Respiration , Breathing & it's Regulation

PARTIAL PRESSURE :-

of a gas defined , the pressure it exerts in a mixture of gas & calculated as total pressure of mixture of gasseous >< percentage of gas in a micture 

Condition for RESPIRATORY SURFACE :- 

For Cutanious Surface :-

1. It Should be Thin , About 1mm 
2. It Should be permeable for gasseous
3. It Should be moist with water & Mucous always
4. it should be have large surface area
5. It Should be highly vascular (rich blood supply )
6. It Should have direct or indirect contact with source of oxygen
7. Presence with respiratory pigment
8. It sHould have surfactant , very important , which prevent collasping of alveoli

EXCHANGE :-

Pulmonary gas Exchange :-

# Inspired air :-

N2 = 78.6 % ---- 597 mm Hg (Partial Pressure)
O2 = 20.84 % ---- 159 mm Hg (Partial Pressure)
Co2 = 0.04 % ---- 0.3 mm Hg (Partial Pressure)

# Alveolar Air :-

N2 = 74.09 % ---- 569 mm Hg (Partial Pressure)
O2 = 13.6 % ---- 104 mm Hg (Partial Pressure)
Co2 = 5.3 % ---- 40 mm Hg (Partial Pressure)

Transport Of CO2:-

i) As In Form of carbonic acid =(7% of total)
ii)As In Form of Bicarbonate of Na+ & K+ = 70%
iii) As In Form of carboamine haemoglobin =(23% of total)
H2O + CO2 <-------Carbonic anhydrase-----> H2CO3 --- Breakdown ----> H+ & HCO3-

# As Carbonic Anhydrase haemoglobin:-

Hb(-) + H(+) <-----> HHb (Haemoglobinic acid ) reduced form of Hb
HHb + CO2 <----> CO2HHb (carboamine haemoglobin

# calculated Amount :-

3ml/100 ml of bloof
* Atrial Blood = 48ml Of CO2 /ml of blood, which divided into two part
i) Plasma (36 ml)
ii) R.B.C (12 ml)
* Venous Blood - 52 ml of CO2 /ml Of Blood
i) In plasma = 36ml
ii) In R.B.C = 14 ml

NOTE :- 

10 ml of blood carry 3.7 ml of CO2

# Haldane Effect On CO2 Transport 

1. Decrease Binding Of CO2 with Hb , so favour dissociation of Carboamini Hb
2. More Acidic Oxyhaemoglobin , it stimulate release Of H+ ion From Reduced (HHb) , So Increases Formation of carbonic acid 

Transport Of Gaseous :-

1. Transport Of Oxygen :-

These occur in two main step as
i) In Solution form (1-3%) in which only 0.3 ml/100 ml of blood transported
ii) In Oxyaemoglobin (90-97%)
For Calculated Amount = Solubility Coefficient of O2 At 37 degree Celcius & 760mmHg >< Partial Pressure 
= 0.00003ml >< 100 
For actual Amount = 19.80ml/100ml of arterial Blood 
=> Human Body Required 375 litre of oxygen /day , which mean we have to take 1900 litre of fresh air to fulfil demand of 375 litre of oxygen/day
=> 15 gm of haemoglobin /100ml of blood can transport 19.80ml (round off 20ml) of oxygen called 20 volume percentage

@ Requirement Of different Animal Of oxygen :-

Fishes = 9 ml
Amphibian = 12 ml
Reptiles = 9 ml
Birds = 18.5 ml

@ oXygen Dissociation Curve :-

# Significance Of Haemoglobin

- It increases carring capacity in form of oxyhaemoglobin
- it also increases CO2 carring capacity in form of carbonic acid
- also act as acid base buffer
- Readily combine with high partial pressure of O2 & release easily in low partial pressure of O2 into tissue

@ Bohr Effect :-

it based upon Partial Pressure Of CO2 . Which Relates Also with pH, temperature,Oxygen Dissociation Curve move Right side with increase in Hb For O2 resulting Less % saturation

Control Of Breathing :-

Breathing are controlled by some centre in brain named as:-

i) Inspiration Centre :- in medulla oblongata at ventral side in position
ii) expiration Centre :- in medulla oblongata at dorsal side of brain
iii) Peripheral chemoreceptor , which having 2 parts
- aortic arch
- Carotid Sinus

iv) Chemoreceptor In Brain
v) Mechano-receptor or stretch receptor in lung alveoli in branchional tree