Defining the Reproductive Tracts Flashcards
Introduction
- Unlike most other body systems the reproductive system is in ‘slumber’ until puberty.
- It is composed of the primary sex organs (testes and ovaries) that produce the gametes and associated structures such as glands, ducts and external genitalia.
•In the adult the reproductive structures are located in the true or lesser pelvis.
- Provides a link to the external environment via genitalia.
- Function is Production, storage and delivery of germ cells
Female Reproductive System
The Female Reproductive System includes the;
1. Gonads= Ovaries
2. Internal Ducts= Uterus, fallopian tubes, cervix, vagina
3. External Genitalia= Vulva- Clitoris, vestibule of vagina.
Principle function of the Female Genital System
1. To produce oocytes- female gametes
2. To produce hormones (estrogen, testosterone, progesterone)
3. To transport oocyte to the site of fertilization
4. Nourish fertilized oocyte to term
5. Deliver fetus
Ovaries Appearance and Location
Almond-shaped and size
•Location: Develop retroperitoneal and remain in the abdominal cavity. Suspended by the ligament of the ovary and mesovarium
Blood supply to the ovaries
Supplied by ovarian artery/vein within the suspensory ligament
*because the ovary came from the abdomen, it dragged with it its ovarian artery and vein so they are coming from much more superiorly.
-There is will also branch from the Uterine artery.
-The ovary actually has a good anastomotic blood supply
*its venous drainage will either go to the inferior vena cava or to the renal vein, it depends on which side.
Ovaries on a microscopic level
- A woman has around 400,000 gametes- only a fraction make it to maturation.
- Within each ovary are follicles. Within each follicle is a primary oocyte and hormone producing support cells. Within the follicle the oocyte matures before being released for fertilization.
- This development from Oocyte- Promordial follicles- Primary follicles- Secondary follicle-Graafain follicle
•Ovulation- secondary oocyte release from graafian follicle. The secondary oocyte is arrested in metaphase of second meiotic division.
-The remainder of the folicle forms the corpus luteum.
•Corpus luteum – secretes progesterone which will help maintain pregnancy if the oocytes has been fertilised.
•Theca cells in the ovary will secrete androgens and granulosa convert to oestrogen
An oocyte is an immature egg (an immature ovum). Oocytes develop to maturity from within a follicle. … Typically, only one oocyte each cycle will become a mature egg and be ovulated from its follicle. This process is known as ovulation.
ovarian artery is a branch of
The ovarian artery is a direct branch of the abdominal aorta.
venous drainage of the ovaries
The left ovarian vein drains into the left renal vein, and the right ovarian vein empties directly into the inferior vena cava.
Nerve: supply to the ovaries
Ovarian plexus
Uterine Tube
•Function: conduct oocyte. its helps bring the oocyte from he ovary towards the uterus.
•Structure: 10cm long and divided into four parts from lateral to medial
*Some people who are struggling with infertility can have a look at the Patency of their uterine tube and this is performed with dye injected into it.
four parts of the uterine/fallopian tube
1. Infundibulum; sits over the top of the ovary, in close proximity to the ovary. it has finger-like projections known as FIMBRIAE. The Frimbriae move and help scoop the oocyte. because the ovary is not enclosed in something, it can well off release an egg that can go into the abdominal cavity if the infundibulum does not scoop properly. if an oocyte is fertilised and sits outside i.e in the abdominal cavity, it can be an ectopic pregnancy. ectopic pregnancies can also occur in the uterine tube.
2. Ampulla; The longest part of the uterine tube and its often a site of fertilisation.
3. Isthmus; a small narrow region
4. Uterine; goes through the muscular part to enter into the uterine cavity.
Arterial supply to the fallopian tubes
–supplied by branches from uterine + ovarian arteries.
The arterial supply to the fallopian tube arises from anastomoses between the ovarian and tubal branches of the ovarian artery and ascending branches of the uterine artery.
Venous drainage of the Fallopian tubes
- drained by branches from uterine + ovarian arteries and veins
The uterine plexus drains the medial two-thirds of the fallopian tubes into the internal iliac vein whereas the pampiniform plexus drains the lateral two-thirds. The pampiniform plexus drains into the ovarian veins, which in turn drain into the renal vein on the left and the inferior vena cava on the right.
Innervation of the Fallopian Tubes
sympatethic from ovarian (abdomen) and parasmpatethic from pelvic splanchnic nerve.
The uterine tubes receive both sympathetic and parasympathetic innervation via nerve fibres from the ovarian and uterine (pelvic) plexuses. Sensory afferent fibres run from T11- L1.
Uterus
•Function: Site of implantation of fertilized egg and foetus development
•Structure: Hollow pear-shaped muscular organ. Body – cone shaped, upper 2/3rd Cervix – cylindrical, lower 1/3rd. Has a uterine cavity that communicates to vagina via internal os
3 layered walls of the uterus
Perimetrium – outer serous wall covering the uterus
Myometrium – thick muscular layer, responsible for process of parturition (giving birth)
Endometrium – inner mucous layer; site of implantation; thickness changes through menstrual cycle
Arterial supply to the uterus
Uterine artery
Venous drainage from the Uterus
the uterus is drained via the uterine vein. The uterine veins form a uterine venous plexus on each side of the cervix. Veins from the uterine plexus drain into the internal iliac veins.
Nerve supply to the Uterus
Autonomic innervation
- sympathetic supply from the hypogastric plexus (along uterine artery);
- parasympathetic via the pelvic splanchnic nerve. Note: also vagina
pelvic splanchnic nerve are the cranial nerves that come all the way from the brain and come off in the sacral spinal cord segment.
Somatic innervation
• Touch and Pain (birth): via somatic afferents to S2-S4
Position of the uterus
The position of the uterus is normally considered as being anteflexed – the fundus and body point forward relative to the cervix and anteverted- the uterus is angled forward relative to the vagina. In ~20% of women the uterus is retroverted – angled backwards.
The key things is that the anterior body of the uterus is normally located on top of the posterior part of the superior bladder.
The uterus can be retroverted. A retroverted uterus means the uterus is tipped backwards so that it aims towards the rectum instead of forward towards the belly. This can happen due to changes in the hormone.
Alos, after pregnancy and post partum, the uterus might not always return to its original position.
Uterine Ligaments
•Ligament of ovary; stalk-like projection from the uterus to the ovary
•Round ligament of uterus; its what remains of the structure called the gubernaculum. The female gubernaculum is an embryonic structure that gives rise to the uterine round ligament and seems to be important in Müllerian development. the gubernaculum goes all the way from the uterus down into the labia majora.
•Broad ligament; a flat sheet of peritoneum, associated with the uterus, fallopian 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.
- Transverse cervical ligament
- Uterosacral ligament
Peritoneal pouches
Because we have a fold of peritoneum covering the organs, we end up with 2 different spaces.
1. Vesicouterine pouch; between the uterus and the bladder.
2. Rectouterine pouch; between the rectum and the uterus . This is also known as the pouch of Douglas
*these potential pouches/spaces are important in infection.
Subdivisions of the broad ligament
1. Mesometrium – Surrounds the uterus and is the largest subsection of the broad ligament. It runs laterally to cover the external iliac vessels, forming a distinct fold over them. The mesometrium also encloses the proximal part of the round ligament of the uterus.
2. Mesovarium – Part of the broad ligament associated with the ovaries. It projects from the posterior surface of the broad ligament and attaches to the hilum of the ovary, enclosing its neurovascular supply. It does not, however, cover the surface of the ovary itself.
3. Mesosalpinx – Originates superiorly to the mesovarium, enclosing the fallopian tubes.
Cervix
- Inferior portion of uterus; cylindrical tube
- Thick muscular layer – support developing foetus
- Lumen – cervical canal
- Constricted openings at ends (os)
The cervix has 2 parts
•Constricted openings at ends (os)
1. Internal OS – where the cervix communicates with uterus
2. External OS– where the cervix communicates with vagina
Vagina
•Function: Canal for menstrual fluid, birth canal, receives penis/ejaculate
-It has the ability to stretch and dilate
•Musculomembranous tube (7-9cm)
Vagina has 2 recesses or fornixes.
1. posterior fornix ; much larger. its the posterior fornix that is able to expand more to accommodate the penis in intercourse.
2. Anterioir fornix
-At the inferior end, the vagina opens onto the vestibule of the vagina.
Vasculature
We have the internal iliac artery giving rise to the uterine and vaginal artery.
look at the;
Ovarian (gonadal) artery
Uterine artery
Vaginal artery
Internal pudendal artery
External Genitalia Consists of:
1. mons pubis (the fatty part that covers the pubic bone/vagina)
2. labia majoria; the hair bairing slightly fat filled
3. labia minoria; hairless and fatless folds. •encloses the vestibule (openings for vagina and urethra) and the clitoris
4. clitoris; erectile organ consists of: root, body and glans
5. bulb of vestibule; erectile tissue over bulbospongiosus muscle
6. vestibular glands; secrete mucus to help provide friction-free environment.
Arterial supply to the external genitalia
Pudendal artery (erectile)
Innervation of the external genitalia
branches of genitofemoral and pudendal nerve (e.g. dorsal n of clitoris)
Female Genital Mutilation
Part of the clitoris have been removed as well as part of the labia minora .
Prolapse
The vaginal canal has extended into the external environment.
•Genital Warts
Vulvitis
Male Reproductive System
The Gonads are the testis
Internal Ducts
- Efferent ductules
- Epididymis
- Vas deferens
- Accessory glands (e.g. prostate)
- Urethra
Arterial supply to the testes
paired testicular arteries, which arise directly from the abdominal aorta. They descend down the abdomen, and pass into the scrotum via the inguinal canal, contained within the spermatic cord.
Venous drainage from the testes
venous drainage of the testis forms the pampiniform plexus, which is primarily drained by the testicular veins.
pampiniform plexus, a mesh that goes around the testes and enables them to keep at a nice cool temperature because this is needed for spermatogenesis.
Nerve supply to the testes
•spermatic plexus (abdomen)
Testis ducts
Sperm travel – exiting the testis:
1• Seminiferous tubules – coiled tubules; sperm is produced
2• Rete testis – straight tubules (‘rete’ = net)
3• Efferent ductules – ducts leaving (efferent) testis
4• Epididymis – transport and storage of sperm
5• Vas deferens – thin muscular tube about 45 cm long
Microscopic (Semifiniferous tubules)
•Each testis is subdivided into approx. 250 pyramid shaped lobules contain seminiferous tubules
•Function- production of spermatozoa (spermatogenesis)
•Structure- highly tortuous, lined by seminiferous epithelium
- Tunica propria-loose connective tissue, fibroblasts and myoid cells
- Stroma-surrounds semifiniferous tubules, loose connective tissue, vascular and houses small clusters of large interstitial cells of Leydig
Sertoli Cells sits in between the seminiferous tubules and hep nourish the developing sperm
•Stretch from basal lamina to the lumen, linked by tight junctions
Inguinal Canal
The inguinal canals are the two passages in the anterior abdominal wall
•Formed between deep and superficial inguinal ring
•Male; contains ductus deferens, testicular artery, veins and nerves
•Female ; contains round ligament
Inguinal Hernia
- caused by Weakness in muscle and surrounding tissue.
- Variety of causes, including congenital
- 1 in 50 boys get a hernia. 98% of inguinal hernia affect men.
- Surgery to correct.
Spermatogenesis
•600 sperm per gram of testis per second!
- Mature spermatozoa-highly specialized cell
- Involves extensive and elaborate remodelling during development
- It involves mitosis and meiosis
- Takes 64 days
- Spermatids transformed into spermatozoa.
Ductus Deferens Gross Anatomy
To leave the testes, the sperm cell are going through the ductus deferens.
As sperm ascends , the ductus deferens ascends out of the lesser supperficial inguinal ring through the deep inguinal ring to come back into the pelvis.
Flow as from the perspective of sperm leaving the testis.
Structure: Tube continuous with epididymis that is joined by duct seminal gland => ejaculatory duct
Ductus/vas deference Location
Ascends in spermatic cord- which contains: vas deferens, Blood (testicular) and lymphatic vessels, cremaster muscle, nerves (e.g. branch of genitofemoral). Passes through the Inguinal canal- superficial ring first then canal- then deep inguinal ring. Deferens travels posteriorly, crosses over external iliacs and towards the back of bladder
Function of the Ductus Deferens
to enable movement of sperm from testis to urethra for deposit into female tract.
Venous supply to the vas deference
blood follow the arteries and so have the same name.
Seminal Vesicles
Structure:
Coiled tubes in sac, bound by adventitia, Epithelium folded, androgens affect height and secretion of the epithelium .
Location; Posterior aspect of the bladder
Function: Secrete- fructose, amino acids, prostaglandins, citric and ascorbic acids that nourish spermatozoa.
Prostate gland
Structure: Largest accessory gland of reproductive system (3cm long), 2/3 glandular. 1/3 fibromuscular
Location: Prostatic ducts open into prostatic urethra
Function: Support sperm
The prostate is more liuke an acidic mixture. so you have alkaline seminal vesicles, acidic prostate and the bubourethral gland is also alkaline.
The overall makeup fo the ejaculted sperm needs to be alkaline because the famale enviroment in the vagina can be quite acidic so you need a bit of neutralising power for that.
Bulbourethral glands
Structure: Paired gland, Pea shaped, Open into spongy urethra
Location: in external urethral sphincter
Function:lubrication of urethra. they are secreting an alkaline substance into the urethra just before ejaculation. they will go first before any ejaculation follows and also help get rid of any remaining urine that would have been in there that can also be damaging to sperm.
-sperm itself only accounts for 2-5% of the ejaculate. seminal vesicles (aboput 60-70%). largest volume, the prostatic fluid creates about 30-40% and thus
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Penis Gross Anatomy
Structure: Consists of a root, body (part that can be seen externally) and glans, body contains 3 cylindrical bodies.
The body of the penis itself does not actually contain any muscles. instead it contains Paired corpora cavernosa and 1 corpus spongiosum.
Location: Anterior aspect of the pelvis
- The Glans of the penis is made up by an extension of the corpus spondiosum. with the external urethral orifice opening on to the tip.
- between the body and the Glans of the penis, we have the neck of the glands and a rim edge structure known as the corona of the glans. we also have the prepuce or the foreskin of the penis which is being retracted in this photo or can be missen if the individual has been circumcised.
Penis Microscopic Anatomy
- Each cavernous body is encapsulated by tough fibrous sheath (Tunica Albuginea)
- Interior of each cavernous body-irregular vascular spaces, lined by endothelium, with dense fibroelastic tissue and smooth muscle
Urethra
• The urethra in males is Divided into three parts:
1• Prostatic (as it goes through the prostate)
2• Membranous (as it goes throught the membrane/ the pelvic floor)
3• Penile (as it goes throiugh the penis).
Erection, Emission and Ejaculation
- Unders sexual stimulation, parasympathetic activity is key.
- before any of that sexual stimul;ation occured, the deep arteries supplying the corpora are actually just allopwing arterial-venous shunting to occur
- so where thjefre are empty spaces, there is no direction of blood to those empty spaces in the erectile body
- but under sexual stimulation, there then become increased and direversion of that blood flow into the vascular soces of the purppora.
- At the same time, developing increase in pressure of the erectile tissue also decreases venous return so its making more blood stay within the erectile tissue.
- Alot of this is all under parasympatethic (point)
- At the point of orgasm emission, semen is under sympatethic (shoot) activity.
- at the point of the emission, semen is then delievered into the prostatic urethra.
- the bubourethra tract has already secreted their own fluid, the prostatic fluid is then added and then ejaculation occurs as semen is expelled through the urethra.
- under the inhibition on sympatethic activity, the erectile body then returns to flacid state.
•Testicular Torsion
the spermatic cord can easily get twisted as a result of injury, locks to the testes etc.
this is a clinical emmergency because vessels can become occluded and necrosis could occur.
Cryptorchidism
an undescended testes. if this occurs then the medic will palpate to see if the testes can be palpated anywhere along that route or in the inguinal canal.
•Patent processus vaginalis
one of the layers that got dragged down as part fo the testes can remain open so the process vaginalis and if it remains opens it means that fluid can move from the abdomen into that area which then expands iot.
Hydrocele or Hematocele
this is where you have an accumulaytion of either fluid if its a hydrocele or blood if its a hematocele into the scortum.
