The Human Digestive System: A Comprehensive Overview
Introduction
The digestive system is
used for breaking down
food into nutrients
which then pass into the
circulatory system and
are taken to where they
are needed in the body.
Introduction
There
are four stages to
food digestion:
1.
Ingestion
: taking in food
2.
Digestion
: breaking
down food into nutrients
3.
Absorption
: taking in
nutrients by cells and
circulatory system
1.
Egestion
: removing any
leftover wastes
The Human Digestive System
Begins when food enters
the mouth.
It is physically broken
down by the teeth
.
It is begun to be
chemically broken down
by an enzyme in saliva
that breaks down
carbohydrates.
The Human Digestive System
The tongue moves the
food around until it
forms a ball called a
bolus
.
The bolus is passed to
the
pharynx
(throat) and
the
epiglottis
makes sure
the bolus passes into the
esophagus
and not down
the windpipe!
The Human Digestive System
The bolus passes down
the esophagus
by
peristalsis
.
Peristalsis
is a wave of
muscular contractions
that push the bolus down
towards the stomach.
The Human Digestive System
The stomach
has folds
called
rugae
and is a big
muscular pouch which
churns the bolus
(
Physical Digestion
) and
mixes bolus with gastric
juice, stomach acid, and
enzymes then churns it.
The Human Digestive System
The
acid
kills off any
invading bacteria or
viruses.
The enzymes help break
down proteins and lipids
= Chemical Digestion
.
The
mucus
protects the
lining of the stomach
from being eaten away
by the acid.
The Human Digestive System
The stomach absorb
some medicines (i.e.
aspirin), and water
The digested bolus is
now called
chyme
and
enters small intestine.
The Human Digestive System
Chyme goes into small
intestine (SI).
nutrients absorption
occurs in SI .
The liver and pancreas
adds more enzymes
SI is broken down into
three parts:
The Human Digestive System
1.
Duodenum
Bile
, produced in the
liver
but stored in the
gall bladder
, enters
through the
bile duct
.
It breaks down fats.
The
pancreas
secretes
pancreatic juice
to
reduce the acidity of
the chyme.
The Human Digestive System
2.
Jejunum
The jejunum is where
the majority of
absorption takes place.
It has tiny fingerlike
projections called
villi
lining it, which
increase the surface
area for absorbing
nutrients.
The Human Digestive System
Each villi itself has tiny fingerlike projections called
microvilli
, which further increase the surface area for
absorption.
Blood going to the Small
Intestine
The circulatory system sends blood to the digestive
system (especially the small intestine) to carry away
the digested nutrients to other parts of the body.
Your muscles, bones, skin, organs (in essence,
everything) needs nutrients from the digested food. It
is your blood that delivers all of these nutrients.
Circulatory Sys.
This slide shows how
blood enter the
microvilli to carry
nutrients away to other
parts of the body.
The Hormone Gastrin
The circulatory system’s role…
What percentage of the
blood leaving heart goes
directly to the digestive
system?
The Hormone Gastrin
The Human Digestive System
3.
Ileum
The last portion of the
small intestine is the
ileum,
which has fewer
villi and
basically
compacts the leftovers
to pass into the large
intestine.
The Human Digestive System
The
large intestine
(or
colon
) is used to
absorb
water
from the waste
material leftover and to
produce
vitamin K
and
some
B vitamins
using
the helpful bacteria that
live here.
The Human Digestive System
All leftover waste is
compacted and stored at
the end of the large
intestine called the
rectum
.
Digestion and Homeostasis
The endocrine, nervous,
digestive and circulatory
systems all work together
to control digestion.
Before we eat, smelling
food releases
saliva
in
our mouths and
gastrin
in our stomachs which
prepares the body for a
snack.
The Hormone Gastrin
Digestion and Homeostasis
A large meal activates
receptors that churn the
stomach and empty it
faster.
If the meal was high in
fat, digestion is slowed,
allowing time for the fat
to be broken down.
Hence why we feel fuller
after eating a high fat
meal.
The digestive system plays a vital role in breaking down food into nutrients for absorption. This process involves stages like ingestion, digestion, absorption, and egestion. Beginning with the mouth, food moves through the esophagus, stomach, and small intestine for digestion and absorption of nutrients. Each organ and enzyme in the digestive system has a specific function in ensuring nutrients are properly processed and absorbed by the body.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
Introduction The digestive system is used for breaking down food into nutrients which then pass into the circulatory system and are taken to where they are needed in the body.
Introduction There are four stages to food digestion: 1. Ingestion: taking in food 2. Digestion: breaking down food into nutrients 3. Absorption: taking in nutrients by cells and circulatory system 1. Egestion: removing any leftover wastes
The Human Digestive System Begins when food enters the mouth. It is physically broken down by the teeth. It is begun to be chemically broken down by an enzyme in saliva that breaks down carbohydrates.
The Human Digestive System The tongue moves the food around until it forms a ball called a bolus. The bolus is passed to the pharynx (throat) and the epiglottis makes sure the bolus passes into the esophagus and not down the windpipe!
The Human Digestive System The bolus passes down the esophagus by peristalsis. Peristalsis is a wave of muscular contractions that push the bolus down towards the stomach.
The Human Digestive System The stomach has folds called rugae and is a big muscular pouch which churns the bolus (Physical Digestion) and mixes bolus with gastric juice, stomach acid, and enzymes then churns it.
The Human Digestive System The acid kills off any invading bacteria or viruses. The enzymes help break down proteins and lipids = Chemical Digestion. The mucus protects the lining of the stomach from being eaten away by the acid.
The Human Digestive System The stomach absorb some medicines (i.e. aspirin), and water The digested bolus is now called chyme and enters small intestine.
The Human Digestive System Chymegoes into small intestine (SI). nutrients absorption occurs in SI . The liver and pancreas adds more enzymes SI is broken down into three parts:
The Human Digestive System Duodenum Bile, produced in the liver but stored in the gall bladder, enters through the bile duct. It breaks down fats. The pancreas secretes pancreatic juice to reduce the acidity of the chyme. 1.
The Human Digestive System 2. Jejunum The jejunum is where the majority of absorption takes place. It has tiny fingerlike projections called villi lining it, which increase the surface area for absorbing nutrients.
The Human Digestive System Each villi itself has tiny fingerlike projections called microvilli, which further increase the surface area for absorption.
Blood going to the Small Intestine The circulatory system sends blood to the digestive system (especially the small intestine) to carry away the digested nutrients to other parts of the body. Your muscles, bones, skin, organs (in essence, everything) needs nutrients from the digested food. It is your blood that delivers all of these nutrients.
Image result for small intestine function in circulatory system Circulatory Sys. This slide shows how blood enter the microvilli to carry nutrients away to other parts of the body. The Hormone Gastrin
The circulatory systems role Image result for small intestine function in circulatory system What percentage of the blood leaving heart goes directly to the digestive system? The Hormone Gastrin
The Human Digestive System 3. Ileum The last portion of the small intestine is the ileum, which has fewer villi and basically compacts the leftovers to pass into the large intestine.
The Human Digestive System The large intestine (or colon) is used to absorb water from the waste material leftover and to produce vitamin K and some B vitamins using the helpful bacteria that live here.
The Human Digestive System All leftover waste is compacted and stored at the end of the large intestine called the rectum.
Digestion and Homeostasis The endocrine, nervous, digestive and circulatory systems all work together to control digestion. Before we eat, smelling food releases saliva in our mouths and gastrin in our stomachs which prepares the body for a snack. The Hormone Gastrin
Digestion and Homeostasis A large meal activates receptors that churn the stomach and empty it faster. If the meal was high in fat, digestion is slowed, allowing time for the fat to be broken down. Hence why we feel fuller after eating a high fat meal.
