Breathing And Exchange Of Gases Flashcards
Respiratory centre is composed of neurons located where?
Medulla oblongata and pons
Respiratory rhythm centre location
Medulla of hind brain
Pneumotaxic centre location
Pons region of hind brain
Respiratory rhythm centre can?
cause expiration and inspiration
Pneumotaxic centre can ?
reduce duration of inspiration
moderate function of respiratory rhythm centre
Strong signals from Pneumotaxic centre cause?
Shallow and fast breathing by shortening duration of inspiration
Chemosensitive area located ?
Adjacent to respiratory rhythm centre ( medulla oblongata)
What is chemosensitive area sensitive to?
concentration or partial pressure of CO2
concentration of H ions (pH)
Chemosensitive area gets activated due to ____ and ____ concentration ,which in turn activates the ____ centre for altering rate of respiration
Increase in CO2
H ion
Respiratory Rhythm
Disease caused due to allergens
Asthma
Symptoms of asthma
Spasm of smooth muscles in bronchioles
coughing
Wheezing
Inflammation of bronchi and bronchioles
Disease caused due to cigarette smoking
Emphysema
Symptoms of emphysema
Difficulty exhaling
Walls of alveoli damaged causing decrease in respiratory area
chronic disorder
Disease caused due to continuous exposure to dust in work place involving stone breaking or grinding
Occupational Respiratory Disorders
Disease characterised by fibrosis of upper parts of lungs
Pneumoconiosis
Which of the following can activate the chemosensitive area?
High ( or increase) CO2 and high H ion concentrations
Which can alter respiratory mechanism
Pneumotaxic centre
Chemosensitive centre
Chemo-Receptors located at places other than brain
Aortic arch
Carotid artery
How do aortic arch and carotid artery receptors function?
Send signals to the respiratory rhythm centre to make changes when change in CO2 and H ion concentration is detected
Region responsible primarily for respiratory regulation
Respiratory rhythm centre
Organisms that respire through simple diffusion over their entire body surface
Sponges coelenterates, flat, worms, and other lower invertebrates
Which organism respires through moist cuticle
Earth worms
Insects respire through what?
Through a network of tubes to transport atmospheric air within the body
Respiration which insects follow another name
Tracheal respiration
Specialised vascularised structures called gills are used by most of the____and___ and___
Aquatic arthropods.
Molluscs.
Fishes
Respiration through gills is also termed as
Brachial respiration
Vascularised bugs called___ Are used by terrestrial forms of life like___,___and___and___
Lungs
Reptiles
amphibians
Birds.
Another word used for lungs
Pulmonary respiration
Amphibians like___can also respire through their___also
Cutaneous respiration
Respiration through moist skin is also
Cutaneous respiration
Trachea extents upto _______ ,which divides into _____ at the level of the _____ vertebra
Mid thoracic cavity
Bronchi
5th thoracic
Path of flow of gases
External Nostrils , nasal passage , nasal chamber , pharynx , larynx , trachea , Primary bronchi , Secondary bronchi , tertiary bronchi , terminal bronchioles , alveoli
The ___,____,____ and ____ and initial ______ are supported by incomplete cartilaginous rings
Trachea
Primary
Secondary
Tertiary bronchi
Bronchioles
Each terminal bronchiole gives rise to a number of very thin, irregular walled and vascularised bag like structures called___
Alveoli
Protective covering of the lungs is called
Pleura or Pleural membranes
The outer pleural membrane is in close contact with the ____ whereas the inner pleural membrane is in contact with the ______
Thoracic lining
Lung surface
Conducting part of the respiratory system starts from a and ends at?
It starts with the external nostrils and ends up to the terminal bronchioles
Respiratory or exchange part of the respiratory system constitutes what parts?
The alveoli and their ducts
Function of the conducting part
Transporting atmospheric air to the alveoli.
Removal of foreign particles
Humidifiers and brings the air to body temperature.
The thoracic chambers boundaries on all sides
Dorsally by the vertebral column.
Ventrally by the sternum.
Laterally by the ribs.
On the lower side by the diaphragm
Inspiration is initiated by the contraction of ______ which increases the volume of the thoracic cavity in the _______ axis
Diaphragm
Antero- posterior axis
A healthy human breathes how many times per min
12 to 16 times
The volume of air involved in breathing movements can be estimated by using a ……. which helps in clinical assessment of pulmonary functions
spirometer
Tidal volume = …… ml
that means a healthy human can inspire or expire approx …….. ml air per minute
500
6000 to 8000
Total Lung Capacity
Tidal volume + Inspiratory reserve volume + expiratory reserve volume + residual volume
Or
Vital capacity + residual volume
Vital capacity =
ERV + TV + IRV
Expiratory Capacity =
TV + ERV
Inspiratory capacity
IRV + TV
residual Volume ( RV)
1100 - 1200 ml
Inspiratory reserve volume (IRV)
2500 to 3000 ml
Expiratory reserve volume
1000 - 1100 ml
……. are the primary sites of exchange of gases
Alveoli
Diffusion depends on
1) concentration or pressure gradient
2) thickness of membrane
pO 2 in-
Atmospheric air
Alveoli
Blood deoxy
Blood oxy
Tissue
(mm Hg)
159
104
40
95
40
pCO2 of-
Tissue
blood oxy
blood deoxy
alveoli
Atmospheric air
45
40
45
40
0.3
Solubility of CO2 is …….. times higher than O2
20-25
Diffusion membrane is made up of three major layers namely-
Thin squamous epithelium of alveoli
Endothelium of alveolar capillaries ( 1 cell thick)
Basement Membrane between the two
Total thickness of alveolar membrane
less than 1 mm
Conditions in alveoli
high pO2 , low pCo2, low h ion concentration and low temp
Conditions in tissue
low - pO2
High- pCo2 , h ion conc and temp
Every 100 ml of blood delivers approx ….. ml of blood to tissue under normal conditions
5
Oxygen dissociation curve is a ……. Type of curve
sigmoid
1 molecule of haemoglobin can carry …… O2 molecules
4
…… % of O2 is transported thru RBCs. The remaining …..% is transported in a ….. dissolved state thru plasma
97
3
Dissolved
…….% of Co2 is carried by haemoglobin as ……. .
20-25
Caraminohaemoglobin
RBCs contain a very high % of the enzyme ……. and minute quantities are present in the ……. as well
carbonic anhydrase
plasma
…….+……<=> H2CO3 <=> ……. + …..
CO2 H2O
HCO3- H+
Every 100 ml of blood delivers ….. ml of CO2 to the alveoli
4
