🪴 GoDeep
Search
← University Challenge
Portrait of Femur

Anatomy · Bones

Femur

Longest bone in the body

Lower limb · thigh

The femur, or thigh bone, is the single bone of the thigh and the longest, heaviest and strongest bone in the human body, about a quarter of a person's height. Its ball-shaped head fits into the acetabulum of the hip bone, and its lower end, with two condyles, forms the knee joint with the tibia and patella.

How to spot them

  • ▸Long, slightly bowed shaft with a ball-shaped head angled inwards from a long neck to fit the hip socket
  • ▸Two large bumps, the greater and lesser trochanters, at the top of the shaft; the greater is felt on the outer hip
  • ▸A rough ridge, the linea aspera, runs down the back of the shaft
  • ▸Lower end with two large rounded condyles separated behind by the intercondylar fossa, and a groove in front for the patella

What to know

The longest, heaviest and strongest bone in the human body

Femur — the thigh bone.

Its length is roughly a quarter of a person's height, a ratio used by forensic scientists to estimate stature from remains

Femur — about 26% of stature.

Its ball-shaped head has a small pit for a ligament, which carries a small artery to the head

Femur — the fovea capitis and the ligament of the head.

A break in its angled neck is the classic 'broken hip' of the elderly

Femur — the neck of the femur (intracapsular fracture).

Two large bony projections at the top of the shaft, one felt beneath the skin on the outer hip, give leverage to the gluteal muscles

Femur — the greater and lesser trochanters.

A rough ridge runs down the back of its shaft, giving long, thin attachments to many hip and thigh muscles

Femur — the linea aspera.

A fracture of its shaft can hide a litre or more of blood in the thigh

Femur — femoral shaft fractures cause major blood loss.

Key ideas

  • The femur is angled inwards from hip to knee, so that the knees lie close together beneath the trunk; this angle (the Q-angle) is larger in women because of the wider pelvis.
  • The neck of the femur is a weak point; the head's blood supply comes mainly from vessels running up the neck, so fractures there may cause avascular necrosis.

Quick-fire facts

  • •It is the longest and strongest bone of the body and accounts for about a quarter of a person's total height.
  • •The head articulates with the acetabulum; the fovea capitis is the pit where the weak ligament of the head attaches and carries a small artery.
  • •The greater trochanter is palpable under the skin on the outer side of the upper thigh; the lesser trochanter is on the inner side and receives the tendon of iliopsoas.
  • •The linea aspera is the rough ridge on the back of the shaft; the gluteal tuberosity runs up from its top.
  • •The distal end has medial and lateral condyles that articulate with the tibia and a patellar surface that articulates with the patella.
  • •The Q-angle, of the femur away from vertical, is normally 10–15 degrees, larger in females.
  • •Fractures of the neck of the femur are the typical 'hip fracture' in older people with osteoporosis.
  • •Femur is Latin for thigh; the plural is femora.

Drill it — 8 cards

1 / 8new card

Sources