Download The Human Respiratory System

Human Respiratory
System
By: D. Reis
The Respiratory System
• Air enters the respiratory system through
both the nasal cavity and mouth.
• The nasal cavity is lined with tiny hairs and
mucus to trap foreign particles.
• The air is warmed and moistened.
Respiration and Gas Exchange
The Respiratory System
• Pharynx – where the
nasal cavity and oral
cavity meet
• Epiglottis – flap that
closes over the top of
the trachea(glottis) due
to reflexive action while
eating
• Trachea – the windpipe
through which air passes
Supported by cartilage
rings
The Respiratory System
• Larynx – voicebox
located in the trachea
containing vocal cords.
The vocal cords vibrate
producing sounds.
• Adam’s Apple – thick
band of cartilage
protecting larynx.
The Respiratory System
• Bronchi – extend
from the trachea also
contains cartilage
• Bronchioles – the
smallest passageways
of the respiratory tract
• Alveoli – tiny air sacs
where gas exchange
occurs between the air
and the blood
Alveoli
• Each lung is made up of 150
million alveoli.
• Capillaries surround each
cluster of alveoli and ensure
gas diffusion between the air
and blood occurs.
• Oxygen moves from the air
inside the lungs to the alveoli
while carbon dioxide moves
from the alveoli into the air
inside the lungs.
• Lipoprotein prevents alveoli
from sticking together
Goblet cells
• Goblet cells – mucus
secreting cells lining
the trachea, bronchi
and bronchioles to
trap foreign particles.
• Cilia - hair like
structures that sweep
the foreign particles
up towards the mouth
Thoracic Cavity
• External intercostal muscles
– muscles between the ribs
that raise the rib cage,
increasing volume and
reducing air pressure in
chest.
• Diaphragm – muscle that
separates organs of the chest
from abdominal cavity.
• Pleural membrane – thin fluid-filled membrane
surrounding lungs and inner wall of chest cavity that
reduces friction during inhalation.
The Movement of Air
• Air moves from an area of high pressure to
an area of low pressure.
• Air will move into the lungs when the air
pressure inside the lungs is less than the air
pressure outside the body.
• Air will move out of the lungs when the air
pressure inside the lungs is______ than the
air pressure outside the body.
Inspiration (Inhaling)
• The diaphragm contracts and moves down
• External intercostal muscles expand rib
cage upward and outward
• Volume of thoracic cavity increases
therefore air pressure decreases.
• Movement of air into the lungs.
Expiration (Exhaling)
• The diaphragm relaxes and moves up
• External intercostal muscles move rib cage
inward and downward.
• Volume of thoracic cavity decreases
therefore air pressure increases.
• Movement of air out of the lungs.