APE 9: The genitourinary system Flashcards
The female reproductive tract is __________ in origin
mesodermal
What 3 things does th lower female reproductive tract consist of?
The vulva, the vagina and the cervix
What 6 structures make up the vulva?
Mons pubis, the labia majora, labia minora, the vestibule, Bartholin’s glands and the clitoris
What’s mons pubis?
A subcutaneous fat pad located anterior to the pubic symphysis
What’s the name of the fold of skin formed by the posterior merging of the labia minora?
The fourchette
What’s the vestibule?
The area enclosed by the labia minora, containing the openings of the vagina and urethra
What’s the location and function of Bartholin’s glands?
Bartholin’s glands are either side of he vaginal orifice. They secrete lubricating mucus from small ducts during sexual arousal
What’s the clitoris formed of?
Erectile corpus cavernosa sittue
Where does arterial supply to the vulva come from?
Blood supply is from the paired internal and external pudendal arteries which branch off the internal iliac artery
How’s venous drainage of the vulva achieved?
The pudendal veins provide venous drainage, and the labial veins contribute as tributaries
Describe the sensory innervation of the vulva
Anterior sensory innervation comes from the ilioinguinal nerve and the genital branch of the genitofemoral nerve. Posterior sensory innervation comes from the pudendal nerve and the posterior cutaneous nerve of the thigh
Via what nerves do the clitoris and vestibule receive parasympathetic innervation?
The cavernous nerves, derived from the uterovaginal plexus
Describe the vagina anatomically
The vagina is a muscular distensible tube which extends posterosuperiorly from the external orifice to the cervix
What is found anterior to the vagina?
Anterior to the vagina is the bladder and urethra
What’s found posterior to the vagina?
Posterior to the vagina is the rectouterine pouch, the rectum and the anal canal
What is found lateral to the vagina?
Lateral to the vagina are the ureters and the levator ani muscle
Describe the meeting of the vagina and cervix anatomically
At the upper ending of the vagina, it surrounds the cervix, creating 2 domes (fornices)- an interior fornix and a posterior fornix
What’s the function of the posterior fornix?
The posterior fornix acts as a natural reservoir for semen after intravaginal ejaculation
What are the 4 histological layers of the vagina?
Stratified squamous epithelium
Elastic lamina propia
Fibromuscular layer
Adventitia
Describe the stratified squamous layer of the vagina
This layer provides protection and is lubricated by cervical mucus
Describe the elastic lamina propia layer of the vagina
This layer is a dense connective tissue layer which projects papillae into the overlying epithelium. The larger veins are located here
Describe the fibromuscular layer of the vagina
This comprises of 2 layers of smooth muscle: an inner circular later and an outer longitudinal layer
Describe the adventitia layer of the vagina
The adventitia is a fibrous layer which provides additional strength to the vagina whilst also binding it to the surrounding structures
What’s the arterial supply to the vagina?
The arterial supply comes via the uterine and vaginal arteries, both of which are branches of the internal iliac artery.
Via what veins is venous drainage of the vagina achieved?
The vaginal venous plexus drains into the internal iliac veins via the uterine vein
Innervation of the vagina is predominantly from the autonomic nervous system. Which 1/3rd of the vagina receives somatic innervation?
The inferior 1/3rd
What are the 2 regions of the cervix?
The ectocervix and the endocervical canal
What’s the ectocervix?
The ectocervix is the part of the cervix which projects into the vagina. It’s lined by stratified squamous non-keratinised epithelium.
What’s the name of the opening of the cervix?
The external os
What’s the endocervical canal?
The endocervical canal is the more proximal and inner part of the cervix. It is lined by a mucus-secreting simple columnar epithelium. The endocervical canal ends where the uterine cavity begins.
What’s the name of the proximal opening of the cervix?
The internal os
What 3 things maintain the sterile environment of the cervix?
The shedding of the endometrium, the thick cervical mucus and the narrow external os
What supplies blood to the cervix?
Cervical blood supply comes from the uterine artery
How is venous drainage of the cervix achieved?
A plexus in the broad ligament that drains into the uterine veins.
What 4 nodes are responsible for lymphatic drainage of the cervix?
The iliac, sacral, aortic and inguinal lymph nodes
What’s cervicitis?
Cervitcitis is chronic inflammation and infection of the cervix, most commonly caused by chlamydia trachomatis or neisseria gonorrhoeae. It’s usually asymptomatic, but can cause pelvic pain, vaginal drainage, postcoital bleeding and dyspareunia
What are 2 common types of cervical cancer?
Squamous cell carcinomas are cancers of the endothelial lining of the ectocervix. Adenocarcinomas are cancers of the glands found within the lining of the cervix
What’s the most common cause of cervical cancer?
Infection of the cervix by human papilloma virus (HPV) causes most cervical cancers
Describe the uterus’ development and function
The uterus is a secondary sex organ which matures during puberty under the influence of sex hormones produced from primary sex organs. The uterus is responsible for the maintenance and transportation of gametes
Describe the uterus anatomically
The uterus is part of the upper female reproductive tract. It is a thick-walled muscular organ capable of expansion to accommodate a growing foetus. It’s connected distally to the vagina and laterally to the uterine tubes
What are the 3 parts of the uterus?
The fundus
The body
The cervix
What’s the fundus?
The fundus is the top part of the uterus, above the entry point of the uterine tubes
In which part of the uterus does the blastocyst usually implant?
The body of the uterus
What’s the normal anatomical position of the uterus?
Anteverted and anteflexed
What does anteverted mean?
An anteverted uterus is rotated forwards towards the anterior surface of the body from the point where the cervix meets the vagina
What does anteflexed mean?
Flexed towards the anterior surface of the body, so, in a way, curved caudally
When anteverted and anteflexed, where does the uterus lie in relation to the bladder and rectum?
The uterus lies posterosuperior to the bladder and anterior to the rectum
What are the 3 most common dispositions of the uterus?
Excessively anteflexed
Anteflexed and retroverted
Retroflexed and retroverted
Histologically, the fundus and body of the uterus are composed of 3 tissue layers. What are they?
Peritoneum, myometrium and endometrium
What’s the peritoneum of the uterus?
The peritoneum is a double-layered membrane, continuous with the abdominal peritoneum
What’s the myometrium?
A thick, smooth muscle layer. During pregnancy, the cells of the myometrium undergo hyperplasia and hypertrophy in preparation to expel the foetus
What’s the endometrium?
The endometrium is the inner mucous membrane lining of the uterus that can be divided into 2 parts
What are the 2 parts of the endometrium?
The deep stratum basalis and the superficial stratum functionalis
What layer is shed in menstruation?
The superficial stratum functionalis of the endometrium
What provides the primary support for the uterus?
The tone of the pelvic floor
What’s the broad ligament?
The broad ligament is a double layer of peritoneum that attaches the sides of the uterus to the pelvis. It acts as a mesentery for the uterus and contributes to maintaining it in position
What’s the round ligament?
A remnant of the gubernaculum, extending from the uterine horns to the labia majora via the inguinal canal. It functions to maintain the anteverted position of the uterus
What’s the ovarian ligament?
The ovarian ligament joins the ovaries to the uterus