Anatomy E4: LE

How many regions are in the lower limb? What are they?

6

-gluteal, femoral, knee, leg, ankle, foot

What is the main function of the pelvic girdle?

transfer weight of upper body

How many bones make up the bony pelvis?

3 fused bones

-R hip, L hip, and sacrum

Which 3 bones fuse to form the hip bones

ilium, ischium, pubis

Where on the hip articulates with the femur?

acetabulum

-formed by ilium (superior), pubis (anterior), and ischium (post-inferior)

Which bone forms the posteroinferior part of the acetabulum and hip bone?

ischium

What two features are unique to the ilium?

iliac crest and ASIS

What is the longest and heaviest bone in the body (approx. ¼ person’s height)?

femur

Features of the proximal end of the femur:

femoral head, femoral neck, greater trochanter, lesser trochanter

Features of the distal end of the femur:

lateral and medial epicondyles, lateral and medial condyles, patellar surface

What is the linea aspera?

line on the posterior shaft of the femur

What supplies blood to the femoral head?

medial femoral circumflex a.

-disruption of supply leads to avascular necrosis

What is another word for femoral neck fracture?

broken hip

Describe the patella:

large triangular shaped sesamoid bone

How is the patella attached to the quadriceps?

superior attachment - tendons of quadriceps

Describe the tibia:

larger for weight bearing, medial

Tibia features:

medial condyle, lateral condyle, tibial plateau, tibial tuberosity

What is the medial malleolus?

medial projection on distal aspect of tibia

Describe the fibula:

lies posterolateral to tibia; not involved with weight bearing

-major function is for muscle attachment

What does the knee joint stability depend on?

muscle/tendon strength and ligaments connecting femur-tibia

What are the ligaments of the knee?

LAMP

-lateral collateral ligament (LCL)

-anterior cruciate ligament (ACL)

-medial collateral ligament (MCL)

-posterior cruciate ligament (PCL)

role of the ACL

prevents hyperextension and posterior displacement

role of the PCL

prevents hyperflexion and anterior displacement of femur

What is the role of the meniscus?

protects the tibia and femur from rubbing on each other (shock absorption)

-both lateral and medial (know locations)

Where does the meniscus lie?

tibial plateau

Define bursae:

fluid-filled sac where the muscle or tendon slides across bone

Name the bursae of the knee

suprapatellar, prepatellar, infrapatellar -deep, infrapatellar -superficial

What are the bones of the foot?

tarsals (7), metatarsals (5), phalanges (14) 3 for each digit except for great toe (2)

What are the 7 tarsals?

calcaneus, talus, cuboid, navicular, medial cuneiform, intermediate cuneiform, lateral cuneiform

Talus role

bears body weight, transmitted from tibia

articulates anteriorly with navicular bone

location of the cuboid

most lateral bone in distal row of tarsus, articulates with 2 metatarsals

deltoid ligament

medial, stabilizes during eversion and prevents subluxation

lateral ankle ligaments

CAP

calcaneofibular ligament (CFL)

anterior talofibular ligament (ATFL)

posterior talofibular ligament (PTFL)

1st metatarsal

shorter, stouter

significant role in supporting weight of body

-has sesamoid bones

which metatarsal is the longest?

2nd metatarsal

1st digit of the foot:

great toe -has 2 phalanges (proximal and distal)

Metatarsophalageal joints

MTPs -between metatarsals and phalanges

Which nerve innervates the anterior thigh, hip flexors, and knee extensors?

femoral nerve

what 3 muscles make up the posterior compartment of the thigh (hamstrings)?

biceps femoris m., semitendinosus m., semimembranosus m.

Which 4 muscles make up the quadriceps femurs?

rectus femoris m., vastus lateralis m., vastus intermedius m., vastus medialis m.

What is the longest muscle in the body? (know as the “tailor’s muscle)

sartorius m. (crosses two joints (hip & knee))

What is collectively the most powerful muscle in the body?

Quadricep muscles

What nerve is the primary innervation for the medial compartment of the thigh?

obturator n.

What muscles make up the medial compartment of the thigh?

adductor longus m., adductor brevis m., adductor Magnus m., gracilis m., obturator externus m.

What is the most superficial muscle on the medial thigh?

Gracilis m.

What is the femoral triangle bounded by?

Inguinal ligament (superiorly) (forms the base)

Sartorius m. (laterally)

Adductor longus m. (medially)

What is the femoral triangle?

subfascial space located in the anterosuperior 1/3 of the thigh

When and where is the femoral triangle visible?

when: visible when the thigh is abducted, flexed, and laterally rotated

where: triangular depression inferior to the inguinal ligament

What muscles compose the floor of the femoral triangle?

medially - pectinous and adductor longus

laterally - iliopsoas

Contents of the femoral triangle

NAVeL

femoral Nerve, femoral Artery, femoral Vein, deep inguinal Lymph nodes

What does the femoral sheath hold?

encloses femoral vessels, not nerves

creates a canal for the femoral artery, femoral vein, and femoral canal

Where does the femoral sheath lie?

deep to the inguinal ligament

What is the chief artery of the lower limb?

femoral artery

What is the chief artery of the thigh?

profunda femoris artery

What are the branches of the profunda femoris artery?

medial circumflex femoral artery (femoral head)

lateral circumflex femoral artery (lateral thigh)

Venous drainage of the lower limb

greater saphenous v., femoral v., external iliac v., common iliac v.

What is the function of the sciatic nerve?

supplies most of the leg and foot muscles

Where does the sciatic nerve split? What does it split into?

divides into tibial and common fibular (perineal) nerves in popliteal fossa

Where does the sciatic nerve exit the pelvis?

exits pelvis via greater sciatic foramen

What are the boundaries of the popliteal fossa?

biceps femoris m. (superior lateral)

Semimembranosus m. & semitendinosus m. (superior medial)

gastrocnemius m. (inferolateral and inferomedial)

What is the popliteal fossa?

triangular space posterior to the knee

What does the popliteal fossa contain?

small saphenous v., popliteal artery & vein, sciatic n.

What muscles are in the anterior compartment of the leg?

tibialis anterior m., extensor digitorum longus m., extensor hallucis longus m., peroneus (fibularis) tertius m.

What is in the lateral compartment of the leg?

peroneus (fibularis) longus m. , peroneus (fib) brevis m., superficial peroneal n.

-NO arteries course through lateral compartment

Where does the superficial perineal n. most commonly get injured? What does this lead to?

most often injured in the lower limb; results in foot drop, loss of dorsiflexion of ankle

What nerve supplies the posterior compartment of the leg?

tibial nerve

superficial muscles of the posterior compartment of the leg

gastrocnemius m., soleus m., plantaris m.

deep muscles of the posterior compartment of the leg

popliteus m., flexor hallucis longus m., flexor digitorum longus m., tibialis posterior m.

Where can the dorsalis pedis artery be palpated?

lateral to extensor hallucis longus tendon

Where does inversion of the ankle occur?

occurs at the subtalar joint

What muscles are involved with inversion of the ankle?

tibialis anterior m. and tibialis posterior m.

What muscles are involved with eversion of the ankle?

peroneus longus m. and peroneus brevis m.