Patho Exam 3
What are the three major hypothesized categories of genetically linked physiological alterations that may lead to the development of primary hypertension?
1. Defects in Renal sodium homeostasis 2. Functional vasoconstriction 3. Defects in vascular smooth muscle growth.
A 66-year-old man with Parkinson disease develops pleuritic chest pain. On exam, he has guarding over the right lower lung with dullness to percussion. A chest CT scan shows a focal, wedge-shaped pleural baesed area of hemorrhage in the right lower lobe. Which of the following is the most likely cause for his pulmonary lesion? A Embolism B Atherosclerosis C Vasculitis D Arteriolosclerosis E Thrombosis
(A) CORRECT. A pulmonary infarction is described. A thromboembolus from the venous circulation, usually arising in large leg veins, has lodged in a peripheral pulmonary arterial branch. The bronchial arterial supply to the lung does not provide enough oxygenation to prevent infarction, but does provide blood to make the infarct hemorrhagic. His neurodegenerative disorder with reduced movement is a risk for phlebothrombosis.
A 58-year-old woman has the sudden onset of severe dyspnea with chest pain and diaphoresis. A chest CT scan shows areas of decreased attenuation within the main pulmonary arteries. Her D-dimer assay is elevated. Her acute event is most likely to be a consequence of which of the following? A Placement of a hip prosthesis B Marked thrombocytopenia C Chronic alcoholism D Infection with the human immunodeficiency virus E Rheumatoid arthritis
(A) CORRECT. Immobilization is a major risk for the development of venous thrombosis and subsequent pulmonary embolization (the areas of diminished attenuation). Immobilization occurs following surgery. The postoperative goal: get the patient mobile as soon as possible, and meanwhile employ methods to reduce the risk for thrombosis.
What are the three conditions that promote thrombosis anywhere in the cardiovascular system?
1. Endothelial injury 2. Increased coagulation 3. Decreased blood flow
A 57-year-old woman has had episodes of abdominal pain following meals for the past year. Her BMI is 31. She has hypertension. Her total serum cholesterol is increased. Which of the following types of blood vessel is the most likely location for the pathologic abnormality causing her pain? A Artery B Arteriole C Capillary D Venule E Vein
(A) CORRECT. She has abdominal angina from vascular insufficiency. She has multiple risk factors for atherosclerosis. Atherosclerosis occurs in muscular arteries, because the level of blood pressure in arteries predisposes to endothelial dysfunction.
A 63-year-old man has had increasing exercise intolerance for the past 6 years so that he now becomes short of breath upon climbing a single flight of stairs. Laboratory studies have shown fasting blood glucose measurements from 145 to 210 mg/dL for the past 25 years, but he has not sought medical treatment. If he dies suddenly, which of the following is most likely to be the immediate cause of death? A Myocardial infarction B Nodular glomerulosclerosis C Cerebral hemorrhage D Hyperosmolar coma E Right lower leg gangrene
(A) CORRECT. This is the most common cause of death in persons with diabetes mellitus, because of the high prevalence of advanced coronary atherosclerosis.
What drugs are commonly used to treat CHF and what is the rationale for their use?
ACE Inhibitors: Decrease volume overload and decrease sodium and water retention. ARB: block angiotensin receptor binding site. B-Blocker: reduce heart rate, reduce oxygen demand on heart. Digoxin: increase contractility of the heart. This is given at later stages of CHF to help patients maintain heart function.
An autopsy study reveals that evidence for atheroma formation can begin even in children. The gross appearances of the aortas are recorded and compared with microscopic findings of atheroma formation. Which of the following is most likely to be the first visible gross evidence for the formation of an atheroma? A Thrombus B Fatty streak C Calcification D Hemorrhage E Exudate F Ulceration
(B) CORRECT. A fatty streak on the arterial intimal surface is the first grossly visible sign of atheroma formation. It is benign and reversible, but it may be the precursor to more severe plaques.
A study of atherogenesis is performed. There is a propensity for atheromas to form at muscular arterial branch points, such as the carotid and aortic bifurcations. Which of the following events in the arteries at these locations is most likely to initiate atherogenesis? A Collagen synthesis B Endothelial dysfunction C Lactic acidosis D Cholesterol breakdown E Hypoxemia
(B) CORRECT. A variety of stressors may affect endothelial cells, including the shear stress from turbulent flow at arterial branch points. Endothelial dysfunction is the initiating event that allows insudation of lipids to promote atherogenesis.
Following a meal, lipids are digested and absorbed. Lipids collect within enterocytes. Which of the following chemical components of the blood is mainly responsible for transporting exogenous (dietary) triglyceride from the intestine to the liver? A Apoprotein B Chylomicron C Lipoprotein lipase D Oxidized low density lipoprotein E High density lipoprotein
(B) CORRECT. Chylomicrons formed in intestinal epithelial cells contain apoproteins, triglyceride and cholesterol.
A 30-year-old man goes to his physician for a routine health checkup. On physical examination there are no abnormal findings. Laboratory test findings include serum glucose 80 mg/dL, hemoglobin A1C 4%, total cholesterol 240 mg/dL, LDL cholesterol 180 mg/dL, and HDL cholesterol 20 mg/dL. Through which of the following mechanisms is endothelial vascular injury in this patient most likely to occur? A Accumulation of sorbitol B Insudation of lipid C Inflammation with neutrophils D Deposition of immunoglobulins E Activation of complement
(B) CORRECT. He has hypercholesterolemia with more of the 'bad' LDL cholesterol that can become oxidized and taken up by modified arterial wall LDL receptors. The lipid collects in macrophages that transform to foam cells. These foam cells accumulate and becomes a lipid lesion--the precursor to more serious atheromatous plaques.
An autopsy study is conducted involving the gross appearance of the aorta of adults ranging in age from 60 to 90. In some of these patients, the aorta demonstrates atheromatous plaques covering from 70 to 95% of the intimal surface area, mainly in the abdominal portion, with ulceration and calcification. Which of the following contributing causes of death are these patients most likely to have? A Hyperparathyroidism B Hypertension C Marfan syndrome D Thrombophlebitis E Vasculitis F Colonic adenocarcinoma G Systemic lupus erythematosus
(B) CORRECT. Hypertension is a risk factor that accelerates atheromatous plaque formation.
A 62-year-old man has experienced substernal chest pain upon exertion with increasing frequency over the past 6 months. An electrocardiogram shows features consistent with ischemic heart disease. He has a total serum cholesterol of 262 mg/dL. By angiography, there is 75% narrowing of coronary arteries. In which of the following locations is a mural thrombus most likely to occur in this man? A Left atrium B Left ventricle C Right atrium D Right ventricle E Aorta F Vena cava
(B) CORRECT. The left ventricle is the major user of oxygen and nutrients and requires a good blood supply. A complication of ischemic heart disease with infarction is development of overlying mural thrombus. Such mural thrombi are likely to result from damage to the left ventricle from ischemic heart disease, either acutely with an underlying myocardial infarction, or with a left ventricular aneurysm formed following resolution of a large myocardial infarction
A longitudinal study is conducted to detect serum markers that predict risk for death from acute coronary syndromes. A marker is identified that is synthesized and released from the liver in response to formation of cytokines in atheromatous plaques. This marker increases endothelial adhesiveness to platelets. What is this marker most likely to be? A Prostacyclin B Immunoglobulin G C C-reative protein D Alpha-1-antitrypsin E Acetoacetate
(C) CORRECT. An increased CRP predicts a greater likelihood for adverse events from atherogenesis. One benefit of 'statin' drugs is their CRP lowering effect.
A 63-year-old man has had insulin dependent diabetes mellitus for over two decades. The degree of control of his disease is indicated by the laboratory finding of hemoglobin A1C 10.1%. He has noted episodes of abdominal pain following meals. These episodes have worsened over the past year. On physical examination, there are no masses and no organomegaly of the abdomen, and he has no tenderness to palpation. Which of the following pathologic findings is most likely to be present in this man? A Ruptured aortic aneurysm B Hepatic infarction C Mesenteric artery occlusion D Acute pancreatitis E Chronic renal failure
(C) CORRECT. He has 'abdominal angina' from diminished blood flow to the bowel as a consequence of severe atherosclerosis. Persons with diabetes mellitus may have this finding, because all branches of major arteries to the bowel are affected by atherosclerosis.
A 49-year-old woman has experienced marked pain in her lower extremities on ambulation more than 300 meters for the past 5 months. On physical examination, her lower extremities are cool and pale, without swelling or erythema. No dorsalis pedis or posterior tibial pulses are palpable. Her body mass index is 32. She is a smoker. Which of the following abnormalities of the vasculature is most likely to account for these findings? A Lymphatic obstruction B Arteriolosclerosis C Atherosclerosis D Medial calcific sclerosis E Venous thrombosis
(C) CORRECT. She has claudication from severe peripheral arterial atherosclerosis, most likely from the iliac arteries down. Her major risk factor is obesity that promotes insulin resistance and diabetes mellitus that leads to atherosclerosis.
A 66-year-old woman has the sudden loss of movement on part of the left side of her body. She has smoked a pack of cigarettes a day for the past 45 years. She has vital signs including T 37.1°C, P 80/minute, RR 16/minute, and BP 160/100 mm Hg. A cerebral angiogram reveals occlusion of a branch of her middle cerebral artery. Laboratory findings include a hemoglobin A1C of 9%. Which of the following components of blood lipids is most important in contributing to her disease? A Chylomicrons B Lipoprotein lipase C Oxidized LDL D VLDL E HDL cholesterol
(C) CORRECT. She has had a 'stroke' which is most often a consequence of cerebral atherosclerosis or embolic disease from the heart as a consequence of ischemic heart disease from atherosclerosis. LDL brings cholesterol to arterial walls, and when increased LDL is present or when there is hypertension, smoking, and diabetes, there is more degradation of LDL to oxidized LDL which is taken up into arterial walls via scavenger receptors in macrophages to help form atheromas.
A 54-year-old previously healthy woman is hospitalized for pneumonia. On the 10th hospital day she is found to have swelling and tenderness of her right leg, which has developed over the past 48 hours. Raising the leg elicits pain. An ultrasound examination reveals findings suggestive of femoral vein thrombosis. Which of the following conditions is most likely to have contributed the most to the appearance of these findings? A Trousseau syndrome B Protein C deficiency C Immobilization D Pregnancy E Chronic alcohol abuse F Hypertension
(C) CORRECT. The immobilization while in hopsital would predispose to thrombosis of leg veins. This is the most common cause for deep venous thrombosis.
A 25-year-old man experiences chest pain on exercise when he attempts to climb three flights of stairs. This pain is relieved by sublingual nitroglycerin. He is 178 cm tall and weighs 101 kg. His blood pressure is 130/85 mm Hg. Laboratory studies show a total serum cholesterol of 550 mg/dL with an HDL cholesterol component of 25 mg/dL. The blood glucose is 120 mg/dL. He is worried about these findings because his brother died of a myocardial infarction at age 34. Which of the following conditions is this man most likely to have? A Diabetes mellitus, type II B Hypertensive emergency C Familial hypercholesterolemia D Cushing syndrome E Morbid obesity
(C) CORRECT. The very high cholesterol with symptoms of coronary artery disease at such a young age, coupled with the family history, are all consistent with familial hypercholesterolemia. In most persons with hypercholessterolemia from multifactorial causes, including diet and exercise patterns, the cholesterol rarely exceeds 400 mg/dL.
A 44-year-old woman has a family history of heart disease. Her father and mother both developed myocardial infarction and congestive heart failure as a result of occlusive coronary atherosclerosis. A dietary modification to include consumption of which of the following is most likely to reduce her risk for ischemic heart disease? A 40% of total caloric intake as fat B Increased saturated fat C Foods with cholesterol D Cold water fish oil E Fat found in beef products F Hydrogenated oils with trans-fats
(D) CORRECT. Fish oils diminish arachidonic acid metabolites and reduce platelet aggregation.
A 56-year-old reports reduced exercise tolerance over the past 5 years. In the past year he has noted chest pain after ascending a flight of stairs. He smokes 2 packs of cigarettes per day. On examination he has a blood pressure of 155/95 mm Hg. His body mass index is 30. Laboratory findings include a total serum cholesterol of 245 mg/dL with an HDL cholesterol of 22 mg/dL. Which of the following vascular abnormalities is he most likely to have? A Hyperplastic arteriolosclerosis B Lymphedema C Medial calcific sclerosis D Atherosclerosis E Deep venous thrombosis F Plexiform arteriopathy
(D) CORRECT. He has multiple risk factors for atherosclerosis, including his weight, smoking, hypertension, and high total cholesterol with low 'good' HDL cholesterol. His findings suggest coronary artery disease with risk for an acute coronary syndrome.
A 53-year-old man has the sudden onset of chest pain. He is found to have a serum troponin I of 5 ng/mL. A year later he has reduced exercise tolerance. An echocardiogram reveals an akinetic segment of left ventricle, and he has reduced cardiac output, with an ejection fraction of 25%. He then experiences a transient ischemic attack (TIA). His serum troponin I is now <0.5 ng/mL. Thrombus formation involving which of the following locations is most likely to have put him at greatest risk for the TIA? A Cerebral vein B Vertebral artery C Superior vena cava D Left ventricle E Coronary artery F Saphenous vein
(D) CORRECT. Mural thrombi can form over the damaged area of ventricular wall following myocardial infarction. This can happen acutely overlying the necrotic myocardium; it can occur remotely in a ventricular aneurysm. Portions of the mural thrombus can break off and embolize via the systemic arterial circulation to places such as the cerebral circulation.
What are the principal features (signs and symptoms) included in the clinical definition of Unstable Angina?
- Chest Pain or Pressure - Pain or pressure on back, neck, jaw, abdomen, shoulders or arms. - Sweating - Dyspnea - Nausea and vomiting - Dizziness or weakness - Fatigue
A 45-year-old man dies suddenly and unexpectedly. The immediate cause of death is found to be a hemorrhage in the right basal ganglia region. On microscopic examination his renal artery branches have concentric endothelial cell proliferation which markedly narrows the lumen, resulting in focal ischemia and hemorrhage of the renal parenchyma. An elevation in which of the following substances in his blood is most likely to be associated with these findings? A Ammonia B Calcium C Cholesterol D Renin E Troponin I F Triglyceride G C-reactive protein
(D) CORRECT. The findings suggest hyperplastic arteriolosclerosis, which accompanies hypertensive emergency when systolic pressure is >=180 and/or diastolic pressure &>=120 mmHg along with signs of acute or ongoing end-organ damage. Reduced renal blood flow increases renin, driving hypertension.
A 34-year-old previously healthy woman notes that she has bruises form on her arms and legs with just minor trauma. Physical examination reveals areas of purpura from 1 to 3 cm in size over her trunk and extremities, but no swelling, warmth, or erythema. Peripheral pulses are all palpable and full. Her blood pressure is 110/70 mm Hg. An ultrasound examination of her lower extremities with Doppler flow measurement reveals no evidence for thrombosis. Laboratory findings include serum urea nitrogen of 16 mg/dL, LDH 300 U/L, total protein 6.9 g/dL, albumin 5.3 g/dL, alkaline phosphatase 50 U/L, AST 40 U/L, and ALT 20 U/L. Which of the following additional laboratory findings is most likely to be present in this patient? A Hyperglycemia B Hypercholesterolemia C Lactic acidosis D Thrombocytopenia E Hypoprothrombinemia F Anemia
(D) CORRECT. The platelets are responsible for dealing with small leaks in small vessels. Thrombocytopenia is marked by petechiae and purpura. She does not have evidence for peripheral vascular disease, since her circulation is good. Venous thrombosis should lead to swelling and tenderness.
A 70-year-old man has noted coldness and numbness of his lower left leg, increasing over the past 4 months. He also experiences pain in this extremity when he tries walking more than the distance of half a city block. On physical examination, his dorsalis pedis, posterior tibial, and popliteal artery pulses are not palpable. Which of the following laboratory test findings is he most likely to have? A Protein S deficiency B Blood culture with Staphylococcus aureus C Decreased arterial oxygen saturation D Hyperglycemia E Hypercalcemia
(D) CORRECT. This is peripheral arterial vascular disease from severe atherosclerosis, which is promoted by diabetes mellitus. The absence of pulses defines this as an arterial process, as does the claudication (pain with exercise). Thrombophlebitis is a venous process and leads to swelling and pain in the leg, but not loss of pulses.
What are the principal features (signs and symptoms) included in the clinical definition of Myocardial Infarction?
- Intense, oppressive, excruciating chest pressure, radiation of pain to Left Arm. - Impending sense of doom - Pale Skin - Nausea, Dsypnea, Vomiting - Tachycardia - Increase/Decrease in Blood Pressure - ST-Elevation (or No ST-Elevation) - Elevated Troponin Markers
What are the common sites of Atherosclerosis?
*Abdominal aorta. *Coronary arteries. *Popliteal artery. *The internal carotid arteries. *The vessels of the circle of Willis.
What are the key pathological features and progression of CHF? Explain how the body's compensation mechanisms for a failing heart only worsen the condition?
1. Myocardial hypertrophy and remodeling result in decreased cardiac output. Cardiac remodeled and scar tissues has decreased cardiac function and an altered ionotropic function. 2. Decreased CO results in decrease Renal Blood flow activating the RAS and SNS. 3. Angiotensin II stimulates vasoconstriction and stimulates the Adrenal Gland to secrete Aldosterone. 4. Aldosterone increases sodium and water retention which increases vascular volume and venous return, thus overstimulating cardiac stretch receptors. 5. SNS innervation to blood vessels results in vasoconstriction resulting in increased vascular resistance. SNS also increases the contractility and heart rate.
Describe the many functions of Angiotensin II and how each functions relates to the overall goal of recovering plasma volume.
1. Stimulates Aldosterone release. Aldosterone stimulates sodium reabsorption at the DCT and collecting duct 2. Vasoconstriction of the arteries and afferent arterioles 3. Stimulates Tuboglomerular Feedback System 4. Stimulates the Na++/H+ Exchanger at the PCT to increase sodium reabsorption. 5. Stimulates Central Osmoreceptors to release ADH.
What are the four requirements or steps to normal external respiration?
1. Ventilation 2. Gas Exchange 3. Gas Transport 4. Tissue Extraction
What are the ways in which CO2 is transported in blood and in what proportions?
60% - Bicarbonate Buffer System 30% - Bound to Hb 10% - Physically dissolved in blood
What are the ways in which O2 is transported in blood and in what proportions?
98% bound to Hb 1.5% dissolved in plasma
An open pneumothorax is associated with the rupture of which pleural membrane in the thoracic cavity? Rupture of which pleural membrane in the thoracic cavity cause a spontaneous pneumothorax?
A tension (open) pneumothorax is a break within the parietal pleura. A spontaneous pneumothorax is a break within the visceral pleura.
Explain how a pneumothorax interferes with lung ventilation? (ie. what are the mechanics of breathing and is that disturbed by a pneumothorax?)
A pneumothorax results in a break in either the parietal or visceral pleura. This results in pressure equalizing between the outside environment and inside of the pleural cavity causing the lung to collapse. This causes problems with ventilation due to the loss of negative pressure.
What ECG changes are consistent with acute MI? Are the different ECG changes thought to correlate to location or severity of the MI?
Acute MI may present itself with ST elevation or a T-wave inversion which is a precursor to ST elevation. Different ECG changes can be correlated to location or severity of the MI.
What is the difference between acute prerenal failure and ischemic acute tubular necrosis?
Acute Prerenal Failure is a precipitous and significant drop in GFR (~50%) over several hours-days with an accompanying accumulation of nitrogenous wastes. This is typically REVERSIBLE! Ischemic Acute Tubular Necrosis is the sloughing and necrosis of tubular epithelial cells which can lead to obstruction and increased intraluminal pressure. This can result in PERMANENT and IRREVERSIBLE damage. This can progress to chronic renal failure.
Describe the vascular components of the nephron. Which vascular parts engage in exchange of any kind with the tubule?
Afferent Arteriole -> Bowman's Capsule ->Efferent Arteriole -> Peritubular Capillary/Vasa Recta Exchange can occur at Bowman's Capsule, Peritubular Capillaries, and Vasa Recta
What two ethnic/racial groups seem to be similar in their increased risk for primary hypertension?
African Americans and Asian Men
What is a fatty streak?
An accumulation of foam cells in the sub endothelial space in blood vessels
What is an embolus? What is the most common cause of an embolus? What is the major difference in terms of clinical manifestation between an embolus that originates in the venous system vs. the arterial system?
An embolus can be a blood clot or any abnormal structure found in circulation that can travel from one area to another. The most common cause of an embolus is a DVT. The major difference in clinical manifestation between venous vs arterial embolism is where they present. Arterial embolisms will typically present at the site of occlusion, whereas venous embolisms will present further from the occlusion site.
Explain how someone's PaO2 can be normal while their total blood O2 content is dangerously low. Name at least one disease state in which this can happen?
Anemia - pO2 remains unchanged. pO2 only reflects amount of oxygen physically dissolved in plasma, not bound to Hb.
What are the most common types of obstructive lung diseases? List basic characteristics, etiologies, clinical manifestations, pathological development, evaluation, and treatments for each disease.
Asthma: Underlying inflammation makes the airway more reactive causing the airway to spasm and develop an acute attack. Clinical Manifestations: Dsypnea Pathological Development: Allergy Irritant -> Immune Activation -> Mast Cell Degradation -> Vasoactive Mediators and Chemotaxic Factors -> Increase vascular permeability and cellular infiltration of neutrophils, lymphocytes, eosinophils, and release of toxic neuropeptides -> BRONCHOSPASMS Treatment: Decrease inflammation via steroids, mast cell stabilizers, long-acting Beta agonists. Provide rescue inhalers: fast acting beta-agonists. Bronchitis: excess mucus build-up due to Acute Inflammation Clinical Manifestations: Dsypnea, Cough, Hypoxemia, Hypercapnia Pathological Development: Irritants from pollution or smoking -> Inflammation of airways -> Inflammatory Cells release cytokines -> Continuous bronchial irritation and inflammation -> Chronic Bronchitis, ciliary malfunction, bacterial colonization -> Airway obstruction, air trapping, loss of SA for gas exchange, frequent exacerbations. Emphysema: break down of lung tissue. Increase RV, decrease VC, FEV1, and FVC. Clinical Manifestations: Dsypnea, Cough, Hypoxemia, Hypercapnia. Pathological Development: Tobacco smoke, air pollution -> Inflammation of airways -> Infiltration of inflammatory cells and release of cytokines -> continuous bronchial irritation and inflammation and increased protease activity -> Airway obstruction, air trapping, loss of SA for gas exchange, frequent exacerbations.
How are heart failure patients clinically categorized with respect to treatment recommendations?
At risk for heart failure: A and B Heart Failure: C and D
What is the goal of autoregulation by the kidneys? By what mechanisms is this goal met?
Autoregulation involves feedback mechanisms INTRINSIC to the kidney that can cause either dilation or constriction in the AFFERENT arteriole in order to counteract BP changes and maintain GFR.
Which of the following is most likely to be the first visible gross evidence for the formation of an atheroma? A) Thrombus B) Fatty streak C) Calcification D) Hemorrhage
B) Fatty streak
What is the most common cause of postobstructive acute renal failure? What sex and age group would you expect would predominate these cases?
Benign Prostate Hyperplasia. Affects older men.
A UA contains blood. What do you suspect?
Bleeding
What are the differences between "Chronic Ischemic Disease" and "Acute Coronary Syndromes?"
Both Chronic Ischemic Disease and Acute Coronary Syndromes are caused by ischemia. Chronic Ischemic Disease typically manifests itself as angina: stable, variant, and silent myocardial ischemia. The plaques within the coronary vessels are typically stable, contain more protein, and less lipid. Acute Coronary Syndrome results from unstable angina and results from acute cardiac tissue death caused by a plaque that has ruptured and blocking blood flow.
What factors can alter the relationship between percent Hb saturation and pO2?
CO2 Acidity Temperature Increased CO2, acidity, and temperature will cause result in Hb-saturation due to Hb dumping off oxygen to working tissues.
What are the forces involved in glomerular filtration? Which ones promote filtration, which ones oppose filtration?
Capillary Blood Pressure: INCREASE Filtration Plasma Colloid Osmotic Pressure: Oppose Filtration Bowman's Capsule Hydrostatic Pressure: Oppose Filtration
The most common clinical manifestation of cardiac ischemia is cardiac ischemic pain. Is cardiac ischemia always symptomatic? What are the ways in which cardiac ischemic pain manifests? What is anginal pain? Are there any gender differences with regard to expression of anginal pain?
Cardiac Ischemia is not always symptomatic. 70% of events are silent myocardial ischemia. Cardiac Ischemic Pain manifests itself as angina. Anginal pain is a type of chest pain caused by reduced blood flow to the heart. Pain can either be diffuse visceral where they feel uneasiness, discomfort, and non-localized pain, defined somatic pain which refers by dermatome, or interpretive pain. Stable angina pain can be exacerbated by predictable or non-predictable physical activity. Patients typically feel retro-sternal chest discomfort or distress. Discomfort is located outside chest, arms, shoulders, back, jaw, or epigastrum. ~20% of patients experience "warm-up" angina, but the pain generally goes away after the warm-up period.
Why is it dangerous to give a steroid or anti-inflammatory drug to individuals in the weeks following an acute MI?
Cardiac tissue heals through the inflammatory response. By taking an anti-inflammatory, you are interfering with the healing process which can result in ventricular rupture.
How is Creatinine handled differently by the kidneys compared to Substance X?
Creatinine is freely filtered, not absorbed, and minimally secreted.
What are some causes and consequences of renal failure?
Causes: Cystic Disorders Neoplasms Chronic Kidney Infections (Streptococcal Infections) Diabetes Consequences: 1. Reduced Renal Reserve (GFR 50%) - No symptoms of impaired renal function - Increased risk of azotemia and susceptibility to nephrotoxic drugs. 2. Renal Insufficiency (GFR 20-50%) - Will maintain normal function until about 75% nephron loss - Compensatory hypertrophy and hyperfiltration. Leads to injury, fibrosis, loss. - Symptoms of azotemia, anemia, and HTN arise. 3. Renal Failure (GFR <20%) - Kidneys unable to regulate volume or solute concentration. - Results in edema, metabolic acidosis, and hyperkaemia. - Uremia, neurologic, GI, and CV manifestations 4. End Stage Renal Failure (GFR < 5%) - Dialysis
"Cheerios" claims to reduce cholesterol levels if eaten daily for at least a few weeks. By what mechanism is this accomplished?
Cheerios contains a substantial amount of soluble fiber. Soluble fiber has been demonstrated to inhibit the reuptake of bile salts from the small intestine. Soluble fiber binds to bile salts thus inhibiting their reuptake.
If the clearance rate of Substance X is equal to GFR, how is substance X handled by the kidneys?
Clearance Rate = GFR, so Substance X will be 20% filtered. The remaining 80% will remain in the blood stream.
What is meant by "collateral circulation?" What causes it to develop? What impact can it have on the outcome of an acute MI?
Collateral circulation is the alternate circulation around a blocked artery by way of other smaller veins or arteries. Collateral circulation can occur during an MI and can help maintain a certain percentage of perfusion to the ischemic tissue. They could potentially reduce the infarc size and post-infarc complications.
What are the structural and functional differences between the juxtamedullary nephrons and the cortical nephrons?
Cortical Nephrons: (80%) Short Loops of Henle that do not go deep into the medulla, contain peritubular capillaries Juxtamedullary Nephrons: (20%), Long Loops of Henle that extend into the medulla, only have vasa recta. Responsible for producing concentrated urine and retaining water.
A UA contains protein. What do you suspect?
Decreased Renal Function
A UA has a high specific gravity. What do you suspect?
Dehydration due to increased amount of solutes.
Which of the tubular segments is impermeable to sodium?
Descending Loop of Henle
What determines the % hemoglobin saturation?
Determined by pO2 in blood.
Which part of the medullary respiratory center is responsible for driving quiet resting breathing?
Dorsal Respiratory Group
What cell types are involved in the development of atherosclerosis?
Endothelial cells secrete inflammatory mediators Platelets, monocytes and macrophages secrete radical oxygen species which oxidizes LDL.
What are FVC and FEV1? How does FEV1 relate to FVC in a normal lung?
FEV1 is the volume of air moved out of lungs in the first second and used to assess the collapsibility of the alveoli. It is used to assess for obstructive lung disease. FVC is forced vital capacity. This value is typically lower than Vital Capacity since the airways close sooner.
What are the major risk factors for primary hypertension?
Family history Old age Gender (males < 55, females > 74) Race Increased sodium intake Diabetes Stress Smoking Obesity Alcohol Decrease dietary intake of potassium, calcium, and magnesium.
Define the basic renal processes: filtration, reabsorption, and secretion.
Filtration: ~20% filtration. Passive and non-selective. Glomerular Filtration typically occurs at Bowman's Capsule. There is no filtration of blood proteins. Tubular Reabsorption: Passive and ACTIVE. Selective Reabsorption of sodium, water, and potassium. Tubular Secretion: Selective, active or passive process that allows for a excretion of waste products.
Sarah has discovered a neat trick. She first holds her breath for as long as she can and take note of that time. Next, she begins to breathe very rapidly with exaggerated exhalations for 30 seconds. Finally, she holds her breath again for as long as she can and notices that she is able to hold her breath for nearly twice as long as the first time. Briefly explain why Sarah was able to hold her breath longer the second time.
Forceful exhalations result in decreases pCO2. She is able to hold her breath longer the second time because it takes a little longer for pCO2 to build up in the blood and for her central chemoreceptors to pick up the change.
Clinically, what is the generally accepted measure of functional renal (nephron) mass and therefore renal function?
GFR and/or Urine Output per hour
A patient visits her HCP complaining of UTI symptoms (burning upon urination, increased urinary frequency). This patient also has uncontrolled diabetes. What urinalysis findings would you expect for this patient?
Glucose, leukocyte esterase, bacteria, and RBCs.
What is the chloride shift?
HCO3- ions move out of red blood cells into the plasma down a concentration gradient when RBCs are deoxygenated. To maintain the electrical balance, Cl- ions take their place. When RBCs are oxygenated, Cl- ions leaves the cell while HCO3- ions move in
What is HDL? Where does it come from? What role does it play in regulating circulating lipid levels? Why is it considered the "good" cholesterol?
HDL is a High Density Lipoprotein. It is synthesized and excreted by the liver and small intestine. It regulates lipid levels by bringing excess cholesterol back to the liver to be broken down and excreted via the scavenger pathway. It is considered the good cholesterol based on its function of controlling blood cholesterol levels.
What initiates the process of atherosclerosis?
Inflammatory mediators, increased LDL levels, HTN, and smoking
Diseases that involve the glomerulus or tubules affect what part of the kidney? What can result?
Intrinsic. Diseases may affect the glomerulus or tubules which are associated with the release of vasoconstrictors on Afferent Arterioles. The result is Acute Tubular Necrosis and ischemia.
Why does the infracted myocardium heal through fibrosis rather than by regeneration?
When myocardial tissue dies, it sets a massive inflammatory response for the heart to undergo remodeling.
What is an LDL? What purpose does it serve? What are the possible routes of elimination for LDLs in circulation? Why are LDLs considered the "bad" cholesterol?
LDL is a Low Density Lipoprotein that contains ~50% cholesterol and responsible for delivering cholesterol to the cells. Possible routes of elimination of cholesterol include the liver where HDL brings LDL back and cholesterol is converted into bile and excreted. Other routes are degradation and phagocytosis by neutrophils and macrophages. LDLs are considered bad cholesterol because high LDL levels contribute to atherosclerosis.
The presence of LVH increases the risk of several other cardiovascular disorders/conditions. What are those conditions and how/why does LVH increase the risk for them?
LVH leads to smaller a ventricle and increased EDV filling pressure which reduces CO and HR. LVH increases the risk of ventricular arhythmias, sudden cardiac death, and death from MI and CHF.
Think of one example of a possible cause for "primary hypercholesterolemia"?
Lack of LDL receptors or deficiency in receptors.
What is a foam cell?
Lipid engorged macrophage. Macrophages contain receptors for LDLs. Cholesterol from the LDL is released into the macrophages and the macrophages become fatty.
What are the physical features of a plaque?
Lipid-laden cells located in the intima of the arteries. They may contain collagen, macrophages (foam cells), smooth muscle cells, endothelial cells, and lymphocytes.
What is a lipoprotein? What types of lipoprotein exist?
Lipoproteins are is a soluble protein that combine and transport fat or other lipids within the blood. There are 5 primary types of LPL: HDL, LDL, IDL, VLDL, and Chylomicrons.
A UA contains urobilinogen. What do you suspect?
Liver disease such as Hepatitis or Cirrhosis.
The medullary osmotic gradient plays a key role in the kidneys ability to produce urine of varied concentrations. What structure(s) establishes this gradient and which structure(s) uses the gradient to vary the concentration of urine? How is the medullary osmotic gradient used to vary the concentration of urine? What role does ADH play?
Loop of Henle in Juxtaglomerular Nephrons establishes the gradient. Countercurrent flow causes the osmolarity differences to multiply as the renal tubule descends into the medulla. The filtrate inside the descending limb becomes progressively more concentrated, but then as it ascends back toward the cortex, active reabsorption of ions causes it to become progressively less concentrated. Effectively, the thick ascending limb transfers osmolarity to the descending limb and medullary interstitial fluid. The result is that osmolarity becomes trapped in the medulla ADH stimulates the formation of aquaporin channels on tubular membranes to reabsorb water.
Why do post MI patients have an increased risk for cardiac arythmias?
MI results in cardiac muscle ischemia causing contractile cells to depolarize. This leads to altered impulse formation and/or altered impulse formation.
For someone suffering from CO poisoning what would expect the status of each of the following parameters to be? PaO2, PaCO2, %Hb saturation measured by standard pulse oximetry, and skin color?
PaO2: ~100% PaCO2: 100% %Hb Saturation: 100% Skin Color: Bright Red
Ischemic Heart Disease is an imbalance between myocardial O2 supply and O2 demand. What factors determine myocardial O2 demand? What factors determine O2 supply?
O2 Supply: Coronary Vessel Patency, Ventricular Wall Patency, Diastolic Filling Time O2 Demand: Myocardial contractility, HR, and wall stress.
What is the most common cause of MI?
Obstruction of blood flow due to plaque accumulation of rupture.
Compare and contract obstructive vs. restrictive lung disease with respect to underlying cause, impact on pulmonary function, and alterations in lung volumes and function testing?
Obstructive Lung Disease Causes: Asthma, Acute Chronic Bronchitis, Emphysema. Anything that can cause airway trapping, air trapping, or expiratory wheezing. - Increased Residual Volume (RV) - Decrease in Vital Capacity (VC) - Decrease in FEV1 and FVC. Restrictive Lung Disease Causes: Pulmonary Fibrosis d/t asbestos/dust exposure, chronic inflammation of connective tissue, repeat infections, and radiation therapy to the chest. Elastic fiber replaces collagen resulting in decreased lung compliance and increase in respiration rate. - Decreased Inspiratory Capacity (IC) - Decreased Vital Capacity (VC)
What role do oxidized LDLs play in the process of atherosclerosis?
Oxidized LDL further damages vascular smooth muscle and endothelial cells.
Compare and contrast the use of plasma creatinine vs. BUN levels in assessing renal function.
Plasma Creatinine is generally stable, has minimal fluctuations, and is proportional to muscle mass. Decreasing renal function results in an increase in plasma Creatine. BUN is ~50% filtered, ~50% reabsorbed, and has a slower clearance rate than Creatinine. Urea clearance is secondary to Na++/H2O absorption, therefore increased [Na++]/[H2O], increases urea retention. If someone is severely dehydrated, GFR decreases and H2O retention increases. BUN and Cr will also increase. Comparing both BUN and Cr is effective at determining renal function. If there is an increase in BUN and Cr, it is typically indicative of decreasing renal function.
How does the body regulate plasma volume? How does it regulate plasma osmolarity?
Plasma Volume - Kidneys Decrease in Plasma Volume ---> Decrease in BP --> (+) JGA Baroreceptors and Aortic and Carotid Baroreceptors --> (+) Renin and SNS --> Increase in Aldoesterone, Vasoconstriction of Afferent Arteriole, Thirst. Plasma Osmolarity - Central Osmoreceptors Angiontensin II, Increased Plasma Conc, and SNS stimulate Central Osmoreceptors. Central Osmoreceptors stimulate THIRST and ADH release.
Obstruction of urine flow occurs at what part of the kidney? What are the potential causes?
Post-Renal. Caused by kidney stones or any other blockage. Increases hydrostatic pressure, which increases capillary pressure and decreases GFR.
Explain how potassium secretion is linked to sodium reabsorption, but only in the distal tubule and collecting duct.
Potassium secretion occurs at the DCT and Collecting Duct. Aldosterone stimulates the Sodium/Potassium ATP pumps and opens luminal sodium channels. Potassium is secreted while sodium is retained.
Decreased renal perfusion causes depression of GFR.What part of the kidney is affected and what are the causes?
Pre-Renal. Caused by decreased blood pressure, MI, or massive blood loss.
What factors will determine if a segment of tubule is permeable to water?
Presences of tight junctions. Water diffuses through tight junctions following sodium concentration gradients. Presence of aquaporin channels in the PCT and Loop of Henle.
What muscular events are involved in: Quiet inhalation Forceful inhalation Passive exhalation Forceful exhalation
Quiet inhalation: External Intercostals and Diaphragm Forceful inhalation: Internal Intercostals, SCM Passive exhalation: Relaxation of External Intercostals and Diaphragm Forceful exhalation: Abdominal Muscles
What is residual volume? Is residual volume normal? How does it come about?
Residual Volume is the amount of air trapped after expiration, typically ~1200mL. It is normal.
What portions of the heart are perfused by the right coronary artery, the left anterior descending branch of the left coronary artery, and the left circumflex branch of the left artery?
Right Coronary Artery: Right Atrium, Right Ventricle, SA Node, and AV Node. Left Anterior Descending Branch of the Left Coronary Artery: Perfuses intraventricular septum (Bundle of His and Purkinje Fibers. Left Circumflex Branch of the Left Artery: The Posterior and lateral free walls of the left ventricle
What is ST segment depression and ST segment elevation? What patterns of ischemia are these two ECG changes associated?
ST segment depression: Demand Ischemia. We will see some ST-depression during stress testing if CAD is causing ischemia. ST segment elevation: Supply Ischemia Related to cardiac muscle injury or death due to plaque rupture and ischemia.
What subtypes of MI exist (based on ECG changes and location of infarction)?
STEMI or NSTEMI Right Coronary Artery Obstruction Proximal: Right Ventricle, moderate, large inferior, posterior, lateral occlusion Distal: Small, inferior occlusion Left Anterior Descending Artery Obstruction Proximal LAD: Quickly Fatal. High mortality due to proximity to the first septal perforation. Compromises perfusion to the Purkinje Fibers. Mid LAD Distal LAD: Less Common Left Circumflex Artery Obstruction: Left Ventricle, moderate to large inferior, posterior, and lateral obstruction.
What is the difference between primary and secondary hypertension?
Secondary hypertension is typically secondary to another problem (renal, endocrine, neuro, hemodynamic instability). Primary HTN is considered essential or idiopathic HTN.
Describe all the possible transport events that occur in the proximal tubule.
Sodium helps brings in the following... Glucose Amino Acids Water Urea Potassium
Explain how you know for certain that the kidneys do not regulate plasma levels of glucose.
Sodium is actively reabsorbed and is a co-transporter of glucose. Sodium/Glucose co-transporters open to aid in the reabsorption of glucose. 100% of sugar filtered is reabsorbed at a rate of ~100mg/100mL of plasma. 300mg/100mL is the THRESHOLD.
Describe the various mechanisms for sodium reabsorption throughout the renal tubule. What is sodium reabsorption coupled to and where?
Sodium is reabsorbed in all areas of the lumen except the Descending Loop of Henle. Sodium reabsorption occurs through sodium channels, secondary active transport, or sodium co-transporters at the PCT and Ascending Loop of Henle. Sodium reabsorption at the DCT and Collecting Duct can be stimulated by Aldosterone.
What are the categories of atherosclerosis ?
Stable Asymptomatic. Contain extracellular matrix and smooth muscle cell Unstable Contain macrophages, foam cells, and the extracellular matrix and known as fibrous cap
What factors influence the likelihood that an atherosclerotic plaque will rupture?
Stress on the cap: Tension is directly related to intraluminal pressure times radius. The increased volume of blood increases stress. Additionally, overall weakness of the plaque. Newer plaques have a tendency to rupture more frequently.
What factors determine the amount of gas transported across the alveoli and into the pulmonary capillaries?
Surface Area Thickness of Diffusion Barrier Partial Pressure Gradients.
Consider the Renal Corpuscule, how does it manage to filter out small proteins like albumin that can fit through the pores of the capillary walls?
The Glomerular Membrane is composed of: - The wall of glomerular capillaries - Basement membrane - Inner layer of Bowman's capsule. They allow for the passage of everything except proteins and cells.
What is the LDL receptor? What role does it play in influencing circulating LDL levels?
The LDL receptor is the apoprotein. It signals to target cells regarding it's contents. LDL receptors signal cells to uptake the LDL. A deficiency or reduction in receptor function or numbers will typically result in primary hypercholesteremia.
What influence does the coronary endothelium have over the overall balance between myocardial O2 supply and O2 demand?
The coronary endothelium responds to changes in myocardial O2 supply and demand by releasing vasoactive mediators. High [O2]: Vasoconstriction Low [O2]: Vasodilation
Kussmal breathing is characterized by very deep and rapid respirations and is often seen with severe diabetic acidosis. What sensors stimulate this type of breathing? What is the purpose of Kussmal breathing in a patient with diabetic acidosis? Would you expect the systemic arterial PCO2 of this patient to be high, low, or normal?
The initial sensors are the peripheral chemoreceptors that sense a change in Hydrogen levels. Depth and rate of breathing is controlled by the pons. The Pons will adjust rate and depth based on metabolic demands. The purpose of Kussmal breathing is respiratory compensation to metabolic acidosis. The systemic arterial pCO2 may be lower due to increased exhalation of CO2.
What is the VQ ratio?
The ratio is used to assess the efficiency and adequacy of V - ventilation of air to the alveoli and P-perfusion of blood to the alveolar capillaries. Ideal ratio is one. If there is a mucus plug, ventilation will go down, while perfusion remains the same. If perfusion goes down such as a PE, ventilation remains the same, while perfusion goes down.
Why are you better off being over-hydrated than dehydrated for very long?
There is a minimal amount of urine that the body needs to excrete in order to get rid of waste.
Why are chronic large vascular plaques not usually the cause of acute MI?
They are typically more stable
My what mechanism do the "Statin" class drugs lower cholesterol?
They block HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis.
What is Left Ventricular Hypertrophy (LVH)? What causes it?
Thickening of the cardiac muscle in the left ventricle due to persistently elevated cardiac afterload or aortic valve stenosis.
Define tubular maximum and renal threshold. How are those concepts related to renal regulation of plasma concentrations of any given substances?
Tubular Maximum: Max RATE OF ABSORPTION in the kidneys. Renal Threshold: Max plasma CONCENTRATION a substance can reach before it starts to appear in urine.
What cell types make up the interface between the alveoli and the pulmonary capillaries? What are the functions of each?
Type 1 Alveolar Cells: Contain Air Type 2 Alveolar Cells: Secrete pulmonary surfactant Macrophages: protection Endothelial Cells: structure/support
A UA pH is alkaline. What do you suspect?
UTI
Describe a pathological state or condition that involves an abnormality of the following: 1. Ventilation 2. Gas Exchange 3. Gas Transport 4. Tissue Extraction
Ventilation: pneumothorax, hemothorax, pleural effusion Gas Exchange: pulmonary edema, pulmonary embolus, tumor obstruction Gas Transport: carbon monoxide poisoning Tissue Extraction: CN poisoning. CN blocks oxygen transport chain.
What part of the medullary respiratory center gets recruited in forceful breathing?
Ventral Respiratory Group
What are "White Coat Hypertension" and "Masked Hypertension"? By what method can you screen someone for these conditions?
White coat hypertension occurs when an individual may have a higher than normal blood pressure in the medical environment. Masked hypertension occurs when someone may have a decreased blood pressure while in clinic. You can give them a home monitoring blood pressure unit, teach them paced respirations, and screen for anxiety.
What do HDL "good cholesterol" do?
mobilizes cholesterol from developing and existing atheromas and transports it to the liver for excretion in the bile.
