Short note of Respiratory system

1. WelcomeRespiratory
System

2. RespiratoryRespiratory
SystemSystem

3. Cardiovascula
r
System

4. Respiratory System
NoseNose

5. • Respiration :
• The interchange at gases between an organism & medium in
which it lives that the taking of oxygen (O2), its use in tissue & the
giving of CO2 is called respiration .
•
• C6H12O6 + 6O2 → 6CO2 + 6H2O + Large amount of energy
• Two Phages :
•
• A. Inspiration :- It means intake of air into lungs . Its duration is
about 2 sec.
• B. Expiration :- It means output of air from lungs . Its duration is
about 3 sec.

6. Functions of Respiration :
• I. Gas Transfer :- O2 from alveoli to venous blood & CO2 is opposite
direction .
• II.Metabolic function :- O2 is essential for maintenance of metabolism in
the tissue .
• III.Excretion :- It excretes volatile substance like NH3 , ketone bodies ,
essential oils , alcohols , water vapour etc .
• IV.Regulation of partial pressure of CO2 (PCO2 ):- The most important
functions of respirations is to keep the arterial PCO2 at 40 mmHg which is
essential for many vital functions of the body .
• V.Regulation of pH of blood :- It regulates the pH of blood by the following
reversible reaction –
• H2CO3 ↔ H--+ + HCO3
• VI.Pumping action :- The rhythmic movement at the diaphragm & chest
wall causes rhythmic alteration of pressure in the abdomen & chest
cavity . This assist in drawing blood from the lower part of the body to the
abdomen & then to the chest ,it helps in maintaining venous inflow of the
heart .

7. Functions of Respiration :
• VII.Maintenance of temperature balance :- When water is
transformed into gaseous form heat is absorbed , so heat is lost
through H2O vapour . About 10% of body heat is changed in this way
.
• VIII. Maintenance of H2O balance :- 600-800 ml of water per day is
lost or water vapour during expiration .
• IX.Blood & Lymph return :- Effect heart rate & CO through
nervous mechanism.
• X.Blood pressure :- Increase or decrease due to respiration .
• XI.Body Defense :- Secondary protection of the body from inhaled
the particle . Filter the blood that enter into the systemic circulation .
• XII.Endocrine function :- Conversion of Angiotensin- I to II by the
help of ACE , thus control BP . Also help to secrete Prostaglandin ,
Bradykinin , Histamine , Serotonin , Ach .

8. Types of Respiration :-
1. External respiration
2. Internal respiration
• 1. External Respiration :- O2 in & CO2 out
(removal) .
• 2. Internal Respiration :- The utilization of O2
& production of CO2 by cell & the gaseous
exchange between the cell and their fluid
medium is called internal respiration .

9. • Four Stages of Respiration :-
1. Pulmonary Ventilation :- Inflow & outflow of air between alveoli and
atmosphere .
2. Diffusion of O2 & CO2 between alveoli and blood .
3. Transport
4. Regulation
• Respiration Rate :-
• The rate of respiration depends upon the following things ---
• Age
• Sex
• Size
• Work
• Rest
• Sleep
• At Birth :- 14 – 60 per min
• Adult ( male or female ) :- 10 – 18 per min

10. Conditions increase rate of Respiration :-
( Respiration & level of Metabolism )
• Physiologic → Nervous excitement , Muscle
exercise , High altitude, Increase temperature .
• Chemical → Increase CO2 , decrease O2
• Pathological → Fever , Defective formation of
blood .
• Conditions decrease rate of Respiration :-
Opium , Barbiturate poisoning .

11. • Muscles of Respiration :-
1. Inspiration :
• Quite Inspiration :-
Diaphragm : It increases the vertical diameter of the
thoracic cavity .
External Intercostals : It increases the anterio-posterior
& transverse diameter of the cavity .
• Forceful Inspiration :-
Sternomastoid , Anterior serrati , Scalenus posterior ,
Latissimus dorsi .
2. Expiration :
• Quite Expiration :- Does not involve any muscle .
• Forceful Expiration :- Abdominal recti , Internal
intercostals , Serratus posterior , Interior muscles .

12. Mechanism of Respiration / Breathing Mechanism :-
1. Mechanism of Inspiration :-
•
•
• Signals from respiratory center
•
•
•
•
• Phrenic Nerve Intercostal nerve
• ( it arises from the ( these are the anterior
• 3rd,4th,5th cervical division of the thoracic
• Spinal nerve ) spinal nerve from T1- T2)
•
•
• Contraction of Diaphragm Contraction of external
• Intercostals muscle
•
• ↑vertical diameter of
• Chest cavity ↑Anterio-posterior &
• transverse diameter of
• chest cavity .
• Chest wall expansion
•
•
• Negative intrapleural Negative alveolar pressure
• pressure, -7.5 cm of H2o/ -1 cm of H2O / 1 mm of Hg
• -6 mm of Hg
•
•
• Expansion of lung
•
•
•
• Air flow into the lung
•
•
• Inspiration
•

13. Mechanism of Expiration :-
• Signals from respiratory centers
•
•
•
• Phrenic nerve Intercostal nerve
•
•
•
• Relaxation of diaphragm Relaxation of respiratory
• muscles & contraction of
• expiration muscle .
•
• ↓vertical diameter of
• Chest cavity
• Lungs recoil pulls the back
• to expiratory position .
•
• Contraction of lungs
•
• ↑ Recoil pressure
•
•
•
•
• Slightly positive airway pressure
•
•
• Air flown out from lungs
•
•
•
• Expiration

14. Differences between Respiration & Ventilation:-
• Respiration is a dynamic process,involves gas exchange (eg-CO2 & O2 )
either at the alveolar capillary level or that the tissue-cellular level.
• Ventilation also a dynamic process,that involves contraction of the
respiratory muscles with subsequent changes of air through the airways &
into the alveoli.
• Lung Volume:-
• Lung volume are non overlapping fraction of the gas content.
• Lung Capacities:-
• The lung capacities are dynamic entities & are employed to describe events
in the pulmonary cycle, and also to assess lung function.
• There are four types of volume & four capacities exist.
Volume
• The Tidal volume(TV)- It is the volume of air inspired or expired during
normal quiet breathing. It amount to about 500 ml in adult male.
• The inspiratory reserve volume(IRV)- It is the extra volume of air that can be
inspired over & above the normal tidal volume when the person inspire with
full force.It is usually to about 3000
• The expiratory reserve volume(ERV)- The expiratory reserve volume is the
maximum extra volume of air that can be expired by forceful expiration after
the end of a normal tidal expiration.This normally amounts to about 1100 ml.
• The residual volume(RV)- The RV is the volume of air remaining in the
lungs after the most forceful expiration. This volume average about 1200 ml.

15. Position of Lungs

16. The Lungs
LarynxLarynx

17. The Bronchial Tree
TracheaTrachea
BronchusBronchus
BronchioleBronchiole
Alveolar ductAlveolar duct

18. The organs of the respiratory system
 nose
 pharynx
 larynx
 trachea
 bronchi
 bronchioles
 alveolar ducts and
the alveoli
 Within the lungs
Leading to the lungs

19. The Pathway
• Air enters the nostrils
• passes through the nasopharynx,
• the oral pharynx
• through the glottis
• into the trachea
• into the right and left bronchi, which branches and
rebranches into
• bronchioles, each of which terminates in a cluster of
Alveoli
Only in the alveoli does actual gas exchange takes place. There are
some 300 million alveoli in two adult lungs. These provide a surface
area of some 160 m2
(almost equal to the singles area of a tennis court
and 80 times the area of our skin!).

21. The nose
 The external nose is formed
by the two nasal bones and
by cartilage.
 It is both covered and lined
by skin and inside there are
hairs which help to prevent
foreign materials from
entering.
 The nasal cavity is a large
cavity divided by a septum.

22. ……nose
• Some of the bones
surrounding the nasal
cavity are hollow.
• The hollows in the
bones are called the
paranasal sinuses.
• All the paranasal
sinuses are lined with
mucous membrane
and all open into the
nasal cavity
PS

23. The Pharynx
1. The naso-pharynx -
lies behind the
nose,
2. The oro-pharynx-
lies behind the
mouth,
3. The laryngeal
pharynx- lies behind
the larynx.
1
2
3

24. The larynx
• The larynx is
composed of
several irregular
cartilages joined
together by
– ligaments and
– membranes.

25. Alveoli
Alveolus

26. The trachea
• Begins below the larynx
and runs down the front of
the next into the chest.
• It divides into the right and
left main bronchi.
• It is about 12 cm long.
• On either side of the
trachea, lie the lungs with
the lobes of the thyroid
gland above them.

27. The bronchial tree
TracheaTrachea
BronchusBronchus
BronchioleBronchiole
Alveolar ductAlveolar duct

28. Trachea
• The wall of the trachea is
made of involuntary muscle
and fibrous tissue
strengthened by the horse-
shoe like incomplete ring of
hyaline cartilage.
• The trachea is lined with
ciliated epithelium containing
goblet cells which secrete
mucus.
• The cilia sweep the mucus and
foreign particles upwards
towards the larynx.

29. The lungs
• The lungs are a pair of
spongy conical-shape
organs, each enveloped
in a serous membrane.
They extend from the root
of the neck to the
diaphragm.
• The lungs are divided into
lobes. The left lung has
two lobes, separated by
the oblique fissure. The
right lung has three lobes.
1
2
3
1
2

30. The alveolar ducts
• The terminal
bronchioles branch
repeatedly to form
minute passages
called alveolar ducts,
from which alveolar
sacs and alveoli
open.

31. The Alveoli
• The alveoli are surrounded
by a network of capillaries.
• Deoxygenated blood enters
the capillary network from the
pulmonary artery
• It is the capillary network that
the exchange of gases takes
place between the air in the
alveoli and the blood vessels.

32. The pleura
• The pleura is a serous membrane which
surrounds each lung.
• It is composed of flattened epithelial cells
on a basement membrane and it has two
layers.
• The visceral pleura are firmly attached to
the lungs, covering their surfaces.

33. ……….pleura
• At the root of the lungs the visceral layer is
reflected back to become the parietal layer
which lines the chest wall and covers the
superior surface of the diaphragm.
• The space between the two layers of the
pleura contains serious fluid which
enables them to glide over another without
friction.

34. Gaseous Exchange

35. Disorders
• Bronchitis
• Common Cold
• Bronchiectasis
• Cough
• Epiglottitis
• Hay Fever
• Pertussis
• Alveolitis
• Tuberculosis
• Pneumonia
• Pneumothorax
• Pleurisy
• Croup
• Sinusitis
• Tonsilitis
• pharyngotonsilitis
• Lung Cancer

36. Disorders of the Respiratory
System
• Obstructive Airways Disease
• Asthma
– Asthma is a reversible obstructive airways
disease of varying severity.
– The symptoms are caused by constriction of
the bronchial smooth muscle
(bronchospasm),
• oedema of bronchial mucous membranes, and
• blockage of the smaller bronchi with plugs of
mucous.

37. ………asthma
• Asthma may occur, particularly in children,
as a result of identifiable trigger factors or
allergen (extrinsic asthma).
• Immunological mechanisms involving
specific allergens (e.g. house-dust mite,
pollens and animal dander) may be
responsible.

38. ….asthma
• Non-specific trigger factors
include
– viral infection
– exercise
– dust and irritants (e.g. cigarette
smoke)
– beta-adrenoceptor blocking drugs
– NSAIDs (e.g. aspirin, indomethacin
etc.) and
– emotional disturbances

39. Chronic Obstructive Pulmonary
Disease (COPD)
Irritation of the lungs can lead to asthma, emphysema, and chronic bronchitis.
And, in fact, many people develop two or three of these together. This
constellation is known as chronic obstructive pulmonary disease (COPD).
Among the causes of COPD are
•cigarette smoke (often)
•cystic fibrosis (rare)
Cystic fibrosis is a genetic disorder caused by inheriting two defective genes
for CFTR, a transmembrane protein needed for the transport of Cl-
ions. The
lungs produce copious amounts of a heavy mucus that plugs the airways
interfering with breathing and causing a persistent cough. Cystic fibrosis is
the most common inherited disease in the U.S. white population.

40. Emphysema
In this disorder, the delicate walls of the
alveoli break down, reducing the gas
exchange area of the lungs. The condition
develops slowly and is seldom a direct cause
of death. However, the gradual loss of gas
exchange area forces the heart to pump ever-
larger volumes of blood to the lungs in order
to satisfy the body's needs. The added strain
can lead to heart failure.

41. Chronic Bronchitis
Any irritant reaching the bronchi and
bronchioles will stimulate an
increased secretion of mucus. In
chronic bronchitis the air passages
become clogged with mucus, and this
leads to a persistent cough. Chronic
bronchitis is usually associated with
cigarette smoking.

42. Pneumonia
Pneumonia is an infection of the alveoli. It
can be caused by many kinds of both
bacteria (e.g., Streptococcus pneumoniae)
and viruses. Tissue fluids accumulate in
the alveoli reducing the surface area
exposed to air. If enough alveoli are
affected, the patient may need
supplemental oxygen.

43. Drugs
• Bronchodilators
– Pulmolin
– Filin
• Antihistamine
– Citin
– Lora
– Histal
• Antibiotics
– Moxin
– Cephran
– Azicin
– Ceftid
– Ciprox

46. Asthma
In asthma, periodic constriction of the
bronchi and bronchioles makes it more
difficult to breathe in and, especially, out.
Attacks of asthma can be
•triggered by airborne irritants such as
chemical fumes and cigarette smoke
•airborne particles to which the patient is
allergic. Link to discussion of allergic
asthma.

48. 1. The SINUSES (frontal, maxillary, and sphenoidal) are hollow spaces in the
bones of the head. Small openings connect them to the nose. The functions
they serve include helping to regulate the temperature and humidity of air
breathed in, as well as to lighten the bone structure of the head and to give
resonance to the voice.
2. The NOSE (nasal cavity) is the preferred entrance for outside air into the
respiratory system. The hairs that line the wall are part of the air-cleaning
system.
3. Air also enter through the MOUTH (oral cavity), especially in people who
have a mouth-breathing habit or whose nasal passages may be temporarily
obstructed, as by a cold or during heavy exercise.
4. The ADENOIDS are lymph tissue at the top of the throat. When they
enlarge and interfere with breathing, they may be removed. The lymph
system, consisting of nodes (knots of cells) and connecting vessels, carries
fluid throughout the body. This system helps to resist body infection by
filtering out foreign matter, including germs, and producing cells
(lymphocytes) to fight them.

49. 5. The TONSILS are lymph nodes in the wall of the throat (pharynx) that often
become infected. They are part of the germ-fighting system of the body.
6. The THROAT (pharynx) collects incoming air from the nose and mouth and
passes it downward to the windpipe (trachea).
7. The EPIGLOTTIS is a flap of tissue that guards the entrance to the windpipe
(trachea), closing when anything is swallowed that should go into the esophagus
and stomach.
8. The VOICE BOX (larynx) contains the vocal chords. It is the place where moving
air being breathed in and out creates voice sounds.
9. The ESOPHAGUS is the passage leading from the mouth and throat to the
stomach.
10. The WINDPIPE (trachea) is the passage leading from the throat (pharynx) to
the lungs.
11. The LYMPH NODES of the lungs are found against the walls of the bronchial
tubes and windpipe.

50. 12. The RIBS are bones supporting and protecting the chest cavity. They move to
a limited degree, helping the lungs to expand and contract.
13. The windpipe divides into the two main BRONCHIAL TUBES, one for each
lung, which subdivide into each lobe of the lungs. These, in turn, subdivide
further.
14. The right lung is divided into three LOBES, or sections. Each lobe is like a
balloon filled with sponge-like tissue. Air moves in and out through one opening --
a branch of the bronchial tube.
15. The left lung is divided into two LOBES.
16. The PLEURA are the two membranes, actually one continuous one folded on
itself, that surround each lobe of the lungs and separate the lungs from the chest
wall.
17. The bronchial tubes are lines with CILIA (like very small hairs) that have a
wave-like motion. This motion carried MUCUS (sticky phlegm or liquid) upward
and out into the throat, where it is either coughed up or swallowed. The mucus
catches and holds much of the dust, germs, and other unwanted matte that has
invaded the lungs. You get rid of this matter when you cough, sneeze, clear your
throat or swallow.

51. 18. The DIAPHRAGM is the strong wall of muscle that separates the
chest cavity from the abdominal cavity. By moving downward, it
creates suction in the chest to draw in air and expand the lungs.
19. The smallest subdivisions of the bronchial tubes are called
BRONCHIOLES, at the end of which are the air sacs or alveoli (plural
of alveolus).
20. The ALVEOLI are the very small air sacs that are the destination
of air breathed in. The CAPILLARIES are blood vessels that are
imbedded in the walls of the alveoli. Blood passes through the
capillaries, brought to them by the PULMONARY ARTERY and taken
away by the PULMONARY VEIN. While in the capillaries the blood
gives off carbon dioxide through the capillary wall into the alveoli and
takes up oxygen from the air in the alveoli.