anatomy and physiology respiratory system

1. Respiratory
system
SUPRIYA BATWALKAR

2. NOSE
Organ of Sense of Smell
Dual function : sense of smell and respiration
Warms and moistens the inspired air
Cleans the air
Olfactory receptors are placed in it to perceive the odours borne by the
air

3. PARTS
The external nose
Largely cartilaginous
The external nose consists of the nasal bones ( the bridge of the nose)
Upper and lower nasal cartilages
Septum
Alar cartilage - forms the lateral boundary of the nostril - elastic cartilage
- moved by the compressor and dilator naris muscles
Covered by adherent skin containing numerous sebaceous glands
The skin extends into the vestibule within the nostrils - has stiff hairs

4. PARTS
The floor of the nose is the hard palate
Soft palate acts as a flap valve; breathing is stopped during swallowing;
the valve shuts off the nasopharynx from the oro pharynx
The nasal cavity- nasal septum - divides the nasal cavity into two halves
The nasal cavity opens posteriorly into the nasopharynx - choanae
The respiratory mucous membrane of the nasal cavity is very vascular
and red in colour. (ciliated columnar epithelium)

6. PARTS
Olfactory mucous membrane
The epithelium in non ciliated Called the neuroepithelium
Olfactory fibres are formed from this epithelium and they pierce the
cribriform plate and pass to the olfactory bulb

7. PARTS
The cavity of the nose
Floor - roof of the mouth - hard palate
Lateral wall
orbit (the ethmoidal air cells intervening)
The maxillary antrum
Three nasal conchae (turbinate bones) project downwards
Beneath the free inferior border of each concha is a meatus, called
superior, middle and inferior meatus respectively
Paransal sinuses and the lachrymal duct open into the nose.
Supplied by external nasal nerve

9. PARTS
Paranasal sinuses
The ethmoid sinus opens into the superior meatus
The maxillary and frontal sinuses open into the middle meatus
The nasolacrymal duct opens into the inferior meatus

11. APPLIED ANATOMY
The mucous membrane covering the inferior concha can swell and
'block the nose' instantaneously.
When there is collection of pus or mucus in the maxillary or frontal
sinuses antral puncture at the middle meatus is done to let out the
pus/mucus
Pituitary surgery - through nose - trans sphenoidal approach

12. PHARYNX
The pharynx or the throat is divided into three parts viz.
the naso pharynx,
the oro pharynx and
the laryngo pharynx.
Oropharynx and laryngopharynx are associated with the alimentary
tract
Food passes from the oral cavity to the pharynx and then into the
oesophagus with which it is continuous.

13. PHARYNX
The various layers of the Pharynx
The lining membrane is stratified squomous epithelium
The middle layer - fibrous tissue - contains blood and lymph vessles and
nerves
The outer layer - a number of involuntery constrictor muscles which are
involved in swallowing.
Blood supply:
Branches of the facial arteries
Venous drainage : into the facial veins and the internal jugular veins

14. PHARYNX
Nerve supply:
Pharyngeal plexus and consists of parasmpathetic and sympathetic
nerves
parasympathetic : glossopharyngeal and vagus nerves
Sympathetic from the cervical ganglia

15. APPLIED ANATOMY
Eustachian Tube opening into the nasopharynx gets inflamed :
eustachian catarrh; the pressure equilibrium between the external and
internal ears is disturbed and the ear gets a blocked sensation.
Retropharyngeal abscess produces a swelling in the back of the throat

19. LARYNX
Definition
- Is a structure which produces voice; situated at the neck.
- Extends from the root of the tongue and the hyoid bone to the
trachea.
- In front of the laryngopharynx at the level of C 3,4,5,6,
- Larger in the male Adam's apple.

20. LARYNX
Structure
Cartilages
Thyroid cartilage :
- most prominent, two flat pieces of hyaline cartilages or laminae fused
anteriorly,
- upper border : thyroid notch
- superior cornu and inferior cornu - two processes projecting up and down
- upper part covered with stratified squamous and lower part with ciliated
columnar epithelium.
- Gives attachment to many muscles at the outer surface.

21. LARYNX
The cricoid cartilage:
- below the thyroid cartilage
- encircles the larynx
- Articulates with the arytenoid cartilages above and with the inferior
cornu of the thyroid cartilage below.
- Lined with ciliated colunar epithelium
- muscles and ligaments atached to its outer surface.
- Lower border of cricoid is the end of upper respiratory tract.

22. LARYNX
The arytenoid cartilages :
- pyramid shaped
- hyaline cartilage
- Forms part of posterior wall
- Give attachment to the vocal cords and to muscles and are lined with
ciliatd columnar epithelium.

23. LARYNX
The epiglottis:
- Leaf -shaped
- fibroelastic cartilage
- attached to thyroid cartilage immediately below the thyroid notch.
Blood supply
Superior and inferior laryngeal arteries
Drained by the thyroid veins, which join the internal jugular vein.
Nerve supply
Superior and recurrent laryngeal nerves
parasympathetic from vagus
Sympathetic supply from superior cervical ganglia.

24. LARYNX
Interior of the larynx
Vocal cords - pale folds of mucous membrane with cord-like free edges
Extend from thyroid prominence to the arytenoid cartilages posteriorly.
Vibration of the cords produce voice

25. LARYNX
Function of larynx
- Production of voice pitch, volume and resonance.
- Speech : voice produced by the larynx modified by tongue, cheeks
and lips.
- Protection of the lower respiratory tract
- Passage way for air
- Humidifying, filtering and warming the air that enters the lungs.

26. LARYNX
Relations
Superiorly- the hyoid bone, root of tongue
Inferiorly - trachea
Anteriorly - muscles attached to the hyoid bone and the muscles ofhe
neck
Posteriorly - the laryngopharynx and the 3rd to 6th cervical vertebrae.
Laterally - thyroid gland.

30. PLEURA
Definition
The membrane lining a body cavity containing the lungs and covering
the lung also
The lungs are surrounded by two serous membranes, the pleurae.

31. PLEURA
The layers
The outer pleura (parietal pleura) is attached to the chest wall.
The inner pleura (visceral pleura) covers and is attached to the lung and
other structures, i.e. blood vessels, bronchi and nerves.
The pleura is derived from embryonic coelomic lining
Between the two is a thin space known as the pleural space
The space contains a small amount of pleural fluid.
The parietal pleura is highly sensitive to pain; the visceral pleura is not,
because
it receives no nerves of general sensation

32. PLEURA
The various parts
of the parietal pleura are :
costal
diaphragmatic
mediastinal
cervical (cupola)

33. PLEURA
The surfaces and cavities
In health they are in actual contact with one another
But the potential space between them is known as the pleural cavity.
The adjacent surfaces of the pleura are moistened by a serous fluid
When the lung collapses or when air or fluid collects between the two layers, the cavity becomes apparent.
The right and left pleural sacs are entirely separate from one another;
between them are all the thoracic viscera except the lung.
on the sides the lung does not fill the sac formed by the two layers of the pleura - costophrenic sinus -
in the chest X-ray - costophrenic angle
The right pleural sac is shorter, wider, and reaches higher in the neck than the left.
Pulmonary Ligament : the root of the lung is covered Here the pleura forms
a fold called the pulmonary ligament,

34. PLEURA
Structure of Pleura :
the pleura is covered by a single layer of flattened, nucleated cells
Vessels and Nerves.—The arteries of the pleura are derived from the
intercostal,
internal mammary, musculophrenic, thymic, pericardiac, and
bronchial vessels.
The veins correspond to the arteries.
The nerves are derived from the phrenic and sympathetic nerves
along the vessels

37. DIAPHRAGM
Definition
Dome shaped structure separating the thoracic and abdominal cavities.
It is the floor of the thoracic cavity and the roof of the abdominal cavity

38. DIAPHRAGM
Features
Has a central tendon
From the central tendon muscle fibres arise
Get attached to the lower ribs and sternum.
To the vertebrae it is attached by two crurae.
When the diaphragm is relaxed the central tendon is at the level of
the T8 vertebra.
When it contracts its muscle fibres shorten and the central tendon is
pulled downwards, enlarging the thoracic cavity in length.

39. DIAPHRAGM
Openings
Three large openings —
the aortic
the esophageal
the caval opening
a series of smaller ones

40. DIAPHRAGM
Aortic hiatus : T12 - The aorta does not pierce the diaphragm but rather passes behind it in between
the left and right crus.
Is in the posterior part of the diaphragm, between the left and right crus.
It contains the aorta, the azygos vein, and the thoracic duct
Esophageal hiatus : contains the esophagus, and anterior and posterior vagal trunks.
.Caval Opening : The inferior vena cava passes through this opening
two lesser apertures of right crus : greater and lesser right splanchnic nerves
two lesser apertures of left crus : greater and lesser left splanchnic nerves and the hemiazygos vein
behind the diaphragm, under the medial lumbocostal arch : sympathetic trunk
Nerve supply
Phrenic nerve C4

42. TONSILS
Definition
The palatine tonsils are dense compact bodies of lymphoid tissue
Located in the lateral wall of the oropharynx
Bounded by the palatoglossus muscle anteriorly
Palatopharyngeus and superior constrictor muscles posteriorly and
laterally

43. TONSILS
The adenoid is a median mass of lymphoid tissue.
Situated in the roof and posterior wall of the nasopharynx
Both tonsils and adenoid are part of the Waldeyer ring
Provide defense against pathogens & involved in the production of
immunoglobulins and the development of both B cells and T cells
The tonsils develop in the second pharyngeal pouch
The size of the tonsil varies according to the age. At the fifth or sixth
year of life, the tonsils rapidly increase in size, reaching their maximum
size at puberty.

44. TONSILS
Anatomic relations
Anteriorly and posteriorly - palatoglossus and palatopharyngeus
muscles, lying within their respective folds.
Superiorly - the tonsil extends into the edge of the soft palate
Inferiorly - the tonsillar capsule is firmly attached to the side of the
tongue

45. TONSILS
Applied Anatomy
Tonsillitis - inflammation of the tonsils
Quinsy - Peritonsillar abscess

47. TRACHEA
Definition
Tube that connects the pharynx and larynx to the lungs, allowing the
passage of air
The Extent
Extends from the larynx and branches into the two primary bronchi.
Situation
Trachea lies in the midline of the neck
Below the Cricoid cartilage
The tracheal bifurcation is at the level of sternal angle (T5)

48. TRACHEA
Structure
Below the larynx lies the cricoid cartilage
Crico-tracheal ligament lies between the lower border of cricoid and the
upper end of trachea.
Trachea has 18 - 22 C shaped cartilagenous rings
Annular Ligament - between two rings
Trachealis muscle connects the ends of the incomplete rings; ovrlies
oesophageal muscle and forms the posterior wall of trachea
Inner surface pinkish
Stratified ciliated columnar epithelium lines the inner surface; the
epithelium contains mucous glands and musle fibres.

49. TRACHEA
Longitudinal elastic fibers enable the trachea to stretch and descend with
the roots of the lungs during inspiration.
The trachea divides between the T5 and T7 vertebral levels.
The carina - a ridge seen internally at the bifurcation and is a landmark
during bronchoscopy.
The arch of the aorta is at first anterior to the trachea and then on its left
side immediately superior to the left main bronchus.
Other close relations include the brachiocephalic and left common carotid
arteries.

50. TRACHEA
Blood Supply
The inferior thyroid arteries.
Nerve Supply
Its smooth muscle is supplied by parasympathetic and sympathetic
fibers - by the vagi.
Applied Anatomy
Trachiostomy - done to reduce respiratory effort

54. BRONCHI
Main bronchi
Right and Left
Each main bronchus extends from the tracheal bifurcation to the hilus of the' corresponding lung.
The right main bronchus - has
(1) an upper part, from which the segmental bronchi for the upper lobe arise
(2) a lower part, from which the segmental bronchi for the middle and lower lobes arise
The left main bronchus divides into two
(1) one for the upper lobe
(2) one for lower lobe.

55. BRONCHI
The upper lobar bronchus has an upper division and a lower, or lingular,
division.
The right main bronchus shorter, wider, and more vertical than the left.
So foreign objects traversing the trachea are more likely to enter the right
main bronchus.
The left main bronchus crosses anterior to the esophagus, which it indents.
Both bronchi have cartilaginous rings that are replaced by separated plates
at the roots of the lungs.

56. BRONCHI
Blood Supply
The bronchi supplied by the bronchial arteries and veins,
Nerve Supply
Its smooth muscle is supplied by parasympathetic and sympathetic
fibers - by the vagi.

58. LUNGS
Definition
Organ of respiration
2 lungs - Right & Left
Right lung - 3 lobes : Upper, middle and lower lobes : 10 segments - 3 in the upper lobe, 2
in the middle lobe and 5 in the lower lobe
Left lung - 2 lobes : Upper and lower lobes : 8 segments - 4 in the upper lobe and4 in the
lower lobe
The Pleura
A membrane covering the lung closely - Visceral pleura - forms invaginations called
fissures - 2 fissures in the right lung and one in the left lung
Pulmonary ligament - a double layer of pleura along the mediastinum

59. LUNGS
The Pleura
A membrane covering the lung closely - Visceral pleura - forms
invaginations called fissures - 2 fissures in the right lung and one in the
left lung
Pulmonary ligament - a double layer of pleura along the mediastinum

60. LUNGS
Blood Supply
Pulmonary artery and pulmonary vein
Pulmonary artery from the right ventricle; the pulmonary vein from the alveoli
Pulmonary artery ends in the lung parenchyma; pulmonary vein empties into the left
atrium
They enter and exit the lung through the hilum of the lung
The pulmonary artery divides into truncal, lobar, segmental and subsegmental
arteries and follow the branches of the bronchial tree.
The veins from the alveoli receive blood from the bronchial and pleural branches.
form 2 pulmonary veins, superior and inferior on each side; these 4 join at or near
their junction with the left atrium and usually this common area is intrapericardial.

61. LUNGS
Pulmonary lymphatic system
Lymphatic vessels drain into intraparenchymal lymphatics and lymph
nodes reach Hilar lymph nodes and then subcarinal, tracheobronchial
and paratracheal lymph nodes and then ultimately reach the thoracic
duct
Nerve Supply
Vagus nerves -Parasympathetic nerves
Sympatheric nerves from sympathetic trunks of the vagus nerves

62. LUNGS
Lymphatic Drainage
Drain to the pulmonary nodes → bronchopulmonary nodes → inferior
(carinal) and superior tracheobronchial nodes → the tracheal
(paratracheal) nodes → bronchomediastinal nodes and trunks,
→thoracic duct on the left and right lymphatic duct on the right.

64. ALVEOLI
Definition
Pulmonary alveoli are air spaces in the lungs where CO2 leaves the
blood and O2 enters the blood
Approximately 300,000,000
At the end of bronchioles
Form clusters called alveolar sacs

65. ALVEOLI
Structure
The wall of each alveolus is lined by thin flat cells (Type I cells)
The wall contains numerous capillaries
It also contains a mesh of elastic and collagenous fibres (collagen -
supports; elastic - expansion and contraction)
It has pneumocytes (Type II cells)
Pneumocytes secrete surfactant - a film of fatty substance (lowers
surface tension to prevent collapse of the alveolus)
another type of cell - alveolar macrophage - engulf foreign particles like
dust, bacteria, carbon particles, blood cells and carry them away

66. ALVEOLI
Function
Exchange of gases between the blood and the atomospheric air
Brings the blood in the capillaries into close contact with the inspired
air, only two layer of epithelium separating the two.
Oxygen is absorbed and carbon di oxide is released by the haemoglobin
in the blood which get excreted by the expired air