1. BY
MONALISA GAIKWAD
1st YEAR
M.Sc CLINICAL RESEARCH
PADMASHREE INSTITUTION

2. OBJECTIVES
 To explain the Anatomy of Respiratory System.
 To explain the Functions and Respiration Process.
 To explain the Lung Volume and Lung Capacities.

3. Respiration
Respiration is the process of taking in
oxygen (Inhaling), producing energy
with it (within Cell) and excreting
gaseous waste products (Exhaling).

4. Classification of Respiratory system
 Structural classifications:
 upper respiratory tract
 lower respiratory tract.
 Functional classifications:
 Conducting portion: transports air.
 Nose
 nasal cavity
 Pharynx
 Larynx
 Trachea
 progressively smaller airways, from the primary bronchi to the bronchioles
 Respiratory portion: carries out gas exchange.
 respiratory bronchioles
 alveolar ducts
 air sacs called alveoli
 Upper respiratory tract is all conducting
 Lower respiratory tract has both conducting and respiratory portions.

6. Structural Classification
Upper Respiratory Tract Lower Respiratory Tract
 Composed of  Conducting portion
 the nose  Larynx
 the nasal cavity  Trachea
 Bronchi
 the paranasal sinuses
 bronchioles and their
 the pharynx (throat)
associated structures
 and associated structures
 Respiratory portion of the
respiratory system
 respiratory bronchioles
 alveolar ducts
 alveoli

7. Nose
Functions Structure
The only externally visible
part of the respiratory system
that functions by:
Providing an airway for
respiration
Moistening
(humidifying) and
warming the entering air
Filtering inspired air and
cleaning it of foreign
matter
Serving as a resonating
chamber for speech
Housing the olfactory
receptors

9. Nasal Cavity
Lies in and posterior to the external nose
Is divided by a midline nasal septum
Opens posteriorly into the nasal pharynx via internal nares
The ethmoid and sphenoid bones form the roof
The floor is formed by the Anterior hard palate (bone) and posterior soft
palate (muscle)
The nasal cavity is separated from the oral cavity by the palate
 Olfactory receptors are located in the mucosa on the superior surface
 The rest of the cavity is lined with respiratory mucosa
 Moistens air
 Traps incoming foreign particles
 Lateral walls have projections called conchae
 Increases surface area
 Increases air turbulence within the nasal cavity

10. Paranasal Sinuses
 Cavities within bones surrounding the nasal
cavity
 Frontal bone
 Sphenoid bone
 Ethmoid bone
 Maxillary bone
Communicate with the nasal cavity by ducts.
Covered with the same pseudostratified
ciliated columnar epithelium as the nasal cavity.
 Function of the sinuses
 Lighten the skull
 Act as resonance chambers for speech
 Produce mucus that drains into the nasal
cavity

11. Pharynx
Common to both the respiratory and digestive
systems.
Commonly called the throat.
Funnel-shaped
slightly wider superiorly and narrower inferiorly.
Originates posterior to the nasal and oral cavities
Extends inferiorly near the level of the bifurcation
of the larynx and esophagus.
Walls:
 lined by a mucosa
contain skeletal muscles primarily used for
swallowing.
Flexible lateral walls
distensible
to force swallowed food into the esophagus.
Partitioned into three adjoining regions:
nasopharynx
oropharynx
Laryngopharynx
The oropharynx and laryngopharynx are
common passageways for air and food

12. Nasopharynx
Superiormost region of the pharynx.
Location:
posterior to the nasal cavity
superior to the soft palate
separates it from the posterior part of the oral cavity.
Normally, only air passes through.
Soft palate
Blocks material from the oral cavity and oropharynx
elevates when we swallow.
Auditory tubes
paired
In the lateral walls of the nasopharynx
connect the nasopharynx to the middle ear.
Pharyngeal tonsil
posterior nasopharynx wall
single
commonly called the adenoids.

13. Oropharynx
The middle pharyngeal region.
Location:
Immediately posterior to the oral cavity.
Bounded by the soft palate superiorly,
the hyoid bone inferiorly.
Common respiratory and digestive pathway
both air and swallowed food and drink pass through.
2 pairs of muscular arches
anterior palatoglossal arches
posterior palatopharyngeal arches
form the entrance from the oral cavity.
Lymphatic organs
provide the “first line of defense” against ingested or inhaled foreign materials.
Palatine tonsils
 on the lateral wall between the arches
Lingual tonsils
At the base of the tongue.

14. Laryngopharynx
Inferior, narrowed region of the pharynx.
Location:
Extends inferiorly from the hyoid bone
is continuous with the larynx and esophagus.
Terminates at the superior border of the esophagus
is equivalent to the inferior border of the cricoid cartilage in the larynx.
The larynx (voice box) forms the anterior wall
Lined with a nonkeratinized stratified squamous epithelium
(mucus membrane)
Permits passage of both food and air.

15. Lower Respiratory Tract
Larynx
Short, somewhat cylindrical airway
Location:
bounded posteriorly by the laryngopharynx,
inferiorly by the trachea.
Prevents swallowed materials from entering the lower respiratory tract.
Conducts air into the lower respiratory tract.
Produces sounds.
Nine pieces of cartilage
three individual pieces
Thyroid cartilage
Cricoid cartilage
Epiglottis
three cartilage pairs
Arytenoids: on cricoid
Corniculates: attach to arytenoids
Cuniforms:inaryepiglottic fold
held in place by ligaments and muscles.
Intrinsic muscles: regulate tension on true vocal cords
Extrinsic muscles: stabilize the larynx

17. Sound Production
Two pairs of ligaments
Inferior ligaments, called vocal ligaments
covered by a mucous membrane
vocal folds: ligament and mucosa.
are “true vocal cords”
they produce sound when air passes between them
Superior ligaments, called vestibular ligaments
Covered by mucosa
vestibular folds: ligament and mucosa
Are “false vocal cords”
no function in sound production
protect the vocal folds.
The vestibular folds attach to the corniculate cartilages.
The tension, length, and position of the vocal folds determine the quality of the
sound.
Longer vocal folds produce lower sounds
More taunt, higher pitch
Loudness based on force of air
Rimaglottidis: opening between the vocal folds

18. Trachea
A flexible, slightly rigid tubular organ
 often referred to as the “windpipe.”
Extends through the mediastinum
immediately anterior to the esophagus
inferior to the larynx
superior to the primary bronchi of the lungs.
Anterior and lateral walls of the trachea are supported by 15 to 20 C-shaped tracheal
cartilages.
cartilage rings reinforce and provide some rigidity to the tracheal wall to ensure
that the trachea remains open (patent) at all times
cartilage rings are connected by elastic sheets called anular ligaments
At the level of the sternal angle, the trachea bifurcates into two smaller tubes, called
the right and left primary bronchi.
Each primary bronchus projects laterally toward each lung.
The most inferior tracheal cartilage separates the primary bronchi at their origin and
forms an internal ridge called the carina.

20. Bronchial Tree
A highly branched system
air-conducting passages
originate from the left and right primary bronchi.
Progressively branch into narrower tubes as they diverge
throughout the lungs before terminating in terminal bronchioles.
Primary bronchi
Incomplete rings of hyaline cartilage ensure that they remain open.
Right primary bronchus
shorter, wider, and more vertically oriented than the left primary bronchus.
Foreign particles are more likely to lodge in the right primary bronchus.

21. Bronchial Tree Division
Primary bronchi
enter the hilum of each lung
Secondary bronchi (or lobar bronchi)
Branch of primary bronchus
left lung:
two lobes
 two secondary bronchi
right lung
three lobes
three secondary bronchi.
Tertiarybronchi (or segmental bronchi)
Branch of secondary bronchi
left lung is supplied by 8 to 10 tertiary
bronchi.
right lung is supplied by 10 tertiary
bronchi
supply a part of the lung called a
bronchopulmonarysegment.

22. Respiratory Zone
Defined by the presence of alveoli; begins as terminal bronchioles feed into
respiratory bronchioles
Respiratory bronchioles lead to alveolar ducts, then to terminal clusters of
alveolar sacs composed of alveoli
An alveolus is about 0.25 to 0.5 millimeter in diameter.
Its thin wall is specialized to promote diffusion of gases between the
alveolus and the blood in the pulmonary capillaries.
Gas exchange can take place in the respiratory bronchioles and alveolar
ducts as well as in the lungs, which contain approximately 300–400 million
alveoli.
The spongy nature of the lung is due to the packing of millions of alveoli
together

23. Respiratory Bronchioles, Alveolar
Ducts, and Alveoli

24. LUNGS
Occupy most of the thoracic cavity
Each lung has a conical shape.
Its wide, concave base rests upon the muscular diaphragm.
Its relatively blunt superior region, called the apex or (cupola), projects
superiorly to a point that is slightly superior and posterior to the clavicle.
Both lungs are bordered by the thoracic wall anteriorly, laterally, and posteriorly,
and supported by the rib cage.
Toward the midline, the lungs are separated from each other by the
mediastinum.
The relatively broad, rounded surface in contact with the thoracic wall is called
the costal surface of the lung.

25. LUNG cont….
Left lung
divided into 2 lobes by oblique fissure
smaller than the right lung
cardiac notch accommodates the heart
Right lung
divided into 3 lobes by oblique and horizontal fissure
located more superiorly in the body due to liver on right side

28. Pleura and Pleural Cavities
The outer surface of each lung and the adjacent internal thoracic wall are
lined by a serous membrane called pleura, which is formed from simple
squamous epithelium.
The outer surface of each lung is tightly covered by the visceral pleura, while
the internal thoracic walls, the lateral surfaces of the mediastinum, and the
superior surface of the diaphragm are lined by the parietal pleura.
The parietal and visceral pleural layers are continuous at the hilum of each
lung.
The potential space between these serous membrane layers is a pleural
cavity.
The pleural membranes produce a thin, serous fluid that circulates in the
pleural cavity and acts as a lubricant, ensuring minimal friction during breathing
called as pleural fluid.

30. Functions of Respiratory System
 supplies the body with oxygen and disposes of carbon dioxide
 filters inspired air
 produces sound
 contains receptors for smell
 rids the body of some excess water and heat
 helps regulate blood pH

31. Respiration Process
A collective term for the following processes:
Pulmonary Ventilation
 Movement of air into the lungs (inspiration)
 Movement of air out of the lungs (expiration)
External Respiration
 Movement of oxygen from the lungs to the blood
 Movement of carbon dioxide from the blood to the lungs
Transport of Respiratory Gases
 Transport of oxygen from the lungs to the tissues
 Transport of carbon dioxide from the tissues to the lungs
Internal Respiration
 Movement of oxygen from blood to the tissue cells
 Movement of carbon dioxide from tissue cells to blood

32. Lung Volume
TIDAL VOLUME (TV): Volume inspired or expired with each
normalﾊbreath. = 500 ml
INSPIRATORY RESERVE VOLUME (IRV): Maximum volume that can
be inspired over the inspiration of a tidal volume/normal
breath. Used during exercise/exertion.=3100 ml
EXPIRATRY RESERVE VOLUME (ERV): Maximal volume that can be
expired after the expiration of a tidal volume/normal breath. =
1200 ml
RESIDUAL VOLUME (RV): Volume that remains in the lungs after a
maximal expiration.ﾊ CANNOT be measured by spirometry.=
1200 ml

33. Lung Capacity
INSPIRATORY CAPACITY ( IC): Volume of maximal inspiration:IRV + TV =
3600 ml
FUNCTIONAL RESIDUAL CAPACITY (FRC): Volume of gas remaining in lung
after normal expiration, cannot be measured by spirometry because it
includes residual volume:ERV + RV = 2400 ml
VITAL CAPACITY (VC): Volume of maximal inspiration and expiration:IRV
+ TV + ERV = IC + ERV = 4800 ml
TOTAL LUNG CAPACITY (TLC): The volume of the lung after maximal
inspiration.ﾊ The sum of all four lung volumes, cannot be measured
by spirometry because it includes residual volume:IRV+ TV + ERV +
RV = IC + FRC = 6000 ml

34. Respiratory rate throughout life
 Infants – 30 respirations per minute
 Age 5 – 25 respirations per minute
 Newborns – 40 to 80 respirations per minute
 Adults – 12 to 18 respirations per minute
 Rate often increases somewhat with old age

35. THANK YOU
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