PUMPING ORGAN-THE HEART

<<< WHAT IS HEART>>>

★HEART IS A MUSCULAR ORGAN RESPONSIBLE FOR PUMPING BLOOD THROUGH

   BLOOD VESSELS BY REPEATED CONTRACTIONS.

CARDIAC;

★CARDIAC MEANS "RELATED TO HEART" 

CARDIAC MUSCLES;

★THE BULK OF THE WALLS OF HEART IS MADE OF CARDIAC MUSCLES.CARDIAC 

   MUSCLES ARE INVOLUNTARY IN ACTION AND ARE COMPOSED OF BRANCHED 

   STRAIGHT CELLS, EACH WITH A SINGLE NUCLEUS.

LOCATION OF HEART;

★IN HUMAN BODY, HEART IS SITUATED BETWEEN LUNGS, IN THE MIDDLE OF CHEST

   CAVITY (THORAX) UNDER BREASTBONE.

PERICARDIUM PERICARDIAL FLUID;

★THE HEART IS ENCLOSED IN A DOUBLE MEMBRANOUS SAC-THE PERICARDIAL

   CAVITY, WHICH CONTAINS PERICARDIAL FLUID,BETWEEN PERICARDIUM AND

   HEART WALLS.

FUNCTION OF PERICARDIAL FLUID;

★IT REDUCES FRICTION BETWEEN PERICARDIUM AND HEART DURING HEART

  CONTRACTIONS. 

CHAMBERS OF HEART;

★HUMAN HEART CONSIST OF FOUR CHAMBERS LIKE THE HEART OF BIRD AND 

  OTHER MAMMALS.

ATRIA;

★THE UPPER THIN-WALLED CHAMBERS ARE CALLED LEFT AND RIGHT ATRIA

   SINGULAR:'ATRIUM '

VENTRICLES;

★THE LOWER THICK-WALLED CHAMBERS ARE CALLED LEFT AND RIGHT

   VENTRICLES LEFT VENTRICLE IS THE LARGEST AND STRONGEST CHAMBER

   IN HEART.

HEART WORK AS A DOUBLE PUMP;

★HUMAN HEART WORK AS A DOUBLE PUMP, IT RECEIVES DEOXYGENATED

  (WITH LESS OXYGEN) BLOOD FROM THE BODY AND PUMPS IT TO THE LUNGS.

   AT THE SAME TIME, IT RECEIVES OXYGENATED (WITH MORE OXYGEN) BLOOD

   FROM LUNGS AND PUMPS IT TO ALL BODY.

MAINTENANCE OF BLOOD;

COMPLETE SEPARATION OF DEOXYGENATED BLOOD (RIGHT SIDE) AND 

OXYGENATED BLOOD (LEFT SIDE) , IN THE HEART, IS MAINTAINED.  

RIGHT ATRIUM;

★RIGHT ATRIUM RECEIVES DEOXYGENATED BLOOD FROM BODY VIA THE MAIN 

   VEINS i.e, SUPERIOR AND INFERIOR VENA CAVAE. 

RIGHT VENTRICLE;

★WHEN RIGHT ATRIUM CONTRACTS IT PASSES THE DEOXYGENATED BLOOD TO

   RIGHT VENTRICLE. 

TRICUSPID VALVE;

★THE OPENING BETWEEN RIGHT ATRIUM AND RIGHT VENTRICLE IS GUARDED BY

   A VALVE KNOWN AS TRICUSPID VALVE (BECAUSE IT HAS 3 FLAPS).

WORKING IN HEART;

PULMONARY TRUNK;

★WHEN RIGHT VENTRICLE CONTRACTS, THE BLOOD IS PASSED TO PULMONARY 

   TRUNK, WHICH CARRIES BLOOD TO LUNGS.

BACKFLOW OF BLOOD;

★TRICUSPID VALVE PREVENTS THE BACKFLOW OF BLOOD FROM RIGHT VENTRICLE 

   TO RIGHT ATRIUM. 

PULMONARY SEMILUNAR VALVE;

★AT THE BASE OF PULMONARY TRUNK, PULMONARY SEMILUNAR VALVE IS PRESENT

  WHICH PREVENTS THE BACKFLOW OF BLOOD FROM PULMONARY TRUNK TO RIGHT

  VENTRICLE.

LEFT ATRIUM;

★THE OXYGENATED BLOOD FROM LUNGS IS BROUGHT BY PULMONARY VEINS TO

   LEFT ATRIUM. 

LEFT VENTRICLE;

★LEFT ATRIUM CONTRACTS AND PUMPS THIS BLOOD TO LEFT VENTRICLE.

BICUSPID VALVE;

★THE OPENING BETWEEN LEFT ATRIUM AND LEFT VENTRICLE IS GUARDED BY A  

   VALVE KNOWN AS BICUSPID VALVE (BECAUSE IT HAS TWO FLAPS).

AORTA;

★WHEN LEFT VENTRICLE CONTRACTS, IT PUMPS THE OXYGENATED BLOOD IN 

   AORTA, WHICH CARRIES BLOOD TO ALL PARTS OF BODY (EXCEPT LUNGS).

BACKFLOW OF BLOOD;

★BICUSPID VALVE PREVENTS THE BACKFLOW OF BLOOD FROM LEFT VENTRICLE 

   TO LEFT ATRIUM.

AORTIC SEMILUNAR;

★AT THE BASE OF AORTA, AORTIC SEMILUNAR VALVE IS PRESENT WHICH PREVENTS 

  THE BACKFLOW OF BLOOD FROM AORTA TO LEFT VENTRICLE.

STRUCTURE AND LABELING OF HUMAN HEART;