Chapter 17: Breathing and Exchange of gases Flashcards
Give some examples of organisms that respire with the help of their body surface?
Lower
invertebrates like sponges, coelenterates, flatworms, etc.,
How do earth worms respire?
with the help of moist cuticle
Which vertebrate uses gills for respiration?
fishes
Where deos the nasal chamber open into?
into the pharynx
Which organ is called the sound box?
larynx
Where is the trachea found ?
it starts form the C3/C5 vertebrae to T5 vertebrae
Which part of the bronchi are supported by cartilegenous rings?
The tracheae, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings.
What gives rise to alveoli?
Each terminal bronchiole gives rise to a number of very thin, irregular-walled and vascularised bag-like structures called alveoli.
What covers the lungs?
the double layer pleura with a pleural fuild in between
What is the funciton of the pleural fuild?
It reduces friction on the lung-surface.
Which part of the pleura is in contact with the lungs and which part is not?
the visceral layer is in contact with the lungs
where are the partiel layer is not in contact with the lungs
Which part of the respiratory tract compreises of the conducting tract?
The part starting with the external nostrils up to the terminal bronchioles constitute the conducting part
Which part of the respiratory tract compreises of the exchange tract?
the alveoli and their ducts form the respiratory or exchange part of the respiratory system
Is the thoracic chamber air tight or not?
it is an air tight chamber
What is present in the dorsal , ventral , aterior, prosterior , lateral side of the thoracic cavity?
do it
How is the pulmonary cavity related to the thoracic cavity?
The anatomical setup of
lungs in thorax is such that any change in the volume of the thoracic
cavity will be reflected in the lung (pulmonary) cavity. Such an
arrangement is essential for breathing, as we cannot directly alter the
pulmonary volume.
What are steps of respiration?
Respiration involves the following steps:
(i) Breathing or pulmonary ventilation by which atmospheric air
is drawn in and CO2 rich alveolar air is released out.
(ii) Diffusion of gases (O2 and CO2) across alveolar membrane.
(iii) Transport of gases by the blood.
(iv) Diffusion of O2 and CO2 between blood and tissues.
(v) Utilisation of O2 by the cells for catabolic reactions and resultant
release of CO2
What are the two stages of breathing?
inspiration and expiration
What is the meaning of intra pulmonay pressure?
it is the pressure in the lungs
What do we mean when we say there is negative pressure i the lungs and what happens ?
Inspiration can occur if the pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure, i.e., there is a negative pressure in the lungs with respect to atmospheric pressure
What helps in making the positive and the negative pressure of hte lungs?
The diaphragm and a specialised set of muscles – external and
internal intercostals between the ribs, help in generation of such gradients.
What initiates hte process of inspiration?
the contraction of diaphragm
the contraction of the external intercoastal muscles
What heppens to the sternums , thorax and ribs when we inspire?
when we inspire :
the sternum and the ribs moves up wards
and the diaphragm does down thus increasing the volume of teh thoracic chamber
How do we increase the sterenght of inpiration and expiration?
with the addition of muscles in the abdomen
How much does an average men breathe in a minute?
12-16 times
What is the devie used for clinical assessment of pulmonary functions?
spirometer
What is do we mean by tidal volume?
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
What is the meaning of inspiratory reserve volume?
Inspiratory Reserve Volume (IRV):
Additional volume of air, a person can inspire
by a forcible inspiration. This averages 2500
mL to 3000 mL.