pelvic viscera and perineum Flashcards
why is there more space in the male pelvis?
most organs are outside
what organs are found in the male pelvis?
bladder and rectum
what organs are found in the female pelvis?
bladder
uterus
vagina
rectum
why is the female bladder smaller than the male?
less room in the female pelvis
what is the urinary bladder?
Hollow muscular organ found in the anterior part of the bony pelvis behind the pubic symphysis
what muscle makes up the urinary bladder?
specialised smooth muscle - detrusor muscle
what nervous control is detrusor muscle under?
autonomic
what effect does sympathetic innervation have on the detrusor muscle?
relaxes the muscle
allows filling of the bladder
what does the ureter do?
drains urine from the kidneys into the bladder
what does the urethra do?
removes urine that’s being stored in the bladder inferiorly
what is the trigone?
smooth triangular region on the posterior aspect between the ureter and urethra
which is shorter; the male or female urethra?
female
describe the course of the female urethra?
goes from bladder, through the pelvic floor and into the perineum
describe the course of the male urethra?
travels through the prostate gland, the pelvic floor and through the penis
why are women more susceptible to UTIs?
shorter urethra
what are the 3 regions of the male urethra and where are they?
o Prostatic – part that passes through the prostate gland
o Membranous – through the pelvic floor
o Spongy/penile – usually longest part, travels through the penis
what type of muscle is the external urethral sphincter?
skeletal
what does the external urethral sphincter control?
Controls flow of urine out of the urethra
which gender has an external urethral sphincter?
both genders
what nervous supply controls the external urethral sphincter?
somatic control - voluntary
where is the external urethral sphincter found?
level of the pelvic floor
which gender has an internal urethral sphincter?
only men
what muscle makes up the internal urethral spincter?
smooth muscle
where is the internal urethral spincter found?
Found at the base of the bladder, above the prostate gland
what are the functions of the internal urethral sphincter?
- serves a dual purpose for both urination and ejaculation
- Internal urethral sphincter contracts during ejaculation to prevent either retrograde flow of semen into bladder or to stop urination during ejaculation
what nerve supply goes to the bladder?
autonomic supply bc its smooth muscle
has both sympathetic and parasympathetic innervation
what are the roots of the sympathetic innervation of the bladder?
T12 - L2
comes from descending sympathetic fibres
what does sympathetic innervation to the bladder do?
relaxes detrusor muscle (allows filling of the bladder) and contracts internal urethral sphincter
what are the roots of the parasympathetic innervation of the bladder?
S2-S4
what does parasympathetic innervation to the bladder do?
contract detrusor muscle (for urination) and relax internal urethral sphincter
what nerve controls the external urethral sphincter?
somatic control via the pudendal nerve S2-S4
name the structures of the male reproductive system in order of how sperm would leave the body
- Testis
- Epididymis
- Vas deferens
- Seminal vesicles
- Ejaculatory duct
- Prostate gland
- Urethra
where do gonads develop and where do they descend?
Gonads develop in the abdomen and during foetal development descend in to pelvis through the inguinal canal to the scrotum.
how does the blood supply and the nervous supply of the testes and scrotum differ? what effect does this have on different types of cancers?
scrotum - takes local pattern of skin in the area
testes - from abdomen
Testicular and scrotal cancers spread differently
what is the tunica vaginalis and its function?
pouch of peritoneum formed by the descent of the testes. Allows the free movement of the testes
what are the seminiferous tubules?
site of spermatozoa production
travel to rete testis
drain into epididymis
what is the epididymis and what is it continuous with?
storage site for spermatozoa
a long coiled tube which becomes continuous with the vas deferens.
what are the vas deferens?
Muscular tube which connects the epididymis in the testes and the prostate gland and ejaculatory duct in the abdomen
what is the route of sperm from the vas deferens to the seminal vesicles?
• Propels the spermatozoa from the epididymis spermatic cord inguinal canal abdomen over the superior aspect of the bladder back of the bladder and joins the seminal vesicles
what is a vasectomy?
surgical cutting of the vas deferens in the scrotum which stops any sperm getting into the ejaculate
why is ejaculate still produced after a vasectomy?
Seminal fluid is added later either by seminal vesicles or prostate glands, so ejaculate is still produced but without sperm in it
what are the ejaculatory ducts and where do they form?
form where the seminal vesicles join the vas deferens. Short duct from base of seminal vesicles through the prostate gland to join the urethra
where is the prostate?
directly inferior to the male bladder
what structure transverses the prostate?
urethra
what can cause enlargement of the prostate?
normal enlargement due to ageing
abnormal enlargement due to prostate cancer
how is prostate cancer diagnosed and why is this method used?
Cancerous growth occurs posteriorly in the gland so rectal exam can help diagnose prostate cancer
what is the uterus?
thick-walled pear-shaped organ
what is the fundus of the uterus?
superior dome of the uterus
where are the fallopian tubes?
continuous with the uterus on either side. Orientated posteriorly towards the ovaries.
what are fimbrae?
Most lateral part of the fallopian tube has finger-like projections
what are the 3 main parts of the fallopian tubes?
o Infundibulum – funnel-shaped region
o Ampulla – expanded portion of the FP. Most usual site of fertilisation
o Isthmus – most narrow portion of the FP going into the uterine wall
what is the normal position of the uterus?
anteverted and anteflexed
what is version?
Version describes position of cervix in relation to rest of uterus
what is flexion?
Flexion describes position of fundus
describe the structure of the wall of the uterus?
Composed of myometrium (smooth muscle) with an outer layer of connective tissue and peritoneum (perimetrium) and inner highly vascular mucous layer (endometrium)
what is the endometrial layer of the uterus?
inner highly vascular mucous layer
where embryos implant and is the layer lost during menstruation
describe the blood supply to the female reproductive system
derived from uterine artery (internal iliac artery) and ovarian artery (abdominal aorta – bc ovaries originated in the abdomen)
what is a hysterectomy?
removal of the uterus
what is the risk during hysterectomy?
uterine artery passes over the ureter and may be mistaken for the ureter - cut accidentally
what is the broad ligament?
when the peritoneum folds over the body of the uterus and creates a broad sheet of peritoneum enclosing the uterus
Creates a pouch of peritoneum anterior and posterior to the uterus
what are the pouches created by the broad ligament?
Vesicouterine pouch
Rectouterine (pouch of Douglas) – lowest point in the peritoneal cavity
where is the suspensory ligament of the ovary?
where ovarian artery and vein is covered in peritoneum
what does the ovarian ligament join?
links ovary to the uterus
what does the round ligament of the uterus connect?
connects uterus to anterior abdominal wall
what is the cervix and what is its function?
- Part of the uterus which projects inferiorly into the vagina
- Highly muscular and keeps bacteria out of the uterus and keeps baby in the uterus – acts as a sphincter
what are the external and internal os?
External os – external opening
Internal os – internal opening
where does the epithelium change abruptly in the cervix?
external os
what is the pelvic floor?
a muscular sheet which closes the pelvic outlet
what muscles make up the pelvic floor?
levator ani and coccygeus
what are the parts of levator ani?
o Puborectalis – made of U-shaped fibres which loop around rectum and help maintain continence
o Pubococcygeus – behind puborectalis
o Iliococcygeus – behind pubococcygeus
how is the pelvic floor divided and what do these areas contain?
o Urogenital triangle – anterior. Contains genitals.
o Anal triangle – posterior. Contains the anus
which area is the perineal membrane found in?
urogenital triangle
where is the deep perineal pouch?
in between the membrane and the floor
where is the superficial perineal pouch?
in between the membrane and the skin. Where external genitalia is located
what is erectile tissue?
vascular tissue that can become engorged with blood
what is the bulb of vestibule and what is the corresponding structure in men?
Small bit of erectile tissue either side of the vagina. Corresponding tissue in men is the bulb of the penis – continuous with the erectile tissue that extends into the penis (corpora spongiosum)
what structure runs through the corpora spongiosum of the penis?
urethra
how does the crura of the penis extend in to the penis?
as the corpora cavernosum
what is the analogous structure to the crura of the penis?
crura of the clitoris
where are Bartholin glands/greater vestibular glands found?
found in the female superficial perineal pouch just behind the bulb of the vestibule
why are Bartholin glands/greater vestibular glands clinically important?
they can become inflamed and there can be swelling in the area
what blood supply is found in the dorsum of the penis?
dorsal artery and vein of the penis found here
what does the ischiocavernosus muscle cover?
crura of the penis
what does the bulbospongiosum muscle cover?
covers the bulb
which muscles are important in maintaining erection?
ischiocavernosus
bulbospongiosus
what is the perineal body?
fibromuscular node where all the superficial peroneal muscles, deep peroneal muscles and the muscles of the pelvic floor converge
when is the perineal body susceptible to tearing? what complications can this cause?
particularly susceptible to tearing during childbirth if the vagina is torn
Disruption of the perineal body can result in prolapse of the pelvic viscera. Increasing chance of prolapsed pelvic organs during childbirth
tearing can continue towards the anus
how can disruption to the perineal be reduced?
episiotomy may be performed – cutting of the vaginal wall to increase the vaginal orifice. Occurs lateral to the peroneal body to direct tearing away from here
what are the 2 major folds of the vagina?
o Labia majora – fat filled and can be covered in hair
o Labia minora – hairless and fat free skin folds
where is the clitoris located?
where labia minora meet anteriorly
where is the vestibule of the vagina?
space between the labia minora that they enclose. Entrance to the vagina
what does the pudendal nerve supply?
all structures in the perineum
sensory to genitals and motor to the external urethral and anal sphincters
what spinal roots does the pudendal nerve come from? which plexus?
spinal roots S2-S4
sacral plexus
describe the route of the pudendal nerve to the perineum
- Leaves pelvis through the greater sciatic foramen, before turning back to enter through the lesser sciatic foramen
- Then runs through the pudendal canal (on top of the obturator internus) to enter the perineum
