BIOL 261 FINAL CHP 14 Flashcards
Gases diffuse from:
HIGH to LOW concentration
Boyle’s law states that:
Pressure is inversely related to volume
Inspiration steps:
Diaphragm and intercostal muscle contact-> vol. of thoracic cavity increases-> pressure decreases-> air into lungs
Expiration steps:
Diaphragm and intercostal muscle relax-> vol. of thoracic cavity decreases> pressure increases> elastic recoil of tissues> air out of lungs
Residual volume
Air that reminds in the lungs
Vital capacity
The max amount of air moved through the lungs
FVC measures your:
Vital capacity when you forcefully exhale
If your %FEV1 is <80% you have:
Obstructive pulmonary disease
If your actual FVC is < predicted FVC you have:
Restrictive pulmonary disease
If you have restrictive respiratory disease what is effected?
Alveolar surface is diminished
If you have obstructive respiratory disease what is effected?
Bronchi are constricted/obstructed
Alveoli:
Functional unit of lungs and site of gas exchange between respiratory and circulatory systems by DIFFUSION
How is CO2 transported in the blood?
- 70% transported as carbonic acid
- 23% bound to amino groups of proteins in hemoglobin
- 7% transported as CO2 and dissolved in plasma
Carbonic acid dissociates into:
2
H+ and bicarbonate (HCO3-)
-chloride ion shift
Central chemoreceptors:
- located in medulla oblongata
- detects interstitial fluid CO2->pH
- monitors arterial CO2, cerebral blood flow and metabolism
Peripheral chemoreceptors:
- located in carotid and aortic arteries
- detects arterial CO2->pH
- monitors alveolar ventilation
Why can you hold your breath longer when you hyperventilate?
Because you are breathing more CO2 out
Why can you not hold your breath as long when you breath into a bag?
Because you are breathing in the CO2 that is in the bag
Alveoli produce:
Surfactant
Respiratory negative feedback loop:
Stimulus: Increase in ppCO2
Sensor: Peripheral chemoreceptors in aortic arch/carotid sinus
Central chemoreceptors in medulla oblongata
Integrator: Medulla Oblongata
Effector: Diaphragm + external intercostal muscles
Response: Increase breathing rate and depth
Result: decrease ppCO2
Why is oxygen released at the tissues?
Pressure in tissues is lower
Carbon dioxide reaction:
CO2 + H20 ->
H2CO3-> H+ + HCO3-
Carbonic acid and bicarbonate reaction:
CO2 + plasma-> carbonic acid-> H+ + bicarbonate ion
How is oxygen transported in the blood?
via hemoglobin in the RBC’s or dissolved in plasma
What happens when chemoreceptors adapt over time from excessive stimulation:
leads to a higher set point for CO2-> causing COPD
