Flashcards in Lecture 66 - Female reproductive anatomy Deck (76):
What is the pelvis?
Pelvis is essentially the area between the pelvic bones.
What is the pelvic diaphragm (aka pelvic floor)?
Layer of connective tissue and muscle, mainly the levator ani, that separates the pelvic cavity from the perineum.
The pelvic floor is divided into two triangles. What are their names?
Urogenital pelvic floor and anal pelvic floor
In female reproductive anatomy, what structure externalizes through the anal pelvic floor?
In female reproductive anatomy, what two structures externalizes through the ureogenital pelvic floor?
The urethra and the vaginal opening.
What is the role of the pelvic floor?
Forms attachments for the external genitalia.
What is the shape of the levator ani?
U-shaped/horseshoe-shaped - Attaches high on the pelvic brim twice and forms a sling around the pelvic openings. (See slide 5)
What happens when the levator ani contracts?
Elevates the anus
The levator ani is comprised of three separate muscles. What is the one that we are focusing on?
The pubrectalis, which is the most medial of the muscles and forms a sling around the anal aperture.
What happens when the pubrectalis contracts? Thus, what is its role in fecal continence?
When it contracts it pulls that part of the gut tube forward and upwards toward the pubis, thus putting a kink in the bottom of the GIT. Thus, it helps stop the passage of the feces through the bottom end of the GIT.
Among other muscles, what muscle do we need to relax in order to defecate?
What is the name of the aperture in the pelvic floor that allows transmission of the vaginal opening and urethra in females?
The urogenital hiatus.
What is the name of the aperture in the pelvic floor that allows transmission of the rectum and anus?
The anal aperture
What is the membrane that is superficial to the pelvic floor?
The perineal membrane
True or false: the perineal membrane only covers the urogenital triangle of the pelvic floor.
What is the space between the perineal membrane and pelvic floor?
The deep perineal pouch
IMPORTANT: What structures are contained within the deep perineal pouch?
External sphincters, made of skeletal muscle, associated with the pelvic viscera, ie the urethra and vagina.
What may injury could a woman suffer if labor occurs too quickly?
If labor occurs too quickly you can tear and rapture muscles of the pelvic floor.
What three structures may be damaged during childbirth?
Perineum, levator ani, and perineal fascia.
Which two muscle of the levator ani are often torn during childbirth?
Medial muscles of the levator ani: pubacoccygus and pubrectalis
What are possible consequences of serious damage to the muscle of the pelvic floor in women? (eg, after childbirth.)
Urinary stress incontinence, prolapse of the uterus, fecal incontinence.
What is the vagina?
Thick, muscular walled organ that facilitates development of the embryo and fetus.
What are the parts of the uterus?
Fundus (top), body, cervix (protrusion into the vaginal cavity)
What is the endometrium?
The inner lining of the uterus that supports pregnancy and is shed if conception does not occur during the menstrual cycle.
What is the cervix?
The inferior part of the uterus that opens into the vagina
What are the uterine tubes? (What is another name for them?)
The uterine/Fallopian tubes are the muscular tubes that go the fundus of the uterus to the ovary.
What are the parts of the Fallopian tube?
intramural part (the bit running through the wall of the uterus), the isthmus (medial bit), the ampulla (intermediate bit), infundibulum (most lateral, distended bit), fimbria (finger like projections above the lateral pole of the ovary)
What is the role of the fimbria?
Facilitate collection of the oocyte
What is the vagina?
Thick walled, muscular tube that serves as a passage for menses, birth canal, and receives penis and ejaculate during intercourse.
What is the fornix?
The spaces around the cervix but that are still a part of the vagina.
Describe the location of the uterus relative to the bladder and the rectum.
Superior and posterior to the bladder, anterior to the rectum.
Describe the position of the uterus.
Anteverted (relative to the vagina) and anteflexed (relative to the bladder)
What is the 'angle of anteversion'?
If you draw a line through the long axis of the uterus and another through the long axis of the vagina there is almost a 90º bend in the axis between the two.
What is the 'angle of 'antflexion'?
Second bend in the body of the bladder about halfway down its long axis. It is what takes the fundus further over the bladder.
Increased abdominal pressure is likely to cause prolapse of the uterus. What structural feature of the uterus (anteversion or anteflexion) protects the uterus from prolapse?
Anteflexion because it puts the body of the uterus over the bladder, which gives it strong inferior support.
A retroverted and retroflexed uterus is at high risk of what injury? Why?
A retroverted and retroflexed uterus is at high risk of prolapse if there is increase intra-abdominal pressure because it is not support inferiorly by the bladder.
Because of the angle of anteversion, does the cervix open facing the posterior or anterior wall of the vagina?
The cervix opens facing the anterior wall
Where is the posterior fornix?
Posterior to the cervix
What structure holds the walls of the uterus to the inferior abdominal wall?
The broad ligament.
What is the broad ligament made out of?
The inferior portion of the abdominal peritoneum.
Are the ovaries intraperitoneal or retroperitoneal?
How are the ovaries connected to the uterus?
The medial pole of the ovaries are attached to the wall of the uterus by the 'ligament of the ovary'
What pole of the uterus expels the oocyte during ovulation?
The lateral pole.
What is the name of the group of vessels that supply the ovaries?
The ovarian vessels
Where do the ovarian arteries originate?
The abdominal aorta
What is the name of the group of vessels that supply the uterus?
What is the name of the group of vessels that supply the ovaries?
Where do the uterine and vaginal arteries originate?
The iliac artery
In what part of the Fallopian tubes is the oocyte usually fertilized?
In what part of the uterus does the oocyte usually implant?
The body of the uterus
What is an 'ectopic pregnancy'?
Implantation at a spot other than the body of the uterus
Why is it dangerous if there is an ectopic pregnancy in which the oocyte has implanted in the fallopian tube?
Fallopian tubes cannot support the growth of the fetus as they cannot expand enough.
Folding of the peritoneum between the pelvic viscera causes formation of what structures?
What are the two para-uterine pouches called? (Hint: location of pouch is in the name.)
Vesico-uterine pouch (vesic, latin for bladder) and the Recto-uterine pouch.
Why are 'backyard' abortions (eg, using a cloth hanger) so dangerous?
If they do not know their anatomy then they may not take into account the anteversion of the uterus, miss the opening in the cervix and puncture the posterior fornix through to the peritoneal cavity. They could perforate the bowl, causing bacterial invasion from the bowl into the peritoneal cavity, uterus and vagina.
What is effusion?
Escape of fluid into a body cavity
What is the most likely location of build up of fluid in a woman with effusion in the abdominopelvic region?
Most inferior and posterior extension of the peritoneal cavity, ie in recto-uterine pouch.
Why is build up of fluid in the recto-uterine pouch relatively easy to treat?
Easy to aspirate by passing a needle up the vagina and behind the cervix, ie through the posterior.
Are the Fallopian tube intraperitoneal or retroperitoneal?
External female genitalia attach to what two structures?
The perennial membrane and the pubic arch.
What are the parts of the external female genitalia made of erectile tissue?
Paired corpora cavernosa, paired bulbs of vestibule, and the glans clitoris
How is erection achieved?
When the blood vessels dilate they engorge the tissue with blood.
Which glands are associated with the bulbs of vestibule?
Greater vestibular glands
What is the function of the greater vestibular glands?
Secrete mucous into the vaginal opening and lubricate the vagina
Which muscle sits exterior to the bulbs of vestibule?
Which muscle sits exterior to the corpora cavernosa?
During arousal, what does contraction of the bublospngiosus and ischiocavernosus do?
When they contract they push some of the blood from the engorged erectile tissue anteriorly towards the glands clitoris for erection.
What is the vulva?
The erectile tissue AND the overlying skin.
What is another name for the vulva?
What is the labia minora?
Two folds either side of the midline, lateral to the urethral and vaginal opening that come together anteriorly to form the hood the glans clitoris.
What is the labia majora?
Larger fold of skin lateral to the labia minora
What is the vascular difference between the labia minora and majora?
Minora is more vascular (so much so that it is pink.)
What structure is homologous to the male scrotum?
How is the male scrotum formed during development?
Midline fusion of labia majora forms the scrotum.
What are the four boney attachments of the pelvic diaphragm?
The pubic symphesis, ischial tuberosity (one on each side = 2), and the coccyx