Week 4 Muscles Breakdown

Question 1

Origin of Diaphragm

Answer 1

Internal surface of ribs 7-12 and their costal cartilage, internal surface of the xiphoid process of the sternum, and anterior vertebral bodies of L1-L3

Question 2

Insertion of Diaphragm

Answer 2

Central tendon (dome) of the diaphragm

Question 3

Action of Diaphragm

Answer 3

Expands the thoracic cavity when abdominal breathing

Question 4

Origin of External Intercostals

Answer 4

Inferior boarder of one rib

Question 5

Insertion of External Intercostals

Answer 5

Superior boarder of the rib directly inferior

Question 6

Action of External Intercostals

Answer 6

Elevates the ribs at the sternocostal and costospinal joints (to assist with inhalation)

Question 7

Origin of Internal Intercostals

Answer 7

Superior boarder of one rib (and its costal cartilage)

Question 8

Insertion of Internal Intercostals

Answer 8

Inferior boarder of the rib (and its costal cartilage) directly superior

Question 9

Action of Internal Intercostals

Answer 9

Depresses ribs at the sternocostal and costospinal joints (to assist with exhalation)

Question 10

Origin of Serratus Posterior Superior

Answer 10

Inferior ligamentum nuchae and spinous processes of C7-T3

Question 11

Insertion of Serratus Posterior Superior

Answer 11

Superior, external surfaces of ribs 2-5

Question 12

Origin of Serratus Posterior Inferior

Answer 12

Spinous processes of T11-L3

Question 13

Insertion of Serratus Posterior Inferior

Answer 13

Inferior. external surfaces of ribs 9-12

Question 14

Action of Serratus Posterior Inferior

Answer 14

Depress ribs 9-12 (in exhalation) at the sternocostal and costospinal joints

Question 15

Action of Serratus Posterior Superior

Answer 15

Elevate ribs 2-5 (during inhalation) at the sternocostal and costospinal joints