Gluteal region, thigh Flashcards
1
Q
lumbosacral plexus
A
- The combined lumbar and lumbosacral plexi contain ventral rami from L2 through S3 (L2-L5, S1-S3)
- L2 and L3 tend to innervate muscles that act more at the hip
- S2 and S3 tend to innervate muscles in the foot.
- The lumbosacral plexus exits the pelvic cavity through the greater sciatic foramen
- This puts these nerves into the gluteal region: the sciatic nerve will exit just inferior to the piriformis muscle
2
Q
What is the shoulder joint?
A
- glenohumeral joint
- “Ball and socket”
- We can move the humerus in all 3 planes: flex/extend, ab/adduct, internally/externally rotate
- Like the hip joint
3
Q
pectoral girdle vs. pelvic girdle
- What bones make them?
- Where is movement possible?
A
- Comparable structures of upper and lower limbs
- Pectoral girdle = clavicle & scapula
- Lots of movement possible
- Pelvic girdle = ilium, ischium, pubis
- No movements possible, fused together at sacroiliac joint
4
Q
What are the nerves of the hip?
Where do they come from?
A
- Hip nerves are branches of the lumbar plexus
- Because they come out of the top of the plexus, both nerves contain L2, L3, and L4
-
Femoral nerve and obturator nerve
- Innervate anterior and medial thigh
5
Q
largest nerve in body?
A
- Sciatic nerve
- Ventral rami. L4, L5, S1, S2, S3
- Innervates mostly leg and foot
- It’s actually two nerves running together in the same connective tissue sheath
- It’s a tibial nerve + common fibular nerve, as emerge from the pelvis and course down the posterior aspect of the thigh
- As the the sciatic nerve approaches the popliteal fossa (pit of knee), it splits into its real branches.
- Common fibular nerve sweeps out to lateral and anterior part of leg
- Tibial nerve continues straight down into posterior leg
- (So it’s incorrect to say that any lower limb is innervated by sciatic nerve. Innervated by either the tibial or fibular.)
6
Q
What is the hip joint?
Contrast with shoulder joint.
A
-
acetabulofemoral joint
-
Formed by head of femur and acetabular fossa of pelvic bone
- Acetabular fossa is formed by fusion of 3 joints that make the pelvic girdle (ilium, ischium, pubis)
-
Formed by head of femur and acetabular fossa of pelvic bone
-
Ball and socket joint (like the shoulder joint)
- We can move the femur in all 3 planes: flex/extend (sagittal), AB/ADduct (coronal), internally/externally rotate
Differences from shoulder joint:
- Hip joint is the proximal joint of the lower limb
- Hip joint has limited range of motion (fused)
- Hip joint has an important weight-bearing function.
7
Q
knee joint
- What kind of joint?
- Actions possible?
- What is it similar to?
A
- Knee joint = modified hinge joint
- Can do flexion and extension in sagittal plane, AND there is also some rotation possible
- Similar to the elbow joint, BUT
- Elbow joint is “pure hinge joint” – limited to just flexion and extension, actions that occur in sagittal plane
- Ankle joint is also a “pure hinge joint”
8
Q
elbow joint
- What kind of joint?
- Actions possible?
- What is it similar to?
- What is it different from?
A
- Humero-radial-ulnar joint
- The elbow joint is a “pure hinge joint”
- Limited to just flexion and extension, actions that occur in sagittal plane.
- Similar to ankle joint, which is also a pure hinge joint
- Whereas knee joint is a “modified hinge joint” – can do flexion and extension in sagittal plane, and there is also some rotation possible.
9
Q
ankle joint
- Formed by what?
- Type of joint? Actions?
A
- Formed by distal end of the tibia, fibula, and tarsus
- It’s a pure hinge joint
- We move it in the sagittal plane (dorsiflexion, plantar flexion)
10
Q
what are the muscles of gluteal region
and their functions
A
-
Gluteus maximus
- Powerful extensor of the thigh at the hip
- Also laterally rotates the thigh at the hip
- Underneath gluteus maximus are the gluteus medius and gluteus minimus
- ABductors of thigh at the hip
- Major role is to ABduct the trunk, to keep the pelvis level when the opposite lower limb is off the ground
- Deep to gluteus maximus, some small muscles:
-
Piriformis
- key bc emerges through greater sciatic foramen, and boundary separates superior from inferior gluteal structures
- 2 gemelli (superior, inferior)
- obturator internus
- quadratus femoris
-
Piriformis
- They’re all just assisting the gluteus maximus, as lateral rotaters of the thigh at the hip.
11
Q
gluteus maximus:
What do we use it for?
Innervation
A
- Largest muscle in the body
- Gluteus maximus = powerful extensor of thigh at the hip
- Use extensor when extending thigh from fully flexed position: rising from sitting position, climbing stairs, running.
- (Not for everyday walking.)
- Use extensor when extending thigh from fully flexed position: rising from sitting position, climbing stairs, running.
- Also laterally rotates the thigh at the hip
- Innervated by inferior gluteal nerve (whereas superior gluteal nerve innervates the gluteus minimus and medius)
12
Q
gluteus minimus and medius:
What do we use them for?
What happens without them?
A
- gluteus medius and gluteus minimus = powerful ABductors
- Allow us to move thigh and rest of lower limb in coronal plane. We don’t abduct the thigh a lot, unless we’re dancers.
-
Most important function actions of gluteus medius and minimus is to abduct the trunk and keep the pelvis level when the lower limb is off the ground.
- Patient’s foot would otherwise be dragging
- When lift foot, nerve on opposite side contracts the muscle on opposite side, to level
- They cross the hip joint
13
Q
what are other gluteal muscles
that assist gluteus maximus in lateral rotation of thigh at the hip?
A
These small muscles are deep to the gluteal maximus:
-
Piriformis
- Boundary that separates superior gluteal structures from inferior gluteal structures
- Gemellus superior and gemellus inferior
-
Obturator internus
- Comes out of the lesser sciatic formane
- Quadratus femoris
- They’re all lateral rotaters of the thigh at the hip, assisting gluteus maximus
- No clinical signficance
14
Q
what is the innervation of gluteal muscles?
A
- Innervated by gluteal nerves (yay)
- Inferior gluteal nerve innervates 1 muscle: the gluteus maximus
- Superior gluteal nerve innervates the gluteus medius, gluteus minimus, and tensor fascia latae
- Piriformis, obturator internus, gemilli are all innervated by nerves that have the same name as the muscle.
- Tiny branches off the lumbosacral plexus.
- No clinical significance. Won’t be tested.
15
Q
tensor fascia latae
A
- Assists gluteus minimus and medius with ABducting the thigh at the hip
- Also flexes thigh at the hip
- Innervated by superior gluteal nerve
- Which also innervates the gluteus medius and minimus
16
Q
What does the piriformis come through?
What emerges superior to the piriformis?
What emerges inferior to the piriformis?
A
- piriformis comes through greater sciatic foramen
- Above: Superior gluteal artery and vein
- Below: Inferior gluteal artery and vein, and the sciatic nerve
- Piriformis is the “key” to the gluteal region
17
Q
What comes out of greater sciatic foramen vs lesser foramen?
A
- Greater has sciatic nerve, piriformis muscle, superior/inferior gluteal neurovascular bundle
- Lesser has pudendal neurovascular bundle and the obturator internus muscle
- Obturator internus muscle acts as lateral rotator
Greater sciatic foramen is more important. All the good stuff.
21
Q
Where does the sciatic nerve emerge?
A
- Just inferior to the piriformis
- Does not innervate any muscle in the gluteal region. Starts innervation in the posterior thigh.
22
Q
anterior compartment of thigh
- Function?
- Innervation?
- Muscles?
A
Function: anterior thigh = hip flexors
- Rectus femoris, iliopsoas = the best flexors of the thigh at the hip
- weak flexors = pectineus muscle, and adductor longus
Innervation
- The muscles of the anterior compartment of the thigh are innervated by the femoral nerve
- No exceptions.
- Muscles
- sartorius - the longest muscle in the body
- iliopsoas
- quadriceps femoris group - the rectus femoris muscle and the three vasti muscles: the vastus lateralis, vastus intermedius, and the vastus medialis
- Best flexors = rectus femoris, iliopsoas
- pectineus, adductor longus
23
Q
flex thigh at the hip -
which muscles are the best for this?
A
- The best flexors of thigh at the hip are in the anterior thigh:
- iliopsoas, rectus femoris, sartorius
-
The very best = the iliopsoas!
- Combination of the psoas + iliacus muscles
- Innervated by femoral nerve
26
Q
medial thigh
- Function?
- Muscles?
- Antagonist to what?
- Innervation?
A
- Function = ADduct thigh at hip
- Muscles = pectineus, gracilis, adductor longus, adductor brevis, adductor magnus
- Antagonist to gluteus medius and gludeus minimus, which ABduct the thigh at the hip
- Innervated by obturator nerve
- (except for part of the adductor magnus, the hamstring portion of it has tibial nerve)
straightforward, adductors
29
Q
What’s special about the SHORT head of the biceps femoris?
A
- Part of the biceps femoris of the hamstrings, but it’s the exception: NOT a true hamstring
- Because it doesn’t cross at the hip joint. Only crosses the knee joint, because it’s short.
- Innervated by common fibular nerve (while the others are all innervated by the tibial nerve)
31
Q
iliopsoas muscle:
What is it the best at?
A
-
Best flexor of the thigh at the hip!
- (One of the anterior thigh muscles. The best even though it’s small.)
- It’s completely anterior to the hip joint.
- It’s a combination of the psoas major + iliacus
32
Q
Femoral triangle
- What are the boundaries?
- What comes through it?
A
- Formed by the inguinal ligament, sartorius muscle, adductor longus muscle
- Contains the major neurovascular bundle that supplies the anterior thigh: the femoral nerve, femoral artery, femoral vein (most medial)
- Femoral artery and femoral vein supply the entire lower limb
33
Q
rectus femoris:
What makes it different from the other quadriceps muscles?
A
- All quadriceps muscles (rectus femoris, and the vastus muscles) can extend the leg at the knee, since their tendon attaches there
- Only the rectus femoris can also flex the thigh at the hip
- all of them are innervated by femoral nerve
34
Q
quadriceps femoris tendon:
what is it, and what’s the name change?
A
- quadriceps muscles converge at quadriceps femoris tendon,
- Embedded in the tendon is the patella (the knee cap, a seed-like bone)
- Quadriceps femors tendon changes name after the patella –> called the patellar tendon/ligament
35
Q
What is the blood supply to entire lower limb?
- Name changes?
A
- One tube, that changes its name 3 times
- Start as external iliac artery
- Once the external iliac artery crosses behind the inguinal ligament, it becomes the femoral artery
- Doesn’t care about the thigh. Its goal is to supply the leg and the foot.
- Once it crosses through adductor hiatus, becomes popliteal artery and supplies leg and foot
- The deep/profunda femoral artery supplies the thigh
- Gives rise to lateral circumflex and medial circumflex arteries
- Gives rise to perforating branches to supply posterior thigh
- So hamstrings are only supplied by these little guys. So takes longer to heal, lousy blood supply.
38
Q
Name the arteries that supply the:
- Anterior thigh
- Posterior Thigh
- Medial thigh
- Leg
- Foot
A
- Anterior thigh = deep femoral artery
- Posterior Thigh = perforating branches of the deep femoral artery (lousy)
- Medial thigh = deep femoral artery (branches = the medial and lateral femoral circumflex arteries)
- Leg = popliteal artery (branches = anterior and posterior tibial arteries)
- Foot = popliteal artery (branches = anterior and posterior tibial arteries)
39
Q
What does the profunda femoral artery supply?
A
Profunda femoral artery supplies:
- Anterior thigh
- Medial Thigh
- Posterior thigh (perforating branches)
-
Hip joint and head of femur (medial circumflex femoral branch)
- Femoral neck fractures commonly result in avascular necrosis of the femoral head.
40
Q
Which nerves innervate anterior thigh, medial thigh, posterior thigh?
A
- Anterior = Femoral nerve
- Medial = Obturator nerve
-
Posterior (hamstrings) = Tibial nerve
- Small exception is the short head of biceps
43
Q
What are the clinical findings of an inferior gluteal nerve injury?
A
- Difficulty getting up from a chair without using upper limbs
- because innervates gluteus maximus - extensor from flexed position
