PBL 1

Question 1

Describe the mechanics of inspiration?

Answer 1

The diaphragm contracts and external intercostal muscles also contract to elevate the ribs and sternum. This increases the volume of the thoracic cavity and decreases the pressure below atmospheric so that air moves into the lungs

Question 2

Describe the mechanics of expiration?

Answer 2

the diaphragm and external intercostal muscles relax to depress the ribs and sternum which decreases the volume of the thoracic cavity and increases the pressure so it’s above atmospheric. This causes air to move out of the lungs

Question 3

What are the accessory muscles of respiration?

Answer 3

The sternocleidomastoids and scalene muscles

Question 4

What are the inspiration muscles of respiration?

Answer 4

External intercostal muscles and the diaphragm

Question 5

What are the expiratory muscles of respiration?

Answer 5

The internal intercostal muscles and the rictus abdominal, transversum abdominal and oblique muscles

Question 6

What is the tripod position?

Answer 6

When one sits or stands leaving forward, supporting the upper body with hands on the knees or another surface - this is an indication of respiratory distress

Question 7

What is hypoxia drive theory?

Answer 7

When you have chronically high levels of carbon dioxide in the blood, the central chemoreceptors become numb and rely on peripheral chemoreceptors to detect the low levels of oxygen in the blood. If you give too much oxygen to the patient then the peripheral chemoreceptors can’t acknowledge the high levels of carbon dioxide so the patient experiences hypercapnia