Patho Test 3

Question 1

What are the many functions of the kidney?

Answer 1

The primary function of the kidney is to maintain a stable internal environment.

• Balancing sodium and water
• Excretion of waste products
• Regulation of acids and bases

The kidney also has several endocrine functions that serve to regulate blood pressure, erythrocyte production, and calcium metabolism

• Renin secretion
• Erythropoietin secretion
• Vitamin D secretion

Question 2

What happens to blood pressure and urine output when the renin-angiotensin-aldosterone system is activated?

Answer 2

Angiotensin is a vasoconstrictor and this vasoconstriction leads to an increase in blood pressure. Aldosterone causes the kidney to retain sodium and water, also causing an increase in blood pressure.

Question 3

Which forces promote filtration and which ones oppose filtration in the kidney?

Answer 3

Hydrostatic pressure pushes the fluid out and osmotic pressure pulls the fluid in. Hydrostatic pressure in the glomerulus will push fluid out of the glomerulus and into Bowman’s capsule or it will promote filtration.

Hydrostatic pressure in Bowman’s capsule will push fluid out of Bowman’s capsule and into the glomerulus or it will oppose filtration. Osmotic pressure in the glomerulus will pull fluid into the glomerulus from Bowman’s capsule or it will oppose filtration.

Question 4

What occurs in each step of urine formation?

Answer 4

1. filtration at the glomerulus
   * the movement of fluids and solutes from the blood into the urine
2. reabsorption at the tubules
   * the movement of fluids and solutes from the urine back into the blood
   * active reabsorption of sodium is the primary function of the proximal tubule
   * the osmotic force generated by sodium reabsorption causes water to be passively reabsorbed
   * the reabsorption of water causes an increased concentration of urea which is then reabsorbed through passive diffusion
   * by the end of the proximal tube, 60-70% of the filtered sodium and water along with 50% of the filtered urea have been reabsorbed. 90% of potassium, glucose, bicarbonate, calcium, phosphate, amino acids, and uric acid have also been reabsorbed
3. secretion at the tubules
   * the movement of substances from the capillaries around the tubules into the urine.
   * substances can include hydrogen, potassium, ammonium, creatinine, urea, and drugs like penicillin.

Question 5

What change occurs in the kidney in the elderly?

Answer 5

In a young kidney urine concentration or dilution occurs in the Loop of Henle, distal tubules, and collecting ducts according to body needs. In the elderly, less urine is being concentrating so this makes the elderly more prone to dehydration.

Question 6

Compare BUN and creatinine

Answer 6

BUN (blood urea nitrogen):

• normal values –> 10-20 mg/dL
• used as an indicator of GFR, but not as accurate as creatinine because:
• BUN levels are not as constant because
• they can change with dietary protein
• some urea filtered at the glomerulus is reabsorbed in the tublues so dehydration can cause the BUN levels to increase
• this allows more urea to be reabsorbed, which increases BUN levels
• when GFR declines, the BUN levels increase

Creatinine:

1. normal values –> 0.7-1.2 mg/dL
2. the product of muscle metabolism
   a. males usually have higher levels than females because they tend to be more muscular
   b. a good indicator of GFR because
   i. the levels are fairly consistent because of the relative size of muscles
   ii. the amount at the glomerulus is the amount secreted in the urine - none is reabsorbed
   iii. a small amount is secreted in the tubules but not enough to invalidate the GFR estimation.
   iv. when the GFR declines, the serum creatinine will increase

Question 7

What organisms cause uncomplicated cystitis and complicated cystitis?

Answer 7

Uncomplicated: occur in individuals with normal urinary tracts, but the organism that generally causes this type is E. coli from the rectum

Complicated: occur in individuals with abnormalities of the urinary tract or health problems that compromise their immune defenses, however the organisms that cause this type are difficult to treat like pseudomonas

Question 8

What clinical manifestations occur with cystitis?

Answer 8

• Frequency
• urgency
• dysuria
• suprapubic or lower back pain
• hematuria
• cloudy would smelling urine

Some people may be asymptomatic especially the elderly.

• Dysuria is uncommon in the elderly and confusion and vague abdominal discomfort are more common

Question 9

Differentiate acute and chronic pyelonephritis.

Answer 9

Acute:

Cause: urinary obstruction or reflux of urine from the bladder.

Clinical manifestations: fever, chills, and flank, or groin pain, frequency, dysuria. Costovertebral tenderness may precede systemic signs of fever and chills. In the elderly and children, fever and malaise may be the only symptoms.

Acute pyelonephritis can lead to chronic pyelonephritis

                                        Chronic:

Cause: persistent or recurrent infection of the kidney leading to scarring. It occurs more commonly in people with urinary obstructive disorders such as vesicoureteral reflux of kidney stones.

Clinical manifestations: early symptoms include hypertension, dysuria, and flank pain.

Chronic pyelonephritis can lead to kidney failure especially if the individual has an obstructive disorder or DM.

Question 10

What is normal GFR? What happens to BUN/creatinine when GFR is low?

Answer 10

Normal GFR is 125 mL/min. As GFR declines, BUN/Creatinine levels rise.

Question 11

What dietary restrictions are required with chronic kidney failure?

Answer 11

Protein restriction is necessary as kidney function declines because the kidney can no longer eliminate urea, the waste product of protein metabolism. By reducing the protein in the diet; BUN, potassium, phosphate, and hydrogen levels will be reduced. This also helps to relieve symptoms of nausea, vomiting, and fatigue. The kidney is unable to eliminate potassium and regulate sodium and water. Foods high in potassium and sodium should be restricted. Water is regulated according to the amount of urine the kidney is making. In the earlier stages of chronic kidney disease when the kidney is still producing urine, 500 ml plus the amount of urine output in 24 hours is the amount of water that can be consumed daily. Later, when the kidney is no longer producing urine (anuria), the amount of water allowed is 800 ml per day.

Question 12

What causes anemia in chronic kidney failure?

Answer 12

Those with CKF have anemia because the kidneys are responsible for producing erythropoietin which is the hormone that stimulates erythropoiesis. Erythropoiesis is the production of red blood cells (RBC).

Question 13

Which acid-base imbalance occurs with chronic kidney failure?

Answer 13

Metabolic acidosis develops in Stage 4 kidney failure when the GFR is less than 30 mL/min. This is because the kidneys are unable to eliminate hydrogen and reabsorb bicarbonate.

Question 14

Why does osteodystrophy occur in chronic kidney failure?

Answer 14

the kidney cannot excrete phosphate so phosphate levels rise causing calcium levels to decrease (when phosphate is high, calcium is low). The low calcium causes hyperparathyroidism (parathyroid hormone is released to try to bring the calcium level up). The low calcium level causes the calcium to leave the bones and the bones become weak and can fracture (osteodystrophy)

Question 15

What clinical manifestations occur when the kidney is unable to excrete uric acid?

Answer 15

Uric acid is produced by the breakdown of purine and is excreted mainly through the kidney. When the kidney is unable to excrete uric acid, uric acid levels can increased causing hyperuricemia. Uric acid can crystallize in the joints causing painful inflammation or gouty arthritis.

Question 16

What clinical manifestations occur when the kidney is unable to excrete uric acid?

Answer 16

Uric acid is produced by the breakdown of purine and is excreted mainly through the kidney. When the kidney is unable to excrete uric acid, uric acid levels can increase causing hyperuricemia. Uric acid can crystallize in the joints causing painful inflammation or gouty arthritis.

Question 17

What clinical manifestations occur with infection in chronic kidney failure?

Answer 17

Infection should be suspected if tachycardia, fatigue and slight rise in temperature occurs

Question 18

Which blood type is the universal donor? Universal recipient?

Answer 18

Donors with type O- red blood cells are universal donors and can donate their red blood cells to any other blood type. Donors with type AB+ are universal recipients and can receive red blood cells from any other blood type.

Question 19

Differentiate hyperacute and accelerated acute kidney transplant rejection.

Answer 19

Hyperacute rejection- Occurs within minutes of the kidney transplant. It occurs when the recipient’s antibodies immediately recognize the kidney as foreign and attack it. This can happen in patients who have had previous blood transfusions from a person whose tissues have the same antigens as the donor kidney

Accelerated acute-Occurs within first 3-7 days after kidney transplant. It is caused by antibodies that may have been inactive at the time of transplant but get reactivated soon afterwards

Question 20

What two main factors contribute to primary hypertension?

Answer 20

The two main factors contributing to primary hypertension:

1. Sustained increase in peripheral resistance (pressure in the blood vessels) due to vasoconstriction of the arterioles
2. An increase in circulating blood volume

Question 21

Differentiate the four classifications of hypertension

Answer 21

1. Normal - blood pressure is less than 120 mmHg systolic and less than 80 mmHg diastolic, patients are still encouraged to make lifestyle modifications including exercise, a proper diet, no smoking, and losing weight
2. Prehypertension - systolic between 120 and 139 mmHg and diastolic between 80 and 89 mmHg, lifestyle modifications are required for patient
3. Stage 1 Hypertension - systolic between 140 and 159 mmHg and diastolic between 90 and 99 mmHg, lifestyle modifications are required for patient
4. Stage 2 Hypertension - systolic greater than or equal to 160 mmHg and diastolic greater than or equal to 100 mmHg, lifestyle modifications are required for patient

If a patient has a reading in two different categories, the patient would be considered in the higher category

Question 22

What clinical manifestations occur with acute arterial occlusion and chronic arterial occlusion?

Answer 22

Acute Arterial Occlusion:

Pain - Due to lack of blood flow and oxygen in the area distal to clot formation.

Pallor - Pale skin is distal to the area of occlusion.

Pulselessness - may be diminished or absent dependent on the area of occulsion.

Poikilothermia - cool skin develops due to lack of blood flow to the area.

paresthesia - Feeling of pins and needles occurs due to damage of the sensory nerves.

Paralysis - Motor nerves are affected with the persistence of the occlusion.

Chronic Arterial Occlusion:

Common cause: Peripheral Artery Disease (PAD) is atherosclerosis of the limbs especially the legs which can plead to chronic arterial occlusion.

intermittent claudication - pain in the legs after walking certain distances.

Pain - usually where occlusion is but patients can also have pain when resting.

Diminished or absent pulses - can occur and are depends on the severity of the occlusion.

Bruit - Is a swooshing sound heard with the stethoscope that indicates turbulent blood flow due to the occlusion.

Skin Changes - when the leg is elevated skin becomes pale when the dependent skin becomes red. Dry skin with hair loss can occur in progressed skin ulceration. Bacteria can contaminate the ulcer-causing gangrene to develop.

Question 23

A deep vein thrombosis can cause which life-threatening complication?

Answer 23

If there is a blood clot in a vein and part of it broke off and started to travel upstream. it would first travel to the vena cava and then into the heart. From there it will go the lungs and get stuck in one of the small blood vessels in the lungs. To get to the brain it would have to be an arterial thrombosis.

Question 24

What clinical manifestations occur with Raynaud Disease?

Answer 24

Raynaud’s disease causes some areas of the body (such as fingers/toes) to feel numb and cold in response to either stress or cold temperatures. With this condition, smaller arteries that supply blood to the skin become narrow, limiting blood flow to the affected area (vasopasm). Patients might have a prickly or stinging sensation when warming or using stress relief

Question 25

Differentiate Prinzmetal and stable angina.

Answer 25

Stable Angina: Caused by an atherosclerotic plaque that is stable. Patients will experience pain with exertion that stops at rest which decreases the work of the heart, and when taking nitroglycerin which dilates the coronary arteries so more oxygen is delivered to the myocardium.

Prinzmetal Angina: Is due to vasospasm of a coronary artery usually occurs when a patient is at rest. Anginal pain may be in the neck, shoulder, chest, epigastric area, arms or midback. Not all patients will experience the same symptoms.

Question 26

How long must ischemia last for infarction to occur?

Answer 26

When oxygen needs are not met and ischemia is prolonged, lasting longer than 20 minutes, irreversible damage to the heart muscle or infarction occurs.

Question 27

What ECG changes occur with ischemia, injury and infarction?

Answer 27

EKG Changes seen with ischemia, injury and infarction-

Ischemia: T-wave inversion or negative deflection from baseline

Injury: ST segment elevation off of baseline

Infarction: ST segment elevation and T-wave inversion are apparent during an MI, but return to WDL post-MI.

“Deep Q-wave” or negative deflection of the Q-wave that is greater that WDL. The Q-wave is the only permanent sign of a previous MI, but not all patients will present with hallmark.

Question 28

Differentiate transmural and subendocardial infarction.

Answer 28

Subendocardial Infarction (non-STEMI): Involves only one layer of myocardial tissue or one muscle layer of the heart. Occurs when a thrombus disintegrates before complete necrosis of all muscle layers can occur.

• EKG presentation: ST segment depression, T-wave inversion, and no apparent Q-wave.

“non-ST segment elevation myocardial infarction”

Transmural Infarction (STEMI): Involves ALL layers of myocardial tissue. Occurs when a thrombus permanently lodges in the coronary vessel. This causes all the myocardial tissue to infarct.

• EKG presentation: ST segment elevation, T-wave inversion, and Deep Q-wave.

“ST segment elevation myocardial infarction”

Question 29

What do elevated troponin levels indicate?

Answer 29

Elevated troponin levels may indicate that an individual is having a heart attack or recently has had one.

Question 30

Which valvular disease causes increased preload? (Think of the left ventricle)

Answer 30

Aortic Regurgitation which affects the bicuspid valve. This condition may be congenital or acquired.

Acquired aortic regurgitation causes include: Syphilis, rheumatic heart disease, HTN, Marfan’s syndrome, trauma and atherosclerosis.

This condition leads to heart failure.

Question 31

What causes increased afterload? (Think of the left ventricle)

Answer 31

Hypertension because it increases peripheral vascular resistance increasing the afterload. An increase in afterload will decrease stroke volume resulting in a decrease in cardiac output.

Question 32

What clinical manifestations occur with left heart failure? Right heart failure?

Answer 32

left: cool clammy skin, weak pulses, and decreased urine output, cough, shortness of breath or dyspnea, and fatigue, Orthopnea, Paroxysmal nocturnal dyspnea (PND).

Right: edema in feet and ankles, then spreads and liver and spleen become engorged generalized edema.

Question 33

What is cor pulmonale? What causes it?

Answer 33

Cor pulmonale is when there is right heart failure that occurs without left heart failure. The cause of cor pulmonale is pulmonary disease that increases lung pressures such as chronic obstructive pulmonary disease, cystic fibrosis, or acute respiratory distress syndrome.

Question 34

What causes rheumatic heart disease?

Answer 34

Rheumatic heart disease is caused by rheumatic fever from an untreated group A streptococcal infection of the throat.

Question 35

Differentiate aortic stenosis and aortic regurgitation.

Answer 35

Aortic stenosis- most common valvular abnormality affecting almost 2% of adults older than 65 years of age. Stenosis is when the valve opening is constricted and narrowed so blood cannot flow forward and the workload of the heart chamber proximal to the valve increases. This causes a rise in pressure in that chamber to overcome the resistance to flow. Hypertrophy occurs in the myocardial muscle due to the increased workload. In this case its an increase in the left ventricle. and Hypertrophy occurs in the left ventricle. Stroke volume decreases leading to inadequate perfusion of tissues in the body

Aortic regurgitation- regurgitation occurs when the valve fails to shut completely and blood is allowed to return to the chamber proximal to the diseased valve. This increases the volume of the blood the heart has to pump increasing the workload of the heart.

Question 36

What is common in all types of shock?

Answer 36

severe hypotension and inadequate tissue perfusion

• Without adequate blood flow to the tissues, oxygen and nutrients cannot be delivered and waste products cannot be removed

Question 37

What clinical manifestations occur with anaphylactic shock

Answer 37

Clinical manifestations include tissue edema, severe hypotension, tachycardia, wheezing, pruritus with urticaria, swollen lips and tongue.

Question 38

What criteria are used to diagnose systemic inflammatory response syndrome?

Answer 38

temperature greater than 38˚C or less than 36˚C

heart rate greater than 90 beats/minute

respiratory rate greater than 20 breaths/minute or PaCO2 level less than 32 mm Hg

White blood cell count greater than 12,000 cells/mm3, less than 4,000 cells/mm3, or less than 10% immature cells

Question 39

What are the most common causes of MODS?

Answer 39

Sepsis and septic shock are the most common causes, but any severe injury or illness can cause MODS.

Question 40

What organ is often the first to fail in MODS?

Answer 40

The lung is often the first organ to fail resulting in acute respiratory distress syndrome requiring mechanical ventilation.

Question 41

Differentiate the medical terms for increased and decreased red blood cells, white blood cells, and platelets.

Answer 41

Red Blood Cells:

increase: polycythemia
decrease: anemia

White Blood Cells:

increase: leukocytosis
decrease: leukopenia

Platelets:

increase: thrombocythemia
decrease: thrombocytopenia

Question 42

What results are included in a differential?

Answer 42

Leukocytes (white blood cells)

Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils

Question 43

What are the normal values for red blood cells, white blood cells, and platelets?

Answer 43

Red Blood Cells: 4.2-5.8 million per mm3

White Blood Cells: 5,000-10,000 per mm3

Platelets: 150,000-400,000 per mm3

Question 44

What are the normal values for red blood cells, white blood cells, and platelets?

Answer 44

Red Blood Cells: 4.2-5.8 million per mm3

White Blood Cells: 5,000-10,000 per mm3

Platelets: 150,000-400,000 per mm3

Question 45

What does the reticulocyte count indicate?

Answer 45

Reticulocyte counts the amount of immature red blood cells in the blood. This test also helps indicate how useful erythropoiesis is at stimulating red blood cell production.

Question 46

What laboratory results will be expected if rapid hemolysis occurs?

Answer 46

When red blood cells are broken down too fast rapid hemolysis occurs. Bilirubin is released in the blood. The liver is unable to conjugate the increased amounts of bilirubin causing the laboratory results will show an increased bilirubin level in the blood, increased reticulocyte count, and increased hemoglobin in the blood and urine. The bilirubin remains in the extracellular fluid and causes the skin and sclera to turn yellow or jaundiced.

Question 47

What type of anemia occurs in chronic kidney failure?

Answer 47

Normocytic normochromic anemia because the kidneys don’t excrete erythropoietin

Question 48

What cells are decreased in aplastic anemia?

Answer 48

Aplastic anemia causes a reduction in erythrocytes, leukocytes, and platelets. This reduction is called pancytopenia or reduction of all cells.

Question 49

What are the causes of iron deficiency anemia?

Answer 49

Blood loss through menstruation, pregnancy, inadequate dietary intake of iron, and persistent blood loss.

This is due lack of iron needed for hemoglobin synthesis.