Download Respiratory System

Respiratory System
The main function of the respiratory system is to
supply oxygen to, & eliminate carbon dioxide
from the body
In order to accomplish this task, the respiratory
system must work in conjunction with the
cardiovascular system
Functions of the Respiratory System
• A. Uptake of oxygen into the blood and the
elimination of carbon dioxide out of the blood
(Pulmonary Ventilation, External Respiration)
• B. Vocalization (Larynx)
• C. Olfaction (Smell)
Regions of the Respiratory System
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A. Nasal Cavities
B. Pharynx – Throat
C. Larynx – Voicebox
D. Trachea – Windpipe
E. Lungs
Anatomy Overview
Nasal cavity
Pharynx
Larynx
Trachea
Bronchi
The respiratory tract includes:
Nose (nasal cavity) Pharynx
(nasopharynx, oropharynx,
laryngopharynx) Larynx
Trachea Bronchi (primary,
secondary (lobar), tertiary
(segmental) Bronchioles
Terminal bronchioles Respiratory
bronchioles Alveolar ducts
Alveoli
Bronchioles
Respiratory
bronchioles
Right
Lung
Left
Lung
Alveolar duct
Alveoli
Histology
Respiratory Epithelium =
Pseudostratified Ciliated
Columnar (PSCC)
III. The Nasal Cavities
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A. Nasal Cartilages
B. Anterior Nares (Nostrils)
Rhinitis – clinical term for cold
Rhino means nose
C. Olfactory Receptors
D. Cribriform Plate of the Ethmoid Bone
E. Nasolacrimal Aperture
Cribriform Plate
Ethmoid Bone
Nasolacrimal Aperture – tears come
out of your nose
• F. Nasal Septum
• G. Nasal Conchae (“Shelves”)
• H. Paranasal Air Sinuses – when you inhale air
it goes into the paranasal air sinuses lined
with ciliated epithelium
• * Frontal Sinus to the Sphenoid Sinus
• * If the sinuses become infected it is called
sinusitis
• I. Choanae (Posterior Nares)
• Sinuses are lined with ciliated epithelium that
warms and humidifies the air
Choanae (Posterior Nares)
• Pharyngeal Tonsil – if it is enlarged it is called
an adenoid
The Pharynx
• A. Nasopharynx
Pharynx
Air passes from nasal cavity, across internal nares into nasopharynx, past
oropharynx & through laryngopharynx to larynx
Nasopharynx lined with PSCC epithelium, but oro & laryngopharynx lined with
stratified squamous epithelium because they are also part of digestive system
A. Nasopharynx
• 1. Eustachian Canal (Auditory Tubes)
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Earache (Otitis Media)
• 2. Pharyngeal Tonsil (Adenoids)
Eustachian (auditory) tube – connects nasopharynx & middle ear cavity
Pharyngeal tonsil – lymphatic tissue embedded in wall of nasopharynx
Palatine tonsils - lymphatic tissue embedded in wall of oropharynx
Uvula – posterior tissue from soft palate; protects nasopharynx when
swallowing
Eustachian Canal (Auditory Tubes)
Nasopharynx and Phryngeal Tonsil
• Oropharynx and Laryngopharynx shared by
the respiratory and digestive system but it is
also in the laryngopharynx where the
respiratory and digestive system separate
Larynx (Voicebox) – large, outer part is
made up of cartilage
• A. projects outward as the “Adam’s apple”
• B. lined by non-keratinizing stratified
squamous epithelium
• Laryngeal Aperture
• Ventricle – chamber where the vocal cords are
Larynx
Air passageway made of 9 pieces of cartilage – (1) Thyroid cartilage, (1)
Epiglottis, (1) Cricoid cartilage, (2) Arytenoid, (2) Corniculate, (2)
Cuneiform
A.K.A your “voicebox” because it contains the vocal cords
Larynx
Thyroid cartilage –
protects anterior &
lateral walls of airway
 Epiglottis – leafshaped cartilage that
protects opening
(“glottis”) of airway
when swallowing
 Cricoid cartilage –
complete ring of
cartilage; protects
posterior wall of airway;
attaches to trachea
Larynx
 Arytenoid, corniculate
& cuneiform cartilages –
attach to upper
(vestibular) vocal folds &
lower (true) vocal cords
Vocal Cords
Laryngeal Cartilages
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3 large single cartilages
a. epiglottis
b. thyroid cartilage
c. cricoid cartilage
• The epiglottis and thyroid cartilage are part of
the larynx
Laryngeal Cartilages
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3 pairs of small elastic cartilages
A. arytenoids
B. corniculates
C. cuneiforms
Muscles of the Larynx
• 1. Extrinsic Muscles
• - circular constrictor muscles
• Guys have large larynx than women thus they
have deeper voices
Intrinsic Muscles
• - open and close the glottis by changing the
tension on the vocal cords
• - innervated by the Laryngeal Nerve
• Laryngospasm – spasmodic contractions of
the laryngeal muscles. Use Heinlich
Maneuver; form a bear-hug around the victim,
and then press fist against the victim’s
abdomen just below his xiphoid process = this
will cause reflex exhalation
• Abdominal Thrust or Heimlich Maneuver
• Laryngitis – hoarse throat
Carcinoma of the Larynx
• Associated with heavy smoking and heavy
drinking
• After a laryngectomy, train patient to use:
• a. esophageal speech
• b. electric voicebox
• c. artificial voicebox
Trachea
 Lined with
respiratory epithelium
 “C”-shaped pieces
of hyaline cartilage
protecting airway
while allowing for
swallowing
 Trachealis muscle
(smooth muscle) runs
across posterior wall
of trachea connecting
ends of tracheal
cartilage
Trachea or windpipe have cartilage to prevent it
from collapsing
Trachea
Low power
Medium power
High power
Bronchi
Carina
 Trachea splits into a left & right
primary bronchus which enters into
the hilus of each lung
 Within the lung, the primary
bronchi branch into secondary
(lobar) bronchi (3 in right lung/2 in
left lung)
 Secondary bronchi then branch
into 10 tertiary (segmental) bronchi
 Tertiary bronchi then continue to
branch into smaller & smaller
bronchi & then into very narrow
bronchioles
This branching patterns creates
the “bronchial tree”
Changes In Airway
As you go further down into the bronchial tree of each
lung, changes in the airway occur:
 increased number of airways (1 primary; 2 or 3
secondary; 10 tertiary bronchi; 6000 terminal bronchioles;
millions of alveolar ducts)
 decreased diameter of each airway
 decreased amount of cartilage in the airways (no
cartilage at all by terminal bronchioles)
 increased amount of smooth muscle (relative to
diameter)
 lining epithelium changes from PSCC  simple squamous
epithelium (in alveoli)
Lungs
Located within the thoracic cavity,
surrounded by the double-layered pleural
membrane –
parietal pleura – lines cavity wall
visceral pleura – covers the lungs
Lungs- Anatomical Features
Apex – extends 1” above clavicle
Hilum – at medial surface;
where primary bronchus,
pulmonary artery & veins
enter/exit lung
Superior
lobe
Horizontal
fissure
Middle lobe
Superior lobe
Right
lung
Left
lung
Oblique
fissure
Oblique fissure
Cardiac notch
Inferior
lobe
Inferior lobe
Base – rests on diaphragm
Lung – medial surface
Groove for
aorta
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Hilum
Cardiac notch
of Lt. lung
Airways within Lungs
 Each lung has a
primary bronchus
entering at the hilus
 Each lobe of a lung
has a secondary (a.k.a.
lobar) bronchus
 Lobes are functionally
divided into
bronchopulmonary
segments & each
segment has a tertiary
(segmental) bronchus
 Segments are
functionally divided into
many lobules & each
lobule receives a
terminal bronchiole
Alveoli
 Alveoli are expanded
chambers of epithelial
tissue that are the
exchange surfaces of
the lungs
 There are about 150
million alveoli in each
lung
 Multiple alveoli
usually share a
common alveolar duct,
creating “alveolar sacs”
AlveoliThere are three types of
cells found within alveoli:
 Alveolar Squamous
epithelial (aka “type I”) cells
– primary cells making up
the wall of the alveoli
 Septal (aka “type II”)
cells – secrete “surfactant”
to reduce surface tension
which prevents alveoli from
sticking together & allows
for easier gas exchange
 Alveolar macrophages
(aka “dust cells”) –
phagocytic cells that remove
dust, debris & pathogens