L16: Musculo-neuro-vascular systems of medial compartment of the thigh

Question 1

anterior compartment nerve:

Answer 1

femoral nerve

Question 2

posterior compartment nerve

Answer 2

sciatic nerve

Question 3

medial compartment nerve:

Answer 3

mostly obturator nerve

Question 4

medial compartment muscles (5)
‘‘groin muscles’’

Answer 4

muscles of the groin - they adduct the hip at the groin
1. adductor longus
2. adductor brevis
3. adductor magnus
4. gracilis
5. obturator externus

Question 5

Adductor Longus; origin + insertion

Answer 5

origin: body of pubis inferior to pubic crest

insertion: middle 1/3 of linea aspera on femur

Question 6

Adductor Longus; innervation + action

Answer 6

innervation: obturator nerve

action: adducts thigh at hip joint

Question 7

Adductor Brevis; origin + insertion

Answer 7

origin: body and inferior pubic ramus

insertion: pectineal line of femur, superior 1/3 of medial lip of linea aspera of femur

Question 8

Adductor Brevis; innervation + action

Answer 8

innervation: obturator nerve

action: adducts thigh at hip, modest contribution to flexion of hip

Question 9

Adductor Magnus; origin + insertion

Answer 9

largest of 3 adductor muscles, 2 portions
origin:
- adductor: inferior ramus of pubis and ramus of ischium
- hamstring: ischial tuberosity

insertion:
- adductor: gluteal tuberosity, linea aspera, medial supracondylar line
- hamstring: adductor tubercle of femur

Question 10

Adductor Magnus; innervation + actions

Answer 10

innervation:
- adductor: obturator
- hamstring: sciatic nerve (tibial)

actions:
- adductor: adducts thigh at hip, modest thigh flexion at hip
- hamstring: modest thigh extension at hip

Question 11

Gracilis; origin + insertion

Answer 11

most superficial muscle in medial compartment
origin: body and inferior ramus of pubis

insertion: superior part of medial tibial surface (pes anserinus)

Question 12

Gracilis; innervation + actions

Answer 12

innervation: obturator nerve

action: adducts thigh at hip, flexes leg at knee, assists with medial rotation of leg

Question 13

Obturator Externus; origin + insertion

Answer 13

origin: anterior surface of obturator membrane and bony margins of obturator foramen

insertion: trochanteric fossa of femur

Question 14

Obturator Externus; innervation + actions

Answer 14

innervation: obturator nerve

actions: lateral rotation of thigh at hip, steadies head of femur in acetabulum

Question 15

muscle injury in groin

Answer 15

adductor muscles commonly injured while sprinting, twisting and turning

groin injures can involve multiple muscles at the same time e.g. a grade 2 gracilis tear and a grade 1 magnus tear etc.

Question 16

Femoral triangle; boundaries, floor, roof

Answer 16

boundaries: ‘‘SAIL’’
- lateral: medial border of Sartorius
- medial: lateral border of Adductor longus
- superior: Inguinal Ligament

floor:
- lateral: iliopsoas
- medial: pectineus

roof:
- fasciae lata, subcutaneous tissue (fat), skin

Question 17

Femoral triangle contents

Answer 17

contents: ‘‘NAVEL’’
- femoral Nerve
- femoral Artery
- femoral Vein
- Empty space
- Lymphatics

Question 18

why is empty space important in femoral triangle:

Answer 18

*If you start running, your muscles need more oxygen to function.
*More oxygen comes from increased arterial supply and venous drainage.
*This is achieved partly by increasing the diameter of the femoral vessels.
*There needs to be some spare space in order to accommodate the increased size of the femoral vessels.

Question 19

femoral sheath

Answer 19

• a fibrous funnel 3-4 cm long
• deep to inguinal ligament
• divided into 3 compartments:
  
  • lateral: femoral artery
  • intermediate: femoral vein
  • medial: femoral canal, lymph
• great saphenous vein pierces femoral sheath lateral to femoral canal, to drain into common femoral vein

Question 20

Femoral canal:

Answer 20

• most medial of the 3 femoral sheath compartments
• contains lymph nodes and vessels
• femoral hernias occur here
• hernia / herniation: when part of the body protrudes through its own cavity into a different cavity. e.g. femoral hernai

Question 21

femoral hernia

Answer 21

protrusion of small intestine
- through femoral ring
- through femoral canal
- through saphenous opening in fasciae latae

Question 22

lower limb vascular emergency

Answer 22

*Applying pressure to femoral triangle reduces the amount of blood reaching lower limb, by compressing femoral artery
*Easy to do because it is very superficial
*Useful if someone sustains a serious injury to the lower limb and is bleeding out.

Question 23

Adductor Canal:

Answer 23

• aponeurotic tunnel in middle 1/3 of thigh
• extends:
  -from: inferior apex of femoral triangle
  
  • to: adductor hiatus (the opening in
    adductor magnus)
• function: passageway for structures moving between anterior thigh and popliteal fossa

Question 24

the adductor canal; boundaries

Answer 24

• anteromedial and roof: sartorius
• anterolateral: vastus medialis
• posterior: adductor longus and adductor magnus

Question 25

the adductor canal; contents

Answer 25

• femoral artery and vein
• branches of femoral nerve
  
  • saphenous nerve
  • nerve to vastus medialis