Exam 3: BIOS255 / BIOS 255 (Latest Update 2025 / 2026) Anatomy and Physiology III with Lab | Questions & Answers | 100% Correct | Grade A - Chamberlain

Exam 3: BIOS255 / BIOS 255 (Latest
Update ) Anatomy and
Physiology III with Lab | Questions
& Answers | 100% Correct | Grade
A - Chamberlain


Question:
how do O2 and CO2 move across the alveolar membrane?
Answer:
simple diffusion




Question:
what variables affect alveolar gas exchange?
Answer:
pressure gradient, membrane area, membrane thickness, solubility of gases

,Question:
how much oxygen is delivered to the tissues?
Answer:
22%




Question:
hemoglobin affinity
Answer:
drop in pH causes hemoglobin to have decreased affinity to O2


increase in o2 delivery or unloading from hemoglobin




Question:
what factors affect hemoglobin affinity?
Answer:
ambient PO2, temperature, ambient pH, diphosphoglycerate (BPG)

,Question:
ventral respiratory group (VRG)
Answer:
- primary generator or respiratory rhythm responsible for
-inspiratory and expiratory processes




Question:
where does the VRG relay signals?
Answer:
to the diaphragm by phrenic nerves & to the external intercostal muscles by
intercostal nerves
-located in medulla




Question:
dorsal respiratory group (DRG)
Answer:
- primarily responsible for the initiation of inspiration
- modifies respiratory rhythm depending on signals from chemoreceptors in
medulla & arteries stretch in receptors in airway & higher brainstem functions
-located in medulla

, Question:
pontine respiratory group (PRG)
Answer:
- interacts w/ both VRG & DRG
- reg. & control breathing
-located in pons region of brainstem




Question:
central chemoreceptors
Answer:
brainstem neurons that respond to changes in pH




Question:
peripheral chemoreceptors
Answer:
carotid & aortic bodies