Class XI Biology Unit V

1. Chapter-18
BODY FLUIDS AND
CIRCULATION
Presented by
B.Prabhakar
Principal
JNV. Panchmahal (Guj)

2. • The food material which is digested in
human alimentary canal will be
transported to each & every part of the
body. How Is this possible?

3. • By the
circulatory
system

4. – What is the organ that pumps the blood to
different body parts

7. Water pumping station Blood pumping station

9. electrical impulse that originates
in the pacemaker region
(sinoatrial node) of the heart and
initiates contractions of cardiac
muscle

11. Conducting pathways of heart beat

18. SA Node Atria Atrial
systole
AV
Node
AV
bundle
Right & left
bundle
branches
Purkinji
branch
es
Ventricular
muscles
Ventricular
systole

22. Picture of Pacemaker After InstallationPicture of Pacemaker Before
Installation

25. Heart Beat
The heart beats approximately 75 times per
minute in an adult, at rest. However, this can
change with exercise, emotional stress or
disease. The resting heart rate also varies
slightly with age, fitness and genetics.
At rest, the average heart rate (beats per
minute) for infants is 100-120,
for children aged 6-10 it is 80-100
for adults it is 60-80.

26. Cardiac cycle
• The cardiac cycle is
the sequence of
events that occurs
when the heart beats.
• It involves three steps
• 1. Atrial systole
• 2. Ventricular systole
• 3. Joint diastole

27. Atrial systole
• Contraction of
the auricles
• AV Valves will
be opened
• Blood flows
from auricles
to ventricles

28. Ventricular systole
Contraction of the ventricles
Semilunar valves are opened
AV Valves are closed
Blood flows from ventricles to
great arteries

29. JOINT DIASTOLE
• Auricles are
receiving the blood
from veins
• Opening of AV
valves
• Blood comes from
auricles to ventricles
• Closing of Semi
lunar valves

31. Lup & Dup sounds
These Two sounds are
together known as Heart
beat

34. • Why there is a delay in the contraction
of the Ventricles