ORGAN
SYSTEM
ORGAN
TISSUE
CELLS
Organ System - group of organs working together
Organ - Tissue form organs
Tissue - cells with similar structure and function
form tissue
Cells – Basic unit of life
Body Systems
• Digestive System –
Living organisms require
energy to survive.
Humans obtain energy from:
1. Carbohydrates (sugar and
starch)
2. Lipids (fats and oils)
3. Protein (meat and
legumes)
This food energy must be
processed by the digestive
system in order for the body
to use it.
Types of Digestion
1. Mechanical digestion –
involves the physical
breakdown of food into
very small pieces.
2. Chemical digestion –
involves the breakdown of
large particles into smaller
particles by substances
called Enzymes.
Parts of the Digestive System
The digestive system is a long
tube that starts at your mouth
and ends at the rectum.
Mouth and Esophagus
1. Mechanical – teeth
2. Chemical – saliva (contains
water and enzymes called
Salivary Amylase. The
enzyme digests large starch
molecules into smaller
molecules.
Swallow food – Epiglottis
covers the trachea (wind
pipe), food moves down the
Esophagus in a wave like
movement called Peristalsis.
Peristalsis is caused by
contraction of smooth muscle
tissue.
2) Stomach
1. Mechanical – muscles
churn food.
2. Chemical – Gastric juices,
mucus, hydrochloric acid,
water, and digestive enzymes
break down proteins into
smaller particles. The food
(now a liquid) is released into
the small intestine.
3) Small Intestine – chemical
digestion continues.
Pancreas sends digestive
enzymes to the small
intestine and along with
enzymes released by the
small intestine, the
breakdown of the food is
complete.
Gall bladder – stores bile,
which breaks up lipids (fat)
into smaller droplets. The bile
is sent to the small intestine.
Bile is produced in the Liver.
The small intestine now
absorbs the nutrients into the
Epithelial Tissue, and then
into the blood stream.
The inner surface of the small
intestine is covered by Villi –
small, finger-like projections,
that increase the small
intestines surface area.
Villi – small
intestine
4)Large Intestine –
mechanical and chemical
digestion is complete.
Water is absorbed, along
with some vitamins and
minerals. Anything not
absorbed collects in the
rectum.
http://kitses.com/animation/swfs/digestion.swf
Respiratory System
Responsible for supplying
your blood with oxygen and
removing Carbon dioxide
from your blood.
Breathing
Occurs because of your ribs
and diaphragm muscles.
Inhale – muscles contract,
pulling ribs up and diaphragm
down. This increases the size of
the chest and lungs, decreasing
the pressure and pulling air
into the lungs.
Exhale – muscles relax,
pulling ribs down and
diaphragm up. This decreases
the size of the chest and lungs,
increasing the pressure and
forcing air out of the lungs.
Breathing
Your cells need oxygen to
release energy. Carbon
dioxide is produced when
energy is released and it must
be removed from the body.
Respiratory System
Oxygen – rich air enters the
Trachea via the mouth and
nose. Air travels down the
trachea through the Bronchi.
The bronchi narrow to form
Bronchioles, which end in air –
filled sacs called Alveoli.
Alveoli air hollow sacs (one
cell thick) surrounded by
capillaries. Gas exchange
happens in the alveoli.
Oxygen into the blood, carbon
dioxide into the lungs.
Alveoli