• breathing is the process that brings oxygen in the
air into your lungs and moves oxygen and
through your body.
• Our lungs remove the oxygen and pass it through
our bloodstream, where it's carried off to the
tissues and organs that allow us to walk, talk, and
• Our lungs also take carbon dioxide from our
blood and release it into the air when we breathe
• the SINUSES are hollow spaces in the bones of your head. frontal
(the lower forehead), maxillary (cheekbones), ethmoid (beside the
upper nose), and sphenoid (behind the nose).
• Small openings connect them to the nasal cavity.
• The sinuses help to regulate the temperature and humidity of air
your breathe in, as well as to lighten the bone structure of the head
and to give tone to your voice
• Air can also enters through your ORAL
CAVITY (mouth), especially if you have a
mouth-breathing habit or your nasal passages
may be temporarily blocked.
5. THE HUMAN RESPIRATORY SYSTEM
consists of the
6. Parts of respiratory
Structurally, the respiratory
system consists of two
1. The upper respiratory
system includes the nose,
nasal cavity, pharynx and
2. The lower respiratory
system includes the
larynx, trachea, bronchi and
8. conducting zone
• consists of a series of interconnecting cavities
and tubes both outside and within the lungs.
• These include the nose, nasal cavity, pharynx,
larynx, trachea, bronchi, bronchioles, and
• Their function is to filter, warm, and moisten
air and conduct it into the lungs
9. Respiratory zone
• consists of tubes and tissues within the lungs
where gas exchange occurs.
• These include the respiratory bronchioles,
alveolar ducts, alveolar sacs and alveoli. (Gas
exchange occur in these zone)
It provides an entrance for air in which air is
filtered by hairs inside the nostrils.
• The hairs that line the inside wall are part of the
• Nose is primary route for air entering
• Dorsum of nose (bridge) formed by two nasal
bones Supported by hyaline cartilage
• Nasal cartilages—small, elastic cartilages
extending laterally from bridge; help keep
• Nostrils (external nares) are paired openings
into nasal cavity
13. The Functions of the Nose
• Filter the air
• Humidify the air
• Warm the air
• Site for sense of small
• To generate resonance in speech
14. NASAL CAVITY
• The entrance of the
respiratory system that is
divided into an external
portion and an internal
portion called the nasal
• It divided medially by the
• The anterior portion of the nasal
cavity just inside the nostrils,
called the nasal vestibule, is
surrounded by cartilage.
• The superior part of the nasal
cavity is surrounded by bone.
• A vertical partition, the nasal
septum, divides the nasal cavity
into right and left sides.
• The anterior portion of the nasal
septum consists primarily of
• is a funnel-shaped tube
• shared by respiratory and digestive systems
• about 13 cm long that starts at the internal nares
and extends to the level of the cricoid cartilage,
• the most inferior cartilage of the larynx.
The pharynx lies just
posterior to the nasal and oral cavities,
superior to the larynx, and anterior to the cervical
• is the middle portion of the
• between the soft palate and the
level of the hyoid bone.
• Both swallowed food and fluid
and inhaled air pass through it.
• The base of the tongue forms the
anterior wall of the
• is the lowermost
portion of the pharynx.
• It extends inferiorly
from the level of the
hyoid bone to the
• opens into the
esophagus and larynx
• Lies between base of tongue and
• Protrusion is the thyroid cartilage, aka
• Connection point-upper and lower
The larynx has two functions.
• primary function is to prevent food or
fluid from entering the trachea and
lungs during swallowing and to permit
passage of air while breathing.
• A secondary role is to produce sound.
• The larynx contains a number of
cartilages that keep the
passageway to the trachea open
during breathing and closes the
respiratory passageway during
(a) The epiglottis is a spoon-shaped
structure that aids in closing the
laryngeal opening, or glottis,
(b) The vocal folds in the larynx are
controlled by intrinsic muscles and
are used in sound production.
• The trachea commonly called
the “windpipe,” is
• a semirigid, tubular organ,
approximately 12 cm (4 in.)
long and 2.5 cm (1 in.) in
diameter, connecting the larynx
• Flexible and mobile tube
extending from the larynx into
• Has 15–20 C-shaped
• tracheal cartilages ensure that the airway will
always remain open.
• The open part of each of these cartilages faces
the esophagus and permits the esophagus to
expand slightly into the trachea during
• Medial to the lungs, the trachea splits to form
the right and left principal bronchi.
• The bronchi carry air into your
lungs. At the end of the bronchi,
the bronchioles carry air to small
sacs in your lungs called alveoli.
The alveoli perform your body's
• are air passages inside the lungs
that branch off like tree limbs from
the bronchi—the two main air
passages into which air flows from
the trachea (windpipe) after being
inhaled through the nose or
29. Bronchial Tree
• It is a highly branched
system of air-conducting
passages that originate from
the left and right primary
• Right primary bronchus is
shorter, wider, and more
vertical than the left primary
30. Anatomy of the Lungs
• Lung occupies most of the space
within the thoracic cavity. It has a
• Toward the midline, the lungs are
separated from each other by the
mediastinum and this is called the
• The mediastinum is a complex
anatomic space within the central
thoracic cavity, surrounded by the
31. Costal surface of the lung.
• The relatively broad, rounded surface in
contact with the thoracic wall is called the
costal surface of the lung.
• The lungs extend laterally from the heart to
the ribs on both sides of the chest and
continue posteriorly toward the spine.
32. Costal surface of the lung.
• The superior end of each lung
forming the point of the cone and
the inferior end forming the base.
• The superior end of the lungs
narrows to a rounded tip known as
• The apex projects superiorly to a
point that is slightly superior and
posterior to the clavicle.
• The inferior end of the lungs,
known as the base.
• 2lobes by oblique 1 fissure
• Smaller than the right lung
• Cardiac notch accommodates the heart
• Weight- left lung - 550 gms
• 3lobes by oblique and horizontal 2 fissure
• Located more superiorly in the body due to liver on right side •
• Weight- right lung - 600 gms
35. Pleura and Pleural Cavity
• The rib cage is separated from
the lung by a two layered
membranous coating called the
• The potential space between
the serous membrane layers is
a pleural cavity.
• The pleural membranes
produce a thin, serous pleural
fluid that circulates in the
pleural cavity and acts as a
lubricant, ensuring minimal
friction during breathing.
36. • The outer surface of
each lung is tightly
covered by the visceral
• • while the internal
thoracic walls, the
lateral surfaces of the
mediastinum, and the
superior surface of the
diaphragm are lined by
the parietal pleura.
1. What is the names of the sinuses?
2. What is the human respiratory system consist
3. What are the nasal cartilages?
4. Mention three functions of the nose?
5. How many sections is the left and right lung