Download Respiratory System Honors Biology Mr. Lee Room 320

Respiratory System
Honors Biology
Facilitator: Mr. Lee
Room 320
Objectives
• Describe respiration
• Identify the function of the respiratory
system
• Describe gas exchange
Introduction
• The respiratory system transports gases to
and from the cardiovascular system
• The respiratory systems involves:
– External respiration- exchange of gases
between the atmosphere and the blood
– Internal respiration- exchange of gases
between the blood and the cells
Human Respiration System
• Exchanges oxygen and carbon dioxide between
blood, air, and tissues
• The respiratory system consists of:
– Nose
– Pharynx (throat)
– Larynx (voice box)
– Trachea (windpipe)
– Bronchi
– Lungs
Respiration 3D Medical Animation
Human Respiration System…
• Nose:
– Air is warmed,
moistened, and filtered
before entering the lungs
– There are hairs lining the
nasal cavity that trap
large dust particles.
– Mucus moistens the air
and traps dust and smoke
Human Respiration System…
• Pharynx (throat):
– Passage way for both air and
food
• The Larynx (voice box):
– Located on top of the trachea
• Trachea (windpipe):
– Epiglottis- flap of tissue that
covers the trachea when you
swallow
– Cilia sweep the trapped
particles and mucus away from
the lungs (to be either
swallowed or spit out)
– At the lungs, branches into
bronchi
Human Respiration System…
• The Bronchi:
– Are two large
passageways in the chest
cavity
– Lined with cilia and
mucus
– Each one leads to a lung
Human Respiration System…
• In the lung, each bronchus subdivides
into smaller bronchioles, and then to
millions of tiny air sacs called alveoli
• Alveoli are grouped in clusters like
grapes and are surrounded by capillaries
Gas Exchange
• The average healthy lung has over 150 million
alveoli
• Oxygen dissolves in the moisture on the
surface of the alveoli, and then diffuses
through the capillaries
• Carbon dioxide diffuses in the opposite
direction
Gas Exchange…
• The air that you inhale usually contains 21%
oxygen and .04% carbon dioxide
• The air you exhale usually contains less than
15% oxygen and 4% carbon dioxide
• 97 % of the oxygen moves into red blood cells
– Hemoglobin has four iron atom, each one
can hold one oxygen molecule
• Most of the CO2 reacts with water in plasma to
form carbonic acid, and then bicarbonate ions
Mechanism of Breathing
• There are no muscles connected
to the lungs
• The force that drives the air into
the lungs comes from air pressure
• The lungs are sealed in two sacs
called the pleural membranes
inside the chest cavity
• At the bottom of the chest cavity
is a large flat muscle called the
diaphragm
Breathing…
• As you breathe, the diaphragm contracts and
the rib cage rises up making a partial vacuum,
causing air to rush into the lungs
• Breathing is such an important function that
your nervous system will not let you take
complete control of it
• Inspiration- taking air into the lungs
• Expiration- releasing air out of the lungs
Breathing…
• Controlled by the medulla oblongata
• Cells in its breathing center monitor the
amount of carbon dioxide in the blood
• As CO2 level increases, nerve impulses from
the breathing center cause the diaphragm to
contract
Review
• Describe respiration:
– The respiratory system transports gases to
and from the cardiovascular system
– The respiratory systems involves:
• External respiration- exchange of gases
between the atmosphere and the blood
• Internal respiration- exchange of gases
between the blood and the cells
• Identify the function of the respiratory
system:
– Exchanges oxygen and carbon dioxide
between blood, air, and tissues
Review…
• Describe gas exchange:
– Oxygen dissolves in the moisture on the
surface of the alveoli, and then diffuses
through the capillaries
– Carbon dioxide diffuses in the opposite
direction
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