Respiration. Types of respiration. Various modes of respiration in animals. Human respiratory system. Upper respiratory tract. Nose. Pharynx. Larynx. Lower respiratory tract. Trachea. Bronchi and bronchioles. Lungs. Mechanism of respiration. Exchange of gases. Functions of respiratory system.

1. TEACHINGOF BIO-SCIENCE
TOPIC: ANIMAL RESPIRATION.
Submitted By:
Kubra Sadiq.
Enrollment NO.:1914Cukmr29.
Subject Code: BTE-E-206.
Submitted To:
Mr. Reyaz Ahmad Wani.

2. CONTEXT
• Respiration.
• Types of respiration.
• Various modes of respiration in animals.
• Human respiratory system.
 Upper respiratory tract.
1. Nose.
2. Pharynx.
3. Larynx.
 Lower respiratory tract.
1. Trachea.
2. Bronchi and bronchioles.
3. Lungs.
 Mechanism of respiration.
 Exchange of gases.
 Functions of respiratory system.
 Reference.

3. RESPIRATION:
 Respiration is the exchange of life sustaining gases, such as Oxygen,
between an animal and its environment.
 Gas exchange occurs by diffusion, moving necessary gases like
Oxygen into animals and taking away waste gases like Carbon
dioxide.
 Performed by special respiratory modes, which differs from species
to species.

4. • Types Of Respiration:
• 1.AEROBIC RESPIRATION: The process of breakdown of food(glucose) in
the presence of oxygen is known as aerobic respiration.
• It takes place in all organisms and leads to the production of carbon dioxide,
water and energy.
oxygen
Glucose Carbon dioxide +Water + Energy.
• 2. ANAEROBIC RESPIRATION: This process takes place in absence of
oxygen.
• Occurs in organisms such as yeast.
• It leads to the production of alcohol and carbon dioxide.
without oxygen
Glucose Alcohol + Energy + Carbon dioxide.

5. Various Modes Of Respiration In Animals:
 In simple unicellular animals like Amoeba, respiration takes place by the simple
diffusion of gases through the cell membrane. Most of the animals have, however,
specific organs for respiration.
 The animals like earthworms which live in the soil use their skin to absorb oxygen
from air and remove carbon dioxide. So, the respiratory organ in the earthworm is the
skin.
 The aquatic animals like fish, prawns and mussels have gills as the respiratory
organs which extract oxygen dissolved in water and take away carbon dioxide from
the body.
 In the insects like grasshopper, cockroach, housefly and mosquito, the tiny holes
called Spiracles on their body and the air tubes called tracheae are the respiratory
organs.
 The respiratory organs of the land animals such as man (humans), birds, lizard, dog
and frog etc. are the lungs. However, Frogs breathe both by lungs and skin.

6. Respiratory structures for the exchange of gases in different groups of animals:
ANIMALGROUP RESPIRATORYSTRUCTURE
1. Amoeba Plasma membrane.
2. Tapeworm No exchange of gases (anaerobic respiration).
3. Earthworm Skin (cutaneous respiration).
4. Prawn,crayfish Gills (Branchial respiration).
5. Insects,centipedes,millipedes,ticks Tracheae (tracheal respiration).
6. Scorpions , spiders Book lungs.
7. Herdmania Pharyngeal wall.
8. Fishes Gills.
9. Amphibians Skin , Buccopharyngeal lining, lungs.
10. Reptiles Lungs.
11. Birds Lungs.
12. Mammals Lungs.

7. THE HUMAN RESPIRATORY SYSTEM
 The human respiratory system is a series
of organs responsible for taking in oxygen
and expelling carbon dioxide.
 The primary organs of the respiratory
system are the lungs, which carry out the
exchange of gases.
 Human respiratory system is divided into
two parts:
1. Upper respiratory tract: It includes the
nose and nasal passages, paranasal
sinuses, the pharynx and the portion of
the larynx above the vocal cords.
2. Lower respiratory tract: It includes the
portion of the larynx below the vocal cords,
trachea, bronchi and bronchioles.

8. The Upper respiratory tract:
 Also known as Upper airways.
 It contains abundant
microflora of aerobic and
anaerobic bacteria, which
provides an essential
competitive barrier to the
pathogen colonization.
 Include the nose and nasal
passage, paranasal sinuses,
the pharynx and portion of
larynx.

9. NOSTRILS:
• Are the external openings of the nose.
• Also called external nares.
• Similarly, a pair of internal openings is present. They open into pharynx. These are called internal nares.
NASALCHAMBER:
• The space between the external and internal nares is known as nasal chamber.
• Internally, each one is lined by a mucous membrane.
• Ciliated epithelium is present in nasal chamber.
• It is divided into right and left part by a cartilage known as mesethmoid.
Each nasal chamber is further divided into three regions:
 VESTIBULE:
• Anterior most part of the nasal chamber.
• It has hair to trap dust particles and prevent them from going inside.
 RESPIRATORY PART:
• This part is richly supplied with capillaries.
• It warms the air and makes it moist.
 SENSORY PART:
• This is lined by sensory epithelium for detection of smell.
NOSE

10. PHARYNX
• Nasal chamber opens in the pharynx.
• It is a short, vertical tube measuring about 12 cm in length.
• The respiratory and the food passage cross each other in the pharynx by two separate
passages.
• Its upper part is known as naso-pharynx which help in conduction of air and the lower part
is called laryngo-pharynx or oro-pharynx conducting food to oesophagus.
• In the pharynx, there are tonsils which are made up of lymphatic tissues. They kill bacteria
trapped in the mucous.

11. LARYNX
• It is the sound sound producing organ, hence also called sound box.
• In males, the larynx increases in the size at the time of puberty. Hence, it is called Adam's
apple and can be noticed in the neck region.
• From the pharynx, air enters the larynx through an opening called glottis.
• The glottis is guarded by a flap called epiglottis. It prevents the entry of food particles into
the respiratory passage.
• Along the sides of the glottis are two folds of elastic tissue called vocal cords. These are
responsible for producing sound.

12. THE LOWERRESPIRATORY TRACT:
• Also known as lower airways.
• Consists of trachea, the bronchi
and bronchioles, and the alveoli,
which makes up the lungs.
• These structures pull in the air
from the upper respiratory
system, absorb the oxygen, and
release the carbon dioxide in
exchange.

13. TRACHEA
• It is also known as wind pipe.
• It is about 12 cm long and 2.5 cm wide.
• It lies in front of the oesophagus and extend downwards into the neck.
• The wall of the trachea is made up of fibrous muscular tissue supports by C-shaped
cartilage rings. These are 16-20 in number. They make the trachea rigid.
• The trachea is internally lined with ciliated epithelium and mucous glands.
• If any foreign particle enters, it is immediately expelled out by coughing action.
• Dust particles get trapped by the mucous. By the ciliary movement, they are swept
towards the larynx and finally they enter the oesophagus.

14. BRONCHI ANDBRONCHIOLES
• The distal end of the trachea is divided into two bronchi behind the sternum.
• Each bronchus is supported by a complete ring of cartilage.
• It enters into the lungs of its respective side.
• On entering the lung, each bronchus further divides into secondary and then tertiary
bronchi.
• Tertiary bronchi divide into many minute bronchioles.
• Wall of each bronchiole does not have cartilage rings.
• Each bronchiole end into a balloon like alveolus.
• These alveoli makes the lung spongy and elastic.

15. LUNGS
• These are the principal respiratory organ, located in the thoracic cavity.
• Lungs are paired, hollow, elastic organ.
• Each lung is enclosed in a pleural sac.
• Pleural sac is made up of two membranes, outer parietal and inner visceral. The enclosed
cavity is called the pleural cavity. It is filled with a pleural fluid, which lubricant the pleura
and prevents the friction when the pleural membrane slide over each other.
• Lungs are pink in color, soft, elastic and distensible.
• They are highly vascular(richly supplied with blood capillaries).
• Each sac has about 20 alveoli which look like grapes. They are covered with a network of
capillaries from the pulmonary artery and vein.
• The alveoli have very thin(0.0001mm) wall composed of simple non-ciliated, squamous
epithelium. It has collagen and elastin fibers. This makes the alveoli more flexible.
• Each alveoli is about 0.1 mm in diameter. Thus human lungs have about 750 million
alveoli, which increase surface area for exchange of gases. Total area covered by them is
50 times the surface area of skin.
• Alveoli are supplied by a network of pulmonary capillaries.

16. MECHANISMOF BREATHING
INHALATION(INSPIRATION): EXHALATION(EXPIRATION):
• Diaphragm is stimulated by
phrenic nerve.
• Diaphragm relaxes and rises
back into thoracic cavity.
• Diaphragm contracts and
flattens( descends).
• Chest cavity enlarges. • Chest cavity decreases in size.
• Decrease in pressure within
the thorax.
• Increase in pressure with the
thorax.
• Air is drawn into the lungs. • Air is forced out of lungs.

17. EXCHANGE OF GASES
• Alveoli are the primary sites of exchange of gases. Exchange of gases also occur between blood and tissues. Oxygen
and carbon dioxide are exchanged in these sites by simple diffusion mainly based on pressure/concentration gradient.
• Pressure contributed by an individual gas in a mixture of gases is called partial pressure and is represented as pO2 for
oxygen and pCO2 for carbon dioxide.
Respiratory gas Atmospheric air alveoli Blood
(deoxygenated)
Blood (oxygenated) Tissues
O2 159 104 40 95 40
CO2 0.3 40 45 40 45
• The data given in the table clearly indicates a concentration gradient for oxygen from alveoli to blood
and blood to tissues. Similarly, a gradient is present for CO2 in the opposite direction, that is, from
tissues to blood and blood to alveoli. As the solubility of CO2 is 20-25 times higher than that of O2, the
amount of CO2 that can diffuse through the diffusion membrane per unit difference in partial
pressure is much higher compared to that of O2.
Table: Partial pressure of CO2 and O2.

18. FUNCTIONS OF RESPIRATORY SYSTEM
 Supplies the body with oxygen and disposes off carbon dioxide.
 Filters inspired air.
 Produces sound.
 Contains receptors for smell.
 Rids the body of some excess water and heat.
 Helps to regulate blood Ph.
REFRENCE:
• Campbell, Neil A.(1990). Biology (2nd ed.). Redwood city.
• West, John B(1995). Respiratory physiology-the essentials.
• NCERT textbook 11th class