Download The Respiratory System

The Respiratory System
Parts and function
Acquiring Energy

ATP is the energy currency for all cells


It is required as an energy source for
performing activities such as building proteins
to moving to a new location, to secreting a
message to other cells, or to splitting into two
new cells.
Cells use energy in food molecules to build
ATP

There are two ways in which a cell can do this
• Fermentation or Cellular Respiration
Fermentation

This is a means of breaking down
food into ATP without the presence
of Oxygen
Fermentation is used primarily by
single-celled microscopic fungi called
yeast and some bacteria.
 It may also occur in the muscle cells of
animals when oxygen is depleted by
vigorous exercise

• A biproduct of this reaction is lactic acid
which causes muscle cramps
Cellular respiration



This process requires molecular oxygen
In summary: There is an enzymecontrolled chemical reaction between the
food molecules and some oxygen which
results in the release of energy from the
food. The energy is used to make ATP.
Reaction

Glucose + Oxygen = CO2 + Water
The net gain is 36-38 molecules of ATP per
molecule of glucose
The Respiratory System
In order for cellular respiration to
occur, organisms must have oxygen
and that oxygen must somehow get
to all of the cells in the body
 This is the purpose of the
Respiratory System

It includes lungs, bronchi, and trachea
 It also requires the circulatory system
to transport gases to and from the cells

The alveoli are surrounded by capilaries which
allow the oxygen to be moved from the lungs into
the circulatory system for transport to the rest of
the body
The Function

It draws oxygen into the body for
eventual distribution to cells and to
remove carbon dioxide from the body



These two gases are exchanged between the
blood and the atmosphere by diffusion in
opposite directions across an external surface
In fish this surface is the gills
In terrestrial animals, the surface must be
inside the body or it would quickly dry out is
exposed to the environment.
Moving oxygen in and
carbon dioxide out


Because the lungs are located internally,
there must be a way to get the air
containing oxygen into one’s body and
moving air containing carbon dioxide
away from the surface
This is solved by breathing or ventilation

Lungs are able to ventilate the body through
alternating expansion and contraction
Inhalation


Stimuli from the neurons cause the
diaphragm to contract and the intercostal
muscles to raise the rib cage
These actions increase the volume of the
thoracic cavity, resulting in lower air
pressure within the thoracic cavity

At this point there is a higher air pressure
inside the lungs that outside in the thoracic
cavity resulting in the expansion of the lungs
and air being drawn in through the trachea
Exhalation



Relaxation of the diaphragm causes it to
push up into a dome shape below the
lungs
Relaxation of the intercostal muscles
cause the ribs to come down
These actions cause the thoracic cavity to
decrease in volume resulting in greater
air pressure outside the lungs than inside,
causing the lungs to compress, forcing air
out of the lungs.
The Heimlich Maneuver


This is an effective way to remove food
from the throat of a choking victim
Before performing, you must first
determine if person is really choking


If the person can speak, do NOT use the
Heimlich maneuver
If they cannot speak and have their hand at
their throat, it is appropriate to perform the
maneuver