BIOL 207 Exam 3 Respiratory System

Primary functions of the Respiration System

oxygenation, removal of metabolic wastes, regulate blood pH

Conductive Zone

airways where no gas exchange occurs

Respiration Zone

areas where gas exchange occurs

Ventilation

mechanical process of inhalation & exhalation (Contraction/relaxation of diaphragm & intercostal muscles, Expansion/compression of lungs)

Respiration

diffusion of gases between blood vessels of the alveoli (the structure that makes up the lungs)

Explain Inhalation

1. Intercostals & diaphragm contract. 2. Parietal & viscera pleura are pulled towards the edge of the cavity. 3. Alveoli enlarges (volume increases). 4. Alveolar pressure drops. 5. Higher atmospheric pressure “pushes” air in

Explain Exhalation

1. Intercostals & diaphragm relax. 2. Pushes on the pleural membrane & the alveoli. 3. Volume decreases. 4. Pressure increases in the alveoli forcing air out

Total lung capacity

max amount of air in the lungs

Vital Capacity

max amount of air you can forcibly exhale in a single breath following max inhalation

Residual Volume

Volume of air that remains in lungs even after max exhalation

Tidal Volume

Air entering or leaving the lungs in a single breath @ rest

Inspiratory Reserve Volume

additional air that can be inhaled after resting tidal volume

Expiratory Reserve Volume

Additional air that can be exhaled after resting tidal volume

Blood is a tissue composed of

Plasma & Formed elements (red blood cells, white blood cells, & platelets)

Why can RBCs carry oxygen

they hold Hemoglobin

Hemoglobin

a tetramer that shows high affinity for O2

External Respiration

Gas exchange between alveoli & blood

Deoxygenated blood in External Respiration

Low O2 concentration (partial pressure) & High CO2 partial pressure

Air in alveoli in External Respiration

High O2 concentration (Partial pressure) & Low CO2 partial pressure

Result of External Respiration

O2 is loaded into the bloodstream & CO2 is removed from the body

Internal Respiration

gas exchange between tissues & blood

Oxygenated blood in Internal Respiration

High O2 concentration (partial pressure) & Low CO2 partial pressure

Extra/intracellular fluid in Internal Respiration

Low O2 concentration (partial pressure) & High CO2 partial pressure #2

Result of Internal Respiration

tissues are supplied w/ O2 & CO2 is loaded into the bloodstream

Gas Exchange Homeostasis

gas exchange @ the alveoli & tissues must be maintained to ensure vital functions

What does blood flow do for pressure gradients?

maintains pressure gradients by moving RBCs between systemic & pulmonary circulation

Oxygen Loading

pressure gradient favors diffusion of CO2 into the alveoli & O2 from alveoli into the bloodstream

Oxygen Unloading

pressure gradient favors CO2 from somatic cells into the blood stream & O2 into the somatic cells

CO2 Loading/Unloading Reactions

CO2 + H2O ←→H2CO3 ← → H+ + HCO3-

Chloride shift

HCO3- diffuses into RBCs, from the plasma as Cl- is pumped out the cell

Reverse Chloride Shift

HCO3- diffuses out of RBCs into the plasma as Cl- is brought into the cell

What can hemoglobin bind to?

CO2 & O2

What causes a shift in hemoglobin affinity?

pH, temperature, concentration of CO2, concentration of 2, 3- DPG (molecules that regulate Hb’s O2 affinity)