Breathing and Exchange of Gases Flashcards
Difference between breathing and respiration
Breathing: The process of exchange of oxygen from the atmosphere with carbon dioxide
produced from the cells.
Respiration: Oxidation of glucose to form carbon dioxide, water and energy.
What are the various respiratory organs in different invertebrates
Coelenterates: cell surface gaseous exchange , they are in contact with the environment, so
simple diffusion across their body surface happens.
Earth worms: they respire through their moist cuticles ,the cells are thin, vascular and moist
that diffusion takes place.
Insects: they have network of tubes which is also known as tracheal system, small openings
through the tubes are known as spiracles where gas exchange happens.
Aquatic arthropods: They use highly vascularised organs such as gills, they are also plate like
and filament out.
What are the various respiratory organs used in vertebrates
Fishes: use gills
Amphibians:
Frogs: use moist skin, buccal cavity and lungs
Breathing and exchange of gases 2
Tadpole: use gills.
Reptiles, birds and mammals: use lungs.
What is nasal chamber lined by
pseudo stratified ciliates columnar epithelium, which also has goblet cells which produce mucus. This also contains sensory neural epithelium
3 types of pharynx
nasopharynx, oropharynx and
laryngopharynx.
What is trachea lined by
it’s lined
by incomplete rings of hyaline cartilage, this makes sure that this does not easily
collapse.
At which vertebrae does the wind pipe divide into right and left
5th thoracic vertebrae
What is lecithin
Lecithin is a surfactant, it reduces tension between air and alveolar fluid thus protecting from
the collapsing of lung alveoli. It is secreted by type 2 alveolar epithelial cells.
Distinguish right and left lung
The right side lung is shorter by 2.5 cm due to the diaphragm which has to accommodate
the liver.
Left lung is narrower due to a cardiac notch which accommodates the heart, the heart is
slightly tilted to the left.
The left lung has 2 lobes, this is divided by oblique fissure. The right lung has 3 lobes,
these are divided by horizontal and oblique fissures.
Left lung- left inferior and left superior lobes.565grams.
Right lung- Right inferior , right middle and right superior lobes.625grams.
What are conducting and respiratory part
From the external nostrils to the bronchioles is known as conducting part, but from the
alveolar ducts to alveoli form the exchange or the respiratory part.
Stages of breathing
- Breathing: also known as pulmonary ventilation.
- Diffusion of gases between alveoli and blood.
- Transport of gases : gases transported through the blood.
- Diffusion of gas between blood and tissue.
- Utilising the oxygen: cellular respiration takes place to produce energy. It’s a
biochemical reaction that occurs inside the cells.
Inspiration
The pressure in the lungs is reduced so that the air moves from outside to inside.
The diaphragm muscles contract, this causes an increase in the volume of thoracic cavity,
in antero-posterior axis.
Since the volume increases, the pressure decreases and air flows from high to low
pressure.
The external intercostal muscles contract, these causes the ribs to lift up and the sternum
up and outward. This also causes an increase in the volume of thoracic cavity, in the
dorsal ventral axis.
Muscles involved in forceful expiration
Forceful expiration in when the internal intercostal muscles and abdominal muscles
contract. This pulls the ribs downward and inward causing a decrease in pressure.
Rate of breathing
12 to 16 times per minute.
Spirometer
instrument used to measure the volume of air through respiratory
movements.
Tidal volume
the volume of air inspired or expired during normal breathing.
Approx. 500ml. Since breathing rate is 12 to 16 times, 6000 to 8000 ml of air per minute.
Inspiratory reserve volume
Additional volume of air a person can inspire through
forcible expiration. Approx.2500 to 3000ml.
Expiratory reserve volume
Additional volume of air a person can expire through
forcible expiration. Approx.1000 to 1100 ml.
Residual volume
Volume of air remaining in the lungs even after forceful
expiration. Aprrox. 1100 to 1200ml.
Inspiratory capacity
it is the volume of air a person can inspire after normal
expiration. IC = TV + IRV (3000 to 3500 ml)
Expiratory capacity
Expiratory capacity: it is the total volume of air a person can expire after normal
inspiration. EC = TV + ERV (1500 to 1600 ml)
Functional residual capacity
volume of air that will remain in the lungs after
normal expiration. FRC = RV + ERV (2100 to 2300 ml)
Vital capacity
Maximum volume of air a person can inspire after forcible
expiration, or maximum volume of air a person can expire after forcible inspiration.
VC = RV + IRV + ERV (4000 to 4600 ml)
Total lung capacity
total volume of air in lungs after maximum inspiration
TLC = RV + IRV + ERV + TV ( 5100 to 5800 ml)
Partial pressure
pressure exerted by a single gas in a moisture of gases. Diffusion happens
from high to low partial pressure.
Factors affecting rate of diffusion
Solubility of gas: high solubility , faster diffusion rate. Carbon dioxide is more soluble
than oxygen by 20 to 25 times so it has higher diffusion rate.
Partial pressure: Diffusion from high to low partial pressure
Thickness of membrane: more the thickness, lesser diffusion rate, that’s why alveolar
membrane has thin walls.