Transcript Chapter 23 Respirati..

Chapter 23
Respiration and Excretion
When we exercise why do we breathe
hard?
• Because your body needs more energy to
sustain the activity that you are doing.
• The energy comes from the “burning” or
breakdown of food in your cells, which is
called Respiration.
What components make up the
respiratory system?
•
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Nose and Mouth
Pharynx
Trachea
Lungs
Nose and Mouth
• In most cases, air enters the respiratory
system through the nose.
• The nose has 2 openings called the nostrils,
which are lined with short hairs.
• What is the function of those hairs?
– Filter or screen out particles of dirt and dust from
entering the nasal cavity
Nose and Mouth cont.
• Air moving through the nasal cavity is filtered
and moistened done by 2 different types of cells.
• 1st kind of cell secretes a sticky substance called
mucus, which traps particles in the air from
entering the lungs.
• 2nd kind of cell is called cilia (tiny hair like
structures), which move back and forth, pushing
mucus back to the nostrils.
Nose and Mouth cont.
• Mucus that collects in the nostrils can irritate
the nose which causes you to sneeze.
• Sneezing is one way of blowing dirt and dust
from the nose.
Pharynx
• Is the throat and the pathway for both food and
air.
• At the end of the pharynx there is a fork in the
road (2 tubes)
– Esophagus: tube for food to travel to the stomach
– Windpipe: pathway of air to the lungs
Check for understanding
What is the function of the cilia in the nose?
1) Oxygen absorption
2) Movement of mucus to nostrils
3) Secretes musus
4) Kills bacteria
5) Helps you breath
What is the function of the Epiglottis?
• Flap of tissue where the esophagus and
windpipe meet which acts like a trap door.
• When you inhale, the epiglottis raises and air
moves into the windpipe.
• When you swallow the epiglottis lowers and
covers the windpipe.
Trachea (windpipe)
• It is a 13 cm long tube located in front of the
esophagus.
• At the top of the trachea is an organ called the
larynx, which is made of tough elastic tissue called
cartilage.
• The larynx contains 2 thin folds of skin called the
vocal cords.
• During normal, quiet breathing, the vocal cords
are relaxed, but when you speak they tighten
causing them to vibrate and produce sound.
Trachea cont.
• The trachea is made up of rings of
cartilage and smooth muscle .
• The cartilage keeps the trachea
open at all times so air can pass
through.
• Like the nasal cavity there are two
types of cells found in the trachea
one for secreting mucus and the
other cilia.
• Mucus in the trachea can cause
irritation which causes coughing.
Bronchi and Bronchioles
• The lower end of the trachea divides into 2
smaller tubes called the bronchi, which contain
rings of cartilage and smooth muscle.
• Within the lungs, the bronchus branches into
many smaller tubes called the bronchioles, which
are made only of smooth muscle.
• They also both secrete mucus and have cilia that
aid in trapping particles and transfer of mucus.
Check for understanding
• What is the function of mucus?
1) Helps you breath
2) Kills bacteria
3) Traps dirt, dust, and bacteria
4) Keeps respiratory system moist
Air sacs and Alveoli
• Bronchioles end in structures called air sacs or
alveoli.
• Each lung contains millions of alveoli.
– A network of capillaries surround them
– They are 1 cell thick
– Thin walls allow oxygen and carbon dioxide to be
transported easily.
Chapter 23
Respiration and Excretion
Gas exchange in the Alveoli
• The most important part of the respiratory
process is the exchange of gases O2 and CO2.
– Within the lungs these gases are exchanged between
the alveoli and the blood stream.
– O2 moves in the bloodstream at the same time as CO2
moves into the alveoli.
• How does this exchange take place?
– Diffusion
Gas exchange in the Alveoli cont.
Gas exchange in the Alveoli cont.
• When air enters the lungs, the O2 from the air
dissolve within the alveoli.
• The dissolved O2 then diffuses out of the alveoli
into the capillaries.
• At the same time CO2 in the capillaries diffuse
into the alveoli.
Transport and Exchange of Blood
• For Respiration to occur every
cell in your body must have O2.
• O2 from the lungs is carried by
red blood cells to the heart and
then is pumped to the rest of
the body.
• What is the pathway called
when blood is pumped
between the heart and the
lungs?
– Pulmonary Circulation
• Breathing and respiration are
related, but they are not the
same process.
• Respiration is a chemical
process.
• Breathing is a mechanical
process that is a part of the
Respiratory process.
– Breathing: is the process by
which air enters and leaves the
body.
– Your lungs can hold between 5-6 L
of air.
Breathing
How often do you breath?
• About 12 – 15 time per minute.
• The organs that make breathing possible are
the ribs, the rib muscles, and the diaphragm.
• Breathing is an involuntary action.
• 24hrs a day your rib muscles and diaphragm
contract and relax.
• However sometimes the diaphragm can have a
spasm, which causes you to have the hiccups.
Respiratory Diseases
• Pneumonia
• Bronchitis
• Asthma
Pneumonia
• Is one of the most common respiratory diseases.
• It is the inflammation of the lungs that is usually
cause by bacteria.
• Germs invade the lungs, as a result fluid fills the
lungs, which prevents the exchange of O2 and CO2
between the alveoli and the capillaries.
Bronchitis and Asthma
• These are 2 diseases that are
caused by particles trapped
in the bronchioles.
• Bronchitis is an inflammation
of the bronchioles.
– Symptoms: bad lasting cough
and difficulty breathing
• Asthma is when the muscular
walls of the bronchioles
contract, which causes them
to become narrow and there
is less room for air.