Respiratory System Anatomy and Functions

Respiratory System
• Presented By –
Prof.Dr.R.R.Deshpande
Mobile – 922 68 10 630
04/14/16 Prof.Dr.R.R.Deshpande 1

Sharir Kriya -- Paper I –
Part B –Point 3
• Prof.Dr.R.R.Deshpande (M.D in Ayurvdic
Medicine & M.D. in Ayurvedic Physiology)
• www.ayurvedicfriend.com
• Mobile – 922 68 10 630
• mailme.drrrdeshpande@rediffmail.com

Sharir Kriya Paper 1-Part B –Set 3
• Dr.R.R.Deshpande
• Prof & HOD
• CARC ,Pune 44

Sharir Kriya Text Books

Sharir Kriya Hand Book –
1st
to last year BAMS
• Best for Fast Revision
• Paper 1,Paper 2
• Practicals
• Instruments
• Histology
• IMP Schlok
• All basics of
Dodha,Dhatu & Mala

Sharikriya Paper Practical Book
• As per Very New
Syllabus formed By
CCIM IN 2012
• Ayurvedic Practicals like
Prakruti,sara,Agni
• Modern Haematological
Practicals
• CNS & CVS Examination

Clinical Examination
• Systemic Examination
of 8 systems
• Ayurvedic Srotas
Examination
• Clinical significance of
Lab Tests &
Radiology,USG,2D Echo

Sharir Kriya Paper 1
• Book in English
• Total CCIM Syllabus
covered
• Chaukhamba Sanskrit
Pratisthan Publication
• Popular Nationwide &
In Germany also
• Dosha & Prakruti

Sharir Kriya Paper 2
• Book in English
• Total CCIM Syllabus
covered
• Chaukhamba Sanskrit
Pratisthan Publication
• Popular Nationwide &
In Germany also
• Dhatu,Mala

Prof.Dr.Deshpande’s
Popular Links on Internet
• Just Start Internet on Desk top or Lap top or
on your mobile . Copy Following Link & Paste
as Web address –URL
• http://www.youtube.com/user/deshpande1959
• http://www.slideshare.net/rajendra9a/
• http://www.mixcloud.com/jamdadey/

Prof.Dr.Deshpande’s
Popular Links on Internet
• Just Start Internet on Desk top or Lap top or
on your mobile . Copy Following Link & Paste
as Web address –URL
• http://professordeshpande.blogspot.in
• http://professordrdeshpande.blogspot.in/
• http://www.mixcloud.com/rajendra-deshpande
• https://soundcloud.com/professor-deshpande

Respiration
• Every organism requires a constant supply of
energy.
• It is obtained from the oxidation of food
molecules in every cell.
• In animals, the oxygen is supplied by a
specialized system called as Respiratory
System

Functional anatomy of respiratory system
• Respiration in man occurs by lungs. So the
process is termed as Pulmonary Respiration.
• Respiratory system consists of the following
organs.

Conducting organs
• 1) Nostrils & nasal chamber
• 2) Nasopharynx
• 3) Larynx
• 4) Trachea

Main organs
• 5) Bronchi & bronchioles
• 6) Lungs & alveoli (air sacs)

1) Nostrils & Nasal Chamber
• A pair of nostrils leads to nasal chamber /
cavities.
• It is divided into right & left halves by a
cartilage.
• It is differentiated in 3 parts as follows
• Vestibular
• Respiratory
• Olfactory

Vestibular Part
• It is the anterior most region of the nasal
chamber lined by mucus & hairs.
• So dust particles are filtered & settled or
caught in the mucus

Respiratory Part
• It is the middle air conducting chamber with
rich supply of blood capillaries
• This provides moisture by which air is made
warm or cool & moist

Sensory or Olfactory Part
• It is internally lined by olfactory epithelium for
detection of smell.
• Vibrating cilia also push dust particles towards
pharynx where it is swallowed into esophagus.

Respiratory System

2) Nasopharynx
• Nasal chamber opens into ---
• Nasopharynx where respiratory opening
(glottis) & oesophageal opening (gullet) cross
each other forming pharyngeal chisma.

3) Larynx
(Sound Box / Adams Apple)
• It is located in the neck region ventral to
oesophagus.
• It contains vocal cords for producing sound of
different pitch.
• Its anterior opening (glottis) is guarded by a
cartilaginous flap epiglottis, which prevents
the entry of food particles while swallowing.

4) Trachea (Wind Pipe)
• It is about 11 cm long & 2. 5 cm broad tube
supported by 16 - 20 complete C shaped
cartilage rings which avoid the collapsing of
trachea.
• It is internally lined by ciliated mucus
membrane which propel dust particles
towards larynx to oesophagus where they are
swallowed.

5) Bronchi & Bronchioles
• The distal end of trachea bifurcates into 2 bronchi.
• Each bronchus is supported by complete
cartilaginous rings.
• Each bronchus divide & re divide to form branching
system of bronchioles.
• Cartilage rings are absent in bronchioles.
• Each bronchiole terminates in alveolar duct.

Bronchial Asthama

Bronchiectasis

6) Lungs with Alveoli
• A pair of conical brownish gray, highly elastic
& spongy organs situated in thoracic cavity by
the side of the heart.
• Lungs are protected by rib - cage &
intercostals muscles of thorax on lateral side
& dome shaped muscular partition diaphragm
on posterior side

6) Lungs with Alveoli
• Lungs are covered by double pleural
membranes - outer parietal & inner visceral
pleural membranes.
• Inter pleural cavity filled by Pleural fluid.

Lungs
• Right lung is divided into anterior, middle &
posterior lobes
• Left lung is divided into 2 lobes - ant. & post.
lobes

Bronchus – Bronchiole - Alveoli

Alveoli / Air - Sacs
• The spongy nature of lungs is due to alveoli or
air - sacs.
• Lungs contain about 30 millions of air sacs
arranged like bunches of grapes.

• The walls of alveoli are very thin & composed
of one cell thick layer.
• The alveoli are surrounded by fine network of
capillaries to ensure an easy exchange of
oxygen & carbon dioxide.

• Pulmonary artery brings deoxygenated blood
from the right ventricle of the heart to lungs
• Pulmonary vein carries oxygenated blood
from the lungs to the left auricle of the heart

• Inflation & deflation of the lungs ensures that
regular exchange of gases takes place
between the alveoli & the external air.
• This is dependent upon the arrangement of
the pleura, the contraction & relaxation of the
muscles of respiration & the elastic connective
tissue.

Emphysema

Muscles of Respiration
• The expansion of the chest during inspiration occurs
as a result of muscular activity, partly voluntary &
partly involuntary.
• The main muscles of respiration in normal quiet
breathing are the intercostal muscles & the
diaphragm.
• During difficult or deep breathing they are assisted
by the muscles of the neck, shoulders & abdomen

1) Intercostal Muscles
• There are eleven pairs of intercostal muscles
that occupy the space between the twelve
pairs of ribs.
• They are arranged in 2 layers, the external &
Internal intercostal muscles.

• The first rib is fixed.
• Therefore, when the inter costal muscles
contract, they pull all the other ribs towards
the first rib.
• Because of the shape of the rib they move
outwards when pulled upwards.

• In this way the thoracic cavity is enlarged
anterio - posterior & laterally.
• The inter costal muscles are stimulated to
contract by the inter costal nerves

2) Diaphragm
• The Diaphragm is a dome shaped structure
separating the thoracic & abdominal cavities.
• It forms the floor of the thoracic cavity & roof
of the abdominal cavity
• Consists of a central tendon from which
muscle fibers radiate to be attached to the
lower ribs & sternum & to the vertebral
column by 2 cura

2) Diaphragm
• When the muscle of the Diaphragm is relaxed, the central
tendon is at the level of the 8th
thoracic vertebra.
• When it contracts, its muscle fibres shorten & the central
tendon is pulled downward enlarging the thoracic cavity in
length.
• This decreases the pressure in the thoracic cavity & increases
it in the abdominal & pelvic cavities.
•
• The Diaphragm is supplied by the phrenic nerves.

Costo Phrenic angle

Muscles of Respiration
• The intercostal muscles & the Diaphragm
contract simultaneously
• This ensures the enlargement of the thoracic
cavity in all direction.
• From back to front, side to side & up to
bottom.

Cycle of Respiration
• This occurs 16 to 18 times / min. & consists of 3
phases.
• 1) Inspiration, 2) Expiration, 3) Pause
• As described previously, the visceral pleura is
adherent to the lungs & the parietal pleura to the
inner wall of the thorax & to the diaphragm.
• Between them there is a thin film of serous fluid.

Important steps in Respiration Process
• 1) Ventilation
• 2) Diffusion
• 3) Perfusion

Ventilation
• This is the rate at which air enters or leaves the lungs
• It is of 2 types --Pulmonary ventilation - This is the
volume of air, moving in & out of respiratory tract in
a given unit of time during quite breathing.
• This is also called as minute ventilation or
Respiratory Minute Volume (RMV). Pulmonary
ventilation is a cyclic process

Pulmonary Ventilation

Alveolar ventilation
• This is the amount of air utilized for gaseous
exchange every minute.

Inspiration
• When the capacity of the thoracic cavity is
increased by simultaneous contraction of the
intercostal muscles & the diaphragm, the
parietal pleura moves with the wall of the
thorax.

Inspiration
• This reduces the pressure in the pleural cavity to a
level considerably lower than atmospheric pressure.
• The visceral pleura follows the parietal pleura.
• During this process, the lungs are stretched & the
pressure within the alveoli & in the air passages is
reduced, drawing air into the lungs in an attempt to
equalize the atmospheric & alveolar air pressures.

Inspiration
• This process of inspiration is active because it
requires expenditure of energy for muscle
contraction
• The negative pressure created in the thoracic
cavity
• This helps venous return to the heart
• This is known as the respiratory pump

Expiration
• Relaxation of the intercostal muscles &
Diaphragm results in downwards & inward
movement of the rib cage & elastic recoil of
the lungs.

Expiration
• As this occurs, the pressure of gases inside the
thorax exceeds that in the atmosphere & therefore
air is expelled from the respiratory tract.
• The lungs still contain some air & are prevented from
complete collapse by the intact pleura.
• This process is passive as it does not require the
expenditure of energy.

Pause
• After expiration there is a pause before the
next cycle begins.

Physiological Variables
Affecting Respiration
• Elasticity
• Loss of elasticity of the connective tissue in
the lungs necessitates forced expiration &
increased effort on inspiration

Physiological Variables
Affecting Respiration
• Compliance
• This is a measure of the distensibility of the lungs i.e.
the effort required to inflate the alveoli.
• When compliance is low, the effort needed to inflate
the lungs is greater than normal. eg. in some
diseases where elasticity is reduced or when
insufficient surfactant is present

Changes in Thoracic Cavity

Airflow Resistance
• When this is increased eg. in broncho
constriction, more respiratory effort is
required to inflate the lungs.
• Lung function tests are carried out to
determine respiratory function & are based
on the parameters outlined above.

Composition of Air
• Atmospheric pressure at sea level is 760 mmHg.
• With the increase in height above sea level,
atmospheric pressure is progressively reduced & at
18, 000 ft it is about half that at sea level.
• Under water, pressure increases by approximately 1
atmosphere per 10 m below sea level.

Composition of Air
• Air is a mixture of gases, nitrogen, oxygen,
carbon dioxide, water vapour & small
quantities inert gases

The Composition of
Inspired & Expired Air

Parietal Pressure of Gases
• Each gas in the mixture exerts a part of the
total pressure proportional to its
concentration, i.e. the partial pressure.
• This is denoted as PO2, PCO2.

Parietal Pressure of Gases

Alveolar air
• The composition of alveolar air remains fairly
constant & is different from atmospheric air.
• It is saturated with water vapor & contains
more carbon dioxide & less oxygen

Alveolar air
• Saturation with water vapor provides 47 mmHg thus
reducing the partial pressure of all the other gases
present.
• Gaseous exchange between the alveoli & the blood
stream (external respiration) is a continuous process
as the alveoli are never empty so it is independent of
the respiratory cycle.
• During each inspiration only some of the alveolar
gases are exchanged.

Expired Air
• This is a mixture of alveolar air & atmospheric
air in the dead space.
• Its composition is shown in the table above.

Diffusion of Gases
• Exchange of gases occurs when a difference in
partial pressure exists across semi permeable
membranes.
• Gases move by diffusion from the higher
concentration to the lower concentration until
equilibrium is established

Diffusion of Gases
• Atmospheric nitrogen is not used by the body
so its partial pressure remains unchanged & is
the same in inspired & expired air, alveolar air
& in the blood

External Respiration
• This is exchange of gases by diffusion between
the alveoli & the blood.
• Each alveolar wall is one cell thick & is
surrounded by a network of tiny capillaries.
• The total area for gas exchange in the lungs is
70 to 80 sq. meters.

• Carbon dioxide diffuses from venous blood
along its concentration gradient into the
alveoli until equilibrium with alveolar air is
reached

• When blood leaves the alveolar capillaries, the
processed oxygen diffuses from the alveoli
into the blood.
• The slow flow of blood through the capillaries
increases the time available for diffusion &
carbon dioxide concentrations are in
equilibrium with those of alveolar air.

External respiration –
the entire change of gases between air & the
alveoli & the blood capillaries

Internal Respiration
• This is exchange of gases between blood in
the capillaries & the body cells.
• When there is a difference in partial pressures
oxygen diffuses outwards from the arterial
end of capillaries into the surrounding
extracellular fluid then through cell walls

Internal Respiration
• The process involved is that of diffusion from
a higher concentration of oxygen in the blood
to a lower concentration in the cells, i.e. the
concentration gradient.
• Carbon dioxide diffuses from the cells into the
extracellular fluid then the bloodstream
towards the venous end of the capillary.

Internal respiration – Exchange of gases between capillaries &
the tissues.

O2 & CO2 carriage by blood
• Transport of Gases
• 1) Transport of oxygen
• O2 is transported from lungs to the tissues,
through arterial blood.
• Transport occurs by 2 methods.
• a) Oxyhaemoglobin Form
• 98% of O2 is transported by binding with
Haemoglobin & forming Oxyhaemoglobin.

Formation of oxyhaemoglobin

Clinical Application
• In Anaemia / Co poisoning, O2 transport
becomes less. This is called as 'Anaemic
Hypoxia'.
• Hb4O8 → Oxyhemoglobin
• Oxyhemoglobin is formed at lungs, then
transported to tissues.
• At the tissue, O2 is liberated & Hb is made
free.

O2 Dissociation curve
• It is S - shaped curve. At PO2 - 40 mm Hg.
Curve is very sharp, indicating maximum
dissociation of O2 from Hb at tissue level.
• Curve shift to the right (Bohr’s effect) when
PCO2 increases, H+ ion increases &
temperature increases.
• Shift to the left occurs, when PCO2 ↓, H+ ions
↓ & temperature ↓.

b) Dissolved form
• Very little quantity of oxygen (2 %) is
transported in dissolved form.
• The reason for this is solubility of O2 is very
poor.

2) Transport of CO2
• CO2 is transported from tissues to lungs, through
venous blood.
• CO2 transport occurs in the following 3 ways.
• a) Bicarbonate form
• Major quantity of CO2 (93%) is transported by this
method.
• Near tissue CO2 combines with the H2CO3, which
dissociated to form H+ & HCO3 -

2) Transport of CO2
• These bicarbonates are transported to lungs.
Near lungs opposite
• reaction occurs & CO2 & water vapour is
liberated, which is thrown
• out through expiration. These bicarbonates
These Bicarbonates are transported to lungs. Near
lungs opposite reaction occurs & CO2 & water
vapour is liberated, which is thrown out through
expiration.

2) Transport of CO2
• b) Carbamino compound
• CO2 combines with plasma proteins to form
carbamino proteins (plasma)
• CO2 also combines with Hb to form carbamino
- hemoglobin (in RBC’s)
• These compounds are brought to the lung &
CO2 is liberated from them

2) Transport of CO2
• c) Dissolved form
• Less quantity of CO2 is dissolved in plasma &
red cell & is transported to the lungs through
venous blood.
• Near lung CO2 is given out.

Clinical Application
• When acidic metabolites accumulate,
condition is called as ‘acidosis’ this may be
due metabolic or respiratory or renal causes.
• Inj. Sodibicarb is used in this situation

Regulation of Respiration
• 1) Nervous Control
• 2) Chemical Control

Control of Respiration

Nervous Regulation

Functions of centers
• 1) DRGN - inspiratory centre
• Main centre to regulate the respiration. They
produce action potential.
• Centre is connected to spinal cord, phrenic
nerves, intercostal nerves & to inspiratory
muscles.

DRGN - inspiratory centre
• When signals are sent to inspiratory muscles
they contract & inspiration occurs when
centre stops functioning expiration occurs
passively.
• In quite respiration, only this centre is active.

2) VRGN - Expiratory centre
• Centre is connected to expiratory muscles
(internal intercostal & abdominal muscles)
• It works only during exercise, reciprocal to
DRGN (during exercise CO2 ↑, H+ ion ↑,
formation of lactic acid & it is expelled out)

Functions of centers
• 3) Apneustic centre
• It is connected to inspiratory centre &
pneumotaxic centre.
• 4) Pneumotaxic centre
• It is also connected to inspiratory & apneustic
centre.
• Last 2 centres maintain rhythmic function of
DRGN

Different reflexes
to control the process of Respiration
• 1) Herring, Breuer’s reflex (inflation reflex)
• In the wall of Bronchi & pleura, stretch receptors are
present.
• When inspiration takes place & chest expands, these
receptors are stimulated afferent impulses via vagus
nerve go to DRGN which causes its inhibition. This
reflex requires tidal volume of 1. 5 lit.
• So this reflex has no role in quiet respiration. It works
only during exercise.

2) Role of ‘J’ receptors
• Special Nerve endings are located between
alveolus & pulmonary capillary.
• They are stimulated by pulmonary oedema &
send afferent impulses through vagus to the
Respiration

Respiration Control
• 3) Lung irritant receptors
• Located in bronchi irritant substances
stimulates these receptors & R. R.
• 4) Coughing reflex - Foreign particles in
respiratory tract cause cough reflex.

Respiration Control
• 5) Sneezing reflex - Irritation of nasal mucosa
causes sneezing reflex.
• 6) Deglutition reflex - at the time of
pharyngeal stage of deglutition, respiration
stops temporarily (epiglottis )

Control of cerebral cortex
• Higher centers can alter the act of respiration
(Voluntary Control)

Chemical regulation of Respiration
• 1) Role of CO2
• Accumulation of CO2 increases R. R.
• Peripheral chemoreceptors are located in carotid
body & aortic bodies.
• These are sensitive for CO2, H+ ions & lack of O2
• CO2 stimulates the chemoreceptors afferent
impulses go via 9th & 10th cranial N. which
stimulates DRGN & R. R.

Chemical regulation of Respiration
• 2) Role of H+ ions
• Excess H+ ions in the blood also stimulate the
respiration.
• 3) Role of lack of O2
• When PO2 is less than 60 mm of Hg. Afferent
impulses go to DRGN & R. R.
• Important note - CO2 is more potent stimulus for
respiration than lack of O2.

Functions of Respiration
• 1) To supply O2 & remove CO2 from the body.
• 2) To regulate hydrogen ion concentration of
the blood.
• 3) To increase arterial O2 tension.
• 4) To help in the regulation of the body
temperature

Prof.Dr.R.R.Deshpande
• Sharing of Knowledge
• FOR
• Propagating Ayurved
04/14/16 103Prof.Dr.R.R.Deshpande

Respiratory System Anatomy and Functions

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Respiratory System Anatomy and Functions

Similar to Respiratory System Anatomy and Functions (20)

More from rajendra deshpande

More from rajendra deshpande (20)

Recently uploaded

Recently uploaded (20)

Respiratory System Anatomy and Functions