Muscular System (Part 4) - Muscles of the Pelvic Limb

Summary

This presentation covers the muscles of the pelvic limb in animals, grouped by the joints they act upon: hip, stifle, hock, and digits. Key muscles include the hamstrings (biceps femoris, semitendinosus, semimembranosus) for hip extension, the gluteal muscles for abduction, and the tensor fasciae latae for adduction and flexion. The iliopsoas is the strongest pelvic girdle muscle. At the stifle, the quadriceps femoris is the primary extensor, while the hamstrings also act as flexors. The gastrocnemius is a significant hock extensor, with the tibialis cranialis and peroneus longus as flexors. Digital flexion and extension are managed by the digital extensors and flexors, respectively.

Takeaways

• 🦵 The pelvic limb muscles can be categorized based on the joints they act upon: hip, stifle, hock, and digits.
• 🔍 The muscles acting on the hip joint include extensors, flexors, abductors, and adaptors.
• 🐎 The hamstring muscles (biceps femoris, semitendinosus, and semimembranosus) are the main extensors of the hip.
• 🍑 The middle gluteal muscle is another significant extensor of the hip.
• 🦵 The superficial gluteal muscle and deep gluteal muscle are involved in abduction of the hip.
• 🔗 The tensor fasciae latae is an adductor of the hip that also assists in flexing and extending the hip and stifle joints.
• 🤸‍♂️ The adductor muscles, including the gracilis, pectineus, and adductor magnus, are key in hip adduction.
• 🧘 The sartorius is a prominent flexor of the hip, extending diagonally across the thigh.
• 💪 The iliopsoas muscle is the strongest muscle of the pelvic girdle, formed by the union of iliacus and psoas major.
• 🦿 The quadriceps femoris is the primary extensor of the stifle, consisting of four heads: vastus lateralis, rectus femoris, vastus intermedius, and vastus medialis.
• 🦶 The gastrocnemius is the main extensor of the hock, with tendons contributing to the common calcanean tendon.
• 🤲 The superficial and deep digital flexors are the primary flexors of the digits of the pelvic limb.

Q & A

What are the main muscles acting on the hip joint?

The main muscles acting on the hip joint include the hamstring muscles (biceps femoris, semitendinosus, and semimembranosus), the middle gluteal muscle, the superficial gluteal muscle, the deep gluteal muscle, the tensor fasciae latae, and the adductor muscles (gracilis, pectineus, adductor magnus, and adductor longus).

Which muscle is considered the chief extensor of the hip?

The hamstring muscles are considered the chief extensors of the hip.

What is the role of the tensor fasciae latae in the hip joint?

The tensor fasciae latae is an adductor of the hip joint that also helps in flexing and extending the stifle.

What muscles are involved in the abduction of the hip?

The muscles involved in the abduction of the hip are the superficial gluteal muscle and the deep gluteal muscle.

How many parts does the sartorius muscle have in dogs?

In dogs, the sartorius muscle is divided into two distinct parts: the sartorius cranialis and the sartorius caudalis.

What is the primary extensor of the stifle?

The quadriceps femoris is the primary extensor of the stifle, which includes four heads: vastus lateralis, rectus femoris, vastus intermedius, and vastus medialis.

What is the role of the popliteus muscle in the stifle?

The popliteus muscle is responsible for flexing the stifle and may slightly rotate the leg medially.

Which muscle forms the largest bulge of the caudal crus and acts as an extensor?

The gastrocnemius muscle forms the largest bulge of the caudal crus and acts as an extensor.

What are the flexor muscles acting on the digit of the pelvic limb?

The flexor muscles acting on the digit of the pelvic limb are the superficial digital flexor and the deep digital flexor.

What is the function of the tibialis cranialis muscle?

The tibialis cranialis muscle is the most superficial muscle of the cranial crus surface and is involved in flexing the foot.

What is the significance of the common calcanean tendon?

The common calcanean tendon, also known as the tendon of Achilles, is formed by the tendons of the gastrocnemius and the superficial digital flexor, and plays a role in plantar flexion of the foot.