The Respiratory System
Organ System Connections
 The cardiovascular
system and the
respiratory system are
responsible for supplying
the body of oxygen and
disposing of carbon
dioxide
 Respiratory system deals
the gas exchange
 Cardiovascular system
deals with
transportation
Functional Anatomy
 Organs of the
respiratory system (in
order of air passage)





Nose/Mouth
Pharynx
Larynx
Trachea
Bronchi and their smaller
branches
 Lungs and alveoli
Nose
 Air enters the nose by
passing through the nostrils
 Separated by a nasal septum
 The interior of the nose is
called the nasal cavity
 Lined with respiratory
mucosa
 Rests on a rich network of
thin-walled veins that
function to warm the air as
it flows past
 These are what cause
nosebleeds
Pharynx
 Review
 True or false: This organ
is a part of the digestive
system and the
respiratory system
 TRUE! Remember: the
pharynx is for PHood,
PHluids, AND air
Larynx
 “Voicebox”
 Formed by 8 rigid hyaline
cartilage rings
 The epiglottis is also
located in this organ and
separates the larynx from
the esophagus
 What was the epiglottis
again?
 Flap of cartilage that
prevents food from
“going down the wrong
tube”
Trachea
 “Windpipe”
 Walls are reinforced with Cshaped rings of hyaline
cartilage
 Dual functions
 The open part of the C
allows the esophagus to
expand anteriorly when we
swallow
 The solid portions keep it
open during the pressure
changes that occur during
breathing
Bronchi
 There are 2 main bronchi
plus many pairs of
shorter branching
bronchioles
Lungs
 Flank the heart
 Lungs are covered with
serous membrane
 Visceral pleura
 Parietal pleura
 Pleural fluid in between
(basically plain old serous
fluid)
 Sound familiar? This is JUST
like how the heart is set up!
Lungs
 The primary bronchi (the
two main branches) enter
the lungs and then
subdivide into smaller and
smaller branches
 Called bronchioles
 The terminal set of
bronchioles lead into
respiratory zone structures
 Eventually terminate into
alveoli, small air sacs
Lungs: Alveoli
 The walls of the alveoli are
composed of a single, thin
layer of squamous
epithelial cells
 External surface of the
alveoli are covered with a
“cobweb” of pulmonary
capillaries
 Alveoli + capillary walls =
respiratory membrane
 Air (containing gases)
flows past on one side and
blood flows on the other
side
 This is also known as the
air-blood barrier
Gases
 Gas exchange
 Oxygen passes from the
alveolar air into the
capillary blood
 Carbon dioxide leaves the
blood to enter the gasfilled alveoli
Zones
 Respiratory zone
 Includes respiratory
bronchioles and
alveolar sacs
 Conducting zone
 All other respiratory
zone structures
Zones
 List the organs that are considered to be in each zone
 Respiratory zone:
 Bonchioles, alveoli
 Conducting zone:
 Nose, pharynx, larynx, trachea, bronchi
Accessory Organ
 Diaphragm: muscle that helps to inflate the lungs