Respiratory Systems

Question 1

What is atmospheric pressure? What is partial pressure?

Answer 1

Atmospheric Pressure = 1atm or 760mm Hg Dalton’s Law -Each gas exerts its own pressure “partial pressure” as if it was the only gas -Total pressure equals the sum of all partial pressures (ex. 21% Oxygen)

Question 2

What are the gases in atmospheric air? What are the partial pressures of each?

Answer 2

Air =21% 02, 79% N2, 4% H20 and 0.4% CO2

Question 3

Where does gas exchange occur in mammals? Describe the anatomy of the human respiratory system.

Answer 3

Mammilian Respiratory Systems - Nose and mouth o Air is warmed and humidified o Mucus and hairs in the nose cleans the air dust - Pharynx - Larynx o Vocal Cords - Trachea o Glottis (opening to trachea) protected by epiglottis, rings of cartilage, cilia and mucus trap particles - Lungs - Trachea branches into 2 bronchi - Bronchioles – surrounded by circular muscle to dilate or constrict passage - Alveoli – site of gas exchange o One cell thick o Type I cells – gasses diffuse across o Type II cells – secretory cells

Question 4

How does ventilation occur in humans? Why air is inhaled and exhaled (i.e. what forces are in play)?

Answer 4

• Air moves into lungs when pressure inside lungs is less than atmospheric pressure (Patm > Palv) - Air moves out of the lungs when pressure inside lungs is greater than atmospheric pressure (Patm < Palv) - Palv is the pressure in the alveolar sacs

Question 5

What is expiratory reserve volume, Inspiratory reserve volume, tidal volume, dead space?

Answer 5

Expiratory reserve volume (ERV) - Amount you can exhale above and beyond tidal Tidal Volume - Amount of air moving in and out of lungs normally Inspiratory Reserve volume (IRV) - Amount you can exhale above and beyond tidal volume Dead Space - Some inspired air stays in conducting zone - Constitutes anatomical dead space - About 150 mL - TV – 500 mL, only 350 mL for ventilation

Question 6

Describe hemoglobin? Describe the saturation curve? What affects hemoglobin saturation?

Answer 6

Hemoglobin – oxygen transport - Oxygen does not dissolve well in water - Only dissolved oxygen can diffuse into tissue - Bind and dissociate with hemoglobin based on several factors Hemoglobin Saturation Curve can shift in response to metabolic waste products - Increasing amounts of CO2, H+ and temperature make oxygen load and unload

Question 7

Describe IN DETAIL the process of internal and external respiration. Know the partial pressures of the relevant gasses

Answer 7

Internal Respiration - Exchange of gases between blood and tissues - Conversion of oxygenated blood into deoxygenated - Observe Diffusion of O2 Inward o At rest 25% of available O2 o During exercise more O2 is absorbed - Observe diffusion of CO2 outward

Question 8

• How is breathing regulated?

Answer 8