Shared Flashcard Set

Details

PHGY350 - Smith Review
N/A
143
Physiology
Undergraduate 3
10/12/2011

Additional Physiology Flashcards

 


 

Cards

Term
Arteries
Definition
Pressure reservoir of circulation
Conductance vessels; highly elastic and muscular
Term
Arterioles
Definition
Resistance vessels; main site of control of blood flow to tissues
Term
Veins
Definition
Capacitance vessels; volume reservoir of the circulatory system
Term
The pressure gradient which acts as the driving force for blood flow is measured between which two points...
Definition
RA and LV
Term
LCA Branches
Definition
Circumflex & anterior interventricular
Term
RCA Branches
Definition
Marginal, posterior interventricular
Term
Cardiac Tamponade
Definition
Volume expansion into pericardial sac; makes it difficult for heart to pump
Term
Properties of cardiomyocytes:
Definition
Striated, t-tubule network, arrangement into sarcomeres, many mitochondria
Term
Non-Cardiomyocyte Cells in the heart
Definition
Fibroblasts, Endothelial/Smooth muscle, Neural Cells
Term
What makes up the structural matrix of the heart?
Definition
Fibroblasts
Term
Intercalated Disks
Definition
Desmosomes - physically connect cells
Gap Junctions - electrically connect cells; allows for synchronous depolarization
Term
Nerve AP vs. Pacemaker AP
Definition
Nerve: resting membrane potential at -70, depol due to Na influx, repol due to K efflux
Pacemaker: no resting potential (pacemaker potential = slow depol), depol due to Ca influx, repol due to K efflux
Term
Why is the long refractory period important in cardiac muscle cells?
Definition
Allows for complete ventricular filling (prevents tetanus)
Term
P wave
Definition
Atrial contraction and depolarization
Term
PR segment
Definition
Rate of AV conduction
Term
QRS complex
Definition
Ventricular depolarization and contraction
Term
QT interval
Definition
Entire time to depol, then repol ventricles
Term
T wave
Definition
Ventricular repolarization & relaxation
Term
Where do changes in HR normally manifest?
Definition
Change in the length of the DIASTOLIC INTERVAL
Tachycardia = shorter
Bradycardia = longer
Term
What two things can control of the heart be related to
Definition
Chronotropy - control of rate
Inotropy - control of force of contraction
Term
What 4 mechanisms control heart function?
Definition
Autonomic innervation, hormone levels, drugs, intrinsic mechanisms (Frank-Starling)
Term
Where do SNS and PNS innervation act on and with which NTs?
Definition
SNS = B-adrenergic receptors w/ NE
PNS = muscarinic receptors w/ Ach
Term
Difference between SNS and PNS innvervation
Definition
SNS = + chronotropy AND inotropy
PNS = - chronotropy
Term
CO = ?
Definition
CO = HR x SV
Term
Normal parameters for CO, SV, and HR
Definition
CO = 5 L/min
SV = 70 mL/beat
HR = 72 bpm
Term
Pre-Load
Definition
Blood returned to heart from venous circulation
Term
After-Load
Definition
Force required to eject blood from ventricles
Term
SV is dependent on 3 factors:
Definition
Preload
Afterload
Contractility (force of contraction)
Term
Vasoconstriction is caused by...
Definition
Increased O2/decreased CO2
Endothelin
Cold
Increase in myogenic activity
Increase in SNS
Increase in ANGII/vasopressin
Term
Vasodilation is caused by...
Definition
Heat
Decreased myogenic activity
Decreased SNS innervation
Increased levels of NO, Histamine
Decreased O2/Increased CO2
Term
Metabolic Syndrome
Definition
Triad of HTN, hyperlipidemia, and insulin resistance (DM II)
Term
Majority of deaths due to CVD are due to?
Definition
CAD (then CVAs, then PVD)
Term
Arteriosclerosis
Definition
Hardening of the arteries; degenerative changes in small arteries
Associated w/ HTN, DM
Term
Atherosclerosis
Definition
Formation of atheromas in large arteries; INFLAMMATORY process in the vessel wall
Term
What is needed to precipitate athersclerosis?
Definition
Need some sort of endothelial injury
Term
Consequences of Endothelial Injury
Definition
Increased vasoconstrictors, less vasodilators
Less antithrombotic and anti-coagulative substances
Increased immune cell adhesion
Term
Basic Process of Atherosclerosis (4 steps)
Definition
Endothelial Injury
LDL Retention/Fatty Streak
Formation of Stable Plaque (Atheroma)
Complicated Lesion (Unstable Plaque)
Term
Fatty Streak/LDL Accumulation
Definition
Excess LDL accumulates under endothelium and CT (b/c of lesion) -> macrophages enter and take in chol and LDL (become FOAM CELLS)
Fatty streak increases in size and makes vessel lumen smaller
Term
Stable Plaque (Atheroma)
Definition
Fatty streak forms a lipid core; CT forms around core to form a fibrous cap
Smooth muscle proliferates around and thickens wall (further occludes lumen)
Term
Complicated Lesion (Unstable Plaque)
Definition
If plaque becomes calcified, may weaken & rupture - ruptured plaques can throw clots to smaller vessels
Term
Thrombosis in different areas of the body can cause:
Definition
In the coronary circulation -> MI
In the cerebral/carotid arteries -> CVA
In the iliac arteries -> PVD
In the aorta -> aneurysm
Term
Coronary Blood supply to LV, RV, and AV/SA nodes
Definition
LV = LCA & circumflex
RV = RCA
SA + AV nodes = RCA
Term
Examples of lipid lowering drugs
Definition
Fibrates/statins
Term
Pathophysiology of CAD
Definition
Due to atherosclerosis of coronary arteries - leads to myocardial ischemia (less O2 perfusion)
Can lead to angina pectoris
Term
Angina Pectoris
Definition
Chest pain radiating to the left arm triggered by sudden increase in O2 demand
Term
Stable Angina
Definition
Predictably occurring; relieved w/ rest and or < 3 doses of nitro
Term
Unstable Angina
Definition
Occurs at a new onset; can be due to acute coronary syndrome (unstable plaque)
Crescendo pattern
Pain @ rest or minimal exertion
Term
Treatment for Angina
Definition
Rest - reduce O2 demand of myocardium
Nitroglycerine - 3 doses 5 mins apart
Nitroacts as a VASODILATOR
Term
Types of Surgery for CAD
Definition
CABG - vascular tissue taken from left internal mammary artery/saphenous vein and grafted onto coronary circulation to reroute flow
Transluminal ballon angioplasty/stent - opens the occluded vessel
Term
Most common cause of MI's
Definition
CAD (with the CAD being precipitated by some sort of athersclerosis)
Term
Blockage of artery in MI occurs by...
Definition
Thrombus forms on atheroma which embolizes a smaller branch of the artery; vasospasm may cause occlusion
Term
Most common chamber affected in MI's
Definition
LV
Term
What is myocardial damage from the infarct proportional to?
Definition
Proportional to the size of the occluded vessel -> bigger = more damage
Term
Symptoms of MI
Definition
Radiating chest pain to L arm (not relieved by rest or nitro; most telling symptom)
Pallor, diaphoresis
Hypotension - from cardiogenic shock (increased HR)
Term
Diagnosis of MI
Definition
EKG - akinesis of infarct
ECG - elevated ST segment
Isoenzyme tests in blood -> increased CK-MB, TnT/I, AST, LDH, CRP
Term
Peak levels of isoenzymes and relative time post-MI
Definition
CPK-MB = 24 hrs
AST = 48 hrs
LDH = 72 hrs
Term
Complications from MI
Definition
Arrythmias (V fib is leading cause of death post-MI)
CHF
Shock
Ventricular rupture
Term
Cardiac Dysrhythmias
Definition
Deviations from a normal cardiac rate/rhythm
Term
Disorders of HR
Definition
Bradycardia - lower than 60 bpm
Tachycardia - higher than 100 bpm
Term
Disorders of Heart Rhythm
Definition
PVA's/PVC's
Heart Blocks (AV conduction blockage)
A fib/ V fib
Term
Why are dysrhythmias dangerous?
Definition
Decrease in CO (in tachycardia see decreased SV, in bradycardia see decreased HR)
Increase O2 demand - can precipitate angina
Term
Intrinsic Rates of Pacemakers
Definition
SA node = 70-80 bpm
AV node = 40-55 bpm
Bundle, branches, Purkinje = 25-40 bpm
Term
Causes of cardiac dysrhythmias
Definition
SA node abnormalities
Atrial conduction abnormalities - PACs, atrial flutter or fib
AV node conduction abnormalities - heart block
Ventricular conduction abnormalities - V fib, bundle branch block
Term
Causes of SA node abnormalities
Definition
SA node ischemia (supplied by RCA)
Electrolyte abnormality
Activated autonomic NS (tachy = SNS, brady = PNS)
Intrinsic disease (sick sinus syndrome - scar tissue at node)
Drugs (B-blockers, cocaine)
Term
What typically occurs to HR during SA node abnormalities?
Definition
Other pacemaker takes over SA function - get a lower intrinsic rate
Term
Causes of atrial conduction abnormalities
Definition
Ischemia, electrolyte abnormalities, infarct, scar tissue
Term
PACs
Definition
Extra atrial contractions due to contraction of ectopic foci
Term
Atrial Flutter
Definition
Atrial HR of 160-350 bpm; b/c AV node delays conduction, ventricular rate is slower
Term
A Fib
Definition
Atrial HR > 350 bpm; see pooling of blood in atria (NO P WAVE because no coordinated contraction)
See a variable P/QRS ratio (ventricular rate may be slow or fast)
Term
Heart Block
Definition
AV node abnormality; impulses from SA node don't reach ventricles
Term
1st Degree Heart Block
Definition
Impulses from SA node are delayed excessively long in AV node
Prolonged PR interval
Term
2nd Degree Heart Block
Definition
See some "dropped beats" - some SA impulses do not make it past the AV node
Some P waves lack QRS waves (every 2nd to 3rd beat is dropped)
Term
3rd Degree Heart Block
Definition
NO impulse conducted through AV node; need another pacemaker to maintain ventricular contraction rate
"Atrioventricular dissociation" - contract independent of each other
Term
Bundle Branch Block
Definition
Conduction deficiency in one or both bundle branches
WIDE QRS complex (longer depolarization)
Term
V Fib
Definition
MOST serious conduction abnormality
Ventricles "quiver" - no coordinated contractions (no CO)
Need immediate CPR, defib
Caused by = ischemia, drugs, electrolyte deficiency
Term
Arrythmia Drug Treatment
Definition
Anti-Arrythmics = B-blockers (less SNS innervation), Ca channel blockers (less contraction), Digoxin (slows atrial dysrythmia)
Term
Treatment for AV/SA nodal disease?
Definition
Pacemaker
Term
Treatment for V fib?
Definition
CPR, defib
Term
Digoxin
Definition
Slows rate of conduction through AV node; fix atrial dysrhythmias
Term
CHF
Definition
Heart cannot meet metabolic needs of body, OR can only do so with compensatory mechanisms
Term
Signs of CHF:
Definition
Forward decreased output - decreased CO or SV; less perfusion to organs = fatigue & acidosis
Back-up congestion - incomplete emptying of ventricles causes congestion (output < input)
Term
Causes of CHF
Definition
CAD (MAIN CAUSE) - decreased coronary flow, heart works harder (hypertrophy), fails
MI - myocyte death = failure; see dilatation and remodeling
Inherited myopathy
Valve defects - stenosis (increased afterload), incompetence (increased preload)
HTN - increases afterload (hypertrophy & failure)
DM
Pulmonary disease (leads to R sided CHF)
Term
Progression of L sided CHF
Definition
Less CO to systemic circulation -> activate RAA system to increase BP and volume
See backup in pulmonary circulation - pulmonary congestion and edema
Term
Progression of R sided CHF
Definition
Inadequate CO to pulmonary circulation, leads to less CO to systemic circulation as well -> RAA activates to increase blood pressure and volume
See back-up in systemic circulation -> edema in legs and feet, ascites; if severe, distended neck veins & increased ICP
Term
Symptoms of L sided CHF
Definition
Dyspnea, orthopnea
Cough - fluid irritates respiratory passages
IF ACUTE - paraoxysmal nocturnal dyspnea (acute pulmonary edema)
Increases likelihood of lung infections
Term
Symptoms of R sided CHF
Definition
Dependent edema in legs, feet, buttocks
Ascites; splenomegaly, hepatomegaly
Increased BP in jugular veins
If ACUTE - pallor, headache, distended neck veins, blurred vision
Term
Adaptive mechanisms for CHF
Definition
Frank-Starling, Neurohormonal (SNS, RAA), Remodeling Myocardium
Term
Frank-Starling adaptation to CHF
Definition
See a DOWNWARD SHIFT in curve (for any given pre-load, SV is less)
Less able to increase SV in response to increased pre-load
Term
SNS innervation during CHF
Definition
INCREASE in SNS innervation (increased levels of NE)
Acutely - useful; maintains CO, increases BP
Chronically - increased BP = more work = hypertrophy; increased afterload can cause arrythmias as well
Term
How can you reduce SNS compensation in CHF?
Definition
Use of B-blockers
Term
RAA compensastion in CHF
Definition
Less perfusion to kidneys = activate RAA system
Acute - beneficial because of increase in BP and volume
Chronically bad - increased edema because of volume, increased PR = increased afterload, increased pre-load on heart
Develop cardiac fibrosis
Term
How to counteract RAA activation in CHF?
Definition
ACE-I - reduce ANGII
ARB - block receptors
Spironolactone - diuretic; aldosterone antagonist
Term
Other Hormonal Mechanisms in CHF
Definition
ANP/BNP - both aid in Na/H2O excretion; higher levels = worse prognosis
Endothelin - vasoconstrictor; good short term, bad long term
TNF - weakens heart long term
Term
How is the myocardium remodeled in CHF?
Definition
Dilatation - ventricular cavity enlarges
Hypertrophy - ventricular muscle increases in size
Term
What causes dilatation and hypertrophy in the ventricles during CHF?
Definition
Dilatation = chronic volume overload (can't fully empty)
Hypertrophy - chronic pressure overload on ventricles
Term
Difference in treatment for ACUTE and CHRONIC CHF
Definition
Acute - determine precipitant, administer O2 and diuretics, vasodilators
Chronic - Digitalis (decrease force of contraction), Diuretics, Spironolactone, After-load reducers = ACE-I, ARB's, B-blockers
Term
What drugs have been shown to reduce mortality in CHF patients?
Definition
Spironolactone, ARBs, B-blockers
Term
What is the 1st sign of young children with CHF?
Definition
Feeding difficulties (cannot gain weight)
Term
When do congenital defects arise?
Definition
First 8-12 weeks of fetal life
Term
What is the primary cause of death in the first year of life?
Definition
Congenital heart defects
Term
Consequences of Congenital Heart Defects
Definition
Heart murmurs (most common for valvular defects), Cyanosis (w/ R-to-L shunts), Pulm HTN, Decreased CO
Term
Signs of Congenital Heart Defects
Definition
Pallor
Tachycardia (rapid sleeping pulse)
Dyspnea
Squatting position
Clubbed fingers & growth defects
Term
Two main types of congenital defects?
Definition
Septal defects (creating shunts in the heart), valvulopathies (leading to stenosis or incompetence of valves)
Term
What is the most common congenital heart defect?
Definition
Ventricular septal defects
Term
Presentation of a VSD
Definition
1st see L-to-R shunt (because of higher pressure in the L ventricle); this causes decreased CO to systemic circulation
Now see a back-up in pulmonary circulation leading to higher pressures -> causes hypertrophy of RV due to pulmonary HTN, now get a R-to-L shunt leading to cyanosis
Term
What valves are most commonly affected in valvulopathies?
Definition
Aortic and pulmonary valves (semilunar)
Term
Difference between stenosis and incompetence in valvulopathies?
Definition
Stenosis - hardening of the valves; reduces SV (decreaseed flow; increased work on heart)
Incompetence - get regurgitation of blood backwards, see pooling of blood
Term
Effects of Valvular Stenosis
Definition
Increased work on heart because of decreased blood flow, hypertrophies heart muscle; also have increased afterload (b/c of Frank-Starling see additional hypertrophy)
Like CHF, get back-up congestion before valve
Term
Symptoms seen in Aortic/Mitral valve stenosis vs. Pulmonary/Tricuspid valve stenosis?
Definition
Aortic/Mitral - pulmonary edema
Pulmonary/Tricuspid - systemic edema, ascites
Term
Two consequences of Valvular Incompetence
Definition
Chronic volume overload in heart - DILATATION
Chronic pressure overload - HYPERTROPHY
Term
Differences in symptoms between Aortic and Mitral regurgitation?
Definition
Aortic - wide pulse pressure
Mitral - pooling in pulm circulation (pulm edema)
Term
Tetralogy of Fallot
Definition
Pulmonary Valve Stenosis - leads to pooling of blood behind the valve; more work on RV
RV hypertrophy - due to valvular stenosis
VSD - due to RV hypertrophy have increased pressure, get R-to-L shunt
Dextraposition of aorta over VSD - get deoxy blood from RV into systemic circulation (cyanosis)
Term
What causes the inflammation in rheumatic fever?
Definition
Antibodies formed attack collagen in heart (inflammation & scarring)
Term
Aschoff Bodies
Definition
Seen in endocarditis; small fibrous projections from the valves
Term
Signs of Rheumatic Fever
Definition
Fever, Leukocytosis, Tachycardia, Heart murmurs
Term
Effects of inflammation in the various layers of the heart
Definition
Pericardium = effusion (cardiac tamponade)
Myocardium = arrythmias
Endocardium = valvulopathy
Term
Acute vs. Sub-Acute Endocarditis
Definition
Acute - infection with very virulent organism (Staph); rapid progression
Sub-Acute - infection with less virulent organism (Strep); longer onset
Term
Etiology of Endocarditis
Definition
Weakened immune system, bacteremia, pre-existing valve defects
Term
Symptoms of Endocarditis
Definition
Murmurs, fever, fatigue, splenomegaly, Osler nodes (deposition of antibody-antigen complexes in feet and knuckles)
Term
Pathogens causing myocarditis in NA vs. SA
Definition
NA = coxsakievirus (enterovirus)
SA = parasites
Term
Complications of Pericarditis
Definition
Pain, friction rub - due to decrease in pericard fluid
Effusion - accumulation of fluid in pericardial space (decreases CO)
Term
Acute vs Chronic Pericarditis
Definition
Acute = Tamponade -> effusion of fluid compresses heart
Chronic = Constrictive -> prolonged inflammation; get adhesion of membranes & restrict movement
Term
What is most susceptible to acute pericarditis (tamponade)?
Definition
RV
Term
Symptoms of chronic pericarditis
Definition
Pain, dyspnea, tachycardia, distended neck veins
Pulsus Paradoxus
Abdominal Discomfort
Term
Treatment for Chronic Pericarditis
Definition
Pericardiocentesis - aspirate fluid from sac
Term
HTN
Definition
Chronically elevated BP > 140/90 on 3 separate visits spaced 2 weeks apart
Term
Systolic vs. Diastolic HTN
Definition
Systolic = increase in Sys BP; wide pulse pressure
Diastolic = increase in Dias BP; increased PR; rarely occurs without systolic HTN
Term
Multifactorial etiology of primary HTN
Definition
Salt sensitivity - increased NaCl intake causes increased BP
Membrane ion transport deficiency
Accumulation of Ca in vascular muscle = more tone = vasoconstriction
Insulin resistance - increased insulin = increase Na retention, Ca, muscular hypertrophy
Term
When is secondary HTN most likely to occur?
Definition
age 50
Term
Common causes of secondary HTN
Definition
Renal disease
Endocrine causes - hyperaldosteronism (increased blood volume), Cushing's (increased glucocorticoids = vasoconstriction, Pheochromocytoma (increased secretion of E and NE)
Oral contraceptives
Term
End organs affected by HTN
Definition
Heart, Kidneys, Brain, Eyes
Term
End organ effects of HTN on HEART
Definition
Increased PR = increased afterload for heart -> more work = hypertrophy
Later leads to remodeling and dilatation -> CHF
Can also cause angina/MI -> increased O2 requirements
Term
End organ effects of HTN on KIDNEYS
Definition
HTN causes glomerular damage -> DECREASE in GFR (decrease in kidney function)
Vicious cycle - kidneys secrete renin, leads to increased BP and blood volume = more HTN = more damage = more renin secretion
Term
End organ effects of HTN on BRAIN
Definition
Hypertensive encephalopathy - usually due to acute HTN -> altered consciousness, increased ICP, seizures, blurred vision
Often see hemorrhagic CVAs
Term
End organ effects of HTN on EYES
Definition
Hypertensive retinopathy -> **Hallmark of malignant HTN
Scotomata, blurred vision, blindness
Term
Aneurysm
Definition
Localized dilatation of arterial wall
Term
What can weaken the media to lead to an aneurysm?
Definition
Turbulent flow from atheroma/thrombus or bifurcation in vessel
Term
Where are aneurysms most common?
Definition
In the aortic and abdominal aorta
Term
Types of Aneurysms
Definition
Fusiform - circumferential dilatation
Saccular - bulging to one side; see thrombus formation
Dissecting - due to tear in media and intima; blood flows through layers of vessel
Term
Etiology of aneurysms
Definition
Atherosclerosis, trauma, congenital vascular defect, syphilis
Term
Varicose Veins
Definition
Dilated areas in veins due to chronic stretch of wall
Term
What can cause varicose veins?
Definition
Weakness in vein wall or valvular dysfunction in veins
Term
What can cause varicose veins?
Definition
Excessive hydrostatic pressure - long periods of standing, pregnancy, thrombophlebitis (vein inflammation)
Supporting users have an ad free experience!