Patho Lecture 3: Ch. 16, 18, 19 & 20
What is stenosis?
-a murmur will be heard when the valve is open -caused because valves don't OPEN ALL the way, so it is harder for blood to forces its way thru
What is regurgitant?
-a murmur will be heard when the valve should be closed -valves do not CLOSE ALL the way; it leaks when it should be closed -valves are meant to prevent backflow
What are some valve defects?
-blood going thru defective valves makes noise, called heart murmurs -heart murmurs can be identified based on: where they are (near which valve) how they sound (high, low pitch) when they happen (systole or diastole) stenosis regurgitant
How can vasdilation affect blood pressure?
by decreasing peripheral resistance (PR) which causes a decrease in blood pressure
How can decrease stretcing of baroreceptors affect blood pressure?
by turning on the SNS which increases heart rate and vasoconstriction, resulting in high blood pressure
How can hypoxia affect blood pressure?
by turning on the SNS which increases heart rate and vasoconstriction, resulting in high blood pressure
If arteries lose their elasticity and become more rigid, blood pressure increases or decreases?
-blood pressure will increase if arteries become more rigid
Describe coronary heart disease
-aka ischemic heart disease and coronary artery disease -characterized by insufficient delivery of oxygenated blood to the myocardium (ischemia) bcuz of atherosclerotic coronary arteries (CAD) -atherosclerosis causes progressive narrowing of the arterial lumen -abnormal lipid metabolism like LDLs (are high in cholesterol) are the greatest contributor to CHD; while HDLs help to decrease risk of atherosclerosis by removing plaque (remember that lipid filled microphages are called foam cells; foam cells are created when LDLs leak into the endothelium and into vessel walls where they are oxidized by endothelial cells and microphages. microphages and foam cells release inflammatory responses and GF (growth factors) which cause more WBCs to be called and essential make aterial obstuctions -can also be caused by thrombus formation, coronary vasospasm, endothelial cell dysfunction -there are 2 types of coronary heart disease 1. acute coronary heart syndrome which represents spectrum of ischemic coronary disease ranging from unstable angina thru myocardial infarction 2. chronic ischemic heart disease
What is afterload/ systemic vascular resistance?
the pressure required to overcome the blood pressure in the aorta or the pressure required to open the aortic valve -are you vasoconstricted or vasodilated in the the systemic circulation
Describe the blood flow through the heart
1. Superior & Inferior Vena Cava --> 2. Right Atrium --> 3. Tricuspid Valve --> 4. Right Ventricle --> 5. Pulmonary Valve --> 6. Pulmonary Artery --> 7. LUNGS = OXYGENATION / GAS XCHG --> 8. Pulmonary Veins --> 9. Left Atrium --> 10. Mitral Valve --> 11. Left Ventricle --> 12. Aortic Valve --> 13. Aorta --> 14. BODY The blood first enters the heart into the right atrium. Blood passes from the right atrium through the tricuspid valve and into the right ventricle. When the right ventricle contracts, the muscular force pushes blood through the pulmonary semilunar valve into the pulmonary artery. The blood then travels to the lungs, where it receives oxygen. Next, it drains out of the lungs via the pulmonary veins, and travels to the left atrium. From the left atrium, the blood is forced through the mitral valve into the critically important left ventricle. The left ventricle is the major muscular pump that sends the blood out to the body systems. When the left ventricle contracts, it forces the blood through the aortic semilunar valves and into the aorta. From here, the aorta and its branches carry blood to all the tissues of the body. 1. Your AORTA pumps OXYGENATED blood out of your heart to your body The aorta stretches across the back of your heart and pumps blood both above and below your heart to your upper and lower body As oxygenated blood goes to your cells, it drops off oxygen and picks up waste Cells in your body need oxygen so that they can perform cellular respiration to get energy Blood also picks up carbon dioxide from the cells as the waste product of cellular respiration 2. DEOXYGENATED blood returns to your heart through the SUPERIOR VENA CAVA and INFERIOR VENA CAVA to your RIGHT ATRIUM Capillaries separate oxygenated blood from deoxygenated blood and arteries from veins After passing through the capillaries, blood is deoxygenated and needs to head back to the heart to be pumped to the lungs to pick up oxygen The Superior Vena Cava is the vein that gets deoxygenated blood from the upper body and returns it to the heart The Inferior Vena Cava is the vein that gets deoxygenated blood from the lower body and returns it to the heart 3. Your heart beats to the signals of the SA NODE and AV NODE as the right atrium pumps it to the RIGHT VENTRICLE From the superior and inferior vena cava, blood goes through the Right Atrium First, the SA Node (sinoatrial node) (pacemaker) sends electrical signals to pump blood from right atrium to right ventricle Then, as blood enters the right ventricle, the AV Node (atrioventricular node) receives a signal to act as the gateway to the right ventricle and control the speed of blood flow there The SA and AV node combine to make the 'ba-bum' sound of your heartbeat Blood goes through the tricuspid valve/right AV valve (makes sure blood flows in only one direction) as it enters the right ventricle 4. Your RIGHT VENTRICLE pumps deoxygenated blood up to your PULMONARY ARTERY, where it heads to lungs to pick up oxygen First, the right ventricle pumps blood through your Pulmonary Valve (makes sure blood flows in only one direction) Then, the Pulmonary Artery carries the blood away from the heart to the lungs for oxygen 5. DEOXYGENATED blood BECOMES OXYGENATED and drops off waste Deoxygenated blood becomes oxygenated and arteries become veins in the capillaries In the lungs, capillaries are tied around alveoli, which are little sacks storing the oxygen that we inhale Oxygen is transferred into the blood and waste is transferred out of the blood through the capillaries 6. Oxygenated blood leaves the lungs and returns to the heart through the PULMONARY VEINS and enters the LEFT ATRIUM Now that it's oxygenated, it's ready to go and get pumped back to the body! 7. The LEFT ATRIUM pumps blood to the LEFT VENTRICLE, and then it is pumped to the AORTA to do the same thing ALL OVER AGAIN (see step 1) As it goes from left atrium to left ventricle, blood passes through the bicuspid valve/left AV valve (makes sure blood flows in only one direction) Blood then is pumped from left ventricle through the aortic valve (makes sure blood flows in only one direction) back into the aorta to repeat the whole cycle again
What are some disorders that usually appear to affect the whole heart?
1. pericardial disorders 2. coronary heart disease 3. myocardial diseases
Describe the stages of pericarditis
1. pericardial effusion fills up the pericardial cavity 2. causes the heart to not be able to expand 3. if left ventricle can't expand , the left ventricle cannot accept blood as a result which causes it to decrease in cardiac output which means it can't pump out enough blood which causes a decrease in blood pressure and shock 4. the right ventricle cannot accept blood it will backup and as a result it will increase venous pressure which causes jugular distension
What are the different types of angina (chest pain)?
1. stable angina: will experience pain when heart's oxygen demand increases 2. variant angina: pain when coronary arteries spasm 3. silent myocardial ischemia (oxygen is deprived form the heart): this is myocardial ischemia without pain
How many types of hypertension are there?
2 types: 1. Primary or Essential Hypertension: diagnosed with high blood pressure in the absence of an identifiable cause ; most common accounting for 90-95% of hypertensive cases 2. Secondary Hypertension: diagnosis attributed to a specific identifiable pathology or condition ; least common accounting for 5-10% of hypertensive cases ; many of the conditions causing secondary hypertension can be corrected or cured by surgery or medical treatment
Ways to tell if someone had a heart attack and they had no symptoms, this can be used
Changes in ECG like the T wave will be inverted, the ST segments will be elevated or depressed, and abnormal Q wave -serum cardiac markers which are cardiac proteins released from necrotic (dead) heart cells like myoglobin, creatine kinase, troponin
Slight vasodilation in an arteriole prompts a ________.
huge decrease in resistance
Describe the cardiac cylce
left side 1.after blood has filled the left ventricle, it contracts (systole) 2. the seminlunar: aortic valve opens which causes the biscupid valve to close 3. first heart sound "lub" right side 1. after the right ventricle relaxes, blood fills the ventricle (diastole) 2. the triscupid valve opens which causes the semilunar valve: pulmonary valve to close 3. second heart sound "dup"
What are some causes of secondary hypertension?
-renal hypertension: means something is wrong with the kidneys: caused by drop in renal blood flow resulting in excessive release of renin, which activates the RAA system, which causes peripheral vasoconstriction and sodium retention (all three cause an increase in BP) -adrencortical disorders: excess aldosterone and gluccorticoids (cortisol) production, increasing sodium and water retention -coarctation of the aorta: narrowing of the aorta, thus ejection of large stroke volume into narrowed aorta increases systolic BP ; surgery is required -obesity/obstructive sleep apnea -pregnacy
What is diastolic blood pressure?
-lowest pressure during diastole (The period of relaxation that occurs as the chambers fill with blood is called diastole) ; measured in mm Hg -occurs at the end of diastole, just before the next ventricular contraction -once aortic valve closes, the left ventricle can relax and be filled with blood from the left atrium -reflects closure of the aortic valve, the energy stored in elastic fibers of the large arteries and the resistance to flow through arterioles into the capillaries
Coronary heart disease, and its greatest contributor, atherosclerosic plaque blocks the coronary arteries which leads to ischemia. What symptoms will ensue?
-angina -myocardial infarction (heart attack) -cardiac arrhythmias (irregular heart beat) -conduction deficits -heart failure -sudden death
Why are preload/EDV and afteload/systemic vascular resistance important?
-because our heart's stroke volume is dependent on both ; stroke volume of blood pumped out of the heart per beat, this is dependent on contraction of the ventricles, preload and afterload
How can beta blockers affect blood pressure?
-beta blockers (adrenergic-beta blockers): remember to associate "adrenergic" with the SNS, so it block the SNS effect on the heart thereby decreasing heart rate &contractility which result in decreased blood pressure
What happens if a person has right-sided heart failure?
-blood isn't pumped effectively thru the right ventricle to the lungs, causing blood to back up into the right atrium and the peripheral circulation -symptoms: person might gain weight and develop peripheral edema and engorgement of the kidney and other organs -this means that there is a valve defect (regurgitation or stenosis) in the either the tricuspid valve or pulmonary valve which means that blood will back flow and cause peripheral signs like issues with legs, arms,etc. -usually caused by left-sided heart failure
Describe acute myocardial infarction due to reduced oxygen to heart
-due to reduced oxygen to heart one may suffer from acute myocardial infarction -this can cause symptoms such as: 1. chest pain -severe, crushing, constrictive, like heartburn 2. SNS response -body is in panic mode so there will be GI distress, nausea, vomiting -tachycardia and vasoconstriction -anxiety, restlessness and feeling of impeding doom 3. hypotension and shock -weakness in arms and legs
Describe primary/essential hypertension.
-elevated BP -cause is idiopathic -most common form (accounts for 90-95% of all cases) -Has 3 Subtypes 1. isolated systolic hypertension 2. isolated diastolic hypertension 3. combined systolic and diastolic hypertension -high systolic blood pressure is a major risk factor for subsequent cardiovascular disease -make lifestyle modifications, like weight reduction in overweight, DASH diet: high fruits and vegetables and low-fat dairy products, decreased sodium intake, exercise and moderate intake of alcohol
What affect does calcium channel blockers have on BP?
-essentially it slows the heart rate to decreases work load in the heart and cause vasodilation which lowers blood pressure -calcium channel blockers prevents Ca2+ from entering smooth muscles so they will not contract as forcefully which causes vasodilation and decrease in PR -Ca2+ entering cardiac muscle will cause a decrease in heart rate -both cause decrease in blood pressure
What affect does inhibiting angiotensin-converting enzyme (ACE) have on BP?
-essentially it will cause a drop in blood pressure because it can't convert renin and angiotensin I to angiotensin II which means aldosterone cannot be produced. the job of aldosterone is to increase BP -blocks Angiotensin II from occurring which causes a decrease in vasoconstriction, and decease in PR -aldosterone will not be secreted which causes water and sodium to not be reabsorbed which will cause blood pressure to not increase -essentially it does not allow angiotensin I to convert to angiotensin II, so that it can prevent the RAA system from occurring which is meant to raise blood pressure, so essentially we are truing to prevent that from happening
What is Secondary Hypertension?
-high BP attributed to a SPECIFIC identifiable pathology or condition -accounts for 5-10% of all hypertensive cases -unlike primary/essential hypertension, secondary hypertension can be corrected or cured by surgery or medical treatment
What is hypertension?
-high blood pressure: normal: systolic less than 120 ; diastolic is under 80 -increases morbidity (sick) and mortality (death) associated with kidney disease, peripheral vascular disease and stroke -more common in young men vs women (until menopause) , blacks than whites, lower socioeconomic groups than higher, aged vs younger people
What causes chronic ischemic heart disease?
-imbalance of blood supply and demand for oxygen what causes less blood going to the heart? -atherosclerosic plaque buildup -vasospasm of the smooth muscle surrounding the blood vessels which lead to vasoconstriction -thrombosis: blood clots that obstruct blood flow what causes higher oxygen demand? -stress -exercise -cold
What happens if a person has left-sided heart failure?
-ineffective left ventricular contractile function, as the pumping of the left ventricle fails, cardiac output falls and blood is no longer effectively pumped out into the body ; it backs up into the left atrium and then into the lungs, causing pulmonary congestion, dyspnea (difficulty breathing) and activity intolerance ; can also result in right-sided heart failure if condition persists the valves affect are the bicuspid valve and the aortic valve
What are some factors that influence mean arterial pressure?
-represents the "average" pressure of blood in the arteries, that is, the average force driving blood into vessels that serve the tissues -determined : 1. blood volume which is determined by fluid intake and fluid loss (fluid loss may be regulated by passive or regulated at kidneys) [more blood=higher blood pressure ; more fluid you take in the more blood volume which results in higher blood pressure] 2. effectiveness of the heart as a pump (cardiac output) which is determined by heart rate and stroke volume. [if heart rate increases, it causes cardiac output to increase which causes stroke volume to increase which means that blood pressure will increase ; if stroke volume decreases, cardiac output will decrease which will cause blood pressure to decrease] 3. resistance of the system to blood flow which is determined by the diameter of the arterioles [are arterioles vasodilated or vasoconstricted? if vasodilated then blood pressure will decrease; if vasoconstricted then blood pressure will increase] *recall that arterioles have a small lumen so their job is to dramatically slow the flow of blood from arteries ; their job is to transport blood from arteries to capillaries {blood flow goes to arteries then to arterioles then to capillaries ; under the control of the sympathetic nervous system, and constrict and dilate to regulate blood flow} (arterioles are the site of greatest resistance in the entire vascular network, more so than the capillaries) 4. relative distribution of blood between arterial and venous blood vessels which is determined by diameter of the veins
Describe shunts.
-shunt: an opening or connection/pathway that lets blood move from one side of circulation to the other -most shunts occur in the heart and move blood from either Left to Right OR Right to Left ; however since the left side of the heart is stronger, blood usually goes from left to right -in virto shunts move right to left 1. foramen ovale: blood goes from right to left atrium, bypassing the lungs (normal bcuz fetus gets oxygen from placenta of mother) 2. ductus arterisus: blood goes from the pulmonary trunk to aorta, bypassing the lungs (normal bcuz fetus gets oxygen from placenta of mother) 3. blood goes from visceral veins to vena cava, bypassing the liver
What are the essential hypertension manifestations?
-symptoms are usually related to long term effects of hypertension on organ systems of the body. damaged organs include: -heart: increased myocardial work results in heart failure ; left ventricular hypertrophy, angina (chest pain due to low blood flow to the heart) -brain: increased pressure in cerebral vasculature l hemorrhage, stroke, or transient ischemic attack -kidney: (a lot of filtration happens her) glomerul damage results in chronic kidney disease and failure -peripheral vascular disease (PVD) -eyes: affects microcirculation of the eyes -hypertension is a major risk factor for atherosclerosis and all major atherosclerotic cardiovascular disorders like heart failure, stroke, coronary and peripheral artery disease
Describe hypertrophy cardiomyopathy in more detail
-the left ventricle is thickened due to defects in their contractile protein causing the cells to be weakened -they hypertrophy to do the same amount of work as normal cells -because it is thickened there is less blood filled in the chamber -because there is less blood, more oxygen is needed and since there is hypoxia , the ventricle performs less efficiently, so it becomes more prone to heart failure, and sudden death during exertion
What is systolic blood pressure?
-the peak pressure during systole (The period of contraction (corresponds to the ejection of blood from the left ventricle into the aorta) that the heart undergoes while it pumps blood into circulation is called systole); measured in mm Hg -during ventricular contraction , the pressure in the aorta rises to an average peak value, that value is the systolic blood pressure -stroke volume (SV): think how much blood was ejected (initial - after) is the volume of blood pumped out by the heart to the atria per contraction; it is the primary factor affecting systolic blood pressure ; an increase in SV causes an increase in blood pressure; a decrease in SV causes a decrease in blood pressure
What is EDV/preload?
-the volume of blood in the cardiac chamber just before systole (end-diastolic volume) -the amount of blood present in the ventricles just before contraction -the load imposed on the ventricle at the end of diastole
What is compliance of the aorta and large arteries?
-think of a balloon its ability as a compartment to expand to accommodate increased content ; the greater the compliance of an artery, the more effectively it is able to expand to accommodate surges in blood flow without increased resistance or blood pressure. -Veins are more compliant than arteries and can expand to hold more blood. When vascular disease causes stiffening of arteries, compliance is reduced and resistance to blood flow is increased. The result is more turbulence, higher pressure within the vessel, and reduced blood flow. This increases the work of the heart. -expand by stretching allowing for more blood to be accommodated ; blood vessels with a higher compliance deform easier than lower compliance blood vessels under the same pressure and volume conditions Compliance of a vessel is the opposite of its elastance (recoiling back to original shape). The veins are said to be compliant because if you keep increasing the volume of blood in the veins, their walls will distend/expand by stretching allowing for more blood to be accommodated ; how easily your blood vessels stretch -the greater the compliance of the aorta and large arteries, the lower the blood pressure will be ; -a decrease in compliance, causes an increase in systolic pressure which means the heart has to work harder which can result in left ventricular hypertrophy -compliance decreases with age bcuz the aorta and large arteries lose elasticity
What are the risk factors associated with hypertension?
-uncontrollable risk factors family history of hypertension, race and age -lifestyle risk factors: high Na+ intake (water follows sodium and greater fluid intake , higher the blood volume, the greater the blood pressure, obesity, sedentary lifestyle, metabolic syndrome, excessive alcohol consumption, obstructive sleep apnea, oral contraceptives, smoking
What are left-sided valvular disorders?
1. mitral/bicuspid valve disorders -stenosis (narrowing, does not open properly, low-pitched rumbling diastolic murmur -regurgitation (blood leaking back/back-flow, high pitched blowing murmur, systole) -prolapse (think leaflet, does not close properly), may lead to regurgitation 2. aortic valve disorders -stenosis -regurgitation (high-pitched blowing murmur, diastole)
What do to if lifestyle modifications aren't reducing hypertension then...
-you will be put on anti-hypertension medication to reduce BP -these medications aim to reduce stroke volume, reduce systemic vascular resistance or decrease heart rate all of which will lower blood pressure -diuretics: decrease vascular volume, cardiac output (CO) and pulse rate (PR) by making you urinate; which urinating will cause a decrease in blood volume which will decrease blood pressure -beta-adrenergic receptor blockers: decrease heart rate, CO and renin release by kidneys (associate "adrenergic" w/sypathetic NS); essentially, this drug will block the SNS and will indirectly cause a decrease in blood pressure -ACE inhibitors: inhibit conversion of ANG I to ANG II, thus reducing ANG II's affect on vasoconstriction and aldosterone levels ; esstentialy stops the RAA system (renin-angiotensin-aldosterone) from functioning -angiotensin II receptor blockers: -calcium channel blockers: cause decrease in peripheral resistance by inhibiting movement of Ca2+ into arterial smooth muscle ; essentially the muscles require Ca2+ to contract, so by blocking Ca2+, muscles will not contract and this will cause vasodilation -central alpha 2-andrenergic agonists: when activated/turned on, alpha 2 will turn off the SNS ; decrease the sympathetic outflow (associate "adrenergic" w/sypathetic NS also agonists promote) ; essentially when alpha 2 adrenergic is turned on, its job is to turn OFF the SNS, so when it is given an agonist, it turns off the SNS even more -central alpha 1-andrenergic antagonists: cause vasodilation (associate "adrenergic" w/sypathetic NS) -vasodilators: like nitric oxide reduce pulse rate (remember that anything that medications that start with nitric are vasodilators)
How does body respond to changes in blood pressure?
1. Baroreptors senses changes in blood pressure 2. high blood volume leads to an increase in blood pressure (barrocrepots sense an increase in blood pressure, to compensate the body will lower blood pressure which will cause high blood volume to decrease 3. barorecptors will try to decrease blood pressure to go down 4.there are 2 ways that the baroreceptors will try to decrease- fast response by using the cardiovascular system (A) or slow response by using the renal system with the kidneys(B) -4A fast response: if blood pressure is too high, vasodilation will lower blood pressure; high heart rate and contractility will be lowered so that cardiac output will decrease-all of that will cause high blood pressure to drop and go back to normal -4B slow response: produce more urine which causes a decrease in blood volume which will cause blood pressure to drop -Part of the cardiovascular system involving neurons: if high blood pressure high blood volume->high blood pressure which triggers 1. carotid and aortic baroreceptors notice an increase in blood pressure so they relay message back to the medulla which controls the cardiovascular control center to activate the autonomic nervous system 2. if blood pressure is high, the sympathetic NS will be turned off and the parasympathetic NS will be activated 3. Parasympathetic neurons will directly tell SA node to beat slower and lower heart rate 4. Since the sympathetic NS is off, its neurons can't tell the SA node to beat faster and increase heart rate, it can't contract with more force (so contractility will decrease) and can't tell the arterioles to vasoconstrict (as it a result it will vasodilate) 5. blood pressure will decrease -essentially the parasympathetic indirectly lowers high blood pressure by making the the SA node beat slower, because there is no direct neuron that allows it to change heart contractility or blood vessel diameter if low blood pressure: low blood volume->low blood pressure which triggers 1. carotid and aortic baroreceptors notice a decrease in blood pressure so they relay message back to the medulla which controls the cardiovascular control center to activate the autonomic nervous system: parasympathetic and sympathetic NS. 2. if blood pressure is low, the parasympathetic NS will be turned off and the sympathetic NS will be activated 3. sympathetic neurons directly tells SA node to beat faster and increase heart rate 4. sympathetic NS neurons directly tell the ventricles to contract with more force (so contractility will increase) and tell the arterioles to vasodilate 5. blood pressure will increase
What are some congenital heart defects?
1. atrial septal defects: allows blood flow between atria (normal in-utero) but by the time baby is born the passageway that allows blood flow to pass from left atrium to right atrium doesn't fuse (septum doesn't completely grow completely, so there is a small opening) which causes blood to pass freely 2. endocardial cushion defects: mixing of deoxygenated blood and oxygenated blood bcuz there is no septum/separation/wall between chambers of the heart 3. ventricular septal defects: there is no wall/separation between right and left ventricles so 4. coarction of the aorta: narrowing of the aorta; it looks like its being pinched (imagine a bent water hose) 5. patent ductus arteriosus: the ductus arteriosus (connects the aorta and pulmonary artery) remains open , allowing blood to flow between aorta and pulmonary artery 6. pulmonary stenosis 7. transposition of the great vessels: the 2 major vessels (pulmonary artery and aorta) are switched
How does control of the renin-angiotensin-aldosterone system work? *remember: ([renin released by kidenys, angiotensin released by liver, aldosterone released by conversion of angiotensin I to angiotensin II via angiotensin-coverting enzyme (ACE)])
1. decreased blood flow to kidneys 2. kidneys then release renin into blood 3. renin reacts with angiotensinogen to form angiotensin-I 4. angiotensinogen-converting enzyme (ACE) in lungs converts angiotenin-I to angiotenin-II 5.stimulates adrenal gland to secrete aldosterone 6. aldosterone activates the Na+/K+ pump in distal tubules of nephrons 7. Na+ and H2O are reabsorbed and K+ is secreted 8. After Na+ and H2O are reabsorbed it caused an increase of blood volume; after K+ is secreted, K+ is eliminated -renin-angiotensin-aldosterone (RAA): increases blood pressure, increases blood volume, Na+, decreases K+; Dehydration, Na+ deficiency, hemorrhage or too much K+ will cause the body to attempt to retain water and Na+ and flush out K+; activated by SNS; decreases blood flow to kidneys
Myocardial diseases: Malfunctioning heart muscle can cause heart failure if...
1. hypertrophic cardiomyopathy: characterized by thickened ventricular muscle mass ; the left ventricle especially will be enlarged bcuz it pumps blood to the body ; unusually thick ventricles, and so not enough room for blood flow 2. restrictive cardiomyopathy: characterized by small left ventricular volume ; left ventricle is stiff and resists diastolic filling; decreases cardiac output and left-sided heart failure can result 3. dilated cardiomyopathy: aka congested cardiomyopathy is characterized by cardiac failure associated with dilation of one or both ventricular chambers ; the ventricles are too weak to pump blood out due to weakened enlarged heart 4. peripartum cardiomyopathy: weak heart that occurs in the final months of pregnancy 5. MI, myocarditis: ventricles are too weak to pump blood out due to inflammation of the heart
What causes Pericarditis?
1. inflammation of the pericardium due to accumulation of pericardial effusion, which is the buildup of fluid in the pericardial sac -this buildup called the pericardial effusion may lead to cardiac tamponade, which is when fluid accumulates in large amounts and causes abnormal external pressure on the heart that results in poor cardiac filling and decreased cardiac output 2. constrictive pericarditis: the pericardial sac becomes dense, nonelastic, fibrous and scarred; it encases the heart like a stiff cage and impairs diastolic filling ; the fibrous scar tissue makes pericardium stick to the heart
True or False: As blood volume decreases, blood pressure and blood flow also decreas
As blood volume decreases, blood pressure and blood flow also decreases Answer: true
Venoconstriction increases which of the following? a. blood pressure within the vein b. blood flow within the vein c. return of blood to the heart d. all of the above
Venoconstriction increases which of the following? a. blood pressure within the vein b. blood flow within the vein c. return of blood to the heart d. all of the above Answer: D
