Patho II Exam 2
Valvular incompetence
"Leaky" valve Blood regurgitates backward No obstruction of blood flow forward
Explain the three rapid regulation sites of blood pressure
Arterioles Post-capillary venules (capacitance vessels) Heart
What kind of information may be gathered regarding cardiovascular function with the following diagnostic tests? Angiography
Can be used to assess coronary artery blood flow Finds occlusions in all types of blood vessels, including cerebral vessels Uses a radio-opaque dye, and an imaging technique such as CT or MRI
What kind of information may be gathered regarding cardiovascular function with the following diagnostic tests? Chest Xray
Determine the shape and size of the heart: ▪ Cardiomegaly= enlarged heart ▪ Left or right ventricular hypertrophy ▪ Pulmonary congestion ▪ Calcifications in the heart
What kind of information may be gathered regarding cardiovascular function with the following diagnostic tests? ECG
Diagnosis and monitoring of cardiac arrhythmias, myocardial infarctions, and inflammation of the heart or pericardium Holter monitor
What are lipoproteins and why do we need lipoproteins
Differ by the proportion of their core lipids, their apoprotein content, and their transport function Named according to size & density 5 main types: 1. Chylomicrons 2. VLDL 3. IDL 4. LDL 5. HDL
What are some of the diagnostic tests used to determine if a patient has suffered a heart attack?
ECG changes Measure serum cardiac markers: Creatine kinase-MB isozyme (CPK-MB) Troponin T and I (TnT, TnI):released within 4-6 hrs of a heart attack Cardiac markers are released slowly overtime and require 24 hr blood collection
What is congestive heart failure? What are some of the typical causes of congestive heart failure?
Heart is unable to pump enough blood to keep up with the metabolic demands of the body Usually a secondary heart condition Chronic in nature with cycles of exacerbations Dilated cardiomyopathy may be a cause, however the cause of dilated cardiomyopathy may be unknown Typical causes: MI Valve damage Increased workload on the heart due to: ▪ HTN (systemic or pulmonary) ▪ COPD Drug use causing cardiomyopathy (ex: Cocaine) Dilated cardiomyopathy Myocardial hypertrophy Combination of factors
Ventricular septal defect
Hole in the septum of the heart, which normally separates the right and left ventricles Oxygenated blood mixes with unoxygenated blood increases work on the heart 1 out of 500 births
How is long-term regulation of blood pressure accomplished?
Kidneys regulate fluid volume
What is Malignant Hypertension?
Malignant HTN: Sudden and rapid increase of BP Medical emergency Diastolic >130 mmHg End-organ damage
Valvular stenosis
Narrowed opening of the valvelimits blood flow No backflow of blood
In pericardial effusion, there are three types of exudate that may form, which help diagnose the cause of the pericardial effusion. What are the 3 types of exudate and what do they indicate in regards to the cause of the pericardial effusion?
Serous - inflammation Purulent - infection Bloody - trauma or cancer
What is shock? Describe the different types of shock
Severe hypotension such that perfusion to vital organs is compromised Classified by the cause: Hypovolemic - due to severe and rapid blood loss Cardiogenic - heart loses ability to pump blood Vasogenic->Loss of sympathetic tone Anaphylactic-> due to a severe allergic reaction where there is massive histamine release-> widespread vasodilation Septic (or endotoxic)->systemic infection with a gram - bacteria which releases endotoxins->cause widespread vasodilation
Describe in detail the pathological progression of Atherosclerosis
Strong association between ↑plasma lipoproteins (especially those involved in cholesterol transport) and the premature / accelerated development of atherosclerosis In plasma, almost all lipids (i.e. cholesterol & TGs) are transported in a complex with proteins Makes them more water soluble so that they can travel in the blood, which is mostly water Two pathways involved in lipid synthesis and storage: 1. Exogenous pathway: from our diet> intestine>liver 2. Endogenous pathway: liver>Synthesizes and uses lipids to make bile
What is a patent ductus arteriosus? What vessels are involved and how is it treated?
The ductus arteriosus in a fetus connects the pulmonary artery with the aorta, allowing blood to bypass the lungs This connection normally closes shortly after birth patent is when is doesn't close
What kind of information may be gathered regarding cardiovascular function with the following diagnostic tests? Echocardiogram
Transthoracic echocardiogram (TTE) Transesophageal echocardiogram (TEE) Both give info about the size of the heart, its chambers, and the movement of the heart valves
What kind of information may be gathered regarding cardiovascular function with the following diagnostic tests? Auscultation
Valvular abnormalities-->murmurs Turbulent blood flow: ▪ Stenosis of superficial vessels can be detected ▪ Usually laminar blood flow cannot be heard
What is Essential Hypertension
"Essential hypertension" = no identifiable cause
AV valve function
+ Atrioventricular (AV) valves: ◦ Lie between the atria and the ventricles ◦ AV valves prevent backflow of blood into the atria when ventricles contract The AV valve that separates the right atrium from the right ventricle= Tricuspid Valve The AV valve that separates the left atrium from the left ventricle= Mitral valve (or Bicuspid)
Describe the Exogenous and Endogenous Pathways of lipid synthesis and storage
1. Exogenous pathway: from our diet> intestine>liver 2. Endogenous pathway: liver>synthesizes and uses lipids to make bile
What is Tetralogy of Fallot? What are the congenital defects that lead to this abnormality and what are the primary symptoms?
4 heart defects working in concert: Pulmonary stenosis Ventricular spetal defect Right ventricular hypertrophy Dextroposition of the aorta Results in cyanosis
What are some of the initial compensatory mechanisms of congestive heart failure? How do these compensatory mechanisms actually contribute to the worsening of the disease?
Activation of the sympathetic nervous system to increase CO, and HR: Vasoconstriction increased afterload Increased HR and force of contraction increased workload of the heart Renin secretion->↑angiotensin II-> ↑vasoconstriction and ↑aldosterone secretion-> ↑sodium and water retention->↑venous return-> ↑preload
preload
Amount of tension in the L ventricle immediately before it contracts ↑ preload = ↑force of contraction Closely related to venous return (VR) ↑VR = ↑preload
Explain the process of re-entry and why it results in cardiac arrhythmias.
An impulse that has been delayed by damaged tissue ▪ Comes back and re-excites the same area before the next stimulus is generated by the SA node
Compare and contrast the 3 different types of Angina Pectoris Which one is most common? When do symptoms occur? What makes symptoms better or worse? Prognosis?
Angina pectoris--> temporary ischemic episode causes chest pain STABLE Angina -MOST COMMON -fixed or stable plaque 90% all cases Due to plaques that occlude / partially occlude 1 or more coronary arteries, causing ischemia Pain relieved by a few minutes of rest Stable for many years or may deteriorate into unstable angina VASOSPASTIC Angina "Rest angina"; "variant angina", "Prinzmetal's angina" Due to reversible spasm of coronaries, usually at site of a plaque May occur during sleep Can deteriorate into unstable angina UNSTABLE Angina -unstable plaque Increased frequency & severity Due to repeated episodes of diminished blood flow from plaques, platelet aggregation, or vasospasm Often the immediate precursor of an MI & is a medical emergency
Compare and contrast angioplasty with CABG. What does CABG stand for?
Angioplasty: - thread catheter to occluded blood vessel & inflate balloon to compress plaque - acts like a drain snake kinda but causes damage to endothelial layer ▪ Without stent ▪ With stent - metal mesh that stays in there after balloon is inflated to keep vessel open stents will get occluded again Coronary artery bypass graft (CABG). - graft from leg take leg vessel attach one point to aorta and other to muscle bypassing occlusion - lasts longer, more permanent, but needs open heart surgery both help treat coronary artery disease repairing vessels
semilunar valve function
Aortic semilunar valve lies between the left ventricle and the aorta>aortic valve Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk>pulmonary valve Semilunar valves prevent backflow of blood into the ventricles
Compare and contrast Arteriosclerosis and Atherosclerosis.
Arteriosclerosis= any change in the normal structure of arteries Loss of elasticity Thickening of the artery walls Narrowing of the lumen Happens as we age, and in diabetes Atherosclerosis= depositing of fat into the endothelial layer of the arteries, causing plaques Atherosclerosis - specific type of Arteriosclerosis Arteriosclerosis - thickening/stiffening of arteries Artherosclerosis artery wall thickens - specifically bc of accumulation of fatty materials formation of fibrous plaque in lining of large and medium-sized arteries the aorta and its branches the coronary arteries, the cerebral arteries
Compare and contrast an Atrial Flutter with Atrial Fibrillation.
Atrial flutter (Aflutter): HR= 250-350 BPM Ventricles respond to every 2nd or 3rd impulse Both atrial and ventricular rhythm are regular Usually caused by re-entry Symptoms: ▪ Heart palpitations, shortness of breath, chest tightness, fatigue and dizziness Atrial fibrillation (Afib): Multiple ectopic foci atria quiver 350-600 BPM Ventricle responds to an occasional impulse CO compromised as the ventricles don't have enough time to fill Symptoms: ▪ Heart palpitations, shortness of breath, chest tightness, fatigue and dizziness
Define mean arterial pressure (MAP) and show the mathematical relationship of the two main parameters influencing MAP.
Average pressure driving blood forward into tissues throughout cardiac cycle MAP = CO x TPR
blood flow through the heart
Blood enters right atrium from superior and inferior venae cavae. 2 Blood in right atrium flows through right AV valve into right ventricle. 3 Contraction of right ventricle forces pulmonary valve open. 4 Blood flows through pulmonary valve into pulmonary trunk. 5 Blood is distributed by right and left pulmonary arteries to the lungs, where it unloads CO2 and loads O2. 6 Bloodreturnsfromlungsviapulmonary veins to left atrium. 7 Blood in left atrium flows through left AV valve into left ventricle. 8 Contraction of left ventricle (simultaneous with step 3 ) forces aortic valve open. 9 Bloodflowsthroughaorticvalveinto ascending aorta. 10 Blood in aorta is distributed to every organ in the body, where it unloads O2 and loads CO2. 11 Blood returns to heart via venae cavae.
Define autoregulation of blood flow
Blood vessels undergo autoregulation vasodilation or vasoconstriction ▫ No involvement from CNS or hormones ▫ Respond to local chemical and physical changes (ex. stretch= Myogenic response)
What is the relationship between a pressure gradient and flow?
Blood will always flow from an area of high pressure to an area of low pressure F = ΔP/R F = flow rate of blood through a vessel ΔP = pressure gradient R = resistance of blood vessels • Ohm's law
What is a pressure gradient?
Blood will always flow from an area of high pressure to an area of low pressure • Pressure gradient can be adjusted by: ▫ ↑ Pressure to overcome resistance ↑ force of heart contraction ▫ ↓ Pressure in the tissue or organ --> ↓ Resistance F = ΔP/R F = flow rate of blood through a vessel ΔP = pressure gradient R = resistance of blood vessels • Ohm's law
What is C-reactive protein? Why is it used to determine the relative risk of cardiovascular disease?
C-reactive protein: general marker of inflammation and infection
Name the five main types of lipoproteins and describe some of their prominent roles.
CHYLOMICRONS - Largest of lipoproteins -synthesized in the wall of the small intestine -rich in triglycerides(triacylglycerols) -transfer their triglycerides to peripheral tissues, especially adipose tissue and skeletal muscle, for energy and storage -remnant chylomicron particles, which contain cholesterol, are then taken up by the liver and the cholesterol is used in the synthesis of VLDL or excreted in the bile. 2. VLDL -carry their triglycerides to fat and muscle cells, where the triglycerides are removed resulting in IDL particles 3. IDL are reduced in triglyceride content , enriched in cholesterol, then taken to the liver and recycled to form VLDL or converted to LDL. 4. LDL main carrier of cholesterol. ~60% is transported back to the liver where it binds and is internalized 40 carried to extra hepatic tissues which internalize them and use them in synthesis of their cell membranes and steroid hormones 5. HDL -synthesized by several pathways -direct secretion by the intestine and liver -transfer of lipid constituents released during lipolysis of lipoproteins that contain apo-B100 - Retrieves cholesterol from periphery, and returns it to liver -helps with clearance of cholesterol from atheromatous plaques and transports it to the liver, where it may be excreted rather than reused in the formation of VLDL
How are chordae tendineae related to papillary muscles?
Chordae tendineae anchor AV valves to papillary muscles
chronotropy
Chronotrophy= affecting time or rate • Sympathetic system: ▫ ↑HR Positive chronotropic effect • Parasympathetic system: ▫ ↓HR Negative chronotropic effect
Name some factors that increase myocardial oxygen demand
Elevated pressures during systole
Endarterectomy
Endarterectomy: removal of the intimal layer of the artery affected by peripheral artery disease
Explain the different types of aortic aneurysms
Fusiform: Vessel weakened on both sides and pressure exerted outward Saccular: Bulging wall on one side of the vessel Dissecting: When the intima is torn This allows blood flow between the layers of the artery
Liquids (and gases for that matter) flow from areas of _________________ pressure to areas of _________________ pressure.
HI --> LO
Murmur
Heart murmurs are abnormal sounds within the heart due to turbulent blood flow &/or Valvular abnormalities
Cardiac Arrhythmias
Improper beating of the heart, whether irregular, too fast, or too slow.
What organism is usually involved in the development of rheumatic heart disease?
Inflammatory condition where there is an abnormal immune response to an untreated bacterial infection Usually a group A beta hemolytic strep infection Antibodies attack the collagen in the skin, joints, brain, heart, and heart valves Pt presents w/ URI, sore throat, and tonsillitis
Compare and contrast Left-sided heart failure with Right-sided heart failure in terms of pathophysiological mechanisms and symptoms
LEFT Left ventricle is unable to pump sufficient blood to keep up with the metabolic demands on the heart Decreased CO Blood backs up into the pulmonary circulation pulmonary edema Pt has symptoms of shortness of breath (dyspnea), orthopnea, and cough Limits pts activities Pt requires several pillows in order to be able to sleep Left ventricular hypertrophy and/or cardiomegaly RIGHT Right ventricle is unable to pump all of the blood it receives ↓ CO-> activates compensatory mechanisms Blood backs up into the systemic circulation: Peripheral edema pitting edema Ascites Hepato and splenomegaly Distended neck veins Headache Cerebral edema Medical emergency, need to prevent this from happening treated same Diuretics Digoxin LVAD or BIVAD Heart transplant
How does the cardiovascular system create a region of higher pressure?
Liquids and gases flow down pressure gradients from regions of high to low pressure.
Use the equation mean arterial blood pressure = cardiac output × total peripheral resistance to explain the regulation of arterial blood pressure
MAP = CO x TPR TPR is determined by 1. Blood viscosity 2. Vessel length the longer the vessel ↑the resistance 3. Vessel radius or diameter CO determined by SV & HR
diastolic pressure
Minimum arterial BP taken during diastole(relaxing state)
Which type of DVT increases the risk of developing a pulmonary embolism?
Most PE's originate from deep veins of the lower extremities Risk of a DVT becoming a PE ↑ the more proximal the DVT (i.e. above the knee)
Is a myocardial infarction the same thing as cardiac arrest? If not, why not? Explain the differences.
NO. A heart attack is when blood flow to the heart is blocked, and sudden cardiac arrest is when the heart malfunctions and suddenly stops beating unexpectedly.
In the myocardial contractile cell, the rapid depolarization phase is due to the entry of ________.
Na+
mechanisms responsible for short-term regulation of blood flow
Nervous system • Medulla oblongata: ▫ Vasomotor center: -Sympathetic innervation to the heart and blood vessels -The integrating center for 3 reflexes: Baroreceptor reflex Chemoreceptor reflex Medullary ischemic reflex ▫ Cardioinhibitory center: Parasympathetic innervation to the heart ^sympathetic = vasoconstriction Decrease sympathetic = vasodilation inc BP = arterial wall stretch =simulation of baroreceptors in large arteries=inc impulse to brain • Endothelial cell control: ▫ Secrete vasoactive substances: Nitric Oxide (NO) Endothelin ▫ Stimulate angiogenesis Collateral circulation ▫ Modulates capillary permeability Changing pore size • Vasoconstrictors: ▫ Epinephrine ▫ Norepinephrine ▫ Angiotensin I and angiotensin II*** ▫ Serotonin ▫ Vasopressin (ADH) • Vasodilators: ▫ Histamine ▫ Bradykinin ▫ Prostacyclin (PGI2)
total peripheral resistance
Opposition of blood flow through a vessel ▫ Depends on 3 things: 1. Blood viscosity 2. Vessel length - the longer the vessel -->↑the resistance 3. Vessel radius or diameter • Turbulence of blood flow can also ↑ TPR ▫ Major determinant= vessel's radius ▫ Slight change in radius ↑ change in blood flow Arterioles are the major determinants of TPR
Describe the different stages of heart block.
Partial blocks: -First degree: prolongation of PR interval->↑time between atrial and ventricular contractions -Second degree: longer delay->leads to missed ventricular contraction -Third degree or total heart block: NO transmission from the atria to the ventricles Ventricles have to take over as pacemakers of the heart However, they are much slower 30-45 BPM Severely compromised CO leads to syncope May lead to a cardiac arrest Pt will need a pacemaker
Compare and contrast the pulmonary with the systemic circulations.
Pulmonary circulation receives un-oxygenated blood and replenishes the oxygen through the lungs. Systemic circulation receives oxygenated blood and circulates it throughout the body.
Write the mathematical expression that relates resistance and the radius of a blood vessel. When the radius of a blood vessel increases or decreases, what happens to the resistance of that blood vessel? What happens to flow through that blood vessel if its radius changes?
R is proportional to 1/r^4 ↓radius or diameter of blood vessel -->↑friction--> ↑↑ R
Valvular regurgitation
Regurgitation occurs when blood flows back through the valve
Write the mathematical expression that relates flow and resistance. What happens to flow when resistance increases? What happens to flow when resistance decreases?
Resistance opposes fluid blood flow F = ΔP/R F = flow rate of blood through a vessel ΔP = pressure gradient R = resistance of blood vessels
Where do electrical signals in the heart originate?
SA node
What symptoms are associated with bi-ventricular heart failure?
SOB pitting edema fatigue
What are some of the most common ECG changes observed in patients that have suffered an MI?
ST elevation or depression
Describe the Frank-Starling law of the heart.
SV∝ EDV ▫ ventricles eject as much blood as they receive ▫ the more they are stretched, the harder they contract
Sick Sinus Syndrome
Sick sinus syndrome: Alternating bradycardia and tachycardia Requires a pacemaker
What kind of information may be gathered regarding cardiovascular function with the following diagnostic tests? Stress test
Stress tests: assesses general cardiovascular function, including how the heart responds to stress (or ↑ demands) May or may not involve injecting a radioisotope (ex: thallium) Two types: ▪ Exercise: bicycle, stairs, or treadmill ▪ Non-exercise: uses drugs like adenosine and persantine to simulate what happens in the heart during exercise
afterload
The "load" the heart has to push against in order to eject the blood from the ventricles • Blood pressure in the aorta and pulmonary trunk
inotropy
The ability of the heart muscle to generate force during myocardial ventricular contraction Positive inotropic agents ↑ contractility Include: Hypercalcemia Catecholamines and sympathetic stimulation Negative inotropic agents. ↓contractility Include: Hypocalcemia Hyperkalemia Parasympathetic stimulation
cardiac output
The volume of blood ejected by the ventricles per 1 minute ~5L at rest ↑with Sympathetic stimulation and exercise
stroke volume
The volume of blood pumped by the ventricles per beat (or per systole) SV= EDV-ESV ~70 ml at rest SV can be increased during periods of ↑metabolic demand Factors that Affect Stroke Volume 1. Inotropy= contractility 2. Preload 3. Afterload
What is the purpose of AV node delay?
This activates the AV node
Explain the differences between a DVT and a superficial thrombophlebitis.
Thrombophlebitis Development of a thrombus in a vein where inflammation is present Usually happens in the superficial vessels DVTs: Blood clots that occur in the deep vessels of the leg Fibrin rich clot treated with anticoagulants Antiplatelet agents are ineffective Postthrombotic syndrome occurs in 40-80% of patients with DVT
Describe mechanisms involved in the actions of vasoactive substances including Angiotensin II
Vasoconstrictors: ▫ Epinephrine ▫ Norepinephrine ▫ Angiotensin I and angiotensin II*** ▫ Serotonin ▫ Vasopressin (ADH) • Vasodilators: ▫ Histamine ▫ Bradykinin ▫ Prostacyclin (PGI2)
What are three factors that affect venous return? Name them and briefly describe how they influence venous return.
Venous BP alone is too low to promote adequate blood return and is aided by the: Respiratory "pump": Pressure changes created during breathing Muscular "pump": Contraction of skeletal muscles in the legs "milk" blood toward the heart Valves in the veins prevent backflow during venous return
Ventricular hypertrophy
Wall thickness
Tachycardia
abnormally rapid heart rate
Bradycardia
abnormally slow heart action
The highest pressure in the blood vessels is found in the ______________________ and the lowest pressures are found in the _____________________________________.
aorta / vena cavae
Describe in detail how arteries differ from veins.
arteries have more muscle for diameter veins have valves, arteries don't Veins go to the heart, arteries flow away from the heart
The ____________________ are the lower chambers and the ____________________ are the upper chambers. Which chambers have the thickest walls?
atria are higher ventricle lower - thicker walls
Turbulent blood flow
blood does not flow linearly and smoothly in adjacent layers, but instead the flow can be described as being chaotic
Compare and contrast Angina Pectoris and Myocardial Infarction.
both coronary heart diseases Angina pectoris--> temporary ischemic episode causes chest pain no scar tissue formed - no permanent damage only partial occlusion Myocardial infarction (MI) actual damage of the myocardium due to a coronary vessel occlusion ▪ Myocardial cells get replaced by scar tissue full occlusion
The rapid depolarization phase in pacemaker cells is due to the entry of _________.
calcium
The repolarization phase in autorhythmic cells is due to _____________. How does this compare to a contractile cell?
calcium
State the formula for calculating the cardiac output
cardiac output = stroke vol x heart rate
Define systole
contracting and pumping blood into arteries
As blood moves away from the heart, what happens to the pressure? Why?
declines b/c further from ventricle = lower the force Pressure decreases due to friction
Consumption of Omega 3 fats have been identified as a potential cardioprotective strategy, why?
decrease risk of arrhythmias decrease triglyceride levels, slow growth rate of atherosclerotic plaque lower blood pressure (slightly
Blood is flowing through a vessel at a constant rate of flow. What happens to the velocity of flow if the vessel suddenly narrows?
decreases; v=Q(flow rate)/A(area)
Describe the cardiac reserve and relate it to the Frank-Starling mechanism
difference between the rate at which the heart pumps blood and its maximum capacity for pumping blood at any given time
pulse pressure
difference between the systolic and diastolic blood pressure
Dyspnea
difficult/labored breathing
Diagram the mechanism for E-C coupling in cardiac muscle. Why is this also called Ca2+-induced Ca2+ release?
entry of small amount of Ca2+ causes lots of Ca2+ to be released
Describe the structure and function of the capillaries.
exchanges between blood and tissue one layered walls (unlike vein&artery)=faster exchange 3 types continuous -endothelial cells closely joined -lack of intercellular channels in CNS caps creates Blood brain barrier fenestrated -mucoprotein layer restricts passage of molecules (mostly proteins) through large pores discontinuous large distance between endothelial cells look like little cavities
What cell structures allow electrical signals to spread quickly to adjacent cells?
gap junctions
What are the chordae tendineae and what is their function
group of tough, tendinous strands in the heart holding the atrioventricular valves in place while the heart is pumping blood
Cardiomegaly
heart enlargement
What are ectopic beats? Why do they result in cardiac arrhythmias?
heartbeats outside the normal rhythm
What is hypertension
hi blood pressure Diagnosis requires repeated measurements of elevated BP ▪ Normal BP <120 mmHg systolic and <80 mmHg diastolic ▪ Prehypertension= systolic 120-139 mmHg or diastolic 80-89 mmHg ▪ Mild HT = > 140/90 even in young / middle age causes organ damage ▪ Severe HT = >160/100 Risk of hypertension varies with age (pre- menopausal women - low risk), race (African- Americans - high risk) Asymptomatic until organ damage has occurred Damages kidneys, heart, brain Leads to renal failure, CAD, cardiac failure, stroke Risk factors include smoking, hyperlipidemia, diabetes, excessive alcohol intake, and obesity Clinical trials prove that lowering BP prevents vessel damage, morbidity, and mortality ETIOLOGY Identifiable in only 10-15% cases Nonetheless should be investigated to identify those cases with a surgically correctable cause "Essential hypertension" = no identifiable cause
What happens to the pressure exerted on blood when the heart contracts?
high
Why is HDL considered to be the "good cholesterol"
high density = less fat and more denser protein takes away LDL deposited in vessels
explain the effects that venous return, cardiac contractility, and heart rate have on cardiac output
increase = increase increase in venous return = increase in preload which contributes to stroke volume which contributes to CO increase in contractility contributes to stroke volume which contributes to CO CO=HR HR=SV * BPM
Myocarditis
inflammation of the myocardium ▪ May lead to arrhythmias
Pericarditis
inflammation of the outer layer of the heart, and may involve a pericardial effusion impairs the heart's ability to fill with blood
Why do patients with diabetes have an increased risk of cardiovascular disease
insulin resistance and the hyperinsulinemia that occurs in persons with diabetes contribute to hypertension also causes secondary hyperlipidemia ischemia is observed in persons with diabetes mellitus, probably the result of autonomic neuropathy, which is a common complication of diabetes
What are intercalated disks? What role do desmosomes and gap junctions play?
intercalated discs support synchronized contraction of cardiac tissue Gap junctions allow action potentials to spread between cardiac cells by permitting the passage of ions between cells, producing depolarization of the heart muscle. desmosomes hold the cells together and to which the myofibrils are attached
What happens to pressure exerted on the blood when the heart relaxes or the blood vessels dilate?
lo
Heart valve replacements maybe thrombogenic and some require that the patient be anticoagulated for the rest of their life. What types of heart valves are more thrombogenic?
mechanical prostheses are more thrombogenic and require lifelong anticoagulant therapy
Endocarditis
most common. Affects the heart valves ▪ Verrucae form >>>valve damage
Is the heart in atrial and ventricular systole at the same time? Explain
no Atrial systole occurs while ventricles are in diastole. Atrial diastole occurs while ventricles are in systole
Atheroma
plaque within blood vessels containing lipids, cells, fibrin, and/or thrombi on their surface
Why are patients that have suffered a heart attack treated mostly with antiplatelet agents
prevent blood clotting
Aspirin is prescribed to patients that have already had a heart attack to prevent a second heart attack, why
prevents damage from clots don't want any more damage and you now know you are susceptible
What is HMG-CoA reductase and what is its role in cholesterol symthesis? Name the class of drugs that inhibits this enzyme and give one example.
rate controlling enzyme in cholesterol synthesis converts HMG CoA to mevalonate statins inhibit =less cholesterol made ex. lipitor
venous return
rate of blood flow back to the heart
Define venous return. What cardiac volume does it determine?
rate of blood flow back to the heart determines stroke volume
Define diastole
relaxing/filling of chambers
The left and right sides of the heart are separated by a wall known as the _______________.
septum
characterize mechanisms responsible for short-term and long-term regulation of blood flow
short term. - nervous system/chemicals blood vessel diameter heart rate contractility long term - regulate blood volume -kidneys
Clubbed fingers
symptomatic of valvular disease
Laminar blood flow
the normal condition for blood flow throughout most of the circulatory system flows in parallel layers can't be heard ususally
The heart is a muscle that lies in the center of the __________________ cavity, surrounded by a membrane called the _________________________.
thoracic, pericardium
What factors insure the unidirectional flow of blood in the cardiovascular system?
valves A system of valves in the heart and in the veins
Define the term hemodynamics
variables that govern blood flow 2 main 1. Pressure gradient: Fluid flows down its pressure gradient 2. Resistance --> opposes fluid blood flow
Define vasoconstriction and vasodilation in terms of diameter and resistance
vasoconstriction = lo diameter hi resistance vasodilation = hi diameter lo resistance
Verrucae
vegetation
What causes varicose veins?
venous congestion stretches the veins to the point that the valves no longer close effectively
Define end-diastolic volume (EDV).
volume of blood in the right and/or left ventricle at end load or filling in or the amount of blood in the ventricles just before systole.
Cardiac tamponade
when so much pericardial effusion develops that CO is severely compromised Acute tamponade>distended neck veins Chronic tamponade >heart enlargement as a compensatory mechanism
If the SA node is damaged, will the heart continue to beat? At the same rate? Explain.
yea, atrioventricular node (AV node) should take over the pacemaker function
If you cut all nerves leading to the heart, will it continue to beat? Explain.
yes, The heart itself has a natural pacemaker, the sinoatrial node, which does not need a nervous supply to function self excitable has its own nerves
Use the term compliance to describe the characteristics of arterial and venous blood vessels.
• C = V/P ▫ A change in volume (V) causes < of an ↑ in transmural pressure (P) in a more compliant vessel ▫ A vein is 24 times more compliant than its corresponding artery.
Explain the forces that control the fluid exchange between the capillaries and the interstitial spaces.
• Four opposing forces: ▫ Blood hydrostatic pressure drives fluid out of capillary ↑ on arterial end of capillary, ↓ on venous end ▫ Interstitial fluid hydrostatic pressure ▫ Blood colloid osmotic pressure (COP)= oncotic pressure ->draws fluid into capillary -plasma proteins -Interstitial fluid colloid osmotic pressure
Relate the performance of chemoreceptors in the control of cardiovascular function.
• Located in: ▫ Carotid artery ▫ Aortic artery • Sensitive to: ▫ ↓O2 or ↑CO2 ▫ ↑H+ • Main function --> ↑respiration ▫ Also ↑BP via activation of vasomotor center
Relate the performance of baroreceptors in the control of cardiovascular function.
• Stretch-sensitive receptors • Monitor blood pressure • Important in short-term regulation of BP ▫ Postural changes • Baroreceptors adapt to chronic high or low BP NOT useful for long-term BP regulation
Explain the effects of exercise on cardiovascular function
• ↑Perfusion to working muscles • Accomplished by: ▫ ↑BP ▫ ↓TPR • Cortex Medulla Vasomotor center Activates sympathetic stimulation
State the relation between blood volume and blood pressure in arteries, veins, and capillaries of the circulatory system.
•Any fluid driven by a pump through a circuit of closed channels operates under pressure, and the nearer the fluid is to the pump, the greater the pressure exerted on the fluid. The dynamics of blood flow in blood vessels is no exception, and blood flows through the blood vessels along a pressure gradient, always moving from higher- to lower-pressure areas. Arteries must be able to endure high pressure of blood, from the aorta to the ends of the arterioles is about 60 mm Hg Capillaries are fragile and high pressures would rupture them, and most capillaries are extremely permeable and thus even the low capillary pressure forces solute-containing fluids (filtrate) out of the bloodstream into the interstitial space. Venous blood pressure is steady and changes very little during the cardiac cycle. The pressure gradient in the veins, from venules to the termini of the venae cavae, is only about 15 mm Hg •Arteries receive blood from the heart, the blood they receive is under a lot of pressure. Can you picture how much pressure the arteries near the heart (like the pulmonary trunk and the aorta) have to withstand every time the ventricles squirt out a load of blood? At the same time, this pressure helps the blood move through the arteries-- even when the arteries are running in opposition to gravity •The veins only receive the blood after it has travelled quite far from the heart. The blood pressure in the veins is thus much less; the blood is certainly much less likely to burst through walls of the veins than arteries. Also, because the blood pressure is small in the veins, it is not going to be enough to return all that blood to the heart; in fact, the blood could easily back up or collect in these vessels
Describe the roles of the cardioinhibitory center in controlling the function of the heart and blood vessels
▫ Cardioinhibitory center: Parasympathetic innervation to the heart
systolic pressure
▫ Systolic pressure: Peak arterial BP Taken during ventricular contraction (ventricular systole)
Describe the roles of the medullary vasomotor center in controlling the function of the heart and blood vessels
▫ Vasomotor center: -Sympathetic innervation to the heart and blood vessels -The integrating center for 3 reflexes: Baroreceptor reflex Chemoreceptor reflex Medullary ischemic reflex