Accessory Muscles of Ventilation

Question 1

What are the accessory muscles of inspiration?

Answer 1

The accessory muscle of inspiration include pectoralis major, pectoralis minor, serratus anterior, sternocleidomastoid and scalenes.

Question 2

What are the abdominal muscles involved in?

Answer 2

Forced ventilation
Used during expiratory phase

Question 3

Which muscle increases the anterio-posterior diameter of the thorax when the upper limb is fixed, as it originates from the clavicle, sternum and upper six costal cartilages and inserts on the lateral lip of the bicipital groove of humerus.

Answer 3

Pectoralis major

Question 4

Which group of muscles arise from the transverse processes of C4-6 and attach on the first or second ribs? When they contract they fix the upper ribs which makes contraction of the external intercostal muscles more effective.

Answer 4

Scalenes

Question 5

Which muscle helps ribs 3-5 move up and out when the corocoid process of the scapula is fixed?

Answer 5

Pectoralis minor

Question 6

Which muscle elevates the manubrium and medial end of clavicle in order to assist the pump handle action of the ribs during forced inspiration?

Answer 6

Sternocleidomastoid

Question 7

Which muscle group pushes the abdominal viscera up against the underside of the diaphragm and therefore helps decrease the vertical diameter of the thorax?

Answer 7

Abdominal

Question 8

Which muscle arises from the external surface of the upper eight ribs and inserts on the anterior surface of the medial border of the scapula? It therefore helps to stabilize the scapula.

Answer 8

Serratus anterior