A system is made up of interrelated parts that
work together to perform a single task. There
are thousands of systems at work every day in
society, in machines, and in our own bodies.
An example of a system is the digestive system,
which includes the stomach and the intestines.
These organs and others work together to
digest food.
Systems can also be made up of interrelated
processes. For example, energy production in
plants is a system that consists of two main,
interrelated processes - photosynthesis and
respiration.
A closed-loop system is a system with feedback
that can change its processes based on the
feedback. It is the opposite of an open-loop
system.
Change in one part of a system affects the
whole system. Since all the parts are
dependent on each other, the system
processes could come to a stop. An example of
this is a car. Change in just one part, like the
battery failing, means the car will not start or
run, even though the other parts of the car are
running smoothly.
The raw material that is added to a system is
known as the input. For example, the input for
the digestive system is food that is eaten.
The finished product or waste that forms as a
result of a process is known as the output. For
example, the output of the digestive system is
energy and wastes.
When the output of a system comes back to
influence the subsequent functioning of that
system, feedback occurs.
There are two main types of feedback:Positive
feedback occurs when the output of a system
amplifies subsequent outputs of the system.
Negative feedback occurs when the output of
a system causes subsequent outputs to
decrease.
What do the lunar cycle, bird migration, and
cell mitosis have in common?
• They are all natural events that occur in a
pattern.
• They are all included in the discipline called
biology.
• None of them are predictable.
• None of them are studied by scientists
today.
All of the natural events in the list have a
predictable recurring pattern.
In fact, most natural events occur in patterns.
Scientists often look for patterns when
studying a new phenomenon.
In a production system that makes cars, the
bumper division produces an output of
_______ that becomes an input to the
assembly division.
energy
material
information
electricity
The output of the bumper division is bumpers
for the cars. Bumpers are a form of material.
The bumpers are then put on the cars by the
assembly division.
Sending an e-mail is an example of a system
with multiple parts.
An e-mail program takes the input from the
keyboard and changes it into a computer
language output. The output language goes
through the internet system and finds the
account it was sent to. The message becomes
the input for another e-mail program which
changes it into an output of text that the
recipient can read.
What is the primary type of input and output
that is used in an e-mail system?
The primary input and output of an e-mail
system is information. The information in the
email is changed into different forms as it
travels through the system.
Energy is used in the process, but it is not the
primary form of the input and output.
System input is the raw material that is put
into a system for processing. In the case of the
digestive system, food is the input. The output
is energy and waste. The system process is the
digestion itself, including chewing, chemical
breakdown of the food in the stomach, and
nutrient absorption in the intestines.
A system is a set of interrelated parts. The
outputs from one part of a system can become
inputs to other parts of the system.
For example, an e-mail system takes the input
from a keyboard and changes it into a
computer language. The output form of the
message becomes an input to the internet as it
travels to the account it was sent to. This
becomes the input for the other person's email program, which changes it into an output
of text that the recipient can read.
Inputs and outputs in systems may include
material, energy, or information.
Change is a variable. It can come as a result of
new knowledge and better technology. Or it
can happen due to the malfunctioning of a
machine or a broken part. It can happen as a
result of feedback that a system receives. All
systems deal with change. Change in one part
of a system affects the whole system.
Input:
Process:
Feedback?
Process:
Process:
Mouth and esophagus, large intestine,
small intestine, stomach, liver and
pancreas
Output:
POSITIVE or NEGATIVE?
Celiac disease is a digestive disorder caused by
the abnormal response of the immune system
to a protein called gluten, which is found in
certain foods. People with celiac disease have
difficulty digesting the nutrients from their
food because eating things with gluten
damages the lining of the intestines over time.
Some of the symptoms are diarrhea,
abdominal pain, and bloating. The disease can
be managed by following a gluten-free diet.
Gastritis and peptic ulcers. Under normal
conditions, the stomach and duodenum are
extremely resistant to irritation by the strong
acids produced in the stomach. Sometimes,
though, a bacterium called Helicobacter
pylori or the chronic use of certain medications
weakens the protective mucous coating of the
stomach and duodenum, allowing acid to get
through to the sensitive lining beneath. This
can irritate and inflame the lining of the
stomach (a condition known as gastritis) or
cause peptic ulcers, which are sores or holes
that form in the lining of the stomach or the
duodenum and cause pain or bleeding.
Medications are usually successful in treating
these conditions.
Cystic fibrosis is a chronic, inherited illness
where the production of abnormally thick
mucus blocks the ducts or passageways in the
pancreas and prevents its digestive juices from
entering the intestines, making it difficult for a
person to properly digest proteins and fats.
This causes important nutrients to pass out of
the body unused. To help manage their
digestive problems, people with cystic fibrosis
can take digestive enzymes and nutritional
supplements.
Hepatitis is a viral infection in which the liver
becomes inflamed and can lose its ability to
function. Some forms of viral hepatitis are
highly contagious. Mild cases of hepatitis A can
be treated at home; however, serious cases
involving liver damage may require
hospitalization.
Irritable bowel syndrome (IBS) is a common
intestinal disorder that affects the colon. When
the muscles in the colon don't work smoothly,
a person can feel the abdominal cramps,
bloating, constipation, and diarrhea that may
be signs of IBS. There's no cure for IBS, but it
can be managed by making some dietary and
lifestyle changes. Occasionally, medications
may be used as well.
Esophagitis (pronounced: ih-saf-uh-jeye-tus)
or inflammation of the esophagus, is an
example of a noncongenital condition.
Esophagitis is usually caused
by gastroesophageal reflux disease (GERD), a
condition in which the esophageal sphincter
(the tube of muscle that connects the
esophagus with the stomach) allows the acidic
contents of the stomach to move backward up
into the esophagus. GERD can sometimes be
corrected through lifestyle changes, such as
adjusting the types of things a person eats.
Sometimes, though, it requires treatment with
medication. Occasionally, esophagitis can be
caused by infection or certain medications.
congenital - meaning people are born with them
noncongenital - meaning people can develop them after birth
Tracheoesophageal fistula (pronounced: traykee-oh-ih-saf-uh-jee-ul fish-chuh-luh)
and esophageal atresia (pronounced: ih-safuh-jee-ul uh-tree-zhuh) are both examples of
congenital conditions. Tracheoesophageal
fistula is where there is a connection between
the esophagus and the trachea (windpipe)
where there shouldn't be one. In babies with
esophageal atresia, the esophagus comes to a
dead end instead of connecting to the
stomach. Both conditions are usually detected
soon after a baby is born — sometimes even
beforehand. They require surgery to repair.
congenital - meaning people are born with them
noncongenital - meaning people can develop them after birth
Input:
Process:
Feedback?
Process:
Process:
Output:
POSITIVE or NEGATIVE?
Bread Rippage (BR) is a common problem
with today’s store brand breads. The problem
manifests itself by having large holes form in
the bread while you’re trying to spread peanut
butter on the bread. Crunchy style peanut
butter can contribute to BR.
Sticky Fingers occurs when you get
jelly/peanut butter on your hands. It is most
often caused by not using a knife to spread, or
using too short of a knife, or trying to get the
last bit of peanut butter out of an empty jar. It
can effect the quality of your sandwich or
feature sandwiches.
Loss of Jelly is when gobs of jelly fall from the
sandwich. If left untreated, it can further lead
to sticky fingers.
Open Face Disorder is when the two slices of
bread are layered backwards, so the jelly and
peanut butter are on the outside of the bread
instead of the inside. Very bad.