External and Internal respiration Flashcards
What happens During external (pulmonary) respiration,?
oxygen will diffuse from the alveoli into the pulmonary capillaries
-CO2 moves in the opposite direction
What happens during internal (tissue) respiration?
oxygen will diffuse from the systemic capillaries into the tissue
- CO2 moves in the opposite direction
What are the locations of areas of the respiratory center?
-Respiratory center
-Medullary respiratory center
-Pons
-Medulla oblongata
-Phrenic nerve
What does cortical influences allow?
Conscious control of respiration that may be needed to avoid inhaling noxious gases or water
Chemoreceptor
Central and peripheral chemoreceptors monitor levels of O2 and CO2 and provide input to the respiratory center
What is hypercapnia and what does it stimulate?
A slight increase in PCO2 (and thus H+)
- Stimulates central chemoreceptor
What is hypoxia and what is it caused by?
-Oxygen deficiency at the tissue level
- Caused by a low PO2 in arterial blood due to high altitude, airway obstruction or fluid in the lungs
Stimuli that increase breathing rate and depth: Voluntary hyperventilation controlled by
cerebral cortex and anticipation of activity
by stimulation of limbic system.
Stimuli that increase breathing rate and depth: Increase in arterial blood PCO2
above 40 mmHg (causes an increase in H+
) detected by peripheral and central chemoreceptors.
Stimuli that increase breathing rate and depth: Decrease in arterial blood PO2
from 105 mmHg to 50 mmHg.
Stimuli that decrease breathing rate and depth: Voluntary hypoventilation controlled by
cerebral cortex
Stimuli that decrease breathing rate and depth: Decrease in arterial blood PCO2
Below 40 mmHg (causes a decrease in H+
) detected by peripheral and central chemoreceptor
Stimuli that decrease breathing rate and depth:
below 50 mmHg.
