CVS PHYSIOLOGY & PATHOLOGY:
Blood Leaving placenta (Umbilical Vein)…O2 saturation 80 percent , PO2 30 mmhg(26 mmHg)
Blood Going to Placenta (Umbilical Artery)…O2 saturation 60 percent , PO2 20 mmHg ( 15mmHg)
Pulmonary vein has O2 saturation 98 percent at room temperature.
Internal carotid damage…press at c6 to stop bleeding
Mixed venous bloos in Pulmonary Artery
Central and periphral chemoreceptors are sensitive to…PCO2
Raised ICP causes Increased RR due to…Increased PCO2
Highest resistance to blood…Arterioles
Blood flow resulation is mediated by…Arterioles
Highest amount of blood…Veins
Resorvior of blood…Veins
Highest O2 tension…pulmonary capillaries.
Coronalr vasodilation…due to local metabolites
MAP …Highest in Aorta
Systolic B.P…Highest in Renal Artery
Maximum Velocity…Pulmonary Artery
Low Pressure…IVC
TRP is due to…Vasomotor tone
In Isotonic exercise… INcreased HR, SV, CO, Pulse pressure
but decreased TPR
During exercise…blood flow increased to coronary. skeletal muscles ( 20 folds) , decreased to splanchnic & unchanged cerebral. More interstitial fluid is formed
Mean systolic filling pressure regulate Venous return
PULSE PRESSURE increases in…HTN , Aortic regurgitation, Endocarditis, Atherosclerosis, raised ICP, Aortic disease & Beri Beri
Occulocardiac reflex …Decreases heart rate
Brain bridge reflex…Increases Heart rate
Hering breuer reflex… Decreases RESPIRATORY rate (occurs when lungs are expanded)
CNS ischemic response…Most intense response to Hypovolemia
Baroreceptors…Major response to Hypovolemia
HTN & Dissection of Aorta…Medial Necrosis
All are Vasodilators… Histamin , Bradykinin, Substance P, Nitrate
All are Vasoconstrictors…Angiotensin , Serotonin, Epinephrine , Alpha 1 agonists
Decreased peripheral resistance by : ACE inhibitors, Clonidine, Hydralazine, Chronic diuretic ( not by Beta blockers).
Commonest sign of Pulmonary embolism…Tachypnea.
Juglar pulsations as compared to carotid vary with respiration.
CCF …causes generalized edema ( due to increased hydrostatic pressure)
Pleural effusion due to CCF…LDH 100 units (140 to 280 u/L)
In constrictive pericarditis …Diastolic pressure in both ventricles is same.
Heart Inflammation: Streptococcal antigen induce antibody which cross react with heart tissue.
Infective endocarditis sequence: damaged valve → - thrombus → -bacteremia→ - perforation.
Decrease CO: Obstruction of IVC
Cardiac output : Cardio green
70 percent O2 extracted from arterial blood…Cardiac muscles.
Edema in cardiac failure…increased capillary pressure caused by increased venous return.
Remember normally: ESV=50 , EDV =110 to 120
Atrial fibrillation cuses pulses deficit.
Stroke volume is increased by : Digoxin, Caffein, Dopamine, Stretch of cardiac muscle ( not by parasympathetic)
Atrial flutter…circus movements of atria.
PULSE PRESSURE increases in…HTN , Aortic regurgitation, Endocarditis, Atherosclerosis, raised ICP, Aortic disease & Beri Beri
Occulocardiac reflex …Decreases heart rate
Brain bridge reflex…Increases Heart rate
Hering breuer reflex… Decreases RESPIRATORY rate (occurs when lungs are expanded)
CNS ischemic response…Most intense response to Hypovolemia
Baroreceptors…Major response to Hypovolemia
HTN & Dissection of Aorta…Medial Necrosis
TRANSFUSION:
After massive hemolysis
HYPERkalemia
HYPOcalcemia
HYPOthermia
Left shift of oxy Hb curve
Metabolic Acidosis
With stored blood…there is increased risk of exaggerated hemolysis
After bloos transfusion, Prolonged QT & ST on ECG due to…HYPOcalcemia
A +ve transfused with O -ve causes severe transfusion reaction ( Remember for transfusion ABO incompatibility causes more severe reaction tha Rh incompatibility)