Thorax 6 Regulation of Breathing

Question 1

Regulation of Breathing

Answer 1

Apneustic area: promotes inspiration
Pneumotaxic area: controls degree of lung inflation; inhibits inspiration
Medullary rhythmicity center: nerves extend to the intercostals and diaphragm
Expiratory center: activated during force breathing

Question 2

Chemoreceptors

Answer 2

Central chemoreceptors: medulla oblongata monitors CSF; breathing can be controlled voluntarily up to a point

Question 3

Peripheral chemoreceptors

Answer 3

• aortic bodies (vagus nerve)
• carotid bodies
• respond rapidly to flunctuations in blood O2, CO2, and H+

Question 4

3 Muscle Groups for Inhalation

Answer 4

• Diaphragm: contraction draws air into lungs; increases transverse diameter of thorax; 75% of normal air movement
• External intercostals muscles; Assist inhalation; 25% of normal air movement
• Accessory muscles assist in elevating ribs: sternocleidomastoid; serratus anterior; pectoralis major