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Define Heartbeat ?

HEARTBEAT ➤ The alternating  relaxations and contractions make up the cardiac cycle and one   complete  cardiac cycle makes one heartbeat.and in other words, one complete pulsation  of the heart  is called heartbeat. It is the complete regular movement movement of our  heart as it passes  blood around your body. STEPS OF CARDIAC CYCLE ➤ C omplete cardiac cycle consist of the following steps .   CARDIAC DIASTOLE ➤ Atria and ventricles relax and blood is filled in atria. this period is called cardiac   diastole.  In short, it is the period of relaxation of heart muscles.In one complete heartbeat,   diastole  lasts about 0.4 seconds. ATRIAL SYSTOLE ➤ It is the last phase in diastole during which the ventricular filling is  competed.    Immediately  after their  filling, both atria contracts and pump blood towards ventricles.   This period in  cardiac cycle is called  atrial systole.In o...

NOTE ON SPINAL CORD

  SPINAL CORD ★ THE SPINAL CORD IS IN FACT A TUBULAR BUNDLE OF NERVES.   STARTS FROM; ★ IT STARTS FROM BRAIN STEM AND EXTENDS TO LOWER BACK. SPINAL CORD IS THE    CONTINUATION OF MEDULLA OBLONGATA. MEDULLA OBLONGATA NARROWS DOWN    INTO AN OVAL SHAPED HOLLOW CYLINDER, THE SPINAL CORD, RUNNING THROUGH     THE VERTEBRAL COLUMN. CONSIST OF; ★ IT CONSIST OF A VERY LARGE NUMBER OF NEURONS. THE CELL-FIBRES AND BODIES     OF WHICH ARE ARRANGED IN A DEFINITE PATTERN. COVERED BY; ★ LIKE BRAIN, SPINAL CORD IS ALSO COVERED BY  MENINGES. THE VERTEBRAL    COLUMN SURROUNDS AND PROTECTS SPINAL CORD. SIZE OF SPINAL CORD; ★ SPINAL CORD IS ROUGHLY 40cm LONG AND ABOUT AS WIDE AS YOUR THUMB FOR    MOST OF ITS LENGTH. REGIONS OF SPINAL CORD; OUTER REGION; ★ THE OUTER REGION OF SPINAL CORD IS MADE OF WHITE MATTER . ★ CONTAINING MYELINATED AXONS. CENTRAL REGION; ★ THE CENTRAL REGION IS BUTTERFLY SHAPED THAT SURROUNDS THE CEN...

WRITE A DETAILED NOTE ON BRAIN WHICH IS OUR CENTRAL NERVOUS SYSTEM

✦✦✦BRAIN ✦✦✦ ★ IN ANIMALS, ALL LIFE ACTIVITIES ARE UNDER THE CONTROL OF BRAIN. CRANIUM; ★ BRAIN IS SITUATED INSIDE A BONY CRANIUM (PART OF SKULL) . MENINGES; ★ INSIDE CRANIUM, BRAIN IS COVERED BY THREE LAYERS CALLED MENINGES.  FUNCTION OF MENINGES; ★ MENINGES PROTECT BRAIN AND ALSO PROVIDE NUTRIENTS AND OXYGEN TO     BRAIN TISSUE THROUGH THEIR CAPILLARIES. FLUID-FILLED VENTRICLES; ★ THE BRAIN CONTAINS FLUID-FILLED VENTRICLES THAT ARE CONTINUOUS WITH    THE CENTRAL CANAL OF SPINAL CORD. CEREBROSPINAL FLUID; ★ FLUID WITHIN VENTRICLES AND CENTRAL CANAL IS CALLED CEREBROSPINAL     FLUID (CSF) . DIVISIONS OF BRAIN; THE BRAIN CAN BE DIVIDED INTO; ★ FOREBRAIN ★ MIDBRAIN  ★ HINDBRAIN FURTHER DIVISION OF FOREBRAIN;  FOREBRAIN IS FURTHER DIVIDED INTO THREE FUNCTIONAL PARTS THE  ★ THALAMUS, ★ THE LIMBIC SYSTEM  ★ THE CEREBRUM.  THALAMUS; ★ THALAMUS CARRIES SENSORY INFORMATION TO THE LIMBIC SYSTEM AND   CEREBRUM. THE INFOR...

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  ...

WHAT IS BIOLOGY

 BIOLOGY IT IS DEFINED AS THE SCIENTIFIC STUDY OF LIFE. DERIVED FROM THE WORD BIOLOGY IS DERIVED FROM TWO GREEK WORDS BIOS MEANING LIFE AND LOGOS MEANING THOUGHT OR REASONING . COINED BY THE WORD BIOLOGY IS COINED B Y LAMARCK AN D TRAVIRANUS C ELL TO MULTICELLULAR THE ORGANISM CAME INTO EXISTENCE FROM SINGLE CELL AND THEN BECOME A COMPLETE ORGANISM CALLED MULTICELLULAR.  EXAMPLES SINGLED CELL: BACTERIA MULTICELLULAR: ANIMALS , PLANTS, FUNGI ETC. MAJOR DIVISION S ZOOLOGY STUDY RELATED TO ANIMALS AS NAME INDICATED BY ZOO BOTANY STUDY RELATED TO PLANTS MICROBIOLOGY AS NAME INDICATED THIS IS RELATED TO THE STUDY OF MICROORGANISMS.