C21

Question 1

Lumbar plexus and the position of the nerves

Answer 1

Corresponds to the number of lumbar vertebrae

Eq+Ru+ Su=6

Ca + fe= 7

divides into dorsal and ventral branches

dorsal divides into medial and lateral

• N. clunium cranialis - nerves that innervate the rumpthe ventral branches forms the lumbar plexus

Question 2

The main branches of the lumbar plexus

Answer 2

1. N. iliohypogastricus craniale
2. N. iliohypogastricus caudale
   * Only present in the dog as the others have their cranial and caudal combines
3. N. ilioinguinalis
4. N. genitofemorlais
5. N. cutnaeus femoris lateralis
6. N. femorlais
7. N. obturatorius

Question 3

N. iliohypogastricus craniales

Answer 3

L1, divides into medial and lateral branches

Lateral branch - R. cutaneus lateralis - perforates the obliquus internus, descends between oblique muscles

R. cutaneus lateralis

Question 4

N. iliohypogastricus caudale

Answer 4

Present in dog

Question 5

N. ilioinguinalis

Answer 5

L3 in ca L2 in Eq, Ru and Sus

innervates the area caudal to the iliohypogastric nerve with its lateral cutaneus branches

Question 6

N. genitofemoralis

Answer 6

runs caudally between the inner lumbar muscles

reaches the inguinal ring together with the external iliac artery

a branch goes to the internal oblique abdomnial muscle

innervates the skin over the medial aspect of the thigh

a branch goes to the ingunal mammary gland/prepuce

in female: skin surrounding the vulva

In male: scrotum

Divides into

R. femoris - ingunal , sensory

R. genitlais - canalis inginalis with a pudenda externa, parasympathetic and sensory

Question 7

N. cutaneus femoris lateralis

Answer 7

Follow the a circumflexa ilium profunda through the abdomnial wall

Innervates:

• inner lumbar muscles
• skin over the lateral aspect of the distal thigh and the stifle joint

Question 8

N. femoralis

Answer 8

Strong nerve, hidden in the iliopsoas, continous caudally along the iliopsoas and the greater psoas muscle

small muscular branches that will innervate

• M. quadricep femoris
• m. pectineus
• m. sartorius

will aslo innervate

• M. psoas major
• M. psoas minor
• M. iliacus

before it continous as the saphenous nerve, which enters the femoral canal

• r. caudalis
• r. cranialis
• small branch to the knee

Innervates:

• gracilis
• descending genicular
• skin over the medial aspect of the leg

Question 9

N. obturatorius

Answer 9

follows the medial aspect of the shaft of the ilium to the for. obturatorium

leaves the pelvis, and splits into

• r. cranialis
• r. caudalis

innervates

• M. adductor
• M. pectineus
• M. gracilis
• M. obturatorius externus

(can be injured during calving and foaling du to the situation of the nerve on the pelvic bone)