RESPIRATORY SYSTEM

1. DR. PABBA PARAMESHWAR

3. Respiratory system
 Respiratory system is a system through which every
cell in the body receives the oxygen and excretes its
carbon dioxide
 Lungs in hale and exhale the air through the
respiratory passages starting from
 nasal cavity
 nasopharynx
 larynx
 trachea
 bronchi
 bronchioles and finally alveoli.

5.  Inspiration --- breathing in
 Expiration --- breathing out
 These both are called as the External respiration

6. Internal respiration
the air is exchanged in
for oxygen and
out for CO2 in the alveoli,
the exchange of gases
at the cellular level is
called as internal
respiration

7. Anatomy of the respiratory system
 The respiratory system sub divide in to the upper and
lower respiratory system based on the anatomical
structure
 the upper respiratory tract includes- nasal passage,
pharynx larynx
 The lower reparatory tract includes – trachea, bronchi,
lungs.

8. Nose and nasal cavity:
Nose is a external portion of the respiratory system
The nasal cavity divides in to two by the nasal septum –
which is lined by the mucus membrane it is covered by
the ciliated epithelium
Functions
Detection of olfactory stimuli
Modify the speech vibration
By sneezing expels the irritation
Filtering the incoming air

10. Pharynx (throat)
 The pharynx is a tube 12 to 14 cm long that extends from the base of
the skull to the level of the 6th cervical vertebra.
 It lies behind the nose ,mouth and larynx wide in upper end
 The nasal cavity open into the nasopharynx, it is the common path
way for oral cavity
 The pharynx is divide in to three parts
 Nasopharynx – located behind the nose
 The oropharynx – the oral part of the pharynx lies behind the mouth
 laryngopharynx – laryngeal part of the pharynx it extends from the
oropharynx to esophagus

12. Functions
 passage for food and air
 warming and humidifying in coming air
 hearing
Speech
Protection

13. Larynx (voice box)
 The larynx is the voice box extend from the root of the
tongue and hyoid bone to the trachea.
 It locates 3,4,5 th and 6th cervical vertebrae.
 The larynx is composed of several irregular shaped
cartilages attached to each other of by ligaments and
membranes.
The main cartilages are
 thyroid cartilage
 cricoid cartilage
 arytenoid cartilage
 the epiglottis

15. Functions:
 production of sound – pitch, volume and resonance
 speech
 protection of the lower respiratory tract
 passage for air
 filtrating the air

16. TRACHEA OR WINDPIPE
 The trachea is a tube that has an inner diameter of about 20-25
mm and length about 10-16 cm
 It starts from larynx and is bifurcates into the bronchi of left
and right
 It is lined with pseudo stratified ciliated columnar epithelium
cell with mucosa goblet cells which produce mucus
 The mucus lines the cells of the trachea to trap inhaled foreign
particles and expelled out.
The trachea made with incomplete C shaped cartilaginous rings
which provide air passage

18. Functions
 support- the arrangement of the cartilage and elastic nature
protects from the injury
 Mucociliary escalator- it provide regular movants of cilia it
send the foreign particle towards the larynx
 Cough reflex – nerve endings in the trachea and bronchia are
very sensitive to irritation - causes reflex
 Filtration and humidification of air

19. lungs
 There are two lungs , one lying on each side of the
midline in the thoracic cavity.
 they are cone shaped and have apex, a base costal
surface and medial surface through which blood
vessels, lymphatic vessels and nerves are enter and
exit.
apex :
the base
The medial surface
Pleural cavity
Visceral pleura

24. bronchi, bronchioles and alveoli
 At the superior border of the fifth thoracic vertebrae the
trachea divides into right primary bronchus which goes
into right lung and left primary bronchus which is goes it
left lung.
 the right bronchus is wider and shorter – more vertical
than the left one
 after entering into the right lung at the hilum it divides into
three branches, one to each lobe.
 Each branch subdivide into numerous smaller branches.
 The left bronchus is about 5 cm long and is narrower than
right one, after enter in to the lung at the hilum it divide
into two branches, one to each lobe.
 Each branch subdivided into many smallar braches

25.  The bronchi are composed of the ciliated columnar
epithelium.
 The bronchi subdivided into bronchioles
 terminal bronchioles
 respiratory bronchioles
 alveolar ducts
 finally alveoli

27. Respiratory muscles
 The diaphragm and intercostal muscle are the skeletal muscles
involved in the respiratory movements.
Diaphragm:
It is large dome shaped muscle sheath which is separate the
thoracic cavity from the abdominal cavity.
It is innervated by the phrenic nerve on each side.
Contraction relaxation of diaphragm provides in put and out put
of air into the lungs
Intercostal muscles:
There are two series of muscles situated between the ribs one
inner side and other is outer side

29. mechanism of respiration
The mechanism of gas exchange in the body, called
respiration
Pulmonary ventilation (breathing )
External respiration
Internal respiration

31. Pulmonary ventilation
 In pulmonary ventilation air flows between atmosphere and
alveoli of the lungs
it having two steps:
Inhalation/ Inspiration
Air flow in to the lungs – the pressure inside the alveoli become
lower than out side the pressure – this condition is achieved by the
increase the volume of the lungs
Exhalation/ expiration
The pressure in the lungs is greater than the pressure of the
atmosphere.
Here muscular contraction leads to the expiration, the diaphragm
moves up

32. External respiration
 External respiration is the diffusion of the o2 from the
air in the alveoli of the lungs to blood in pulmonary
capillaries and the diffusion of the co2 in the opposite
direction.
Internal respiration
The exchange of oxygen and carbon dioxide between
systemic capillaries and tissues cells is called internal
respiration

35. Transport of the gases
 If the 100 ml of plasma is exposed to an atmosphere
with a P02 of 100mmHg, only 0.3 ml of oxygen would
be absorbed
 If the 100 ml of blood is exposed to an atmosphere
with a P02 of 100mmHg, about 19 ml of oxygen would
be absorbed this is due to the hemoglobin is the main
mean of the oxygen transport in the body

36. Oxygen transport
 In the loading and unloading of oxygen, there is
cooperation between these four heam groups.
 When oxygen binds to the one of the groups, the
others shape slightly changed and then attract to other
molecules
Out of the co2 released from the rspirang cells, 7%
dissolves into the plasma, 23%binds to the multiple amino
groups of hemoglobin, and 70% is carried as bicarbonate
ions

38. Lung volume and capacities

39. Lung volume and capacities
Total lung capacity (TLC):
The volume of air contained in the lung at the end of
maximal inspiration
The total volume of the lung – that is the volume of air
in the lungs after maximum inspiration.
calculation: TLC=IRV+Vt+ERV+RV
VALUE(male /female)= 6/4.7L

40.  Vital capacity (VC)
the amount of the air that can be forced out of the lungs
after a maximal inspiration.
calculation: IRV+Vt+ERV
VALUE = 4.6/3.6 L

41. Forced vital capacity(FVC):
the amount of air that can be maximally forced out of
the lungs after a maximal inspiration
value = 4.8/3.7 L
Tidal volume (Vt):
the amount of air breathed in or out during normal
respiration is called as tidal volume
value = 500/390 ml

42.  Residual volume (RV):
the amount of air left in the lungs after a maximal
exhalation. The amount of air always in the lungs and
can never be expired
value = 1.2/0.93L
Expiratory reserve volume (ERV):
The amount of additional air that can be pushed out
after the end expiratory level of normal breathing
value = 1.2/0.93L

43. Inspiration reserve volume (IRV):
The additional air that can be inhaled after a normal
tidal breath in .
Value = 3/2.3L
Calculation = IRV=VC-(TV+ERV)
Functional residual capacity (FRC):
the amount of air left in the lungs after a tidal breath
out, or the amount of air that stays the lungs during the
normal breathing.
Value= 2.4/1.9 L
Calculation FRC=ERV+RV

44. Inspiratory capacity (IC)
The maximal volume that can be inspired following a
normal expiration
Value = 3.5/2.7L
IC=TV+IRV
Anatomical dead space
The volume of the conducting airways.
Value = 150/120 ml
Physiological dead volume :
The anatomic dead space plus the alveolar dead space
value = 155/120 mL

46. RESPIRATORY DISEASES
Asthma:
Asthma is a complex and characterized by the variable
and recurring symptoms, air flow obstruction, brachial
hyperresponsiveness and inflammation.
Anoxia
Is a condition characterized by an absence of oxygen
supply to an organ or tissue, anoxia results when oxygen
is not being delivered to a part of the body.

47. Apnoea
Is a term for suspension of external breathing. During
apnoea there is no movement of the muscles
Cyanosis
It is a blue coloration of the skin and mucus membrane
due to the presence of more than 5 g/dl deoxygenated
hemoglobin in the blood vessels near the skin surface
Asphyxia
is a condition of severely defective supply of oxygen to
the body that arises from being unable to breath
normally

48.  Tuberculosis
It is a chronic communicable pulmonary disease caused
by the mycobacterium tuberculosis
It attack the lungs