THE RESPIRATORY SYSTEM
The respiratory system is very important in our every day lives. The respiratory system helps
us to breathe and stay alive.
What it does
It helps us to breathe by delivering oxygen to our body and taking away the carbon dioxide or
waste gases.
Organs in the respiratory system –
The main organs of this system are the lungs which are located in our chest or thorax. The other
organs are the trachea or wind pipe, bronchi and diaphragm. There is also the mouth and the
nasal cavity.
How it works –
Red blood cells pick up oxygen in our lungs and take it to all the body cells that need it. They
then pick up carbon dioxide which goes back into our lungs and then we exhale it. The trachea
acts as a filter for the air we breathe. The two air tubes that come off the trachea and carry air to
our lungs are the bronchi. The main muscle used in breather is the diaphragm and is situated at
the bottom of the lungs.
Interrelationships with other systems –
The respiratory system is vital to all parts of the body; eg. oxygen allows parts of the
integumentary system to grow and function. The cardiovascular and respiratory systems are
partners in supplying oxygen to cells and removing waste gases.
Fun facts –
1. The hairs and mucous in the nose filter the air for breathing.
2. When resting you breathe about 15 times every minute.
3. Our brain senses a shortage of oxygen when we are sleepy and this causes us to yawn.
THE DIGESTIVE SYSTEM
The digestive system helps us to break down and absorb food. Without this function we would
starve.
What it does –
Our digestive system turns the food we eat into smaller molecules and digestion is completed in
the small intestine.
Organs in the digestive tract –
The organs that make up the digestive tract are mouth, esophagus, stomach, small intestine,
large intestine or colon, rectum and anus.
How it works The organs in the digestive tract are hollow
and have a lining called mucosa. The
mucosa has tiny glands in the mouth,
stomach and small intestine which make
juices to help digest food. A layer of smooth
muscle helps move it along the tract.
Interrelationships with other systems –
The digestive system has an
interrelationship with the respiratory and
cardiovascular systems.
The cardiovascular and digestive systems
interrelate because some nutrients from the
digestive system are needed to keep the
heart at a normal rhythm. A defense
mechanism is performed by the
interrelationship of the respiratory and
digestive systems. The digestive system
provides important nutrients needed to help
the respiratory system to facilitate breathing.
Fun facts –
1. The small intestine is between 6 and 9 metres long.
2. The large intestine is much smaller at around 1.5 metres long.
3. The stomach is capable of expanding to hold four times its normal capacity.
THE MUSCULAR SYSTEM
The muscular system in our body is vital. Without muscles we couldn’t move, breathe and our
heart would stop. The three types of main muscles in our body are skeletal, cardiac or heart and
smooth muscles.
What it does –
Muscles give us our strength, posture, balance, movement and they also heat our body to keep
us warm.
Organs in the muscular system –
The heart and bladder are two muscles that are also organs.
How it worksThere are more than 650 muscles attached to our skeleton in our body. Smooth muscles are
called “involuntary muscles” because we have no control of them. They surround organs
including stomach and lungs. Skeletal muscles are attached to our bones and allow our body all
the movement it does. The cardiac muscles are found only in our heart. These muscles pump
blood through our body twenty-four hours per day.
Interrelationships with other systems –
The muscular system gives support t the non-skeletal parts of the body like all other organs
including skin etc. Direct support is given to tendons and ligaments and everything else is
indirectly supported.
Fun facts –
1. The largest muscle in the body is the one we sit on called the Gluteus Maximus.
2. There are over 600 different muscles that have been named by scientists.
3. Most muscles come in pairs so that one muscle pulls a bone one way and the other
muscle can pull back the other way.
ENDOCRINE SYSTEM
The endocrine system controls the processes in our body which occur slowly; eg. cell growth
and the endocrine glands produce most of our hormones. Breathing and body movement
are faster processes and are controlled by the nervous system.
What it does –
The endocrine system regulates our mood, growth and development, function of the tissues,
our metabolism as well as the reproductive processes.
Organs and glands in the endocrine system –
Some of the organs and glands in this system are hypothalamus. pituitary gland, thyroid
gland, heart, adrenal gland, kidney, stomach, pancreas and intestines.
How it works –
Some of the functions of the endocrine system are growth, repair and digestion. Hormones
that make this happen are chemicals produced by the endocrine glands. Hormones go
straight into our bloodstream and communicate with the body and this process brings about
changes in our body. The hormone comes from the blood stream and head to a certain cell
in order to change that cell.
Interrelationships with other systems –
The endocrine system relates to the nervous system, cardiovascular system – in fact every
system relates to each other as all body systems rely on each other to make the whole body
function.
Fun facts –
1. You can think of a hormone as a “key” and it won’t act on a part of the body where it
doesn’t “fit”.
2. The pituitary gland is located in the brain and hormone levels are managed by it.
3. The pancreas in inside the abdomen and it makes insulin.
INTEGUMENTARY SYSTEM
The integumentary system is made up of skin, hair, nails, glands and nerves. The skin is the
largest of the organ systems. In an adult it equates to about 16% of our total body weight. It
is 1 to 2 mm thick and has 4 tissue types.
What it does –
The main function of the integumentary system is protection of the body as it is the first
defense against infections and temperature changes.
Organs in the integumentary system –
Nails, skin, hair, glands and nerves belong in the integumentary system.
How it works–
It protects against sunburns, generates Vitamin D through exposure to sunlight, stores
water, fat and glucose, maintains body form and helps the doctor in a physical examination
as colour of the skin can indicate medical problems; eg. if you are jaundiced it becomes
yellow.
Interrelationship with other systems –
The Integumentary system relates to the immune system with the skin usually being the first
defence against diseases and micro organisms as well as the nervous system shown through
our sense of touch which occurs because neurons are embedded in our skin to sense the
outside world.
Fun facts 1. The different colours of skin are possible because of pigmentation.
2. Every minute you lose 30,000 to 40,000 dead skin cells as they fall from your body.
3. Each month our bodies have a whole new layer of skin.