Unit 2 Muscles

Question 1

External Intercostal

Answer 1

a: rib to rib
a: elevates the ribs
i: intercostal nerve
b: anterior and posterior intercostal a.

Question 2

Internal Intercostal

Answer 2

a: rib to rib
a: depress the rib
i: intercostal nerve
b: anterior and posterior intercostal a.

Question 3

Transversus thoracis

Answer 3

a: posterior sternum –> costal cartilages
a: depress ribs
i: intercostal nerve
b: anterior intercostal a.

Question 4

Cremaster

Answer 4

a: medial internal oblique –> spermatic cord
a: elevation of testis
i: genitofemoral nerve
b: cremasteric a.

Question 5

Diaphragm

Answer 5

a: xiphoid –> crura to the central tendon
a: inspiration
i: phrenic nerve
b: musculophrenic, inferior phrenic, subcostal

Question 6

External oblique

Answer 6

a: lower 8 ribs to iliac crest & rectus sheath
a: flex and rotate the trunk; compress abdominal cavity
i: Ventral rami T7-12
b: Superior epigatric

Question 7

Internal Oblique

Answer 7

a: Thoracocolumbar fascia –> inguinal ligament
a: flex and rotate the trunk; compress the abdominal cavity
i: Tower thoracic ventral rami
b: Superior epigastric

Question 8

Quadratus lumborum

Answer 8

a: 12th rib –> Iliac crest/iliolumbar ligament
a: extension and lateral flexion of the trunk; fixes 12th rib
i: Ventral rami T12-L3
b: Subcostal

Question 9

Rectus abdominis

Answer 9

a: xiphoid process –> pubic crest/tubercle
a: flex trunk; compress abdominal cavity
i: Lower thoracic ventral rami
b: superior epigrastric

Question 10

Transversus abdominis

Answer 10

a: Lower six costal cartilages –> inguinal ligament/iliac crest
a: compress the abdominal wall
i: Lower thoracic and L1 ventral rami
b: Superior epigastric

Question 11

Illiacus

Answer 11

a: Illiac fossa –> lesser trochanter
a: Flexion of the thigh
i: Femoral n.
b: Femoral

Question 12

Psoas

Answer 12

a: Anterior transverse provesses –> Lesser trochanter
a: flexion of the hip
i: Ventral rami L1-L3
b: Femoral

Question 13

Piriformis

Answer 13

a: Sacrum –> Upper boarder greater trochanter
a: abducts, laterally rotate thigh
i: Lumbrosacral plexus
b: Superior gluteal

Question 14

Obturator internus

Answer 14

a: Obturator foramen –> Trochanteric fossa
a: Abducts, externally rotate thigh
i: Nerve to obturator internus
b: Inferior gluteal

Question 15

Coccygeus

Answer 15

a: Ishial spine –> coccyx
a: support pelvic floor
i: Ventral rami S4-S5
b: inferior gluteal

Question 16

Levator ani

Answer 16

a: pubic symphasis, obturator fascia, ischial spine –> annococcygeal ligament
a: support pelvic viscera; compress rectum/vagina
i: pudendal nerve
b: inferior gluteal

Question 17

Bulbospongiosus

Answer 17

a: Central tendon –> bulb of penis/vestibular bulb
a: maintains erection
i: perineal of pudendal
b: internal pudendal

Question 18

Ischiocavernosus

Answer 18

a: Ischial tuberosity –> Crus of the penis
a: Compress crus with erection
i: perineal of pudendal
b: internal pudendal

Question 19

Sphincter ani externus

Answer 19

a: central tendon –> anococcygeal raphe
a: closes anal canal/ fixes perineal body
i: Inferior rectal
b: internal pudendal

Question 20

Sphincter urethrae

Answer 20

a: surrounds urethra
a: compresses urethra
i: perineal of pudendal nerve
b: internal pudendal

Question 21

Compressor urethrae

Answer 21

a: Female: ischiopubic ramus –> vagina
a: compresses urethra
i: perineal of pudendal nerve
b: internal pudendal

Question 22

Sphincter urethrovaginalis

Answer 22

a: Central tendon –> contralateral muscle
a: compress urethra and vagina
i: perineal of pudendal nerve
b: internal pudendal

Question 23

Deep transverse perineus

Answer 23

a: Ischial tuberosity –> Central tendon
a: fixes perineal body
i: perineal of pudendal nerve
b: internal pudendal

Question 24

Superficial transverse perineus

Answer 24

a: Ischial tuberosity –> Central tendon
a: fixes perineal body
i: perineal of pudendal nerve
b: internal pudendal