RESPIRATORY
SYSTEM
DR. MOHAMED SEYAM, PHD. PT.
ASS. PROFESSOR OF PHYSICAL THERAPY
RESPIRATORY SYSTEM
 Respiratory tract:
a)
Upper respiratory tract
b) Lower respiratory tract
 Pulmonary zones
A. conducting zone
B. Respiratory zone
 Broncho pulmonary segments
 Muscles of Ventilation,
 Surface Anatomy of lungs,
Respiratory System
1. The Respiratory Tract
A. The upper respiratory tract
•
Nose

lined by ciliated
columnar epithelium

mucus secreting cells

dense vascular
network in submucosa

filtering air

warming air

humidifying air

sneezing reflex
•
Pharynx

•
Epiglottis
Larynx

vocal cords

glottis
B. The lower respiratory tract
•
•
•
•
•
Trachea
Bronchi
Bronchioles
Respiratory bronchioles
Alveolar ducts and alveoli
NASAL CAVITY and PHARYNX
*Nasal cavity Functions : Air conduction,
Filtration ( by hair follicles), Humidification,
Temperature control, Olfaction.
*The pharynx: is a Musculomembranous tube
approximately 5 to 6 inch long and located posterior
to nasal cavity. It extends from the base of the skull to the esophagus.
The Pharynx: consists of three parts
1. Nasopharynx - Extends from Nasal cavity to Soft palate
2. OroPharynx
- Extends from Soft palate to upper border of epiglottis
3. Laryngopharynx - Extends from upper border of epiglottis to cricoid cartilage
LARYNX
Larynx is s complex structure made up of several cartilages and
forms connection between the pharynx and trachea.

The Position of trachea is opposite to third to sixth cervical
vertebrae in the adult male and some what higher in females and
children

Six supporting cartilages, including
* Three large
- Epiglottis, thyroid, and Cricoid
* Three smaller - Arytenoid, corniculate and cuniform
It prevents food, liquid and foreign objects from entering the airway.
Two sets of laryngeal muscles play important roles in swallowing,
ventilation and vocalization .
LOWER RESPIRATORY TRACT
•
Respiratory zones
1) Conducting zone(nose, pharynx, larynx, trachea, Bronchi, Bronchioles)

to warm and humidify the air

to distribute the gas

to serve as part of body defense system
2) Respiratory zone(respiratory bronchioles, alveoli sac and duct)
CONDUCTING AIRWAYS
Tracheobronchial tree : Airway diameter is progressively
decreases with each succeeding generation of branching,
starting at approximately 1 inch in diameter at the trachea and reaching
1 mm or less at the terminal bronchioles
Trachea: is a tube approximately
4 to 4.5 inches long and 1 inch diameter.
Carina: It is cartilaginous wedge that
marks bifurcation of trachea into the
right and left main steam bronchi.
This corresponds to Fifth (T5) thoracic vertebrae
MAIN STEM BRONCHI
Main stem or Lobar bronchi
• Right main stem bronchus is wider, shorter, and more
vertical than left stem bronchus and it diverges 25 degree
angle from trachea
(Note : Right main stem intubation more common than left)
• Left main stem bronchus leaves trachea at an angle of
approximately 40 to 60 degrees.
Secondary Bronchi
• One bronchi per each lobe of lungs
• Three on the right lung
• Two on the left lung
Terminal units
(Acinar Units)
Tertiary Bronchi :
supply Broncho pulmonary segments
– Right lung has 10 segments
– Left lung has 8 segments
• they branch several times and eventually for bronchioles.
Bronchioles:
subsegmental, terminal, and respiratory
• Respiratory passages less than 1 mm in diameter
• Branch several times into terminal bronchioles which
extend into gas exchange bronchioles
• Branch into alveolar ducts
Alveoli Alveolar ducts and sacs
• The normal mature lungs contain about 300
million alveoli (150 million in each one),
each of which is extremely small
(between 200 to 300 micro meter in diameter)
• Type I Squamous pneumocytes
Covers approximately 93 % of alveolar surface.
• Type II Granular pneumocytes
produces surfactants
• Alveolar Macrophages engulf and ingest
foreign materials (Phagocytize)
Terminal
Bronchiole
Respiratory
Bronchiole
alveolus
Alveolar sac
Alveolar ducts
•
Respiratory tract defense system

Mucocilliary transport system: mucus escalator

Cough reflex

Macrophages
Broncho Pulmonary Segments
Bronchpulmonary segments of right lung
Bronchpulmonary segment of left lumg
Functions of Respiratory System
Forms series of passages that conduct air
to area where gas exchange will occur

 Provides surface area for gas exchange
 Protection of respiratory system from
dehydration, temperature change, and
pathogens
Sites Of Respiration In The Body
 External respiration
- Exchange of gases between atmosphere and
blood tissue
- Occurs in alveoli of lung tissue
 Internal respiration
Exchange of gases between blood and cells of the body
 Cellular respiration
Utilization of oxygen to create ATP through oxidative
phosphorylation Krebs cycle
SURFACE MARKINGS OF LUNGS
Sternal angle is at the level of the fifth thoracic vertebra ( b/w 4 th 5 th )
* The second costal cartilage corresponding to the sternal angle is
so readily found that it is used as a starting-point from which to
count the ribs.
* This is point at which trachea divides into two primary bronchus.
Surface lines
Mid sternal
- the middle line ofthe sternum
Para sternal - The Para sternal line runs parallel to the edge of the sternum
Midclavicular - Which runs vertically downward from a point midway
between the center of the jugular notch and the tip of the acromion.
Axillary lines
* Anterior axillary - vertically from the corresponding anterior axillary folds
*Mid axillary
- runs downward from the apex of the axilla.
* Posterior axillary - vertically from the corresponding posterior axillary folds
Bony markers related to lung
Surfaces , Borders, And Apex Of Lungs
 Each lung has an apex, three surfaces (costal, medial, and
diaphragmatic), and three borders (anterior, inferior, and posterior)
 The apices of the lung extend about 3 cm above the medial third of
the clavicles then project inferolaterally to the junction of medial and
middle thirds of clavicle. Anteriorly, the hila lie at the level of costal
cartilages 3-4; this is vertebral level T 5-7.
 The inferior margins of the lung with corresponds to Vertebrae:
T6 - Mid-clavicular line
T8 - Mid-axillary line
T10 - Posteriorly
The Muscles Of Respiration
The muscles of respiration consist of four groups:
1.
the diaphragm
2.
the chest wall muscles
3.
the abdominal muscles
4.
the muscles of the upper airway.
The muscles of the upper airway include the muscles of
the mouth (innervated by cranial nerves IX and X), uvula
and palate (XI), tongue (IX and XII), and larynx (C1). While
these muscles do not have a direct action on the thorax,
they are essential for keeping the upper airway opened
and because they affect airway resistance and airflow, may
impact on lung volume .
Properties of respiratory muscles
The respiratory muscles, especially those that participate in
normal quiet breathing, are skeletal muscles that differ from
other skeletal muscles in three major ways;
(1) They must contract rhythmically and intermittently
throughout life,
(2) The control of these muscles is both voluntary and
involuntary, and
(3) They must primarily work against elastic (chest wall and
lungs) and airway resistive loads, rather than against the
gravitational forces encountered by most other skeletal
muscles.
Main muscles of respiration
INSPIRATORY MUSCLES
Muscle
Innervations
Inspiratory , primary
Diaphragm
C3-C5
Intercostals
T1-T11
Scalene
Anterior
C3-C4
Middle
C5-C6
Posterior
C6-C8
Inspiratory, accessory
Sternocleidomastid
C2-C4 and accessory N. (XI)
Trapezius
C1-C4 and accessory N. (XI)
EXPIRATORY MUSCLE
Expiratory muscles
nerve supply
Rectus abdominus
T6-T12
Transversus abdominus
T2-L1
Internal and external obliques
T6-L1
Pectoralis major
Medial and lateral pectoral N. (C5- T1)
The triangularis sterni or transvarsus thoracis
References
1- Essentials of Cardiopulmonary Physical Therapy, 3rd
edition, Ellen Hillegass DPT CCS FAACVPR, Saunders
elsevier; 2011.
2- Cardiovascular and Pulmonary Physical Therapy:
Evidence to Practice
Elizabeth Dean PhD PT, Saunders Elsevier;2012
3- Cardiac rehabilitation, Louis R. Amundsen, Churchill
Livingstone;
1981.
THANK YOU