5/8/2015 "Gross Anatomy Ant/Medial Thigh and Knee Miriam L. Donohue" Flashcards
Define pes anserine and list its component muscles/tendons; indicate where they insert and their collective function.
Pes anserine = goosefoot, made of: Sartorius Semitendonous Gracilis All insert on anteromedial portion of tibia All FLEX the knee
List the posterior thigh compartment muscles
Posterior thigh muscles = hamstring muscles:
Biceps femoris
Semitendinosus
Semimembranosus
What is the innervation for the posterior thigh muscles?
Posterior thigh muscles = hamstring muscles: Biceps femoris Semitendinosus Semimembranosus All innervated by sciatic nerve
What are the origin and insertion points for the posterior thigh muscles?
Posterior thigh muscles = hamstring muscles: Biceps femoris Semitendinosus Semimembranosus All originate on ischial tuberosity All innervated by sciatic nerve All insert on the tibia Act on both hip and knee
What is the function of the hamstring muscles?
Posterior thigh muscles = hamstring muscles: Biceps femoris Semitendinosus Semimembranosus ***Adductor magnus hamstring portion*** All originate on ischial tuberosity All innervated by sciatic nerve All insert on the tibia Act on both hip and knee Extend hip, flex knee
Name 2 muscles in the anterior thigh compartment that act on more than one joint.
Sartorius: Flexes hip Flexes knee Rectus femoris: Flexes hip Extends knee *Rectus femoris is a quadricep muscle
In what position is the knee most stable?
Extended position
What ligaments stabilize the knee joint?
IT band - lateral stability
Pes anserine - medial stability
MCL - resists valgus forces
LCL - resists varus forces
Injuries to what other structures often accompany traumatic damage to the MCL? What condition is this known as?
ACL and medial meniscus
“the unhappy triad”
Which meniscus is more often injured and why?
Medial meniscus, because it’s attached to the MCL, and lateral forces damage the MCL (valgus forces)
MCL stronger than LCL bc of attachment to medial meniscus.
What are the functions of the menisci?
Add depth and cushioning to the articular surfaces of the tibial plateau
Facilitate weight transfer and distribution from femur to tibia
Which cruciate ligament is more often injured?
ACL because more common injury to have a forward movement stopped abruptly.
Describe the function of the cruciate ligaments.
ACL resists ANTERIOR movement of the tibia on the femur
PCL resists POSTERIOR movement of the tibia on the femur
How is locking of the knee joint accomplished?
As the knee comes into the extended position, the lateral femoral condyle comes into congruency with the lateral meniscus on the tibial plateau. The femur rotates medially on the tibia to allow the medial meniscus to meet the medial condyle. Then the knee is locked.
Locking of the knee permits long periods of standing with little exertion.
What muscle unlocks the knee?
Popliteus muscle
What are the muscles of the anterior thigh compartment?
Sartorius
Iliopsoas
Quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius)
Pectineus
What is the longest muscle in the body?
Sartorius
What is the strongest ligament in the body?
Iliofemoral ligament
What is the common insertion point for all the quadriceps femoris muscles?
Quadriceps tendon (over patella) Becomes patellar ligament
What is the longest bone in the body?
Femur
What separates the compartments of the thigh?
Deep fascia
Where does obdurator nerve (L2-L4) provide cutaneous innervation?
Interior thigh
Where does posterior femoral cutaneous nerve (S1-S3) provide cutaneous innervation?
Back of thigh
What are the functions of the anterior compartment muscles?
Knee extensors
Hip flexors
Innervation by femoral nerve (L2-L4)
What are the functions of the medial compartment muscles?
Hip Adductors
What are the functions of the posterior compartment muscles?
Hip extensors
Knee flexors
What special muscle is the initiator of hip flexion?
Pectineus (ATC)
Can get innervation from femoral AND obdurator bc it is a border muscle
What thigh compartment is innervated by the femoral nerve (L2-L4)?
ATC
What combined action would test the functions of the sartorius muscle?
Lifting up foot to see if you stepped on gum
What part of the quadriceps muscle fails to keep the patella in place during aging?
Vastus medialis
What is the only quadriceps muscle that acts on the hip joint, and is therefore the longest of the quadriceps muscles?
Rectus femoris
What is the femoral triangle?
The femoral triangle is bounded:
superiorly by the inguinal ligament.
medially by the medial border of the adductor longus muscle.
laterally by the medial border of the sartorius muscle.
Its floor is formed by the pectineus and adductor longus muscles medially and iliopsoas muscle laterally. Its roof is formed by the fascia lata, except at the saphenous opening where it is formed by the cribriform fascia.
Contents
The femoral triangle is important as a number of vital structures pass through it, right under the skin. The following structures are contained within the femoral triangle (from lateral to medial):
Femoral nerve and its (terminal) branches.
Femoral sheath and its contents:
Femoral artery and several of its branches.
Femoral vein and its proximal tributaries (e.g., the great saphenous and deep femoral veins).
Deep inguinal lymph nodes and associated lymphatic vessels.
Clinical significance
Since the femoral triangle provides easy access to a major artery, coronary angioplasty and peripheral angioplasty is often performed by entering the femoral artery at the femoral triangle.
What are the muscles of the medial thigh compartment?
Pectineus (more MTC than ATC) Adductor brevis Gracilis Adductor Longus Adductor portion of Adductor Magnus (border of MTC and PTC)
Motor innervation from obdurator nerve
What travels through the adductor hiatus?
Femoral artery –> popliteal artery
Give the origin and insertion of gracilis muscle:
Pubis –> anteromedial tibia
Give the origin and insertion of sartorius:
Anterior superior iliac spine –> anteromedial tibia
Give the origin and insertion of Semitendinosus:
Ischial tuberosity –> anteromedial tibia
What makes up the IT band?
Tensor fascia lata
Gluteus maximus
The 6 P’s describe what syndrome?
Compartment syndrome: Pain Paresthesias Pallor Paralysis Pulselessness Poikilothermia
