respiratory system

1. HUMAN RESPIRATORY SYSTEM
Presenter
Alisha Manas and Afreen Khan

2. RESPIRATION
• “Respiration” is used in several different ways.
• Respiration is a process of release of energy from assimilated
food .
• Cellular respiration is the aerobic breakdown of glucose in the
mitochondria to make ATP.
• Respiratory system are the organ in animals or human being
that exchange gases with the environment.
• Respiratory system allows animals or human being to move
oxygen into the body tissue and remove carbon dioxide from
cells.

3. TYPES OF RESPIRATION
AEROBIC RESPIRATION
• Occur in presence of oxygen.
• Respiratory substrate
(glucose) is completely
oxidized. Complete oxidation
of food.
• Releases more energy 38
molecule ATP.
• By product is CO2,H2O
• Take place in higher plants.
ANAEROBIC RESPIRATION
• Occur in absence of oxygen.
• Partial oxidation of food.
• Releases less energy 2
molecule ATP.
• By product is lactic acid or
ethanol.
• Take place in lower plants
and animals.

4. HUMAN RESPIRATORY SYSTEM
RESPIRATORY TRACT
• Nose
• Nasal cavity
• Nasopharynx
• Pharynx
• Larynx
• Trachea
• Bronchi
RESPIRATORY ORGAN
• Lungs
Primary bronchi
Secondary bronchi
Tertiary bronchi
• Alveoli

5. CONT…

6. NASAL CAVITY
• NOSE :-
• The Nose or the Nares which is present at the base of nose.
• They help in breathing i.e. Inhaling and Exhaling air.
• NASAL CHAMBER :-
• The empty cavity.
• Separated by the nasal septum made up of hyaline cartilage.
• Divided into three parts :-
• Vestibule part: lined by nasal hair.
• Olfactory part: sensory cell for smell & BOWMANN’S gland for
mucus secretion.
• Vascularized part: convert air to warm and moist.

7. NASOPHARYNX
• The top most part of the pharynx.
• The inhaled air would go from the nasal chamber into the
nasopharynx.
• Towards nasopharynx there are tonsils pharyngeal tonsil.
• Nasopharynx leads downward into to pharynx.
• Oropharynx : middle region behind mouth
• Laryngopharynx : inferior region attached to larynx
• The oropharynx and laryngopharynx are common passageways
for air and food.

8. PHARYNX
• Pharynx :- The common passage for food and air.
• The pharynx (throat) is a passageway about 12–14 cm long.
• It extends from the posterior nares, and runs behind the
mouth and the larynx to the level of the 6th thoracic vertebra,
where it becomes the oesophagus.
• The pharynx opens through the larynx region into the trachea.

9. LARYNX
HYALINE CARTILAGE (4)
• Thyroid cartilage -(1)
• Cricoid cartilage -(1)
• Arytenoid cartilage -(2)
ELASTIC CARTILAGE (5)
• Epiglottis -(1)
• Corniculate -(2)
• Cuneiform -(2)
• It lies in front of the laryngopharynx and the 3rd, 4th, 5th and
6th cervical vertebrae
• There are two pairs of vocal cords:-
1. True cords -> produce sound.
2. False cords -> protect true cord.

10. • Epiglottis:- It is flap like cartilage which is present at the
midway of gullet and glottis.
• Prevent the entering of food into larynx.

11. TRACHEA
• It also called the windpipe .
• Muscular tube , 12-14cm long , present in neck and upper part
of chest.
• It is a wide, hollow tube that connects the larynx (or voice
box) to the bronchi of the lungs.
• About one inch (2.6 cm) in diameter.
• Internally Lined by pseudo stratified ciliated mucus membrane.
• Externally the tube contain “C” shaped incomplete hyaline
cartilage rings which makes trachea non collapsible.

12. BRONCHI
• Trachea bifurcates into 2 bronchi and enters into the lungs
through HILUM (also contain pulmonary artery and pulmonary
veins).
• Non-collapsible .
• Ringed with “C” shaped incomplete hyaline cartilage.
• FUNCTION: It carry oxygen to reach in the lungs during
inhalation and let carbon dioxide out of the lungs during
exhalation into the trachea.

13. ALVEOLI
• Lungs contain 750 millions of these.
• Grape-shaped structures.
• Alveoli are made up of 2 types of cells
• Type 1 :- simple squamous epithelium cell.
For diffusion of gases .
• Type 2 :- simple cuboidal epithelial cell
which secrete SURFACTANT

14. CONT…
• The walls of these are thin and moist.
• Surrounded by capillaries.
• Oxygen diffuses from alveoli into capillaries
• Carbon dioxide and water diffuse from capillaries and are
exhaled.
• Alveoli are tiny sacs within our lungs that allow oxygen and
carbon dioxide to move between the lungs and blood stream.

15. LUNG
• Two in number
• LOCATION:-
 Thoracic cavity also called as Mediastinum.
The thoracic chamber is formed dorsally by the vertebral column,
ventrally by the sternum, laterally by the ribs and on the lower
side by the dome-shaped diaphragm.
• SHAPE:-
• Lungs are conical in shape .The apex of lungs is above ,rising
slightly over the clavicle. The base of the lung is near the
diaphragm.
.

16. CONT…
• PROTECTION:-
Bony skeleton i.e. Rib cage
 Anteriorly by sternum, laterally by ribs and posteriorly by
vertebral column.
 Pleura :-
 visceral pleura and parietal pleura.
 Encloses-pleural cavity filled with pleural fluid.

17. FUNCTION OF PLEURAL FLUID
• It protect the lungs from mechanical shock ,absorbing shock.
• It provide friction less movement to the lungs.
• It provide nourishment to the two visceral and parietal pleura.
• It also provide the space for the movement.

18. LOBES
• The right lung is divided into three distinct lobes: superior,
middle and inferior.
• The left lung is smaller because the heart occupies space left
of the midline. It is divided into only two lobes: superior and
inferior. The divisions between the lobes are called fissures.

19. DIAPHRAGM
• A muscle at the bottom of the chest cavity
• It changes the pressure in the chest and causes breathing .

20. STRUCTURE

21. FUNCTION OF RESPIRATORY SYSTEM
• Transport of oxygen to tissue and excretion of carbon dioxide .
• Excretion of volatile substance like ammonia.
• Regulation of temperature through lose of heat in the expired
air.
• Maintenance of pH of blood .
• Regulation of water balance through excretion of water
vapour.

22. GAS EXCHANGE
• Air entering the lungs contain more oxygen and less carbon
dioxide than the blood that flows in the pulmonary capillaries.
• Oxygen diffuses from alveoli into the capillaries
• oxygen loosely bonds with hemoglobin to forming
oxyheamoglobin
• The oxygen separates from the blood in the body tissues .
• Carbon Dioxide and water diffuse from cells into capillaries.
• Carbon dioxide is carried in the form of bicarbonate ions (HCO3-).
• In lungs, these wastes diffuse from capillaries into alveoli

23. BREATHING
• This process of exchange of O2 from the atmosphere with CO2
produced by the cells is called breathing, commonly known as
respiration.
• Breathing involves two stages : inspiration during which
atmospheric air is drawn in and expiration by which the
alveolar air is released out.

24. INSPIRATION
• Inspiration can occur if the pressure within the lungs (intra-
pulmonary pressure) is less than the atmospheric pressure.
• Inspiration is initiated by the contraction of diaphragm which
increases the volume of thoracic chamber
• The contraction of external inter-costal muscles lifts up the ribs
and the sternum causing an increase in the volume of the
thoracic chamber .
• The overall increase in the thoracic volume causes a similar
increase decreases the intra-pulmonary pressure to less than
the atmospheric pressure which forces the air from outside to
move into the lungs.

25. EXPIRATION
• Expiration takes place when the intra-pulmonary pressure is
higher than the atmospheric pressure.
• Relaxation of the diaphragm and the inter-costal muscles
returns the diaphragm and sternum to their normal positions
and reduce the thoracic volume.
• This leads to an increase in intra-pulmonary pressure to
slightly above the atmospheric pressure causing the expulsion
of air from the lungs.

26. CONT…

27. BREATHING RATE
• The rate at which breathing occurs.
• Usually measured in breaths per minute and is set to be
controlled by the respiratory center in medulla oblongata.
• Rate for a healthy adult at rest is 12–18 breaths per minute.

28. CONT…
• Average resting respiratory rates by age are:
• birth to 6 weeks: 30–40 breaths per minute
• 6 months: 25–40 breaths per minute
• 3 years: 20–30 breaths per minute
• 6 years: 18–25 breaths per minute
• 10 years: 17–23 breaths per minute
• Adults: 12-18 breaths per minute
• Elderly ≥ 65 years old: 12-28 breaths per minute.
• Elderly ≥ 80 years old: 10-30 breaths per minute.

29. DISORDER
• Asthma: Allergic reaction where bronchial tubes narrow and it
make difficulty to breath.
• Bronchitis: Inflammation of bronchial tube linings.
Swelling causes air passages to become narrowed and mucus
filled.
• It result in Coughing and difficulty in breathing .
• Emphysema: Walls of the alveoli break down.
• This decreases surface area.
• Shortness of breath, difficulty in breathing, decreased lung
capacity is a result

30. ABNORMAL TYPES OF RESPIRATION
• APNEA:- stopping of respiration for short intervals.
• HYPERPNEA:- increase in depth of respiration.
• DYSPNEA:- difficulty in breathing.
• POLYPNEA:- respiration characterized by rapid rate.
• TACHYPNEA:- exceedingly high rate of respiration.

31. COMMMON SIGNS AND SYMPTOMS OF
DISORDER
• Breathlessness(most common).
• Nonproductive cough.
• Fatigue.
• Chest pain.
• Hemoptysis.
• Slight fever.

32. RESPIRATORY VOLUME AND CAPACITIES

33. CONT…
• Tidal Volume (TV): Volume of air inspired or expired during a
normal respiration. It is approx. 500 mL., i.e., a healthy man
can inspire or expire approximately 6000 to 8000 mL of air per
minute.
• Inspiratory Reserve Volume (IRV): Additional volume of air, a
person can inspire by a forcible inspiration. This averages 2500
mL to 3000 mL.
• Expiratory Reserve Volume (ERV): Additional volume of air, a
person can expire by a forcible expiration. This averages 1000
mL to 1100 mL.

34. CONT…
• Residual Volume (RV): Volume of air remaining in the lungs
even after a forcible expiration. This averages 1100 mL to 1200
mL. By adding up a few respiratory volumes described above,
one can derive various pulmonary capacities, which can be
used in clinical diagnosis.
• Inspiratory Capacity (IC): Total volume of air a person can
inspire after a normal expiration. This includes tidal volume
and inspiratory reserve volume ( TV+IRV).
• Expiratory Capacity (EC): Total volume of air a person can
expire after a normal inspiration. This includes tidal volume
and expiratory reserve volume (TV+ERV).

35. CONT…
• Functional Residual Capacity (FRC): Volume of air that will
remain in the lungs after a normal expiration. This includes
ERV+RV.
• Vital Capacity (VC): The maximum volume of air a person can
breathe in after a forced expiration. This includes ERV, TV and
IRV or the maximum volume of air a person can breathe out
after a forced inspiration.
• Total Lung Capacity: Total volume of air accommodated in the
lungs at the end of a forced inspiration. This includes RV, ERV,
TV and IRV or vital capacity + residual volume

36. RESPIRATORY VOLUME AND CAPACITIES
DEPEND ON:
• Age
• Body size (height & weight)
• Gender
• Pulmonary health
• Altitude(height)
• Irritants

37. REFERENCE
NCERT BOOK
CLASS XI (CHAPTER 17, PAGE NO. 268-276)
ROSS AND WILSON ANATOMY AND PHYSIOLOGY IN HEALTH
AND ILLNESS 12TH EDITION (SECTION 3 ,CHAPTER 10
PAGE NO. 242-259).

38. THANK YOU