Digestion in Human Beings - Nutrition in Animals - CBSE Class 7 Science Video Lecture

digestion in human beings human beings
take food through mouth and digest it in
specific organs for digestion the
undigested food is defecated the food we
take passes through a specific canal
which begins with buccal cavity and ends
at the anus this canal is called
elementary canal or the digestive tract
the paths of the elementary canal are
buccal cavity
ESO Vegas
stomach
large intestine small intestine rectum
and anus the food gets digested
gradually as it passes through the
various parts of the track digestive
juices secreted by the salivary glands
liver and pancreas also aid digestion
mouth and the buccal cavity food intake
in human beings is through mouth this
process of taking food is called
ingestion chewing food is very necessary
for proper digestion as digestion
process starts in the mouth itself what
happens during chewing the large pieces
of food we eat are mechanically broken
down into small pieces teeth helps us in
doing so action of saliva on food during
chewing food mixes with saliva saliva is
secreted from salivary glands located on
the lower jaw between the tongue and
teeth saliva converts starch in the food
into sugars and also soft ins the food
tongue taste of food can be detected by
the taste buds present on the tongue
dung is a fleshy muscular organ attached
to the floor of the buccal cavity it is
free at the front and moves in all
directions taste buds appear as small
bumps on the tongue and have different
regions which help us enjoy different
tastes
esophagus or food pipe the swallowed
food from the mouth passes on to the
east figures the epiglottis which is a
flap like structure behind the tongue
directs the food into the East of Vegas
and prevents entry into the larynx the
peristaltic movements of the east of
pages helps the food to move down the
tract
till it reaches the stomach stomach
stomach is a bag like structure with
thick wall it is in the shape of a
flattened u and is the widest part in
the elementary canal
the food that enters the stomach is
churned and mixes with the mucus
hydrochloric acid and digestive juices
secreted by the inner lining of the
stomach the acid helps to kill the
bacteria present in the food it also
makes the medium in the stomach acid ick
the digestive juice is secreted by the
stomach break down proteins into simpler
substances then the food is emptied into
small intestine
small intestine small intestine is a
highly coiled structure and is about 7.5
meters long as soon as a small intestine
receives food from the stomach the
digestive juices from liver and pancreas
are mixed into it
liver liver is the largest gland in the
human body and is situated in the upper
side of the abdomen to the right it is
reddish-brown in color it secretes bile
which breaks down fats bile is stored in
gall bladder between meals pancreas
pancreas is a leaf shaped and
cream-colored gland located just below
the stomach it secretes pancreatic juice
which acts and breaks down carbohydrates
proteins and fats after this is
completed the partially digested food
reaches the lower part of the small
intestine where intestinal juices act
upon food and completes digestion of any
remaining components in food the
carbohydrates in the food break down
into sugars like glucose fats into fatty
acids and glycerol and proteins into
amino acids the food consumed is
digested and is now ready to be absorbed
into the blood absorption of food in the
small intestine the inner wall of the
small intestine has finger-like
projections called villi which have a
network of thin blood vessels close to
the surface
the Willis increases the surface area of
absorption and absorbs the digested food
materials the substances thus absorbed
are transported through the bloodstream
to different organs in the body and are
used to build complex substances like
proteins this process is called a
simulation in the cells glucose breaks
down into carbon dioxide and water with
the help of oxygen and releases energy
the undigested and unabsorbed food
enters the large intestine large
intestine the large intestine is wider
than small intestine and measures 1.5
metres in length
once the undigested food enters the
large intestine it absorbs water and
some salts from it and passes the
remaining waste into the rectum here it
remains as semi-solid thickest the fecal
matter is removed through the anus this
is called ejection