ORGAN;LUNGS’
Our lungs contains about 750 millions
of air sacs or alveoli. Do you know
how much is the total surface area
of the walls of the air sacs?100 square
meters.Of this gaseous exchange takes
place on 80 square metres.But the total
surface area of the skin is only 1.6square
metre.
THE PARTS OF OUR LUNGS
LUNGS:Millions of minute air sacs in the lungs
give surface area for gas exchange.Lungs
are covered by double layered pleura.
NOSTRILS:Nares through which the respiratory
gases enter and go out.
NASAL CAVITY:A hollow space lined by
mucous membrane and
small hairs which prevent and
micro organisms from entering
trachea.It also warms up the air
PHARYNX:Common part for respiratory and digestive systems.
Epiglottis prevents food from entering the respiratory
duct by closing glottis.
TRACHEA:The continuation
of larynx. Trachean tubes are made
up of cartilagenous rings which divide into two bronchi
DIAPHRAGM:The muscular wall which separates thoracic and
abdominal cavity.
ALVEOLUS:Air sacs coverd by blood capillaries and is the
site of exchange of carbon dioxide and oxygen.
INHALATION
EXHALATION
rises
lowers down
lowers
rises
expands
contracts
decreases
increases
ribs
diaphragm
thoracic cavity
pressure
moves inwards
moves outwards
air circulation
RESPIRATION
During inspiration oxygen is taken into lungs
and during
expiration,carbon dioxide is released out.
Analyse the table of components
components Inhaled air
Oxygen
21
Exhaled air
14

Carbon dioxide
0.03
Water vapour
0.03
2
Temperature
20c
25c
5
CHEMISTRY OF
RESPIRATION
The energy for all activities is derived from the
oxidation
of nutrients in the food.
From each glucose
molecule, two
molecules of pyruvic acid are formed.This
chemical reaction
that occurs in the absence or without the
involvement of
oxygen is called glycolysis.
As a result of glycolysis 2
ATP[Adenosine
tri phosphate] molecules of energy are derived
from one
molecule of glucose.
Pyruvic acid undergoes a series of
chemical
reactions inside the mitochondria in the presence
of different
enzymes and oxygen.
As a result, the energy contained
in it is
released.This liberated energy is utilized for the
synthesis
of ATP.As byproducts carbon dioxide and
water are formed.
The main phase of this complicated chemical
process is called
Kreb’s Cycle.It occurs inside mitochondria.It
was Sir Adolph
Hans Krebs, a famous scientist who first
explained this cyclic
phase.Hence it is known Kreb’s Cycle.
Glycolysis and Kreb’s Cycle
together constitute
cellular respiration.As a result of complete
cellular respiration,
36 ATP energy is produced.
DONE BY,
SRUTHY.S.L,
SREEJA.L.S
1X: D
G.M.H.S.S.PATTOM
TRIVANDRUM