Pelvic Nerves and Vessels Flashcards
What is the sacral plexus
A network of nerve fibres that supplies the skin and muscles of the pelvis and lower limb
Where is the sacral plexus located
The surface of the posterior pelvic wall, anterior to the piriformis muscle
What forms the plexus
The anterior rami of S1-4, it also has contribution form L4 and L5
What are the main branches of the sacral plexus
Superior gluteal, inferior gluteal, sciatic, posterior femoral cutaneous and pudendal
Nerve root of the superior gluteal
L4-S1
Superior gluteal nerve innervation
The gluteus minimus and medius
Nerve root of the inferior gluteal
L5-S2
Innervation of inferior gluteal
Gluteus maximus
Nerve roots of tibial portion of the sciatic nerve
L4-S3
innervation of the tibial portiotn of the sciatic nerve
Muscles of the posterior thigh and hamstring potion of adductor magnus
Indirect innervation of tibial portion of sciatic nerve
Muscles of the leg and foot
nerve roots of the fibular portion of the sciatic nerve
L4-S3
innervation of the fibular portion of the sciatic nerve
short head of biceps femoris, all muscles in anterior and lateral compartment of thigh and extensor digitorum brevis
What do the terminal branches of the fibular portion of the sciatic nerve innervate
Sensory information to the skin of the lateral leg. heel and both dorsal and plantar surfaces of the foot
nerve roots of the posterior femoral cutaneous nerve
S1-S3
Innervation of posterior femoral cutaneous nerve
Skin on the posterior surface of the thigh and leg and also the skin of the perineum
where do most nerves leave the pelvis through
The greater sciatic foramen
Smaller branches coming form the sacral plexus and their nerve roots
nerve to piriformis (S1,S2) nerve to obturator internus (L5, S1) nerve to quadratus femoris levator ani (S4, pudendal) coccygeous (S4,S5)
Nerve roots of the pudendal nerve
S2-S4
Whta does the pudendal nerve innervate
The skeletal muscle in the perineum, the external urethral sphincter, the external anal sphincter, elevator ani, penis/clitoris and most of the skin of the perineum
What does the pudendal nerve travel through to leave the pelvis
The greater sciatic notch
What does nerve to obutrator internus innervate
Obturator internus and superior gemellus
Where is the superior hypogastric plexus
At the bifurcation of the abdominal aorta
functions of sympathetic innervation
Decreases moement ewithin the rectum, contracts internal anal and urethral sphincters and relaxes the detrusor muscle
What does the sympathetic nervous system cause during ejaculation
The contraction of the vas deferens and seminal vesicles
How is the uterus contracted/relaxed
through sympathetic innervation and hormonal control
what effect does the sympathetic system have on arteries
it causes vasoconstriction
What provides parasympathetic innervation
Pelvic splanchnic nerves (S2-S4)
functions of parasympathetic innervation
Increases motility of the rectum and anal canal, relaxes the internal anal sphincter, and contracts the detrusor muscle and inhibits contraction of internal sphincter
What effect does the parasympathetic innervation have on arteries
Vasodilation of arteries
Which branch of the ANS causes erection
parasympathetic
Where does the aorta divide
L4
What does the bifurcation of the aorta give
common iliac arteries
what does the common iliacs split into
the internal and external iliac branches
What supplies blood to the pelvis
internal iliac
divisions of the internal iliac
Anterior and posterior division
branches of the anterior division of the internal iliac
Umbilical, obturator, inferior vesical, middle rectal, inferior gluteal and inferior pudendal
what do the inferior vesical and middle rectal arteries supply in males
Prostate, seminal vesicles and ductus deferens
where do the testicular arteries come from
L2 of the abdominal aorta
What is the equivalent of the inferior vesical artery in females
uterine artery
what does the uterine artery supply
uterus, ovaries and part of the bladder
what artery is present in females but not in males
Vaginal artery
What are the posterior division of the internal iliac
iliolumbar, lateral sacral and superior gluteal
