Transcript 2.External Respiration

THE
RESPIRATORY
SYSTEM
RESPIRATION
Respiration
• supply O2 to & remove CO2 from all body
cells
3 main stages:
RESPIRATION
1. Breathing
Inspiration - taking air into the lungs
Expiration - removing air from the lungs
2.External Respiration
• exchange of O2 & CO2 between air and
blood.
RESPIRATION
3. Internal Respiration
• exchange of O2 & CO2 between blood and
cells
Cellular Respiration
• chemical reactions that take place in the
mitochondria to release energy from
glucose
GAS EXCHANGE
3 requirements:
1. surface area must be large enough to
occur very rapidly.
2. must take place in a moist environment
3. diffusion gradient must be maintained
(move from higher conc to lower conc)
GAS EXCHANGE IN ANIMALS
• respiratory pearson.notebook
HUMAN RESPIRATORY SYSTEM
Organs work together to move gases in and
out of body
NASAL CAVITY
• air enters nostrils or mouth
• warmed and moistened in
nasal cavity
• passes through pharynx
(throat), where the nasal
cavity meets the oral
cavity (for food)
PHARYNX
• the glottis is the opening
of the trachea (windpipe)
that leads air to the lungs.
• trachea is protected by the
epiglottis, which
prevents food from
entering
LARYNX
• larynx (voice box) is a small
opening in the trachea
controlled by muscles.
• contains the vocal cords
which vibrate to produce
sounds.
• pitch is determined by the
length of the cord.
TRACHEA & BRONCHI
• trachea supported by rings of
cartilage -keep it from collapsing
• branches into two forks called
bronchi (now in lungs)
• each bronchus branches into
smaller bronchioles
ALVEOLI
• Bronchioles end in tiny
air sacs, called alveoli.
Gas exchange occurs
in each alveolus.
• surrounded by a
network of capillaries
which allow CO2
and O2 to diffuse.
LUNGS
•
•
•
•
right lung has 3 lobes
left lung has 2 lobes
heart fits between
surrounded by layers of
tissue called pleura,
(allows them to expand
and retract)