Adaptations of Respiratory System

Question 1

Why does each breath become shallower during pregnancy?

Answer 1

• The growing uterus moves up by approx. 4cm
• (This PUSHES the diaphragm and lungs UPWARDS)

Question 2

During pregnancy, is being breathless at rest normal?

Answer 2

Yes.

Question 3

What do progesterone and relaxin do to the ligaments of the ribcage?

Answer 3

• Causes them to relax
• This enables the lungs to fill with a greater vol of air due to this greater range of movement.

Question 4

Why does maternal respiratory efforts increase during pregnancy?

Answer 4

• To meet the increased METABOLIC demands on the maternal and fetal tissues

Question 4

Which hormone stimulates a women’s ventilation to increase during pregnancy?

Answer 4

• Progesterone (INCREASES dramatically during pregnancy)

Question 4

How much does a pregnant women’s ventilation increase by the end of the 3rd trimester?

Answer 4

• By 50%

Question 5

What is the increase intake of air mainly due to?

Answer 5

• Quicker pace of breathing