3. Respiratory System starts at the nares
Major Functions
Upper respiratory system:
1. Air conditioning (warming)
2. Defense against pathogens
3. Gas Transport
Lower respiratory system:
1. Speech & other
respiratory sounds
2. Gas exchange (ventilation)
3. Maintenance of
homeostasis, e.g. pH
10. Upper Respiratory
System
1) Nose
External and internal nares =
Nostrils
Nose Hairs = vibrissae
Alar cartilages on the nose
Paranasal Sinuses
11. Upper Respiratory
System
• 2) Nasal Cavity
• Nasal Conchae:
– Superior, middle and
inferior
– Other name: “Turbinate
bones” because they
create
13. Upper Respiratory
System
4) Pharynx
Shared passageway for respiratory and digestive systems
Nasopharynx - part above uvula and posterior to internal
nares
Oropharynx – portion visible in mirror when mouth is wide
open
fauces = the opening
uvula - posterior edge of soft palate
Laryngopharynx – between the hyoid bone & the esophagus
14.
15. Larynx (voice box)
The larynx consists of three
articulating cartilages,
1. Thyroid
2. cricoid
3. Arytenoid
16. Lungs
Light, soft, spongy
Conical in shape, apex, base, costal surface, medial
surface, hilus. Note various impressions
Right lung
Three lobes; superior, middle and inferior
Oblique and horizontal fissure
Left Lung
Two lobes; superior and inferior also Lingula and Cardiac
notch, oblique fissure
20. Lung Fissures:
Oblique fissure (Right & Left):
It starts at the 3rd thoracic spine while the arms are elevated,
descends downwards, laterally & anteriorly along the medial
border of the scapula touching the inferior angle of the
scapula) cutting the midaxillary line in the 5th rib & ending at
the 6th costal cartilage 3 inches from the midline.
In cadaver it arise at the 2nd thoracic spine.
The transverse fissure (Right):
It arises at the 4th costal cartilage, runs horizontally to meet
the oblique fissure in the midaxillary line in the 5th rib.
30. Airways
Trachea, primary bronchi, secondary bronchi, tertiary
bronchi out to 25 generations
All comprised of hyaline cartilage
Trachea
Begins where larynx ends (about C6)
10 cm long, half in neck, half in mediastinum
20 U-Shaped rings of hyaline cartilage – keeps lumen intact
but not as brittle as bone
Lined with epithelium and cilia which work to keep foreign
bodies/irritants away from lungs
31. From Bronchi to Lungs: The Bronchial
Tree
1 bronchi (enter lungs at
hilus, complete cartilage
rings)
2 bronchi (from now on
cartilage plates)
3 bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Conducting
portion
Respiratory portion
32. Airways
Primary Brochi One to each lung – continuation of
trachea
Right bronchus is wider and shorter 2.5 cm as opposed to
5 cm and branches from the trachea at a greater angle
Secondary bronchi – one to each lobe, three in right,
two in left
Tertiary – one to each bronchopulmonary segment –
approximately 10 per lung
All of the above are hyaline cartilage with no ability
to change diameter
38. Bronchioles
First level of airway surrounded by smooth
muscle (not the cartilage ), therefore can
change diameter as in brocho-constriction and
broncho-dilation
Terminal
Respiratory
3-8 orders
alveoli
41. Borders of the lung:
The apex is about 2-3 cms (1 inch) above the medial
1/3 of the clavicle, then the anterior border of both
lungs run downwards & medially meeting each other
in the middle line behind the angle of Louis (sternal
angle).
The anterior border of right lung continues running
downwards till the 6th costochondral junction.
The anterior border of left lung continues running
downwards till the 4th costal cartilage then curves
laterally ½ inch forming the cardiac notch then
descends downwards till the 6th costochondral
junction.
42. Borders of the lung:
The lower border of the lungs represented by a line
starting from 6th rib in the MCL, 8th rib in the MAL &
10th rib in the scapular line.
44. Bronchial circulation
• The trachea (and esophagus), main-stem bronchi, and
pulmonary vessels into the lung , as well as the visceral
pleura in humans are supplied by the bronchial
(systemic) circulation.
• The bronchial circulation has enormous growth
potential. In long-standing inflammatory and
proliferative diseases, such as bronchiectasis or
carcinoma, bronchial blood flow may be greatly
increased.
45. Pulmonary circulation
• In humans the pulmonary artery enters each lung at
the hilum in a loose connective tissue sheath adjacent
to the main bronchus.
• The pulmonary artery travels adjacent to and branches
with each airway generation down to the level of the
respiratory bronchiole.
• As blood enters the vast alveolar wall capillary
network, its velocity slows, averaging approximately
1000 µm/sec (or 1 mm/sec),where gas exchange take
place.
46. • Anatomically, the pulmonary blood vessels can be
divided into two groups in
1. Extra-alveolar
2. Alveolar.
Extra-alveolar
vessels lie in the loose-binding connective tissue
(peribronchovascular sheaths, interlobular septa).
Extra-alveolar vessels extend into the terminal
respiratory units. Arteries as small as 100 µm in
diameter have loose connective tissue sheaths. This is
in contrast to the bronchioles, which are tightly
embedded in the lung framework from the
bronchioles (1 mm in diameter) onward.
Alveolar vessels
lie within the alveolar walls and are embedded in the
parenchymal connective tissue
47. Innervation
Pleura via intercostal (thoracic) nerves.
Tracheobronchial tree motor pathway
Parasympathetic via CN X efferent function =
broncho-constriction via smooth muscle, also to
epithelial cells in trachea, afferent = responsible for
cough reflex
Sympathetic from T1-T5 efferent = brocho-dilation
48. • Cholinergic, adrenergic, and peptidergic nerve
Endings are present around tracheal glands and do
not show patterns of slective innervation density
between serous and mucous cells . Serous and
mucous granule secretion is stimulated more by
muscarinic than by adrenergic agents.
49. lymphatics
• Superficial plexuses- The superficial plexus is located
n the surface of the lung just beneath the pulmonary
pleura.
• Deep plexuses-accompanies the branches of the
pulmonary vessels and ramifications of bronchi.
50. Right lung lymphatics
• Right upper lobe:
• Upper 2/3rd-Right tracheobronchial nodes
• Lower l/3rd -Dorsolateral hilar nodes
• Right middle lobe:
• Hilar nodes around middle lobe bronchus
• Right lower lobe:
• Porsolateral part-Dorsolateral hilar nodes
• Ventromedial part- Ventromedial hilar and carinal
nodes
51. Left lungs lymphatics
• Left upper lobe:
• Apex-para-aortic node
• Other than apex-Anterior and posterior hilar nodes
• Left lower lobe
• Dorsolateral part-Dorsolateral hilar nodes
• Ventromedial par^Ventromedial hilar and carinal
nodes