5.1 Anatomy of the Muscular System: Intro Part 5

Question 1

What are some of the functions of the abdominal muscles?

Answer 1

1. support and protect abdominal viscera
2. provide support for upright posture and balance

Question 2

What are the abdominal muscles?

Answer 2

rectus abdominis
external oblique
internal oblique
transverse abdominis

Question 3

What is the origin and insertion of the rectus abdominis?

Answer 3

origin = pubic crest, pubic symphysis
insertion = cartilages of ribs 5-7 and xyphoid process

Question 4

What is the action of the rectus abdominis?

Answer 4

flexion of spine, compression of abdominal viscera

Question 5

What is the innervation of the rectus abdominis?

Answer 5

spinal nerves T7-T12

Question 6

What is the origin and insertion for the external oblique?

Answer 6

origin = sternum and ribs 5-12
insertion = linea alba and iliac crest

Question 7

What are the actions of the external oblique?

Answer 7

bilaterally = flexion of the spine and compression of the abdominal viscera
unilaterally = flexes trunk to same side and rotates to opposite side

Question 8

What is the innervation of the external oblique?

Answer 8

lower intercostal, inguinal nerves

Question 9

What is the origin and insertion of the internal oblique?

Answer 9

origin = iliac crest and lumbodorsal fascia
insertion = inferior ribs and linea alba

Question 10

What is the action of the internal oblique?

Answer 10

compresses abdomen, depresses ribs, and flexes spine

Question 11

What is the innervation of the internal oblique?

Answer 11

lower intercostal, ilioinguinal nerves

Question 12

What is the origin and insertion of the transverse abdomina?

Answer 12

origin = lateral inguinal ligament and inner iliac crest
insertion = linea alba and pubis

Question 13

What is the action of the transverse abdomina?

Answer 13

compression of abdomen

Question 14

What is the innervation of the transverse abdomina?

Answer 14

first lumber nerve (T7-L1), iliohypogastric nerve (T12-L1) and ilioinguinal (T12-L1)

Question 15

What is the primary muscle necessary for in taking air?

Answer 15

diaphragm

Question 16

What is the origin and insertion of the diaphragm?

Answer 16

origin = cartilage of ribs 7-12, xyphoid process, and lumbar vertebra
insertion = anterior longitudinal ligaments of vertebral column

Question 17

What is the action of the diaphragm?

Answer 17

expands thoracic cavity, compresses abdominal cavity

Question 18

What is the innervation of the diaphragm?

Answer 18

phrenic nerve (C3-5)

Question 19

What is the origin and insertion of the internal intercostals?

Answer 19

origin = superior border of ribs 2-12
insertion = inferior of ribs 1-11

Question 20

What is the action of the internal intercostals?

Answer 20

depresses ribs for forced expiration