The Complete Anatomy of Respiratory System.

3. What is Respiratory System?
 The respiratory system allows one to obtain oxygen &
eliminate carbon dioxide.
 Breathing consists of two phases, inspiration and
expiration.
 Inspiration
 the process of taking in air.
 Expiration
 the process of blowing out air.

4. What is Respiratory System Consists of?
 Structurally:
1- Upper Respiratory System.
2- Lower Respiratory System.
 Functionally:
1- Conducting Zone.
2- Respiratory Zone.

6. Upper Respiratory System
• Nose.
• Nasal cavity.
• Mouth.
• Pharynx (Throat).
• Larynx (voice box) .

7. Lower Respiratory System
• Trachea( Wind Pipe).
• Lungs.
• Bronchi.
• Bronchioles.
• Alveoli.

8.  Nose
It is a specialized organ at the entrance
of the respiratory system.
• Shape
– Pyramidal
• Structure
– External portion.
– Internal portion (the nasal cavity).
• External Nose:
– Supporting framework of bone.
• The frontal bone,
• Nasal bones.
• Maxilla.
– Hyaline cartilage.
• Septal nasal cartilage
• Lateral nasal cartilages
• Alar cartilages
– External Nares
• Nostrils
View of External Nose.

9.  Nasal Cavity
• Large space in the anterior space of
duct.
• Position.
– Inferior to nasal bone.
– Superior to oral cavity.
• Composition
– Lined with muscle and mucous
membrane .
– Nasal septum divide the nasal cavity
into left and right side.
– It consists of Hyaline cartilage
perpendicular plates of Ethmoid,
Maxilla and Palatine bone.

10.  Pharynx
• The pharynx (or throat) is a funnel-shaped tube about 13 cm (5 in.) long.
• Starts at the internal nares and extends to the level of the cricoid
cartilage.
• Lies
– posterior to the nasal and oral cavities,
– superior to the larynx,
– anterior to the cervical vertebrae
• Composition
– skeletal muscles, lined with a mucous membrane.
• Relaxed skeletal muscles help keep the pharynx patent.
• Contraction of the skeletal muscles assists in deglutition (swallowing).

11. The pharynx can be divided into three anatomical regions:
• Nasopharynx.
• The superior portion of the pharynx.
• lies posterior to the nasal cavity and extends to the soft palate.
• The soft palate is an arch-shaped muscular partition between the nasopharynx and
oropharynx that is lined by mucous membrane.
• Oropharynx.
• The intermediate portion of the pharynx.
• Lies posterior to the oral cavity and extends from the soft palate inferiorly to the
level of the hyoid bone.
• Laryngopharynx.
• The inferior portion of the pharynx.
• Lies at the level of the hyoid bone.
• Inferior end it opens into the esophagus posteriorly and the larynx anteriorly.
• Lined by non-keratinized stratified squamous epithelium.

13.  Larynx (The Voice Box)
• The larynx is a short passageway that connects the laryngopharynx
with the trachea.
• Anatomically
– Connect laryngopharynx with Trachea.
– anterior to Esophagus.
– 4-6 Cervical Vertebrae.
• Composition
– The wall of the larynx is composed of nine pieces of cartilage.
• Three occur singly (thyroid cartilage, epiglottis, and cricoid cartilage),
• Three occur in pairs (arytenoid, cuneiform, and corniculate cartilages).
• Cavity
– The space that extends from the entrance into the larynx down to the
inferior border of the cricoid cartilage.
– The portion of the cavity of the larynx above the vocal folds is called
the vestibule of the larynx.

14. • The Thyroid cartilage.
• Adam’s Apple.
• Two fused plates of hyaline cartilage.
• Triangular shape.
• Present in both males and females.
• The Epiglottis.
• Large, leaf shaped piece of elastic cartilage that is covered with epithelium.
• Stem of the epiglottis is the tapered inferior portion that is attached to the anterior
rim of the thyroid cartilage and hyoid bone.
• The Cricoid cartilage.
• Ring of hyaline cartilage that forms the inferior wall of the larynx.
• Attached to the first ring of cartilage of the trachea by the cricotracheal ligament.
• Arytenoid cartilages.
• Triangular pieces of mostly hyaline cartilage located at the posterior, superior border
of the cricoid cartilage.
• Corniculate cartilages.
• Horn-shaped pieces of elastic cartilage, are located at the apex of each arytenoid
cartilage.

16.  Vocal Cords
• Folds of membranous tissue.
• Position
– Inferior to larynx
• Production of voice
• Composition
– Twin mucous membrane folding.
• Stretched horizontally from back to front across the larynx
• Size
– Males 1.75 to 2-75 cm
– Female 1.25 to 1.75 cm

17.  Trachea
• Tubular passageway for air.
• Position.
– Anterior to Esophagus.
– Extended from larynx.
– Superior border of 5th thoracic
vertebrae (TS)
• Composition.
– Walls are composed of 4 layers
• Mucosa
• Sub mucosa
• Hyaline cartilage
• Adventitia
• Wind Pipe.
– 1 inch in diameter
– 5 inch in length

18. Tracheal Wall
Mucosa
Epithelial layer of
Pseudo stratified
Columnar Epithelium
Sub
Mucosa
Layer of Areolar
Connective Tissue
Hyaline
Cartilage
Type II Collagen
Chondroitin Sulphate
Adventitia
Layer of Areolar
Connective Tissue

19.  Lungs
• Paired cone shaped organs in the thoracic cavity.
• Right and left lungs are separated by Mediastinum.
• Gross:
– Spongy.
– Coned.
– Weight.
• Right Lung 600 gms.
• Left lung 550 gms.
• Surface:
– Costal
• Contact with costal pleura
overlaying thoracic wall.
– Medial
• Posterior / Vertebral.
• Anterior / Mediastinum.

20. • Anatomy:
• Pleural membrane.
• Parietal pleura.
• Visceral pleura.
• Pleural cavity.
• Lubricating fluid.
• Inflammation of the pleural membrane, called Pleurisy or Pleuritis.

21. • Extend from the diaphragm to just slightly superior
to the clavicles and lie against the ribs anteriorly and
posteriorly.
• Partiitions:
• Base
• Apex
• Coastal Surface
• Mediastina Surface
• Hilum.
• Root
• The left lung is about 10% smaller
than the right lung.

22.  Bronchi
• Position
– Superior border of the fifth thoracic
vertebrae
• Trachea divide into left and right
bronchus.
• Contain incomplete rings of cartilage
and are lined by pseudostratified
ciliated columnar epithelium.
• Carina
– Ridges at the point where trachea
divide into left and right bronchi .
• On entering the lungs main bronchi
divided into smaller bronchi the Lober.
• Bronchi divided further into
bronchioles.

24.  Bronchioles
• Bronchi divide further into Bronchioles.
• Bronchioles differ from bronchi both in size. They are smaller
and in the composition of other walls.
• They have hyaline cartilage rings in their walls.
• They are made up of elastic fibers and smooth muscles
tissues.
• The bronchioles further divided into
many terminal bronchioles.
• Terminal bronchioles are the smallest
are the air tubes in the lungs and
terminate at the alveoli of the lungs.
• Bronchioles capable of dilating or contracting air flow into
alveoli.

25.  Alveoli
• Around the circumference of
the alveolar ducts.
• Cup shaped out pouching
lined.
• Simple squamous epithelium
and supported by a thin
elastic basement membrane.
• Functional unit of the lungs.
• Alveolar sacks.
– A cluster of alveoli
– At the end of the
terminal bronchioles.

26. • The wall of alveoli consist of two types of alveolar epithelial cell.
• type – I alveolar cell
• Simple squamous epithelial cell that form a nearly continuous lining of alveolar
wall.
• type –II alveolar cell.
• Also called Septal cell. fewer in number found between type-I alveolar cell.
• Alveolar macrophage (dust cell).