Anatomy of the pelvis and peronium Flashcards
(26 cards)
What are the nerve roots of the obturator nerve?
L2-L4
What are the motor and sensory functions of the obturator nerve?
- Motor: Innervates the medial (adductor) compartment of the thigh.
- Sensory: Cutaneous branch innervates the skin of the medial thigh
Which muscles does the obturator nerve innervate?
All muscles of the medial thigh:
- Adductor Longus – adducts thigh
- Adductor Brevis – adducts thigh
- Adductor Magnus – adductor part adducts and flexes thigh, hamstring part extends thigh
- Gracilis – adducts thigh
- Obturator Externus – laterally rotates thigh
What foramen does the Obturator nerve pass through to get to the leg + how many main branches does it have?
- It passes through the Obturator foramen
* It has 2 main branches, anterior and posterior (all within the medial compartment).
What would damage to the obturator nerve result in?
- Numbness or paraesthesia
- Weakness of hip adduction → Gait problems
- Secondary to surgery involving the pelvis or abdomen
What is the perineum?
- The perineum is an anatomical region located in the pelvis.
- It is the most inferior part of the pelvic outlet, located between the thighs.
- It is separated from the pelvic cavity superiorly by the pelvic floor.
What are the 3 muscles in the urogenital (anterior) triangle?
- Ischiocavernosus
- Bulo cavernosus
- Tansverse perineal
What is the anal triangle?
The anal triangle is the posterior half of the perineum.
The components of the anal triangle are:
- Anal aperture – the opening of the anus.
- External anal sphincter muscle – voluntary muscle responsible for opening and closing the anus.
- Two ischioanal fossae – these are spaces located laterally to the anus.
What does the pudendal nerve do?
- The pudendal nerve supplies sensation to the penis in males and the clitoris in females.
- Branches also innervate muscles of the perineum and pelvic floor
What is the root of the pudendal nerve?
S2-4 (S2, 3, 4 keeps your dick up off the floor)
What are the muscles of the penis called?
- The big one→ Corpus cavernosum
- The one underneath → Corpus spongiosum
- The root of the one underneath → Blubospongiosus
What are the roots of the sacral plexus?
S1-4 with parts of L4+5 joining
What are the roots of the sciatic nerve?
L4 - S3
What 5 major nerves does the sacral plexus give rise to?
- Sciatic
- Superior gluteal
- Inferior gluteal
- Pudendal
- Posterior Femoral Cutaneous
What are the roots of the superior gluteal nerve?
L4 - S1
What are the roots of the inferior gluteal nerve?
L5 - S2
What is the motor function of the sciatic nerve?
- Tibial nerve – the muscles of the posterior leg (calf muscles), and some of the intrinsic muscles of the foot.
- Common fibular nerve – the muscles of the anterior leg, lateral leg, and the remaining intrinsic foot muscles.
What are the 2 main parts of the sciatic nerve?
Tibial + fibular portions
What are the sensory functions of the posterior femoral cutaneous nerve?
Innervates the skin on the posterior surface of the thigh and leg. Also innervates the skin of the perineum.
what 4 muscles make up the Superficial abductors and extenders of the hip?
gluteus maximus, gluteus medius, gluteus minimus and tensor fascia lata.
what are the roots of the lumbar plexus?
L1 - L4 (with a little T12)
what are the 6 main nerves that arise in the sacral plexus?
`• Iliohypogastric Nerve - T12 + L1
- Ilioinguinal Nerve - L1
- Genitofemoral Nerve - L1 + L2 → innervates cremaster muscle
- Lateral Cutaneous Nerve of the Thigh - L2, L3
- Obturator Nerve - L2, L3, L4.
- Femoral Nerve - L2 - L4
What is the motor and sensory function of the femoral nerve?
- Motor Functions: Innervates the muscles: Illiacus, pectineus, sartorius, all the muscles of quadriceps femoris.
- Sensory Functions: Innervates the skin on the anterior thigh and the medial leg.
Where do the pelvic splanchnic nerves arise?
S2 S3 S4
