Muscles of the Thigh Flashcards
1
Q
Muscle compartments of the thigh
A
- Anterior compartment
- Medial compartment
- Posterior compartment
2
Q
Anterior compartment muscles
A
- Sartorius
- Quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermidus)
- Articularis genu
3
Q
Medial compartment of the thigh
A
o Gracilis o Pectineus o Adductor longus o Adductor brevis o Adductor magnus
4
Q
Posterior compartment of the thigh
A
Hamstring muscles:
- Biceps femoris
- Semitendinosus
- Semimembranosus
5
Q
Sartorius
A
Anterior compartment
- Longest muscle in the body
- Descends across the thigh (lateral to its medial position)
- Forms the roof of the adductor (subsartorial) canal
6
Q
Sartorius origin
A
ASIS and notch below it
7
Q
Sartorius insertion
A
Proximal part of medial surface of body of tibia (same as gracilis and semitendinosus) – It extends obliquely from lateral to medial across the upper thigh, then descends nearly vertically to its insertion
8
Q
Sartorius nerve supply
A
Femoral nerve
9
Q
Sartorius function
A
Flexes, abducts and laterally rotates at the hip
Also, flexes the knee and medially rotates the leg from flexed position
10
Q
Variation in sartorius muscle
A
May be absent or may be split into two parts
- May have accessory sites of origin on the inguinal ligament, notch of the ilium, iliopectineal line or pubis
11
Q
Quadriceps femoris group
A
- Four muscles of the thigh are collectively called the quadriceps femoris
- Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
- Each muscle converges at a common insertion
12
Q
Quadriceps femoris origin
A
Unique to each individual muscle
13
Q
Quadriceps femoris insertion
A
Entire group Tibial tuberosity via patellar ligament
- Depends on how you view the patella
- If patella is regarded as a sesamoid bone in the quadriceps tendon, then the proper tendon of insertion is the so-called patellar ligament, which continues to the tibial tuberosity
- If patella is not considered a sesamoid, the muscle can properly be thought of as inserting into the patella
- Regardless of how you see it, the primary function of the quadriceps femoris is extension of the knee, so the ultimate insertion must be the tibial tuberosity
14
Q
Quadriceps femoris nerve supply
A
Femoral nerve
15
Q
Quadriceps femoris function
A
- Extension of the knee
- Rectus femoris also assists in flexion of the hip
16
Q
Rectus femoris origin
A
Two tendons
- Straight (anterior) tendon –> from AIIS
- Reflected (posterior) tendon –> from groove above acetabulum
The tendons merge to form a broad aponeurosis on the ventral surface of the muscle, so fibers of the muscle actually arise from this aponeurosis
17
Q
Rectus femoris insertion
A
The base (superior border) of the patella, via a thick aponeurotic tendon then via the patellar ligament to the tibial tuberosity
18
Q
Vastus lateralis origin
A
Four origins:
- Lateral lip of linea aspera
- Lateral lip of gluteal tuberosity
- Anterior and inferior borders of greater trochanter
- Proximal intertrochanteric line
19
Q
Vastus lateralis insertion
A
Lateral border of patella and tendon of quadriceps femoris then via the patellar ligament to the tibial tuberosity
20
Q
Vastus medialis origin
A
Five origins:
- Distal intertrochanteric line
- Medial intermuscular septum
- Tendons of adductor longus and magnus
- Proximal medial supracondylar line
- Medial lip of linea aspera
21
Q
Vastus medialis insertion
A
Medial border of patella and tendon of quadriceps femoris then via the patellar ligament to the tibial tuberosity
22
Q
Vastus intermedius origin
A
Proximal two thirds of the anterior and lateral surfaces of the femur
23
Q
Vastus intermedius insertion
A
The quadriceps tendon then via the patellar ligament to the tibial tuberosity
24
Q
Articularis genu origin
A
Anterior surface of distal femur
25
Articularis genu insertion
Into the synovial membrane of the knee joint
26
Articularis genu innervation
Femoral nerve
27
Articularis genu fnction
To draw the synovium proximally
28
Articularis genu notes
Small muscle located deep to the vastus intermedius
29
Articularis genu variation
May be blended with the vastus intermedius
30
Medial compartment of the thigh
- Gracilis
- Pectineus
- Adductor longus
- Adductor brevis
- Adductor magnus
31
Gracilis notes
Thin muscle located superficially on the medial thigh
32
Gracilis origin
Three origins:
- Inferior ½ of the pubic symphysis
- Pubic body
- Superior ½ of the pubic arch (inferior pubic ramus)
33
Gracilis insertion
Passes distally posterior to the medial condyle of the tibia to insert on the proximal part of the medial surface of the tibia (same as sartorius and semitendinosus)
34
Gracilis nerve supply
Anterior division of the obturator nerve
35
Gracilis function
- Adductor and medial rotator at the hip
| - Flexor at the knee
36
Pectineus origin
Three origins:
- Pecten pubis
- Bone anterior to pecten pubis between the pubic tubercle
- Iliopectineal eminence
37
Pectineus insertion
Pectineal line (line between lesser trochanter and linea aspera)
38
Pectineus nerve supply
Femoral nerve
- If accessory obturator nerve is present, it gives a branch to pectineus
- The obturator nerve may also provide a branch
39
Pectineus function
Flexion, adduction and medial rotation of the hip
40
Pectineus variation
May have two strata, either completely or incompletely separated
- When present, the dorsal stratum is innervated by the femoral nerve or accessory obturator (when present)
- Obturator nerve supplies ventral stratum when present
41
Adductor longus notes
Most anterior of the adductor muscles
42
Adductor longus origin
Front of the body of the pubis
43
Adductor longus insertion
Medial lip of linea aspera (btw attach. of vastus medialis & adductor magnus)
44
Adductor longus nerve supply
Anterior branch of obturator nerve
45
Adductor longus function
Flexor and adduction of the hip
46
Adductor longus variation
May be doubled, fused with pectineus, or descend as far down as the knee
47
Adductor brevis notes
- Just posterior to the adductor longus is the adductor brevis
- Divisions (ant./post.) of obturator nerve divide to surround muscle
48
Adductor brevis origin
Pubic body and inferior pubic ramus between gracilis and obturator externus
49
Adductor brevis insertion
Proximal part of linea aspera
50
Adductor brevis nerve supply
Obturator nerve (anterior division, usually)
51
Adductor brevis function
Adductor and flexor of the hip
52
Adductor brevis variation
May have two or three parts, or may be fused with adductor magnus
53
Adductor magnus notes
The largest of the adductors
- Lies deep to the adductor brevis
- Upper fibers run nearly horizontally while its lower fibers are nearly vertical in orientation
- There are usually five openings in the muscle, four for the passage of perforating branches of the deep femoral artery
- The most distal opening is the adductor hiatus (hiatus tendineus) which allows passage of the femoral vessels to the popliteal fossa
54
Adductor magnus origin
Three origins:
- Inferior pubic ramus
- Ramus of the ischium
- Ischial tuberosity (triangular region)
55
Adductor magnus insertion
Four insertions:
- Gluteal tuberosity (line)
- Linea aspera
- Medial supracondylar line
- Adductor tubercle of the femur
56
Adductor magnus nerve supply
Posterior division of obturator nerve and tibial portion of sciatic nerve
57
Adductor magnus function
Adductor, flexor and extensor of the hip
| - All of these functions are possible because of the different fiber orientations in the muscle
58
Adductor magnus variation
May be fused with quadratus femoris or with either the adductor longus or brevis
59
Posterior compartment of the thigh - Hamstring muscles
- Three components
o Biceps femoris (found laterally in the posterior compartment and has 2 heads)
o Semitendinosus (found medially in the posterior compartment)
o Semimembranosus (found medially in the posterior compartment)
60
Biceps femoris origin
Long head
- Posterior part of ischial tuberosity below oblique line (by a common tendon with the semitendinosus)
- Sacrotuberous ligament
Short head
- Lateral lip of linea aspera (between the adductor magnus and vastus lateralis muscles)
- Lateral supracondylar line of femur
- Lateral intermuscular septum
61
Biceps femoris insertion
Long head
- Pass laterally in an oblique course across sciatic nerve
- Ends in an aponeurosis which overlies the muscles and is also the insertion of the short head
Combined aponeurosis
- Aponeurosis narrows to a tendon, which is inserted into…
o Lateral side of the styloid process of the head of the fibula
o Lateral condyle of the tibia
- Tendon surrounds the fibular collateral ligament and the common fibular nerve runs along its medial border
62
Biceps femoris nerve supply
Long head
- Tibial portion of the sciatic nerve
Short head
- Common fibular portion of the sciatic nerve
63
Biceps femoris function
Both heads
- Flex the knee
- Laterally rotate the knee from the flexed position
Long head
- Extends and laterally rotates the hip
64
Biceps femoris variation
Short head
- May be absent or there may be accessory heads arising from the ischial tuberosity, linea aspera or the medial supracondylar ridge of the femur
An extension of the biceps femoris may attach to the gastrocnemius muscle
65
Semitendinosus origin
Originates with the long head of the biceps femoris from the…
- Posterior ischial tuberosity below the oblique line
- Aponeurosis which connects the two muscles for about 8 cm from their origin
66
Semitendinosus insertion
Semitendinosus ends in a tendon at the middle of the thigh
- Long tendon lies along medial border of popliteal fossa then curves around medial condyle of tibia and over tibial collateral ligament (there is usually an intervening bursa)
- Then inserts into the proximal part of the medial surface of the tibia
67
Semitendinosus nerve supply
Tibial portion of sciatic nerve
68
Semitendinosus function
- Flexes at the knee and medially rotates from full extension
- Also extends the hip
69
Semimembranosus origin
Two origins:
- Upper outer (lateral) position of the oblique line of the ischial tuberosity above the semitendinosus and biceps femoris
- Aponeurotic expansion of the tendon of origin
70
Semimembranosus insertion
Three insertions:
- Groove on the medial surface of the medial condyle of the tibia
- Posterior surface of the lateral condyle of the femur
Gives rise to fibers that proceed superolaterally to form a popliteal ligament
- This forms the 3rd insertion into the fascia which covers the popliteus muscle
71
Semimembranosus nerve supply
Tibial portion of sciatic nerve
72
Semimembranosus function
- Flexor at the knee and a medial rotator from full extension
- Also extends the thigh
73
Semimembranosus variation
May be absent or doubled
