Anatomy L.9

Question 1

What maintains the forward angulation between the rectum and the anal canal?

Answer 1

Puborectalis

Question 2

What is the nerve supply of the levator ani muscle, which forms the lateral wall of the pelvis and lateral wall of the perineum?

Answer 2

4rth sacral neeve and perineal branch of the pudendal nerve (S2,3,4)

Question 3

What are the specialized fibers of the pubococygeus muscle?

Answer 3

1) puborectalis
Forms U shape around ano-rectal junction and blends with external anal sphincter
Impo: maintains forward angulation of rectum and anal canal
Maintains the continence of feces

2) pubovaginalis in females/ pubovesicalis in males
Males= pass prostate close to neck of bladder
Females= pass side of vagina
Both insert into perineal body

Question 4

What is the role of the pelvic diaphragm when intra-abdominal pressure rises in micturition, defection, and parturition?

Answer 4

It supports all pelvic organs and prevents their prolapse

Question 5

During vaginal delivery, the pelvic diaphragm stretches considerably, this may cause tearing of anterior fibers of the levator ani muscles. What is a consequence of that?

Answer 5

1) Prolapse of uterus or rectum or bladder (cystocele)
2) urinary incontinence as it disturbs the position of the neck of the bladder, which is characterized by dribbling of urine when intra abdominal pressure is raised during coughing and lifting.

Question 7

What determines if vaginal birth is possible or not?

Answer 7

Pelvimetry assesses female’s bony pelvis

Question 8

What anteroposterior measurement of the female pelvis can be measured using digital examination?

Answer 8

Digonal conjugate (DC)

Distance between the inferior pubic ligament to the sacral promontory

Question 9

What are the anteroposterior measurements of the female pelvis?

Answer 9

1) Anatomical conjugate (AC)
distance between the upper margin of the pubic symphysis to the sacral promontory

2) Obstetrical conjugate (OC)
Distance between the posterior part of the symphysis to the promontory

3) Diagonal conjugate (DC)
Distance between the inferior pubic ligament to the promontory

Question 10

What type of pelvic inlet shows the antero-posterior diameter longer than the transverse?

Answer 10

Anthropoid

Question 11

What type of pelvic inlet occursin vitamin D deficiency?

Answer 11

Platypelloid

Transverse more than antero-posterior diameter

Flat with kidney shaped brim

Question 12

What are the nerves of the pelvis?

Answer 12

1) sacral plexus from ventral rami of L4,L5,S1,S2,S3
2) pelvic splanchnic nerves (Nervi eregentes) PSNS, ends by joining inferior hypogastric plexus

Carries pain sensation from cervix of the uterus and urinary bladder

Question 13

What nerves are on either side of the rectum and can be damaged by surgery to the rectum?

Answer 13

Nerves of the Inferior hypogastric plexus

I think pelvic splanchnic nerve (sympathetic) and sacral splanchnic nerve (parasympathetic)

Question 14

What nerves does erection depend on?

Answer 14

Pelvic splanchnic nerves going to inferior hypogastric plexus

Question 15

The maintanence of erection is by actions of ischiocavernosus and bulbospongiosis muscle, what nerve supplies them?

Answer 15

Pudendal nerve

Question 16

What is responsible for ejaculation and subsidience of erection?

Answer 16

Sympathetic nerve fibers present in inferior hypogastric plexus