Transcript Organismsc - ClarissaGBiology2010

In the Human body, everything a human
does has a system.
 All systems work together to help the
body function.


There are four mains systems within the
human body; the Respiratory System, The
Circulatory System, the Nervous System,
and the Digestive System.
The Respiratory System
The anatomical features of the
respiratory system include airways, lungs,
and the respiratory muscles.
 Molecules of oxygen and carbon
dioxide are constantly exchanged,
through diffusion, between external
environment and blood.
 This exchange process occurs in the
alveolar region of the lungs.

Air enters the nostrils, passes through the
nasopharynx, the oral pharynx, through
the glottis into the trachea, into the right
and left bronchi, which branches into
bronchioles, each of which terminates in
a cluster of alveoli.
 In the alveoli does actual gas exchange
take place. There are about 300 million
alveoli in two adult lungs.

The Circulatory System
The circulatory system passes nutrients
(like amino acids, electrolytes, and
lymph), gases, hormones, blood cells, to
and from cells in the body to help fight
diseases and to help stabilize body
temperature and pH to maintain
homeostasis.
 This System does not only distribute
blood, but also lymph (through the
lymphatic system).

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The Circulatory System is so vast, but it
reaches almost every point in the body; first
blood leaves the heart from the left
ventricle into the biggest artery, called the
aorta. It is important that fresh blood from
the aorta goes directly to the brain,
because the brain needs oxygen
constantly. Another important organ for the
blood to pass through is the lung. Here
waste carbon dioxide is replaced with fresh
oxygen. Then blood returns to the heart
through the veins.
The Nervous System
The Nervous system is a network of neurons
that coordinate the actions of a human
and send signals between different parts of
the body.
 The nervous system consists of two parts;
central and peripheral. The central nervous
system of vertebrates contains the brain,
spinal cord, and retina. The peripheral
nervous system consists of clusters of
ganglia (sensory neurons), and nerves
connecting them to each other and to the
central nervous system.


With every touch, a nerve feels the
touch and sends a message to the brain
using electrochemical waves traveling
along fibers called axons. The nerves can
also communicate this way.
The Digestive System

The human digestive system is a complex
chain of organs and glands that process
food. In order to utilize the food humans
eat, the body has to break food down
into smaller molecules that it can process
and has to excrete waste.

The process starts in the mouth. Once
the food is chewed so it can be
swallowed, the esophagus forces the
food into the stomach. Here the food is
partly digested with stomach acids
called chyme. Then it travels through the
small intestine, big intestine, and then it is
on its way out of the body.

Example: The Respiratory system helps us
breathe and gets fresh air to our lung which
gives the air to our blood. Our blood brings
this oxygen to the body helping it process
nutrients that the Digestive system breaks
down from food. We get food through our
nervous system receiving messages that our
body is hungry so we can eat to fuel our
bodies. When these nutrients are broken
down it is carried through the blood stream
to all of the cells in our body so we can
create energy to do things which keeps us
alive.