Muscles of the APP

Question 1

What is the origin of the erector spinae muscles?

Answer 1

Sacrum and iliac crest

Question 2

What is the insertion of the erector spinae muscles?

Answer 2

Thoracic vertebrae and back vertebrae

Question 3

What are the functions of the erector spinae muscles? (2)

Answer 3

• straighten back
• allow for side to side rotation

Question 4

What is the innervation of the erector spinae muscles?

Answer 4

Posterior rami from C1-L5

Question 5

What is the origin of quadratus lumborum?

Answer 5

• 12th rib
• transverse processes of L1-L3 vertebrae

Question 6

What is the insertion of quadratus lumborum?

Answer 6

Iliac crest

Question 7

What is the function of quadratus lumborum?

Answer 7

Fixes 12th rib during inspiration
Lateral flexion of the spine

Question 8

What is the innervation of quadratus lumborum?

Answer 8

• subcostal nerve (T12)
• anterior rami of L1-L4

Question 9

What is the origin of psoas major?

Answer 9

Transverse processes, vertebral bodies, intervertebral disc of T12-L5

Question 10

What is the insertion of psoas major?

Answer 10

Lesser trochanter of femur

Question 11

What is the function of psoas major?

Answer 11

Flexion of hip

Question 12

What is the innervation of psoas major?

Answer 12

Lumbar plexus - Anterior rami of L1-L3

Question 13

What is the origin of iliacus?

Answer 13

Iliac fossa

Question 14

What is the insertion of iliacus?

Answer 14

Lesser trochanter of femur

Question 15

What is the action of iliacus?

Answer 15

Flexion of hip joint

Question 16

What is the innervation of iliacus?

Answer 16

Femoral nerve

Question 17

What is the origin of external oblique?

Answer 17

External surface of ribs 5-12

Question 18

What is the insertion of external oblique?

Answer 18

• linea alba
• pubic tubercle
• anterior half of iliac crest

Question 19

What is the function of external oblique?

Answer 19

• support and compress abdominal viscera
• flexes and rotates trunk

Question 20

What is the innervation of external oblique?

Answer 20

• thoracoabdominal nerves (T5-T11 spinal nerves)
• subcostal nerve (anterior ramus of T12)

Question 21

What is the origin of internal oblique?

Answer 21

• thoracolumbar fascia
• anterior 2/3 of iliac crest
• connective tissue deep to lateral third of inguinal ligament

Question 22

What is the insertion of internal oblique?

Answer 22

Inferior border of ribs 10-12, linea alba and pecten pubis via conjoint tendon

Question 23

What is the function of internal oblique?

Answer 23

• support and compresses abdominal viscera
• flexes and rotates trunk

Question 24

What is the innervation of internal oblique?

Answer 24

• thoracoabdominal nerves (anterior rami of T6-T12)
• 1st lumbar nerve

Question 25

What is the origin of transversus abdominis?

Answer 25

- 7-12th costal cartilages - thoracolumbar fascia - iliac crest - connective tissue deep to lateral third of inguinal ligament

Question 26

What is the insertion of transversus abdominis?

Answer 26

- linea alba with internal oblique - pubic crest via conjoint tendon

Question 27

What is the function of transversus abdominis?

Answer 27

Support and compresses viscera

Question 28

What is the innervation of transversus abdominis?

Answer 28

- thoracoabdominal nerves (anterior rami of T6-T12) - first lumbar nerve

Question 29

What is the origin of rectus abdominis?

Answer 29

Pubic symphysis and pubic crest

Question 30

What is the insertion of rectus abdominis?

Answer 30

Xiphoid process and 5-7th costal cartilage

Question 31

What is the function of rectus abdominis?

Answer 31

- flexes trunk - compresses abdominal viscera - stabilises and controls tilt of pelvis

Question 32

What is the innervation of rectus abdominis?

Answer 32

Thoracoabdominal nerves (anterior rami of T6-T12)

Question 33

What is the origin of coccygeus?

Answer 33

Ischial spine

Question 34

What is the insertion of coccygeus?

Answer 34

Tip of coccyx

Question 35

What is the function of coccygeus?

Answer 35

Pulls coccyx anteriorly after defecation, helps bear body weight by sitting

Question 36

What is the innervation of coccygeus?

Answer 36

S4 & S5

Question 37

What is the origin of levator ani (puborectalis, pubococcygeus, ileococcygeus)?

Answer 37

Body of pubic bones to ischial spines

Question 38

What is the insertion of levator ani (puborectalis, pubococcygeus, ileococcygeus)?

Answer 38

Tendinous arch of levator ani

Question 39

What are the functions of levator ani (puborectalis, pubococcygeus, ileococcygeus)?

Answer 39

- puborectalis - urinary and faecal continence during expiration, sneezing - pubococcygeus - controls urine flow, contracts in orgasm, assists in male ejaculation - ileococcygeus - elevates pelvic floor

Question 40

What is the innervation of levator ani (puborectalis, pubococcygeus, ileococcygeus)?

Answer 40

Pudendal nerve

Question 41

What is the origin of obturator internus?

Answer 41

Obturator foramen (through lesser sciatic foramen)

Question 42

What is the insertion of obturator internus?

Answer 42

Greater trochanter of femur

Question 43

What is the function of obturator internus?

Answer 43

Lateral pelvic rotation, abduction of thigh at hip

Question 44

What is the innervation of obturator internus?

Answer 44

Obturator internus L5-S1

Question 45

What is the blood supply to the anterolateral abdominal wall muscles? (External oblique, internal oblique, transversus abdominis, rectus abdominis)

Answer 45

Superior epigastric arteries (from internal thoracic arteries) + inferior epigastric arteries (from external iliac artery) - anastomose together, and accompanied by veins of the same name

Question 46

What is the blood supply to the posterolateral abdominal wall muscles? (Psoas major, psoas minor, iliacus, quadratus lumborum)

Answer 46

Directly from the abdominal aorta and drainage via the IVC

Question 47

What is the blood and nerve supply to the perineum?

Answer 47

Internal pudendal artery/vein Pudendal nerve