Lecture 36 - Female reproductive system Flashcards
How many sperm are produced from one primary spermatocyte?
1 primary spermatocyte produces 4 spermatozoa
Which accessory gland contributes the most to seminal fluid in terms of volume?
Seminal vesicles supply about 60%
What is the specific name of the process by which spermatids become spermatozoa?
Spermiogenesis
Function of the female reproductive system
To produce oocytes (female gamete)
Transport ova and spermatozoa to the appropriate site for fertilisation
Provides a site for the developing embryo and fetes to grow - protection, nourishment
Delivery of fetus
Female perineum
Region inferior to the pelvic floor and between the upper region of the thighs
Urogenitial triangle - urethrea and the external genitalia (vulva) and the opening to the vagina
Anal triangle contains the anus which is surrounded by fat tissue
Urogenital triangle for females
Urogenitial triangle - urethrea and the external genitalia (vulva) and the opening to the vagina
Anal triangle for females
Anal triangle contains the anus which is surrounded by fat tissue
Vulva
External genitalia
Also known as the pudendum
Mons pubis - in front of the pubic symphysis, this is adipose tissue that is sitting over the pubic symphysis and the skin on the mons pubis groups thick pubic hair from puberty onwards, it is the most anterior
Labia (means lips) - 2 lip like structures
Major (labia majora ) - larger and more lateral (pubic hair also grows on the more lateral surface of the labia majora
Minor (labia minora) - smaller and more medial, the innermost lips
Space between (associated with the vagina) is the vestibule -they surround a region around the opening of the urethra and the opening of the vagina which is known as the vestibule - so the labia are there to close over and protect the vestibule with its urethral and vaginal openings
Deep to the labia are the vestibular glands which lubricate the vaginal orifice
Labia minora spreads around the vagina and the urethral openings
Clitoris - complex erectile organ
Mons pubis
Mons pubis - in front of the pubic symphysis, this is adipose tissue that is sitting over the pubic symphysis and the skin on the mons pubis groups thick pubic hair from puberty onwards, it is the most anterior
Labia
Labia (means lips) - 2 lip like structures
Major (labia majora ) - larger and more lateral (pubic hair also grows on the more lateral surface of the labia majora
Minor (labia minora) - smaller and more medial, the innermost lips
Space between (associated with the vagina) is the vestibule -they surround a region around the opening of the urethra and the opening of the vagina which is known as the vestibule - so the labia are there to close over and protect the vestibule with its urethral and vaginal openings
Labia majora
Major (labia majora ) - larger and more lateral (pubic hair also grows on the more lateral surface of the labia majora
Labia minora
Minor (labia minora) - smaller and more medial, the innermost lips
Vestibule
Space between (associated with the vagina) is the vestibule -they surround a region around the opening of the urethra and the opening of the vagina which is known as the vestibule - so the labia are there to close over and protect the vestibule with its urethral and vaginal openings
Singular of labia
Labium
Vestibular glands
Deep to the labia are the vestibular glands which lubricate the vaginal orifice
There are both lesser and greater vestibular glands, the lesser vestibular glands open into the vestibule and their secretions help lubricate the vestibule and keep it moist on a day to day basis, the greater vestibular glands are deep to the labia and they secrete their secretions when a female is aroused and this is important in not only lubricating the vestibule but also the lower part of the vagina
The vestibular glands or the greater vestibular glands as they are known more specifically are developmentally homologous to the bulbourethral glands in the male
Openings are just at the surface near the opening of the vagina
Clitoris
Complex erectile organ
Glans (can be seen externally), body, crura (x2) (wishbone like structures which sit close and adjacent to the pelvic bone), bulbs (x2) - the crura and bulbs sit deep to the labia minora
Only part of the clitoris that you can see externally is the glans ciltoris which is covered by a fold of skin known as the prepuce (hood of skin surrounding the clitoris)
Developmentally homologous to the penis (to the corpa cavernosa in the penis). But, the urethra does not pass through the clitoris. The urethra has a separate opening to the vagina itself
The perineum is divided into 2 regions known as the …
Urogenital and anal triangle
Which triangle contains the female external genitalia? What is it collectively known as?
Urogenital triangle contains the female external genitialia which is collectively known as the vulva
What does the vulva incorporate?
Incorporates the mons pubis, labia majora and labia minora, vestibule, vestibular glands and the clitoris
Structures that are a part of the female reproductive tract
Ovary Uterine tubes Uterus Cervix Vagina
Ovary
Bilateral structures
Lateral and posterior to the uterus
Lateral portion of the true pelvic cavity
Outer cortex (follicles, is where you find the oocytes) and inner medulla (connective tissue, blood/lymphatic vessels, nerves (these supply the ovary))
Site of oogenesis and hormone production (e.g. estradiol)
Oocytes develop within follicles - Each single oocyte is in a follicle, the oocytes and follicles are developing as a part of an ovarian cycle, follicular cells that surrounded the oocyte produce the hormones (estradiol, inhibin but there is a third one in the female that is produce by corpus luteum which is called progesterone)
Primary ovarian follicle to secondary ovarian follicle to tertiary ovarian follicle
Female gonad
This is where oogenesis takes place
If an oocyte is ovulated, it is released from the surface of the ovary and hopefully it is collected up into the uterine tube (more commonly known as the fallopian tube)
Uterus
The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. The ovaries produce the eggs that travel through the fallopian tubes. Once the egg has left the ovary it can be fertilized and implant itself in the lining of the uterus.
This is the tissue where the blastocyst (an oocyte that has been fertilised) has to implant
It is the uterus that has to interact with the fetal membranes to allow the placenta to develop which is going to provide the nourishment and support for a developing embryo and then foetus
Uterus has the capability to stretch and to grow to allow for the developing foetus and subsequently it has the musculature in order to help with contractions to push the baby out
Fundus contains some very thick muscular tissue that is where the main contractions come from that birth a foetus
Uterus position
The uterus is posterior to the bladder but anterior to the rectum
Located between the bladder and the rectum
Antiverted angle of the uterus over the bladder - Uterus tilts forward at your cervix, toward your abdomen.
Uterine tubes
The uterine tube is divided into 3 parts …
Most lateral portion - Infundibulum = funnel shaped with finger like projections called fimbriae (these fimbriae help to collect up the ovulated oocyte into the tract)
Mid portion - ampulla = dilated area where fertilisation normally occurs, this region has the most dilated lumen, ideal location for fertilisation to happen
Most medial portion - isthmus = means “narrow passage”, uterine tube is narrowed at this point and it opens up into the uterus
Cervix
Cervix protrudes into the top of the vagina
Cervical canal provides passage between uterine cavity and vagina - external os, cervical canal, internal os
Produces cervical mucus - important role in protecting the upper reproductive tract from infection, lined by columnar epithelium
Regulates sperm transports (regulates its movement into the uterus)
Various functions, one of the key functions is to protect the uterus and upper reproductive tract from infection and also regulates the movement of sperm up into the uterus, at most stages of the menstrual cycle the mucus that is produced by the cervix is hostile to spermatozoa but around the time of ovulation and under the influence of estradiol the mucus becomes watery and thinner to allow the movement of sperm up into the uterus
Vagina
Copulatory organ, it is where the penis is inserted to allow ejaculation of sperm into the top regions of the vagina where they can then move in through the cervix depending on the state of the cervical mucus
Fibromuscular, distensible female copulatort organ - distensible to allow for the insertion of the penis and to allow for the birthing of the foetus
Also functions as part of the birth canal
Lies between the urinary bladder and the rectum
Extends from the perineum to the cervix
Infundibulum
Most lateral portion of the uterine tube - Infundibulum = funnel shaped with finger like projections called fimbriae (these fimbriae help to collect up the ovulated oocyte into the tract)
Ampulla
Mid portion of the uterine tube - ampulla = dilated area where fertilisation normally occurs, this region has the most dilated lumen, ideal location for fertilisation to happen
Isthmus
Most medial portion of the uterine tube - isthmus = means “narrow passage”, uterine tube is narrowed at this point and it opens up into the uterus
Layers of the uterine wall
Perimetrium - outer layer (connective tissue)
Myometrium - middle layer (made up of smooth muscle) - makes up majority of the uterus
Endometrium - inner layer (columnar epithelium, uterine glands, and arteries) (highly glandular and it is incredibly vascular also) (it is the inner mucosal lining that is going the growing, developing and then breaking down that is associated with the menstrual cycle)
Myometrium is lined by a layer of tissue known as the endometrium and the endometrium is where all the activity is in terms of menstrual changes and it is this tissue that grows and develops and then breaks down and bleeds as a part of a females menstrual period
All of the glands in the endometrium are lined with columnar epithelium
Metrium means ‘of the womb’
Layers of the endometrium
Functional layer of the endometrium - uppermost layer and it is the layer that is doing the changing throughout the menstrual cycle
Basal layer of endometrium - Layer lying between and adjacent to the myometrium layer
Myometrium is considerably thicker than the endometrium
Portions of the cervix
Cervix protrudes into the top of the vagina
Cervical canal provides passage between uterine cavity and vagina - external os, cervical canal, internal os
External os opens into the vagina
Internal os is the opening of the cervix that joins the uterus
Cervical cavity communicates with the uterine cavity via the internal os and with the vagina via the external os
Posterior fornix and anterior fornix
The anterior (front) and posterior (back) recesses into which the upper vagina is divided. These vault-like recesses are formed by protrusion of the cervix into the vagina.
The gap between the cervix and the wall of the vagina is called the fornix
Complex blood supply of the female reproductive tract
Blood supply - direct branches of the abdominal aorta and internal iliac arteries (often anastomose/connect)
In these arteries (ovarian arteries, uterine artery, vaginal artery), there is lots of branching and particularly in the uterus there is quite a specific and distinct vasculature
Ovaries blood supply
Ovarian arteries
Branches from the abdominal aorta which branches and travels via the suspensory ligament to reach the ovary
Runs through the suspensory ligament
Uterus blood supply
Uterine artery (note the spiral arteries) The uterine artery usually arises from the anterior division of the internal iliac artery.
Branches into the Myometrium where it also branches out to form these arcuate arteries which branch out even further to form the radial arteries which extend up and into the endometrium
When they get into the endometrium they divide to form normal straight arteries that you see in other tissues and these largely feed the basal layer of the endometrium (layer adjacent to the muscle) but there are also coiled arteries that develop during the menstrual cycle known as spiral arteries which are fundamentally important in terms of the function of the uterus, spiral arteries are thought to be the main place of blood loss during a females menstrual period and it is also the spiral arterioles that are changed and remodelled during placentation to allow for the blood supply, nutritrnt exchange and gas exchange in the placenta during pregnancy
Vagina blood supply
Vaginal artery
The vaginal artery is a branch of the anterior division of the internal iliac artery,
Vaginal artery and uterine artery
From the abdominal aorta to the common iliac and then to the internal iliac is where you will find the branches of the uterine and vaginal artery
Fertilisation normally occurs in the …
Ampulla of the uterine tubes
The uterus consists of
The body (with the fundus) and the cervix
The vagina is …
A fibromuscular copulatory organ that also functions as part of the birth canal
Site of oogenesis
Ovary
Ligaments of the female reproductive tract
Broad ligament - Peritoneum folds and presses over structures to create ligaments ….
Mesometrium
Mesosalpinx
Mesovarium
Ovarian ligament
Suspensory ligament
Round ligament
Broad ligaments
The broad ligament is a flat sheet of peritoneum, associated with the uterus, uterine tubes and ovaries. It extends from the lateral pelvic walls on both sides, and folds over the internal female genitalia, covering their surface anteriorly and posteriorly.
Sheets of periotneum, sheet of peritoneum coming down from the anterior wall up over the uterus and down the other side and then back up the posterior wall, where these two sheets come together is called the broad ligament, 3 parts to it depending on which part of the structures it is covering
Mesometrium
Sits lateral to the urteus
the mesentery of the uterus; the largest portion of the broad ligament
Mesosalphinx
mesosalpinx is the fold of peritoneum draping over both uterine tubes
Where it folds up and over the uterine tubes
Mesovarium
and the mesovarium is the fold attaching the anterior portion of each ovary to the posterior part of the broad ligament.
Where it folds up and over the ovary
Ovarian ligament
Runs from the lateral surface to the more medial surface of the ovary to help support the ovary relative to the uterus
Suspensory ligament
Runs from the lateral surface to the more medial surface of the ovary to help support the ovary relative to the uterus
Opposite to the ovarian ligament
Round ligament
The round ligaments are a pair of cordlike structures in the pelvis that help support the uterus by connecting the front of the uterus to the groin region.
Round ligament which goes from the anterior surface of the uterus through the inguinal canal (passage through the abdominal muscle) where the round ligament then embeds itself into the vulva
Vesicouterine pouch
Continuous fold of broad ligament (visceral peritoneum) over anteriorly located bladder
Rectouterine pouch
Continuous fold of broad ligament (visceral peritoneum) over posteriorly located rectum
What do the pouches allow for?
For growth of the uterus
Breasts (mammary glands)
Function is to nourish infants in the form of milk
Lies on pectoralis major muscles
Estradiol and progesterone stimulate development of breast tissue - occurs initially in puberty but you also need further breast development and maturation to allow milk production which occurs during pregnancy
Structure of the breast
Lobes - lobules - alveoli - lactiferous ducts - lactiferous sinuses that open at the nipple pores
Suspensory ligaments support the glands - all the way back up to the pectorals major muscle
15-20 lobes in the human breast and they are supported in fibrous and adipose tissue, it is the variation in the amount of adipose tissue that gives the different shapes and sizes of breasts
Secretary alveoli = found within the lobules and are responsible for the production and secretion of milk products for the infant
Oocytes are found within…
Within follicles which are found in the cortex of the ovary
Female reproductive system structures are held in place by a complicated network of ligaments that …
Anchor and support
Have vasculature and nerves running through them
Form important anatomical boundaries i.e. pouches
