Breathing and Exchange of Gases🟢 Flashcards
What is their respiratory organ -
Lower Invertebrates (Spone, Coelenterate, flatworms, etc):
Earthworms:
Insects:
Aquatic Insects and Mollusca:
Terrestrial forms of insect:
fishes:
Amphibians, Reptiles, Birds and mammals:
Lower Invertebrates (Sponge, Coelenterate, flatworms, etc): By simple diffusion over their entire body surface
Earthworms: use their moist cuticle
Insects: network of tubes (Tracheal system)
Aquatic Insects and Mollusca: gills (Brachial respiration)
Terrestrial forms of insect: Lungs (Pulmonary respiration)
fishes: Gills
Amphibians, Reptiles, Birds and mammals: Lungs
Frogs (Amphibian) can also respire through their moist skin (cutaneous respiration)
Where does Trachea divides into right and left primary bronchi
Trachea is a straight tube extending up to the mid-thoracic cavity, which divides at the level of 5th thoracic vertebra into a right and left primary bronchi
The branching network of bronchi, bronchioles, & alveoli comprises the lungs.
What part of Lungs are supported by incomplete cartilaginous rings
The trachea, primary, sec., tert. bronchi and initial bronchioles are supported by incomplete cartilaginous rings
Tell about Lung’s membrane
What is Conducting part (with functions) and respiratory or exchange part of respiratory system
What is Lung’s location
Covered by a double layered pleura, with pleural fluid filled b/w them, it reduces the friction b/w them
Conducting Part: External nostrils to terminal bronchioles
it clears air from foreign particles, humidifies and brings it to body temperature
Exchange part: Alveoli and their ducts
The lungs are situated in the thoracic chamber which is anatomically an air-tight chamber.
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. 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.
Explain the mechanism of inspiration and Expiration
Inspiration and expiration is carried out by diaphram and external intercoastal muscle b/w ribs, they create a pressure gradient b/w lungs and atmosphere
Inspiration: negative pressure in lungs wrt atm. pressure i.e. Intra pulmonary pressure less than atm. pressure
Initiated by contraction of diaphragm [Increase volume of thoracic chamber in anterio-posterior axis]
Contraction of external Intercoastal muscle [Lift up ribs and sternum, increase volume in dorso-ventral axis]
Increase in thoracic volume = increase in pulmonary volume, Inspiration occurs.
Expiration: Relaxation of diaphragm and the intercoastal muscle, reduces the thoracic volume to normal [i.e. pulmonary volume] th pulmonary pressure increase above atmospheric pressure, expiration occur
We have additional muscle in abdomen to increase the strength of inspiration and expiration
on Avg. a human breathes __________ times /minute
___________ can measure volume of air inspired or expired
12 - 16 times /minute
Spirometer
Explain the four types of respiratory volumes -
Tidal Volume (TV)
[How much air do we normally expire and inspire per minute? ]
Inspiratory Reserve Volume (IRV)
Expiratory Reserve Volume (ERV)
Residual Volume (RV)
Tidal Volume (TV): Normal Respiration (~500 ml)
[500 x (12 - 16) = 6000 - 8000 ml of air inspire or expire per minute]
Inspiratory Reserve Volume (IRV): Additional volume of air a person can inspire forcibly (2500 to 3000 ml)
Expiratory Reserve Volume (ERV): Additional volume of air a person can expire forcibly (1000 - 1100 ml)
Residual Volume (RV): Volume of air remaining even after forcible expiration
Explain the five types of pulmonary capacities -
Inspiratory Capacities (IC)
Expiratory Capacity (EC)
Function Residual Capacity (FRC)
Vital Capacity (VC)
Total Lung Capacity (TLC)
Inspiratory Capacities (IC): After normal expiration, Total volume of air a person can inspire; IC = TV + IRV
Expiratory Capacity (EC): After normal inspiration, Total volume of air a person can expire; EC = TV + ERV
Function Residual Capacity (FRC): Volume of air remaining in lungs after normal expiration; FRC = ERV + RV
Vital Capacity (VC): Maximum volume of air a person can breath in after forced expiration; VC = ERV + TV + IRV
Total Lung Capacity (TLC): Total volume in the lungs at the end of a forced inspiration; TLC = RV + ERV + TV + IRV or TLV = VC + RV
What are the factors affecting of rate of diffusion
solubility of gas, thickness of membrane, partial pressure of gas (ex- Po2, Pco2)
Solubility of CO2 is 20-25 times higher than O2, the amount of CO2 that can diffuse though membrane per unit diffrence of partial pressure is mich higher than O2
Tell the Partial Pressures (in mm Hg) of Oxygen and Carbon dioxide at Different Parts Involved in Diffusion in Comparison to those in Atmosphere
Atmospheric air, Alveoli, Deoxygenated Blood (D.B), Oxygenated Blood (O.B), Tissue
Atmo. air|Alve|D.B|O.B|Tissue O2 - 159 |104| 40 | 95 | 40 CO2 - 0.3| 40 | 45 | 40 | 45
Pulmonary Artery and Vena Cava have same pressure of O2 and CO2 as Deoxygenated Blood
Pulmonary Veins (or Systematics Veins) and Aorta (Systematic Artery) have same pressure of O2 and CO2 as Oxygenated Blood
Above Table - https://i.imgur.com/zRJaDuh.jpg
Dont just click the link, copy it and paste it on search bar, that way you can see the image
What are the three major layers of diffusion membrane
Thin Squamous epithelium of alveoli (1 cell think),
Endothelium of alveolar capillaries and
Basement substance b/w them
Basement substance is a thin basement membrane supporting squamous epithilium + thin basement membrane surrounding endothelium
Diffusion membrane total thickness is less than a millimeter
How is respiration regulated
Regulation of respiration is done by neural system.
Respiratory Rhythm Centre: specialized centre in medulla region of brain, primarily responsible for regulation of respiration
Pneumotaxic Centre: present in pons region of brain, can moderate functions of respiratory rhythm centre.
Neural signals from this centre can reduce duration of inspiration and there by alter respiratory rate
Chemosensitive area: present adjacent to rhythm centre, highly sensitive to CO2 and hydogen ions. Increase in them can activate this which in turn signal rythm centre to make necessary adjustments to eliminate these substance
Receptors associated with aortic arch and carotid artery also recognise change in CO2 and H+ Ions concentration and send necessary signals to rythm centre for remedial actions.
The Role of oxygen in the regulation of respiraotry rythm is quite insignificant.
What are disorders of Respiratory system
Asthma: difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles
Emphysema: chronic disorder in which alveolar walls are damaged thus respiratory surface is decreased. one of the major cause is ciggarette smocking
Occupational respiratory disorders: cuz of industries, especially grinding and stone breaking. too much dust, defense mechanism can’t cope, long exposure cause inflamation = fibrosis i.e. proliferation of fibrous tissue, cause serious lung damage.
Blood is the medium of transport for O2 and CO2
About ___% of O2 is transported by RBC in the blood and ___% of O2 by the plasma (in dissolved state)
Nearly __-__% of CO2 is transported by RBCs as ___________, whereas ___% carried as ____________ and about ___% carried through plasma in dissolved state
About 97% of O2 by RBC in the blood and 3% of O2 by the plasma (in dissolved state)
Nearly 20-25% of CO2 is transported by RBCs as Carbamino haemoglobin, whereas 70% carried as bicarbonate and about 7% carried through plasma in dissolved state
What is hemoglobin? Explain how it binds to Oxygen and what factors affect the bindiing.
Each Hemoglobin can carry maximum of ______ molecules of O2
Oxygen Dissociation Curve or Graph of % saturation of hemoglobin with O2 Vs Partial Pressure of O2 gives ________ Curve
Hemoglobin is red colored Iron containing pigment present in RBCs
O2 can bind with hemoglobin in a reversible manner to form oxyhemoglobin
Factors affecting binding: Primarily Partial pressure of O2 and then other factors like Partial pressure of CO2, Conc. of H+ Ion and temperature
each Hemoglobin can carry maximum of four molecules of O2
Graph of % saturation of hemoglobin with O2 Vs Partial Pressure of O2 gives Sigmoid Curve
