Reproduction Flashcards
Define/function/give examples of androgens
Sex hormone. Testosterone and 5 alpha dihydrotestosterone
Define/function/give examples of oestrogens
Female sex hormone. Maintenance of female characteristics and fertility. Oestradiol, Oestrone and Oestriol.
Define/functions of progestagens
Female sex hormone. Major steroidal hormone of corpus luteum and placenta.
Sex determination
Commitment of bipotential gonad to a testis or an ovary
Sex differentiation
Phenotypic development of genital structures
XX/XY
Normal female/normal male
SRY gene
Sex-determining Region on the Y chromosome
Mullerian duct
Female
Wolffian duct
Male
Male cellular involvement in sex differentiation
Sertoli cells produce anti-mullerian hormone, creating mullerian duct regression
Leydig cells produce testosterone, encouraging wolffian duct development and thus internal male genitals
Female hormonal involvement in sex differentiation
Oestrogens and progestagens encourage mullerian duct development and thus internal female genitals. Wolffian duct regression due to absence of SRY gene thus testis
AMH
Anti-mullerian hormone
Leydig cells
Testosterone
Wolffian duct develops into
Epididymis, vas deferens and seminal vesicles
Mullerian ducts develop into
Upper vagina, cervix, uterus, and uterine tubes.
In external genitalia, presence of androgens fuses what together?
Urethral folds, forming the penis
Androgen insensitivity syndrome
XY but mutation in androgen receptor gene prevents androgen function, thus female external genitalia
First sign of puberty
Increase in blood plasma LH levels
Gonadotrophins
LH & FSH
LH
Luteinising hormone
FSH
Follicle stimulating hormone
GnRH
Gonaotrophin releasing hormone
Define secondary sexual characteristics
Tanner stage, outer representations of sex
Order of puberty signs in females
Breast development (oestrogen), sexual hair development (androgens), then growth spurt and menarche
Order of puberty signs in males
Testicular and penile enlargement (leydig cells enlarge and secrete testosterone), sexual hair growth, spermarche
Female puberty begins when
Weight ~47kg
Precocious puberty
7 in girls, 9 in boys, GnRH dependent problem or hypothalamic tumour
Delayed puberty
Inadequate GnRH signals
Menopause
50-52 yrs, ovaries run out of follicles
Stages of reproductive life in females
Pre-menopause, menopausal transition, peri-menopause, post-menopause, ovarian senescence
All female reproductive organs
Vagina, uterus, uterine/fallopian tubes, ovaires
Define anteflexion/retroflexion, and which is more common
Anteflexion is when uterus is faced anteriorly, retroflexion is when the uterus is faced posteriorly (less common, 20%)
3 functions of the vagina
To pass menstrual fluid, sexual intercourse, birth canal
Sections/parts of the uterus
Endo/myo/perimetrium, utrine cavity, cervix of uterus, body of uterus and fundus of uterus
Fundal height is useful for
Prediction of gestation (cm from pubic bone to fundus = weeks of gestation)
Divisions of the endometrium
Inner functional zone (stratum functionalis) which is for uterine glands.
Outer basilar zone (stratum myometrium) which is for attaching the endometrium to the myometrium
Sections of uterine (Fallopian) tube
Isthmus, ampulla, infundibulum with fimrbiae
Ectopic pregnancy
When the fertilized embryo does not implant in the uterine wall
Regions of the ovary
Ovarian cortex, ovarian medulla and inner hilum
Function of outer ovarian cortex
contains the ovarian follicles
Function of the central ovarian medulla
consists of the ovarian stroma and steroid producing cells
Function of the inner hilum
point of entry for nerves and blood vessels
Order the following:
Mature (Graafian follicle) follicle, corpus luteum, primary follicle, secondary follicle, corpus albicans, primordial follicle, corpus hemorrhagicum
Primordial, primary, secondary, mature, hemorrhagicum, luteum, albicans
Define primordial follicle
Is an oocyte once surrounded by follicular/granulosa cells
Define primary cells in females
pre-antral/primary follicles are slightly larger, immature primary follicles consist of one granulosa cell layer
Zona pellucida
layer around oocyte of glycoproteins
Other name for ovarian stromal cells
thecal cells
What causes transition from primary follicle to secondary follicle
response to FSH
Secondary follicle definition
Has viscous follicular fluid
Corona radiata definition and what follicle it is associated with
In secondary follicles when innermost layer of granulosa cells attaches to zona pellucida
Cumulus oophorus
Mass of loosely associated granulosa cells
Theca interna and theca externa are found where
mature secondary follicle
Ovulation
Follicle ruptures, expelling the oocyte
Corpus luteum
Forms from increased secretion of progestagens
How long does corpus luteum live for
2 weeks
Corpus albicans
death of corpus luteum
hCG
human chorionic gonadotropin, produced with pregnancy, saves corpus lutem
Function of corpus lutem
Endocrine control of early pregnancy
Phases of ovarian cycle
Follicular phase (day 1 to ovulation), and luteal phase (ovulation to menstruation)
Phases of menstrual cycle
Menstruation, proliferative and secretory
What induces ovulation
LH spike
Where does spermatogenesis occur
Seminiferous tubules
What stage of life does spermatogenesis begin
After puberty
Number or sperm per gram of testis tissue per second
300-600
Phases of spermatogenesis
Mitotic division, meiotic division, cytodifferentiation
What are spermatogonial stem cells
First cell in spermatogenesis process
Order the following:
Secondary spermatocytes, spermatogonium, spermatogonial stem cells, spermatids, primary spermatocytes
Spermatogonial stem cells, spermatogonium, primary spermatocute, secondary spermatocyte, spermatid
Outline spermatogenesis
- Spermatogonial stem cell divides through mitosis
- One daughter cell, a spermatogonium, divides through mitosis rapidly
- They move through the adjacent sertoli to adluminal compartment
- The now primary spermatocytes undergo meiosis
- After meiosis l, they are secondary spermatocytes.
- After meiosis ll, they are spermatids
- Cytodifferentiation to become spermatozoa
- Sperm into the lumen of the seminiferous tubules
- Residual body phagocytosed by sertoli cells
Sertoli cell location & functions
In the seminiferous tubules, between the basement membrane and adluminal compartment.
Produce AMH, ABP, and inhibin
What are the interstitial cells called
Leydig cells
LH & FSH come from
Ant. Pituitary
Hypothalamus reduces
GnRH
Function of LH in males
Travels through blood to testis, interacts with leydig cells.
Leydig cells produce testosterone (secondary characteristics)
DHT
Dihydrotestosterone
Function of FSH in males
Travels through blood to testis, interacts with sertoli cells.
Sertoli cells produce ABP (androgen binding protein) which makes testosterone soluble
Some ABP goes into cells, supports spermatogenesis
Outline negative feedback in males
Testosterone tells hypothalamus to reduce GnRH production
Testosterone also tells gonadotrophs to decrease FSH & LH production
Inhibin regulates FSH production
Function of Kisspeptin
Potentially up-regulates/begins cascades of GnRH
Types of male infertility
Oligospermia, azoospermia
Oligospermia
Low sperm count
Azoospermia
No sperm cell production
Threshold sperm count for male infertility
<20 million/ml
IVF definition
In vitro fertilisation, oocytes harvested and 50,000 sperm extracted to fertilize (NEEDS TO BE MOTILE)
ICSI definition
IntraCytoplasmic Sperm Injection, single sperm ejected into oocyte (DOES NOT NEED TO BE MOTILE)
Pathway of sperm
Seminiferous tubules, rete testis, epididymis, vas deferens, ejaculatory duct
Function of epididymis
To store sperm, remove liquid, and provide motility, and ability to fertilize oocyte.
How long are sperm in the epididymis
10-14 days
Ducts of the male reproductive system
Epididymis, vas deferens & ejaculatory duct
Accessory glands of male reproductive system
Seminal vesicles & prostate
Function of seminal vesicles
Secrete mucoid substance (alkaline, frucose, prostaglandins, clotting proteins)
Function of prostaglandins
Cause female contractions
Function of the prostate
Secrete milky substance (acidic, citrate (ATP), phosphate, calcium, prostate specific antigen (PSA))
pH of semen
7.5 ish
Composition of semen
Sperm 10%
Seminal vesicle fluid 60%
Prostatic fluid 30%
Other secretions
Order of ejaculatory substances
Prostate fluid first, then sperm, then seminal vesicle fluid
BPH defintion and symptoms
Benign prostatic hyperplasia, excess growth of prostate occluding the urethra. Causes difficulty voiding bladder, bladder weakening, UTIs & kidney issues
Treatments for BPH
Selective 5 alpha-reductase inhibitor/s (i.e. finasteride or dutasteride)
Surgery
Function of 5 alpha-reductase inhibitors
To stop the conversion of testosterone into dihydrotestosterone
Reason for autopsy cancer
Males die from other reasons whilst having prostate cancer
PSA
Prostate specific antigen (breakdown of seminal vesicle clot)
Structures of penis
- Corpora cavernosa x2
- Corpus spongiosum
- Penile urethra
Causation of erection
Sexual stimulus, NO & prostaglandin E1 causes relaxation of corpora cavernosa
Increased blood flow
Sildenafil
Viagra, causes erection through inhibition of phophodiesterase. Stops regulation of smooth muscle relaxation
cGMP
Guanosine Monophosphate, causes arterial relaxation to corpora cavernosa, thus erection