Sacral Plexus | Roots, Branches, & Innervation

The video tutorial explores the sacral plexus, detailing its connection to the lumbar plexus via the lumbosacral trunk. It covers the superior and inferior gluteal nerves, their contributions, and the muscles they innervate. The posterior femoral cutaneous nerve is discussed as a sensory nerve. The sciatic nerve, its components, and their roles are explained, including the tibial and common peroneal nerves. The video also covers the nerves to quadratus femoris and obturator internus, the nerve to piriformis, and the pudendal nerve. Finally, it discusses the divisions of the sacral plexus.

What is the role of the lumbosacral trunk in the nervous system?

• It connects the lumbar plexus to the sacral plexus.

• It provides sensory information to the posterior thigh.

• It separates the tibial and common peroneal nerves.

• It innervates the gluteus maximus muscle.

Which muscles are innervated by the superior gluteal nerve?

• Quadriceps

• Biceps femoris

• Gluteus medius

• Gluteus maximus

How does the inferior gluteal nerve differ from the superior gluteal nerve in terms of nerve root contributions?

• It starts at L3 and ends at S1.

• It starts at S1 and ends at S3.

• It starts at L5 and ends at S2.

• It starts at L4 and ends at S1.

What is the primary function of the posterior femoral cutaneous nerve?

• Motor innervation to the quadriceps

• Sensory information to the posterior thigh

• Sensory information to the anterior thigh

• Motor innervation to the gluteus maximus

Which two nerves form the sciatic nerve?

• Tibial and common peroneal nerves

• Superior and inferior gluteal nerves

• Femoral and obturator nerves

• Lateral and medial plantar nerves

Which hamstring muscle is innervated by the common peroneal nerve?

• Semitendinosus

• Semimembranosus

• Adductor magnus

• Biceps femoris short head

What is the role of the nerve to quadratus femoris?

• Provides sensory information to the anterior thigh

• Innervates the quadratus femoris and inferior gemellus

• Innervates the tensor fascia lata

• Innervates the gluteus maximus

Which nerve innervates the piriformis muscle?

• Superior gluteal nerve

• Sciatic nerve

• Inferior gluteal nerve

• Nerve to piriformis

What is the primary function of the pudendal nerve?

• Provides sensory information to the posterior thigh

• Innervates the quadriceps

• Innervates the gluteus medius

• Innervates pelvic floor muscles

Which division of the sacral plexus does the common peroneal nerve belong to?

• Neither division

• Anterior division

• Posterior division

• Both anterior and posterior