Respiratory



4 stages

(Purpose: bring in oxygen, remove carbon dioxide)





Respiratory Surface

(Ventilation: pumping air/water over respiratory)



Types of Resp Surface



















Aquatic gas exchange













Terrestrial Gas Exchange







Inhalation








Exhalation









Types of gas exchange





Spirograph

(volume of air inhaled/ exhaled, measured by spirometer)













Upper















Lower






Alveoli




Breathing (inspiration and expiration

External respiration (exchange of gases between lungs and blood)

Internal respiration (exchange of gases between blood and cells)

Cellular respiration (energy - releasing reactions in cells)


  • high surface area

  • moist


Various type of respiratory surfaces and systems




Outer skin

  • diffusion: transports 02 and C02 in and out of cell from blood

  • Must live in moist environment 

Gills

  • Extension of folds in body surface

    • Increase in surface area

  • Diffusion: transports gases to blood and cell

  • Aquatic environment 

Tracheal System (ex. system)

  • Internal system of branching respiratory trachea (tubes)

  • Trachea connect cells to environment through spiracles for gas exchange (blood not required)

Lungs

  • Lungs - more gas exchange - bigger body

  • Sac with moist surface -- sacs increase surface area

  • Blood transports gages to cell by diffusion



Gills: water in mouth, ventilated over gills

  • Dissolved in O2 water diffuses into blood in gills

  • Co2 diffuses blood, across gills into water

Counter- current exchange system where o2 and CO2 flow down diffusion gradients (High to low), since water and blood flow in opp direction


Cocurrent flow


Countercurrent flow

  • Maintains gradient to maintain diffusion 



  • Move air in and out

  • Brain regulates breathing rate and monitors

  • Volume of air in the lungs

  • Muscular diaphragm + intercostal muscles control air pressure

  • Thus inhalation and exhalations


  • Intercostal muscles and diaphragm contract

  • Rib cage moves out 

  • Volume increases

  • Pressure decreases in lungs

  • Air mount = In

  • Air from external environment rushes to balance low pressure





  • Is opposite action

  • Diaphragm and intercostal muscles relax

  • Volume decreases

  • Pressure increases

  • Air mount = out

  • Air rushes out



Fish -- counter- current 

Mammals-- Tidal exchange

Birds-cross current (you don’t need to know)







Tidal volume: air inhaled/ exhaled


Inspiratory reserve volume 

Expiratory reserve volume

Vital capacity


Nose - Nasal cavity -- pharynx - glottis - larynx - trachea - bronchi - bronchioles - alveoli




Air enters mouth or noise

Turbinate bones increase surface area

Warm the air with dense network of capillaries

Cleanses with mucus

Pharynx - glottis ( opening can be closed by epiglottis) - Larynx - Trachea


Larynx

  • Made of cartilage

  • Used for sound production

Trachea

  • Strengthened kept open by semicircular




Trachea - bronchi - bronchioles - alveoli

  • Each lung is surrounded by pleural membrane

  • Decreases friction between lung

  • Chest cavity separates the two lungs



  • Surrounding each alveoli is a network of capillaries

  • Walls of alveoli and walls of capillaries are only one cell thick, 

  • so gas exchange occurs quicker by diffusion


Inhaled air, higher concentration of 02 then capillary blood

  • O2 diffuses out of the alveoli and into the blood

The opposite is true for CO2

  • Diffuses out of the blood into the alveoli into the alveoli

  • Then released into the air in the lungs

O2 carried by hemoglobin (protein in RBCs)