You have
air passages that consist of nasal passages, an oral cavity, throat (pharynx), a
trachea and two
bronchi .
You have
two lungs consisting of thousands of air sacs called
alveoli . This increases the area of the lungs to the size of a badminton court.
The
diaphragm and
intercostal muscles.
Class activity: study of the lungs of a sheep or a pig
If possible, your educator should have the lungs of a sheep or a pig in the classroom for you to examine while working through this unit.
the human respiratory system
Processes:
There are other systems besides the digestive system that are important for the effective functioning of the body. We will examine the systems for respiration, excretion, propulsion and reproduction, as well as the skeleton.
Every cell in the body of a living organism needs oxygen for
RESPIRATION . It is the
ENERGY-GIVING PROCESS during which glucose is “burned” in the presence of oxygen. The waste product of this process is carbon dioxide.
The part of the cell where this occurs, is the
mitochondria .
These substances get to and from the cells by means of the bloodstream.
BREATHING and
EXCHANGE OF GASES are the processes by which oxygen arrives in the blood and carbon dioxide leaves the blood.
BREATHING: the process by which air moves into and out of the lungs with the help of muscle action. The process of breathing in, or inhalation, is also known as
INSPIRATION and breathing out, or exhalation, is known as
EXPIRATION .
EXCHANGE OF GASES : The process by which gases such as carbon dioxide in the blood and oxygen that is in the air in the lungs are exchanged to get oxygen into the blood and to the cells.
RESPIRATION : the energy-giving process that occurs in the mitochondria in cells. Often people use the term Respiration incorrectly when they mean breathing.
Adaptations that facilitate these processes:
for
BREATHING , we have a
DIAPHRAGM, a muscular partition below the lungs that separates the thoracic and abdominal cavities and contracts and relaxes to alter pressure in the thoracic cavity. There are also
INTERCOSTAL MUSCLES that raise and lower the ribcage.
for
GASEOUS EXCHANGE in the lungs, there are thousands of air sacs, or ALVEOLI, with very thin, moist walls filled with blood vessels.
for
GASEOUS EXCHANGE in the tissues there are fine blood capillaries that extend to each cell, and
tissue fluids that surround the cells and the mitochondria.
EXPLAIN EACH OF THE ADAPTATIONS IN THE TABLE:
Diaphragm
Intercostal muscles
Thousands of alveoli
Thin-walled blood capillaries
Alveoli with single-layer epithelia
Mucus membrane with cilia
Class assignment: DRAWING
Make a sketch to illustrate the alveoli and the blood capillaries that facilitate the movement of gases.
