Male and Female Reproductive Systems Flashcards
What is in seminal fluid?
- Fructose
- Citric acid
- Bicarbonate (neutralises acidic environment)
- Fibrinogen
- Fibrinolytic enzymes
Where is the spermatic cord formed?
At deep inguinal ring
What structure are in the spermatic cord?
- Testicular artery
- Pampiniform plexus (v)
- Autonomic & GF nerves
- Lymph vessels
- Vas deferens
What are the muscles in the penis?
- 2 x Corpora Cavernosa
- 1 x Corpora Spongiosum
In the penis what is due to the parasympathetic and sympathetic stimulation?
- Erection due Parasympathetic stim
- Ejaculation due Sympathetic stim
- Point and Shoot
What is the retrial blood supply in the testes?
•Testicular arteries from the aorta via the spermatic cord
Where is the sympathetic drainage for the testes?
•Para-aortic lymph nodes
Where are the ovaries?
inside peritoneal cavity (remainder outside)
Where does fertilisation occur in the female reproductive tract?
-Ampulla
What do the Fallopian tubes have?
cilia and spiral muscle
What is the uterus supported by?
tone of pelvic floor (levator ani & coccygeus) and ligaments (broad, round, uterosacral)
What part of the female reproductive tract is sterile?
•All areas superior to cervix are sterile (shedding, thick mucus, narrow os, pH<4.5)
What is 1cm lateral to the cervix?
The ureter
Where does the endometrium shed?
at menses due to vasoconstriction of arterioles
What is the arterial blood supply for the ovaries and vagina?
- Ovaries: Ovarian arteries (from aorta)
* Uterus/Vagina: Uterine arteries (from internal iliac a)
What is the lymphatic pairing for the ovaries and vagina?
- Ovaries -> Para-aortic LNs
* Uterus/Vagina -> Iliac, sacral, aortic and inguinal LNs
What are the male germ cells like?
Gametogenesis begins at puberty
- Spermatogonia undergo differentiation and self-renewal -> pool available for subsequent spermatogenic cycles throughout life (continuous fertility)
- Produce ~1,500 mature sperm/second
What are the female germ cells like?
BEFORE BIRTH
-Multiplication of Oogonia to ~ 6 million/ovary
-Form 10 Oocytes within ovarian follicles (= primordial follicle)
-These begin meiosis (halted in prophase)
-Some primordial follicles degenerate (atresia).
-At birth ~2 million/ovary remain
PUBERTY
-By puberty <0.5 million/ovary remain (due further atresia
Describe Spermatogenesis
Diploid 1. Spermatogonium 44XY 2. Mitosis 3. Spermatocytes 44XY 4. 1st Meiotic division Haploid: 5. spermatocytes (22X or 22Y) 6. 2nd meiotic division 7. Spermatids (22X or 22Y) 8. Differentation 9. Spermatozoa
Where are Sertoli cells located?
- Within seminiferous tubules
* FSH receptors
What is the function of Sertoli cells?
•Support developing germ cells
•Assist movement of germ cells to tubular lumen
•Transfer nutrients from capillaries to developing germ cells
•Phagocytosis of damaged germ cells
-Homrone synthesis
What hormones are secreted by Sertoli cells?
- Inhibin & Activin (-ve or +ve on FSH)
- Anti-Mullerian Hormone (AMH)
- Androgen-Binding Protein (ABP)
Where are Leydig cells?
- Between seminiferous tubules
- Pale cytoplasm as cholesterol-rich
- LH receptors
What is the function of Leydig cells?
•Hormone synthesis •On LH stimulation, secrete androgens: •Testosterone (oestrogens) •Androstenedione •Dehydroepiandrosterone (DHEA) (can be aromatised to oestrogens)
Describe the process of oogenesis
Diploid: 1. Oogonium (44XX) 2. Oocytes (44X 3. 1st mitotic division Haploid 4. Oocytes (22X) 5. 2nd meiotic divino 6. Ootids (22X) 7. Differentiation 8. Ova (22X)
What happens in the second trimester of pregnancy?
All oogonia develop in 1^0 (step 3) oocytes forming primordial follies
Describe the process of folliculogenesis
- Primordial follicle (10 Oocyte at birth)
- Primary (=Preantral) follicle
-10 Oocyte and layers of granulosa cells
and outer theca cells - Secondary (=Antral) follicle
-Fluid-filled cavity (antrum) develops
-FSH and LH receptors - Mature (=Graafian/Preovulatory) follicle
-Forms due to LH surge
-20 Oocyte formed - Ruptures surface of ovary
6-7. Corpus Luteum
-Progesterone & oestrogen (stim by LH)
-In pregnancy, progesterone & oestrogen production taken over by placenta
What are the reproductive hormones proceed in ovaries?
- Oestrgoens (oestradiol and oestrone, oestriol)
- Progestogens (progesterone)
- Androgens (Testosterone, androstenedione, DHEA but not DHEAs which is made in the adrenals)
- Relaxin
- Inhibin
What are the reproductive hormones proceed in the testes?
- Androgens (testosterone, dihydrotesterone and androstenedione)
- Inhibin
- Oestrogens (from androgen aromatisation)
Where are theca cells?
Associated with outer part of ovarian follicles
What is the function of theca cells?
Support folliculogenesis
•Structural & nutritional support of growing follicle
-Hormone synthesis
What hormones are secreted from the theca cells?
- LH stimulates synthesis of androgens
* Overactivity -> high androgen levels
Where is the granulosa cell?
Associated with inner part of ovarian follicles
What is the function of the granulosa cell?
Hormone synthesis
•FSH stimulates granulosa cells to convert androgens to oestrogens (by aromatase)
•Secrete Inhibin & Activin (effects on FSH)
After ovulation
•Turn into granulosa lutein cells that produce:
•Progesterone (-ve feedback, promote pregnancy by maintaining endometrium)
Relaxin (helps endometrium prepare for pregnancy and softens pelvic ligaments/cervix
What is the hypothalamic pituitary Gland Axes for reproduction?
- Hypothalamus: Kisspeptin which acts on GnRH receptors
- Pituitary: LH/FSH
- Glands/targets: Gonads
- Target Hormones: oestrogen / protest/sndrogen
- Fuction: Reproduction
What happens after signal related from GnRH ns?
- In hypophyseal Portal circulation
- Released in pulsatile fashion
- Reachs gonadotråophs in anterior pituitary gland
- Release LH and FSH in pulsatile function into systemic circulation
- Goes to gonads: diurnal
- Oestrogen and progesterone have a negative/positive feedback directly onto pituitary or the kisspeptin neurones
What happens in hyperprolactinaemia?
- Prolactin binds to prolactin receptors on kisspeptin neurone in hypothalamus
- Inhibits kisspeptin relase
- Decreases in downstream GnRH/LH/FSH/T/oest
- Oligo-amenorrhoea/low libido/infertility/osteoporosis
Why does menstrual cycle occur?
Female reproduce system prepares for possible fertilisation of 2^0 oocytes
What is day 1 of menstual cycle?
- First day of bleeding
- Blood and cellular debris form necrotic endometrial lining
When is ovulation?
Day 14
What is the length of the period?
Average 28d (21-35) >35 = oligomenorrhoea
How does LH change in menstrual cycle?
- LH slowly increase then peak around day 14
- Switch from negative to positive feedback from oestrogen so more LH helps final stage of folice maturation
How does oestrogen change in menstrual cycle?
-Increase as follicle develops and beyond threshold changes LH and FSH form negative to positive feedback which helps to mature
What happens after day 14?
- Secondary oocyte out
- Corpus lutem
- Corpus lutem secretes progesterone so help endometrium secretory ready for possible implantation mucus thicken to protect possible impalnantion
- Oestrogen at start allow thin uterine mucus so sperm can pass
What is the menstrual cycle drive by?
Driven by feedback loops involving:
•Hypothalamic Kisspeptin & GnRH
•Pituitary LH & FSH
•Ovarian Oestrogen, Progesterone, Activin, Inhibin
What is the ovarian cycle?
- Follicular Phase
- Ovulation (=pre-ovulatory phase)
- Luteal Phase
What is the uterine cycle?
Uterine Cycle (=Endometrial cycle):
•Menstrual Phase
•Proliferative Phase
•Secretory Phase
What does the menstrual cycle comprise of?
Ovarian Cycle & Uterine Cycle driven by hormonal level changes
What happens the day after ovulation?
Body temperature increases by at least 0.5 degrees (due to progesterone)
What happens when spermatozoa
- Spermatozoa go through tubules
1. Tubular fluid reabsorption resulting in concentration (induced by oestrogen)
2. Nutrients (e.g. fructose) and glycoprotein secretion into epididymal fluid (induced by androgens).
How far does spermatozoa happen?
- Travels 100,000 x its length from Testis to Fallopian tube
- equivalent to 150km for a 1.5m human
- (South Ken → Brighton → South Ken)
What is in ejaculation?
-Semen: Spermatozoa 15-120 million/ml Seminal fluid 2-5ml -Leucocytes -(potentially viruses e.g. hepatitis B, HIV) -1/100 of spermatozoa in ejaculate enter the cervix -1/10,000 cervix to ovum -Overall 1/million reach ovum
Where has seminal fluid happened?
-Small contribution from:
Epididymis/testis
-Mainly from accessory sex glands: Seminal vesicles, Prostate, Bulbourethral glands
What is in seminal fluid?
- Fructose
- Citric acid
- Bicarbonate
- Fibrinogen
- Fibrinolytic enzymes
When does capacitation occur? What happens during it?
- Loss of glycoprotein ‘coat’
- Change in surface membrane characteristics
- Develop whiplash movements of tail
- Takes place in ionic & proteolytic environment of the Fallopian tube
What is capacitation dependent on?
- Oestrogen-dependent
* Ca2+-dependent
What is the acrosome reaction?
•Sperm binds to ZP3 •(= sperm receptor) •Ca2+ influx into sperm •(stimulated by progesterone) •Release of hyaluronidase & proteolytic enzymes •(from acrosome) -In ampulla • Spermatozoon penetrates the Zona Pellucida
When does fertilisation occur?
- Occurs within the Fallopian tube
* Triggers cortical reaction
What is the cortical reaction?
- Cortical granules release molecules which degrade Zona Pellucida (e.g. ZP2 & 3)
- Therefore prevents further sperm binding as no receptors
- Haploid to Diploid
Describe the development of the conceptus
- Continues to divide as it moves down Fallopian tube to uterus (3-4 days)
- Receives nutrients from uterine secretions
- This free-living phase can last for ~ 9-10 days
What is the attachment phase in implantation?
outer trophoblast cells contact uterine surface epithelium
What happens after attachment phase in implantation?
- Decidualisation phase : changes in underlying uterine stromal tissue (within a few hours)
- Requires progesterone domination in the presence of oestrogen
What factors are involved in attachment?
•Leukaemia inhibitory factor (LIF) from endometrial cells stimulates adhesion of blastocyst to endometrial cells
•Interleukin-11 (IL11) also from endometrial cells is released into uterine fluid, and may be involved
•Many other molecules involved in process (e.g. HB-EGF)
What are some of the endometrial changes due to progesterone in decidulaisation?
- Glandular epithelial secretion
- Glycogen accumulation in stromal cell cytoplasm
- Growth of capillaries
- Increased vascular permeability (→oedema)
What are the factors involved in decidualisation?
•Interleukin-11 (IL11), histamine, certain prostaglandins & TGFb (TGFb promotes angiogenesis)
What happens in the first 40 days of pregnancy with progesterone and oestrogen production?
- Produced in corpus luteum (in maternal ovary)
- stimulated by hCG (produced by trophoblasts) which acts on LH receptors
- Essential for developing fetoplacental unit
- Inhibits maternal LH & FSH (-ve feedback)
What happens from day 40 of pregnancy with progesterone and oestrogen production?
–Placenta starts to take over and makes oestradiol and oestrogen na progesterone
- DHEAS is main substrate
- Oestriol (from fetes and mother?)
What increase in maternal hormones?
- ACTH
- Adrenal steroids
- Prolactin (can obstruct visual fields)
- IGF1 (stimulated by placental GH-variant)
- Iodothyronines
- PTH related peptides
What decreases in maternal hormone?
- Gonadotrophins
- Pituitary GH
- TSH
Describe the endocrine control of lactation
- Mechanical stimulation of nipple and surrounding area activates afferent pathways
- Afferent sig al integrated in the hypothalamus and stimulate oxytocin-relating neurone activity and inhibit dopamine relase from dopaminergic neurones
- Less dopamines in the hypothalamic pituitary portal system causes less inhibition of anterior pituitary lactrotrophs
Action potentials travel down oxyctoin neurone and oxytocin is secreted into eh bloodstream - Increased plasma oxytocin increase milk ejection in mammary glands
Increase plasma prolactin increases milkn secretion in mammary glands
How do hormones change in pregnancy?
- hCG (form placenta) peaks at week 9 and then decreases
- Human placental lactogen and oestrogen (mainly oestrous) general increases
- Progesterone increase more gradually
What is the endocrine control of parturition?
- Oxytocin (from posterior pituitary)
1. Uterine contraction
2. Cervical dilation
3. Milk ejection
