NEET 2019 preparation notes

1. BODY FLUIDS AND
CIRCULATION
BY,
DR.R.KARTHIKEYAN
BIOLOGY FACULTY , CONCEPTREE LEARNING

2. OBJECTIVES – SESSION 2
• CIRCULATORY PATHWAYS
• HUMAN CIRCULATORY SYSTEM:
STRUCTURE OF HUMAN HEART
CONDUCTING SYSTEM IN HEART
CARDIAC CYCLE
HEART SOUNDS
ELECTROCARDIOGRAM ( ECG)

3. CIRCULATORY PATHWAYS
• TWO TYPES OF PATHWAYS:
OPEN : HEART TO SINUS
CLOSED : CLOSED NETWORK OF BLOOD VESSELS
• TWO TYPES OF CIRCULATION:
SINGLE: HEART – DEXOYGENATED ; GILLS – OXYGENATED ;
DEXOYGENATED
RETURNED TO HEART
DOUBLE:
INCOMPLETE: 3 CHAMBERED HEART ( AMPHIBIANS AND
REPTILES)

4. CIRCULATORY PATHWAYS

5. STRUCTURE OF HUMAN HEART
• PERICARDIUM ( PARIETAL AND VISCERAL )
• SEPTUM: INTERATRIAL , INTERVENTRICULAR AND ATRIOVENTRICULAR
• AV VALVES: TRICUSPID VALVE ( RIGHT ) AND BICUSPID VALVE ( LEFT)
• CHORDAE TENDINAE AND PAPILLARY MUSCLES

6. STRUCTURE OF HUMAN HEART

7. CONDUCTING SYSTEM IN HEART
 SAN
 AVN
 PURKINJE FIBRES
 BUNDLE OF HIS

8. CARDIAC CYCLE
STEPS INVOLVED IN ONE CYCLE:
JOINT DIASTOLE
ATRIAL SYSTOLE ( 0.1S)
VENTRICULAR SYSTOLE
ATRIAL DIASTOLE ( 0.3 S)
COMPLETE CARDIAC
DIASTOLE ( 0.4S)
1.AV VALVES OPEN
2.SAN GENERATES
AP
3.BLOOD FLOW
INCR
4.SEMILINAR
CLOSED.
1. AP TO VENT. BY BOH
2… AV VALVES CLOSE
3. PRESSURE INCR.
SEMILUNAR OPEN
BLOOD FLOWS
VALVES CLOSED
AV OPEN , RELAXES

9. CARDIAC CYCLE
• TIME : 0.8s
• HEART RATE : 72 BEATS/MIN
• STROKE VOLUME:
AMOUNT OF BLOOD PUMPED OUT BY VENTRICLE DURING EACH
CYCLE .
IT IS APPROXIMATELY 70mL
. CARDIAC OUTPUT:
PRODUCT OF STROKE VOLUME AND HEART RATE
APPROX 5L/min

10. HEART SOUNDS
• HEARD DURING VENTRICULAR SYSTOLE AND DIASTOLE
FIRST HEART SOUND ( LUBB) SECOND HEART SOUND ( DUBB)
CLOSURE OF AV VALVES CLOSURE OF SEMILUNAR
VALVES
LOW PITCH , LONG DURATION HIGH PITCH , SHORT DURATION

11. ECG
• P WAVE:
ATRIAL SYSTOLE
ABNORMAL OBTAINED DUE TO ENLARGEMENT OF ATRIA
• QRS WAVE:
VENTRICULAR SYSTOLE
ENLARGED DURING HEART ATTACK
• T WAVE :
END OF SYSTOLE
FLATTENED DURING INSUFFICENT OXYGEN SUPPLY
ST SEGMENT:
ELEVATED IN HEART ATTACK, FLATTENED IN INSUFFICENT

12. ECG

13. THINK ON THIS…….