surrounding interstitial fluid

Answer 441

The osmolarity of the final urine equals that at the bend of the loop of Henle (1200mOsm/L)

Answer 442

is a disorder of glomeruli. It is characterized by body tissue swelling (edema), high blood pressure, and the presence of red blood cells in the urine

Answer 443

Primary, affecting only the kidneys. Secondary, caused by a vast array of disorders that affect other parts of the body.

Answer 444

Acute glomerulonephritis most often occurs as a complication of throat or skin infection by streptococcus, a type of bacteria.

Answer 445

Acute glomerulonephritis that occurs after a streptococcal infection

Answer 446

such as: staphylococcus and pneumococcus, viral infections, such as chickenpox, parasitic infections, such as malaria

Answer 447

membranoproliferative glomerulonephritis, immunoglobulin A (IgA) nephropathy, systemic lupus erythematosus (lupus), Acute glomerulonephritis that develops into rapidly progressive glomerulonephritis most often results from conditions that involve an abnormal immune reaction

Answer 448

Occasionally, chronic glomerulonephritis is caused by hereditary nephritis, an inherited genetic disorder. In many people, the cause of chronic glomerulonephritis cannot be identified.

Answer 449

Puffiness of the face, Eyelids but later is prominent in the legs

Answer 450

Blood pressure, headaches, visual disturbances, coma, nausea, general feeling of illness (malaise), weakness, fatigue, fever, Loss of appetite, nausea, vomiting, abdominal pain, joint pain

Answer 451

Following a diet that is low in protein and sodium may be necessary until kidney function recovers. Restricting the amount of protein in the diet is modestly helpful in reducing the rate of kidney deterioration

Answer 452

Diuretics may be prescribed to help the kidneys excrete excess sodium and water

Answer 453

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs)

Answer 454

When a bacterial infection is suspected as the cause of acute glomerulonephritis, antibiotics

Answer 455

End-stage kidney failure can be treated with dialysis or a kidney transplant.

Answer 456

is a bacterial infection (90% is by Escherichia Coli) of one or both kidneys. Infection can spread up the urinary tract to the kidneys, or the kidneys may become infected through bacteria in the bloodstream

Answer 457

Chills, fever, back pain, nausea, and vomiting can occur. Urine and sometimes blood tests are done to diagnose pyelonephritis

Answer 458

Antibiotics are given to treat the infection.

Answer 459

Stones (calculi) are hard masses that form anywhere in the urinary tract and may cause pain, bleeding, obstruction of the flow of urine, or an infection

Answer 460

Stones may form because the urine becomes too saturated with salts that can form stones or because the urine lacks the normal inhibitors of stone formation

Answer 461

calcium, and the remainder are composed of various substances, including uric acid, cystine; hyperparathyroidism.

Answer 462

Small stones that are not causing symptoms, obstruction, or an infection usually do not need to be treated

Answer 463

Drinking plenty of fluids has been recommended to help stones pass, but it is not clear that this approach is helpful

Answer 464

Drugs that may help the stone pass include alpha-adrenergic blockers (such as tamsulosin)

Answer 465

Potassium citrate Calcium channel blockers (such as Verapamil) Once a stone has passed, no other immediate treatment is needed The pain of renal colic may be relieved with nonsteroidal anti-inflammatory drugs (NSAIDs) or opioids.

Answer 466

occurs primarily in the proximal tubule

Answer 467

H+ and HCO3- are produced in the proximal tubule cells from CO2 and H2O. CO2 and H2O combine to form H2CO3 Carbonic acid, catalyzed by intracellular carbonic anhydrase

Answer 468

H2CO3 dissociates into H+ and HCO3-. H+ is secreted into the lumen via the Na+-H+ exchange mechanism in the luminal membrane. The HCO3- is reabsorbed

Answer 469

In the lumen, the secreted H+ combines with filtered HCO3- to form H2CO3, which dissociates into CO2 and H2O, catalyzed by brush border carbonic anhydrase. CO2 and H2O diffuse into the cell to start the cycle again

Answer 470

The process results in net reabsorption of filtered HCO3-. However, it does not result in net secretion of H+.

Answer 471

Increases in the filtered load of HCO3- result in increased rates of HCO3- reabsorption. However, in the plasma HCO3- concentration becomes very high (metabolic alkalosis), the filtered load will exceed the reabsorptive capacity, and HCO3- will be excreted in the urine

Answer 472

Increases in Pco2 result in increased rates of HCO3- reabsorption because the supply of intracellular H+ for secretion is increased

Answer 473

Decreases in Pco2 result in decreased rates of HCO3- reabsorption because the supply of intracellular H+ for secretion is decreased

Answer 474

These effects of changes in Pco2 are the physiologic basis for the renal compensation for respiratory acidosis and alkalosis

Answer 475

ECF volume expansion results in decreased HCO3- reabsorption ECF volume concentration results in increased HCO3- reabsorption (contraction alkalosis)

Answer 476

stimulates Na+-H+ exchange and thus increases HCO3- reabsorption, contributing to the contraction alkalosis that occurs secondary to ECF volume contraction.

Answer 477

Fixed H+ produced from the catabolism of protein and phospholipid is excreted by two mechanisms, titratable acid and NH4+

Answer 478

the amount of H+ excreted as titratable acid depends on the amount of urinary buffer present and the pK of the buffer

Answer 479

H+ and HCO3- are produced in the cell from CO2 and H2O. The H+ is secreted into the lumen by an H+-ATPase, and the HCO3- is reabsorbed into the blood (new HCO3). In the urine, the secreted H+ combines with filtered HPO4-2 to form H2PO4-, which is excreted as titratable acid

Answer 480

This process results in net secretion of H+ and net reabsorption of newly synthesized HCO3-

Answer 481

As a result of H+ secretion, the pH of urine becomes progressively lower. The minimum urinary pH is 4.4

Answer 482

The amount of H+ excreted as titratable acid is determined by the amount of urinary buffer and the pK of the buffer.

Answer 483

Overproduction or ingestion of fixed acid or loss of base produces an increase In arterial (H+) (acidemia)

Answer 484

HCO3- is used to buffer the extra fixed acid. As a result, the arterial (HCO3) decreases. This decrease in the primary disturbance

Answer 485

Acidemia causes hyperventilation (Kussmaul breathing), which is the respiratory compensation for metabolic acidosis

Answer 486

Renal correction of metabolic acidosis consists of increased excretion of the excess fixed H+ as titratable acid and NH4+, and increased reabsorption of new HCO3-, which replenishes the HCO3- used in buffering the added fixed H+.

Answer 487

an adaptive increase in NH3 ammonia synthesis aids in the excretion of excess H+.

Answer 488

Loss of fixed H+ or gain of base produces a decrease in arterial H+ (alkalemia)

Answer 489

As a result, arterial HCO3- increases. This increase is the primary disturbance. For example, in vomiting H+ is lost from the stomach, HCO3- remains behind in the blood, and the HCO3- increases

Answer 490

Alkalemia causes hypoventilation, which is the respiratory compensation for metabolic alkalosis

Answer 491

Renal correction of metabolic alkalosis consists of increased excretion of HCO3- because the filtered load of HCO3- exceeds the ability of the renal tubule to reabsorb it

Answer 492

the reabsorption of HCO3- increases (secondary to ECF volume contraction), worsening the metabolic alkalosis.

Answer 493

is the progressive activation of a muscle by successive recruitment of contractile units (motor units) to accomplish increasing gradations of contractile strength.

Answer 494

one motor neuron and all of the muscle fibers it contracts.

Answer 495

it sets up an impulse in the Sarcolemma that signals the Sarcoplasmic reticulum to release Calcium ions

Answer 496

diffuses through cytoplasm and triggers the sliding filament mechanism. Impulses further conducted by t tubules (deep invaginations of the sarcolemma)

Answer 497

Myosin heads attach to actin in the thin filaments Then pivot to pull thin filaments inward toward the center of the sarcomere Contraction mechanism is activated by binding of Ca++ to the thin filaments and powered by ATP.

Answer 498

Muscle spindles (groups Ia and II afferents), Golgi tendon organ (group Ib afferents), Pacinian corpuscles (group II afferents), Free nerve endings (group III and IV afferents)

Answer 499

are arranged in parallel with extrafusal fibers.

Answer 500

are arranged in series with extrafusal muscle fibers. They detect muscle tension.

Answer 501

are distributed throughout muscle. They detect vibration.

Answer 502

detect noxious stimuli

Answer 503

make up the bulk of muscle. are innervated by alpha-motoneurons. provide the force for muscle contraction.

Answer 504

are smaller than extrafusal muscle fibers. are innervated by gamma-motoneurons. are encapsulated in sheaths to form muscle spindles. run in parallel with extrafusal fibers. But not for entire length of the muscle.

Answer 505

Muscle spindle reflexes oppose (correct for) increases in muscle length (stretch).

Answer 506

Sensory information about muscle length is received by group Ia (velocity) and group II (static) afferent fibers.

Answer 507

When a muscle is stretched, the muscle spindle is also stretched, stimulating group Ia and group II afferent fibers.

Answer 508

Stimulation of group Ia afferents stimulates alpha-motoneurons in the spinal cord. This stimulation in turn causes contraction and shortening of the muscle. Thus, the original stretch is opposed muscle length is maintained.

Answer 509

intrafusal muscle fibers

Answer 510

adjust the sensitivity of the muscle spindle so that it will respond appropriately during muscle contraction.

Answer 511

coactivated so that muscle spindles remain sensitive to changes in muscle length during contraction

Answer 512

Cells are spindle-shaped, cells are non-striated and contain no sarcomere. Separated by endomysium. Contain one centrally located nucleus. Grouped into sheets in walls of hollow organs Are in longitudinal layer or circular layer, both layers participate in contraction.

Answer 513

Walls of circulatory vessels, Respiratory tubes, Digestive tubes Urinary organs, Reproductive organs, Inside the eye etc.

Answer 514

Extracellular Ca++ diffusing into the smooth muscle cell is responsible for sustained contractions

Answer 515

Opening of ca++ channels is graded by the amount of depolarization, the greater the depolarization, the more Ca++ will enter the cell and the stronger will be the smooth muscle contraction

Answer 516

Ca++ combines with a protein, calmodulin, the calmodulin-Ca++ combines with and activates myosin light-chain kinase, an enzyme that catalyzes the phosphorylation of myosin light chains, then it binds to actin and thereby produce a contraction.

Answer 517

Relaxation of the smooth muscle follows the closing of the Ca++ channels.

Answer 518

Sex-linked recessive inherited disease, males are most exclusively affected, 1/3500 boys, diagnosed between age 2-10, muscle weakens first pelvic muscles affected, then muscles of shoulder and head, rarely live over 20 years. Fibers lack a submembrane protein called dystrophin.

Answer 519

is an inherited disorder in which the muscles contract but have decreasing power to relax. With this condition, the muscles also become weak and waste away

Answer 520

mental deficiency, hair loss and cataracts.

Answer 521

young adulthood. However, it can occur at any age and is extremely variable in degree of severity.

Answer 522

found on chromosome 19, codes for a protein kinase that is found in skeletal muscle, where it likely plays a regulatory role

Exam 3 Flashcards

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