ST120
Concorde Career College, Portland
Objectives
Define the term respiration.
 Describe the functions of the respiratory
system.

Objectives

List and identify the structures of the
respiratory system and describe the
function of each.
Objectives
Describe the process of respiration.
 Describe the mechanism by which the
respiratory system helps to maintain
homeostasis.

Objectives
Describe common diseases, disorders,
and conditions of the respiratory system
including signs and symptoms,
diagnosis, and available treatment
options.
 Demonstrate knowledge of medical
terminology related to the respiratory
system verbally and in the written form.

Respiration
More than breathing in and out.
 Process by which oxygen is obtained
from the environment, delivered to the
cells, and waste products such as
carbon dioxide are removed from the
body.

Terms

Respiration- Inhaling and exhaling facilitate
the process of taking in oxygen and getting
rid of waste CO2.
 Internal respiration- exchange of O2 and CO2
between the blood and body cells.
 External respiration- exchange of O2 and CO2
between the lungs and the circulatory system.
 Cellular respiration- the use of O2 by the cells of
the body & production of CO2.

Ventilation- movement of air in & out of the
lungs (breathing)
Functions of the Respiratory System



Pulmonary ventilation
 Inhalation
 Exhalation
Diffusion of gases
 Into and out of the blood
Transport to and from the cells (cellular
respiration)
 Oxygen
 Carbon dioxide
Primary Structures of the
Respiratory System


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Nasal cavities
Pharynx
Larynx
Trachea
Lungs
Diaphragm
Upper Respiratory Tract

Nose Covered by skin and supported by bone and
cartilage. Air enters through the external nares
and coarse hairs line the internal part of the
nares to act as filters.

Nasal Cavities
 Separated by nasal septum. Lining is made of
ciliated epithelium (nasal mucosa). Highly
vascularized, which warms inhaled air.

Nasal conchae
 Curved scroll-like bones
 Superior, middle, and inferior turbinates
Nasal Cavities
External nares
(nostrils)
 Nasal Cavities

 Nasal septum
 Conchae (turbinates)

Sinuses
Sinuses
 Maxillary, frontal, sphenoid, and ethmoid
○ Named for associated bones
 Move mucus into nasal cavities
 Make skull lighter in weight
Paranasal Sinuses (Anterior)
Paranasal Sinuses (Lateral)
Upper Respiratory Tract

Pharynx



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Tubular structure
Posterior to oral & nasal cavities
Conducts air and food
Three sections:
○ Nasopharynx
○ Oropharynx
○ Laryngopharynx
 Composed of muscle, lined with mucous
membrane
Pharynx
Nasopharynx
 Oropharynx
 Laryngopharynx

Lower Respiratory Tract

Larynx
 “voice box” contains vocal cords (2 short fibrous




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bands that stretch across the interior of the
larynx)
The space between the vocal cords is called the
glottis
Connects pharynx to trachea
Serves as part of the air passageway
Lined with mucous membrane
Composed of cartilaginous rings:
○ Thyroid
 Adam’s apple = thyroid cartilage
○ Cricoid
 Sellick’s maneuver
Lower Respiratory Tract

Larynx
 During swallowing, larynx elevates &
epiglottis closes over opening to prevent
food from entering
 Vocal cords-located on either side of glottis
○ Breathing- cords close over glottis.
○ Speaking- cords are stretched & exhaled air
vibrates cords causing speech.
Larynx
Lower Respiratory Tract

Trachea
 “wind pipe”
 Extends from layrnx to carina
 Composed of 20 C-shaped rings of hyaline cartilage.
○ Flexible, keep trachea continuously open.

Primary bronchi = right and left bronchus
 Mediastinal space
 Lined w/ resp. epithelium
 Enter lung & continue to divide
○ AKA “bronchial tree”
Trachea & Bronchi
Respiratory System
Bronchi
Trachea divides
(bifurcates) into two
primary bronchi
 Secondary bronchi
 Tertiary bronchi
 Bronchioles

Lower Respiratory Tract

Bronchial Tree
 Trachea
 2 primary bronchi
 Secondary branches
 Segemental/tertiary bronchi
 Bronchioles
 Terminal bronchioles
 Alveolar ducts
 alveoli
Lower Respiratory Tract

Bronchioles
 Simple epithelium
 Lack cilia, goblet cells, & cartilage
 Contain smooth muscle bundles-regulate
diameter of lumen
 Exchange of gases
 Divide into alveolar ducts w/ alveoli
surrounding each duct = alveolar ducts
Pleural Cavity
Pleura = covers the outer surface of
lungs and the lining of the inner surface
of the rib cage
 Parietal pleura lines the walls of the
thoracic cavity
 Visceral pleura covers the lungs
 Contains:

 Lungs
 Pleural membranes
○ divided into parietal pleura and visceral pleura
○ Pleural space- space between parietal &
visceral pleura, contains serous fluid,
Pleural Cavity

Lungs

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Spongy, elastic tissue
Right-3 lobes
Left-2 lobes
Conical shape
Layers○ External visceral pleura
○ Sub serous layer of areolar tissue
○ Parenchyma
 Blood supply
○ Arterial: bronchial arteries, branch from thoracic
aorta
Lungs
Respiratory System
Alveoli
Located at the end of the terminal
bronchioles
 Tiny sacs surrounded by vascular
capillaries
 Gas (O2 and CO2) occurs in the alveoli

Pleural Cavity

Alveoli
 Primary functioning unit
 Responsible for gas exchange

Alveolar walls
 Squamous epithelial cells-type 1 pneumocytes
 Each alveolus is surrounded by pulmonary
capillaries
○ Consist of a single layer of endothelial cells
○ A thin, filmy layer of fluid that covers the alveoli to
reduce surface tension forces and aid in the
expansion of alveoli is called Pulmonary
Surfactant
Alveoli
Cluster of Alveoli at the Terminal
Bronchiole
Pleural Cavity

Alveolar-capillary barrier
 3 layers
○ Between air in alveoli & blood in pulmonary
capillaries

Pneumocytes
 Type 2
○ round in shape
○ Contain
 large nucleus
 Lamellar bodies-contain phospholipids that release
surfactant
One alveolar sac is made up of numerous alveoli pg. 293
A&P
Microscopic View of Alveolar Sac
Pleural Cavity

Diaphragm
 Separates thoracic & abdominal cavity
 Divided into:
○ Crura
○ Central tendon
 Subdivided into 3 divisions-leaflets
 Major openings
○ Aortic
○ Esophageal
○ Inferior vena cava
The diaphragm muscle flattens out when it contracts
during inspiration
The diaphragm muscle returns to upward position
during expiration
Pleural Cavity

Diaphragm
 Blood supply
○ Branches of
 internal thoracic arteries
 Thoracic aorta
 Inferior phrenic arteries
 Lymph nodes
○ Located on superior surface
○ Receive drainage from liver &
esophagogastric junction
Pleural Cavity

Intercostal muscles
 Located between ribs
 Divided:
○ External intercostal muscles covered by
intercostal fascia
 Intercostal nerves innervate muscles
○ Primary structures responsible for movement
during respiration.
Physiology of Respiration

Inhalation
 Diaphragm contract
 Intercostal muscles
relax

Exhalation
 Diaphragm relaxes
 Intercostal muscles
contract
Pulmonary and Systemic Circuits

Pulmonary circuit
 From the heart to
the lungs and
back to the heart

Systemic circuit
 From the heart to
the tissues and
back to the heart
External Respiration
O2 diffuses from alveoli into blood
 CO2 diffuses from blood to alveoli
 Blood high in O2 returns to heart,
pumped out by left ventricle through the
aorta to the body

Exchange of gasses between the blood
and the lungs by diffusion
Internal Respiration
O2 diffuses from blood to body cells
 CO2 diffuses from body cells to blood
 Venous blood is low in O2 returns to
right ventricle to lungs for reoxygenation.

Regulation of Respiratory System

Nervous system
 Medulla
○ Responsible for inspiration & expiration
 Pons
○ Regulates normal rhythm of breathing
 Centers
- apneustic center
- Pneumotaxic center
Regulation of Respiratory System

Nervous System
 Chemoreceptors
○ Located in medulla, aortic bodies & carotid
bodies
○ Detect changes in pH & blood gas levels

Phrenic nerve stimulates the diaphragm
Respiratory Monitors

Pulmonary volumes
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Tidal volume
Minute ventilation
Inspiratory reserve volume
Expiratory reserve volume – amount of air that
can be forcibly exhaled after expiring the total
volume
Vital capacity – largest amount of air we can
breathe out in one expiration
Residual volume
Total lung capacity
Forced expiratory volume
Conditions

Pulmonary edema-abnormal accumulation of fluid in
extravascular spaces or alveoli

Pneumothorax-abnormal accumulation of air between the
parietal & visceral pleura

Pneumonia- acute infection of lungs

Chronic Obstructive Pulmonary Disease (COPD)-chronic airway
obstruction

Emphysema-abnormal, irreversible enlargement of the alveoli
due to destruction of alveolar walls

Pleurisy-Inflammation of the pleura that causes pain when the
membranes rub together
Empyema
Rhinorrhea
Why is a tracheotomy done?
-
Gain access to airway before blockage
Create an open airway for breathing
Tracheotomy
Tracheotomy
Thoracentesis
Pulmonary Lobectomy
Excision of one or
more lobes
 Performed to
excise
benign lesions,
malignant and
metastatic
malignant
lesions

Terms
Bronchoscopy –
TB –
Pulmonary edema –
Pharyngitis –
Pertussis –
COPD –
Hyperventilation –
Inspiration –
Medulla –
Inhalation –
Respiratory arrest –
Pneumothorax –
Infant Respiratory
Distress Syndrome –
Epyema –
Rhinorrhea –
Thoracentesis –
Pneumonia –
Emphysemia -