Lower Appendicular Skeleton Flashcards
What parts make up the pelvic girdle?
- left and right os coxae
- with the sacrum and coccyx, it forms the pelvis
What parts make up the os coxae, and when do these parts fuse together?
- ilium
- ischium
- pubis
- between 13-15 years old
What are the articulations of the os coxae?
- anteriorly: with other os coxae
- posteriorly: with the sacrum
- laterally: with the femur at the acetabulum (all 3 bones of the os coxa contribute to its acetabulum)
Where is the ilium located?
- superior portion of os coxa and acetabulum
- largest of the 3 fused bones
Name 13 parts of the ilium.
- ala
- arcuate line
- iliac fossa
- anterior gluteal line
- posterior gluteal line
- inferior gluteal line
- iliac crest
- anterior superior iliac spine
- anterior inferior iliac spine
- posterior superior iliac spine
- posterior inferior iliac spine
- greater sciatic notch
- auricular surface
Briefly describe the ala of the ilium.
wide, fan-shaped portion
Briefly describe the arcuate line of the ilium.
ridge along inferior border of the ala
Briefly describe the iliac fossa of the ilium.
large depression on the medial surface
Briefly describe the anterior, posterior, and inferior gluteal lines.
lateral sites of muscle attachments
Where is the iliac crest located?
superior ridge of ilium
Briefly describe ASIS, AIIS, PSIS, and PIIS of the ilium.
projections along the iliac crest
What is the greater sciatic notch of the ilium for?
for sciatic nerve entering the lower limb
What is the auricular surface of the ilium for?
medial articulation with the sacrum
Where is the ischium located?
superior/posterior margin of the acetabulum
Name 3 parts of the ischium.
- ischial spine
- ischial tuberosity
- ischial ramus
Briefly describe the ischial spine.
prominent medial process
Briefly describe the ischial tuberosity.
- rough inferior projection that supports weight of the body when seated
- origin for deep gluteal muscles and hamstrings
Where is the ischial ramus located?
extends from tuberosity to pubis
Where is the pubis located?
anterior region of os coxae
Name 5 parts of the pubis.
- superior ramus
- inferior ramus
- pubic crest
- obturator foreman
- pectineal line
Where is the superior and inferior rami located?
extend between acetabulum and ischial ramus
Briefly describe the pubic crest.
rough ridge on anterosuperior side of the superior ramus; ends as the pubic tubercle
Briefly describe the obturator foreman.
large space bordered by pubic and ischial rami
Briefly describe the pectineal line.
ridge on medial surface of pubis continuing from arcuate line of ilium
What is the pelvic brim?
continuous oval ridge formed by pubic crest, pectineal line, arcuate line, and sacral promontory
What is the true pelvis?
bony basin inferior to pelvic brim containing pelvic organs
Where is the false pelvis?
superior to pelvic brim bound by ilia laterally and abdominal wall anteriorly
What is the pelvic inlet?
superior entrance to the true pelvis, at pelvic brim
What is the pelvic outlet?
exit of true pelvis, defined by coccyx, ischial tuberosities, and inferior border of pubic symphysis
Name 3 differences between the female and male pelves.
- female ilia laterally flared = wider pelvis
- female pelvic inlet = wide oval; male’s = heart-shaped (bowl vs. funnel)
- female subpubic angle is wider: greater than 100 degrees compared to less than 90 degrees in males
What is the largest, strongest, heaviest bone in the body?
femur
Name 5 proximal parts on the femur.
- head
- fovea
- neck
- greater trochanter
- lesser trochanter
What does the head of the femur articulate with?
with os coxa at the acetabulum
What is the fovea of the femur?
dent in head of femur for ligament to acetabulum
What are the greater and lesser trochanters on the femur?
massive processes for attachment of powerful hip and thigh muscles
What is the intertrochanteric line on the femur?
anterior line between the trochanters marking the distal edge of the hip capsule
What is the gluteal tuberosity on the femur?
posterior rough region for attachment of gluteus maximus muscle
What is the linea aspera on the femur?
ridge on posterior shaft for attachment of many thigh muscles
Distally, what does the linea aspera split into?
medial and lateral supracondylar lines
Name 6 distal parts of the femur.
- medial condyle
- lateral condyle
- medial epicondyle
- lateral epicondyle
- intercondylar fossa
- patellar surface
Describe the medial and lateral condyles on the femur.
smooth, rounded articular surfaces
What are the medial and lateral epicondyles on the femur?
projections just superior to the condyles for muscle and ligament attachment
What is the intercondylar fossa on the femur?
deep posterior depression that separates the condyles
What is the patellar surface on the femur?
smooth anterior region between condyles where the patella articulates with the femur
Describe the patella
- triangular with broad superior border and inferiorly pointed apex
- articulates with patellar surface of femur
Describe the 2 bones in the crural region.
- tibia and fibula are parallel to each other
- tibia is medial to the fibula
- tibia and fibula connected by interosseous membrane
Name 3 proximal parts of the tibia.
- medial condyle
- lateral condyle
- fibular articular facet
What are the medial and lateral condyles on the tibia?
smooth surfaces for articulation with the femur
What is the fibular articular facet on the tibia?
articulation site for the head of the fibula under the lateral condyle
What is the tibial tuberosity on the tibia?
rough anterior projection inferior to the condyles. Attachment site of patellar ligament
What is the tibial border on the tibia?
ridge along anterior surface extending from tuberosity distally; the “shin”
What is the medial malleolus and what bone is it on?
- most distal prominent medial process
- tibia
What is the articular surface on the tibia?
surface on the underside of the tibia; articulates with the talus
Name 3 features of the fibula.
- proximal head with flat articular facet for articulation with the tibia
- narrow neck and slender shaft
- distal end expands into lateral malleolus
How many bones are in the tarsals? Name them.
- 7 bones
- calcaneus
- talus
- navicular
- cuneiforms (medial, intermediate, lateral)
- cuboid
How many bones are in the metatarsals and how are they named?
- 5 bones in the sole of the foot
- identified by Roman numerals I-V from medial to lateral
What do the metatarsals articulate with?
- proximally with tarsals
- distally with phalanges
How many phalanges bones do we have?
- 14 bones per foot
- 3 phalanges for toes 2-5 (proximal, middle, distal)
- 2 phalanges for big toe (hallux) (proximal, distal)
Why is the foot normally arched?
helps prevent pinching of muscles, nerves, and blood vessels
Name and describe the 3 major arches of the foot.
- medial: from heel to hallux; highest arch
- lateral: from heel to fifth toe; lowest arch
- transverse: perpendicular to other arches; along distal row of tarsals
