In considering the iliopsoas, what statement is not true?
A. The iliopsoas flexes the thigh at the hip joint
B. The iliopsoas is partially controlled by the femoral nerve
C. The iliopsoas originates from the ilium and lumbar vertebrae
D. The iliopsoas includes the psoas major and pectineus muscles
The correct answer and explanation is:
The correct answer is D. The iliopsoas includes the psoas major and pectineus muscles.
Explanation:
The iliopsoas is a group of muscles that plays a crucial role in flexing the hip joint. It is composed of two primary muscles: the psoas major and the iliacus. The psoas major originates from the lumbar vertebrae (lower back) and the iliacus originates from the inner surface of the ilium (the part of the pelvis). When these two muscles work together, they help in flexing the thigh at the hip joint, an essential movement for activities like walking, running, and bending the torso.
- A. The iliopsoas flexes the thigh at the hip joint is true. As mentioned, the iliopsoas is a key flexor of the hip, which is vital for numerous lower body movements.
- B. The iliopsoas is partially controlled by the femoral nerve is true. The femoral nerve innervates the iliacus muscle and is responsible for the sensory and motor functions related to the hip flexion.
- C. The iliopsoas originates from the ilium and lumbar vertebrae is also true. As previously explained, the psoas major originates from the lumbar vertebrae, while the iliacus arises from the ilium.
- D. The iliopsoas includes the psoas major and pectineus muscles is false. The iliopsoas does not include the pectineus muscle. The pectineus is a separate muscle that is involved in hip flexion and adduction but is not part of the iliopsoas group.
Therefore, the correct answer is D because it inaccurately includes the pectineus, which is not part of the iliopsoas complex.