Reproductive Flashcards
What 2 processes do sexual reproduction involve
Meiosis & fertilisation
What does reproductive meiosis produce
Haploid gametes, male sperm & female ova
What is a zygote
Cell produced after fertilisation containing 46 chromosomes, full genetic code
How many lobes are found in the mammary glands
Consists of 15-20 lobes, containing small grape like clusters of glands called alveoli which are separated by adipose tissue
How is milk ejected from the breasts
Contraction of myoepithelial cells that surround the alveoli which help propel milk into lactiferous ducts
The milk itself can be stored in lactiferous sinuses
What are the 3 tissue layers of the uterine wall
- Perimetrium - visceral peritoneum outer
- Myometrium - 3 smooth muscle layers
- Endometrium - highly vascular inner layer divided into the ‘stratum basalis’ which is permanent deep layer that regenarates the ‘stratum functionalis’ (sloughs off during menses)
What is the main ligament that keeps the uterus suspended
The ‘broad ligament’
What hormone helps to build up the endometrium vs maintain
Oestrogen helps build
Progesterone helps maintain
What are the functions of the placenta
The site of exchange of nutrients, oxygen & wastes between the mother & foetus, attached to the endometrium through diffusion of blood
It produces hormones that are needed to maintain pregnancy
Nutrient transfer is mediated by proteins called nutrient transporters
Provides a form of protective barrier to separate blood from the two placental systems
What are the two placental systems
Formed in 12th week of gestation, maternal placenta & foetal side
Preventing blood from transferring whilst still allowing mother breathing & eating for the foetus
What 2 main hormones does the placenta produce
Progesterone - maintains endometrial lining
Oestrogen - promotes growth of breast tissue & myometrium
What is the hormone human chorionic gonadotropin (hCG)
only produced during pregnancy by placenta (tests!) which ensures adequate nutrient transfer to foetus & is related to morning sickness
What is the hormone human placental lactogen (hPL)
Increases the amount of glucose & lipids in maternal blood
What is the hormone relaxins role in pregnancy
Targets ligaments & relaxes them in preparation for birth as well as growth in uterus
Produced by corpus luteum & placenta
What is the role of CRH in pregnancy
Produced by placenta
Triggers release of cortisol from adrenals which prevents rejection of foetus / placenta (immunosuppressant)
What are monozygotic twins
(30%)
Identical twins that originate from one fertilised ovum
Zygote splits into 2 embryos but share 1 placenta
What are dizygotic twins
(70%)
Non-identical twins, release of two ova & fertilisation of each. Implanted independently with 2 placentas
What are the main functions of the fallopian tubes
Provide a route for the ova to travel to the uterus & for sperm to travel to the ova
What are fimbriae
Finger-like projections that surround the ovary & sweep the ova into the fallopian tube
They are lined with ciliated columnar epithelium which function to help move the ova towards the uterus
A smooth muscle layer also performs peristalsis to assist ova movement
What hormones do ovaries secrete
Oestrogen & progesterone
What is the function of the ovarian ligament
Anchors the ovaries to the uterus, whilst the broad ligament also assists in maintaining the position of the ovaries
What does oogenesis refer to
The formation of female gametes (ova) in the ovaries
It begins in the foetus
What is a primary oocyte & how is it formed
An immature egg cell
Formed from germ cells during foetal development which stops at birth (approx 20thousand - 2million)
During female lifetime around 400 will mature & ovulate with rest degenerating
What is a germ cell
An embryonic cell capable of becoming a gamete
Why do primary oocytes have follicular cells
The primordial follicles are needed to help primary oocytes to grow & mature
What hormone does the anterior pituitary release to help maturation of primary oocytes
FSH stimulates maturation of the primordial follicles into a mature follicle
This follicular structure remains & becomes the corpus luteum
What hormone triggers ovulation
LH triggers the release of the mature ovum - secondary oocyte
How does the placenta connect from the mother to the baby
Maternal part extends from the endometrium whereas the foetus connects to the embryo through the umbilical cord
How is the corpus luteum formed
When LH causes the release of the secondary oocyte from the mature follicle, it leaves behind the follicular cells in the ovary which release progesterone & sustain the endometrium
How long is an average menses cycle
24-35 days with 28 being average
What are the four main phases of menses
- Menstrual (day 1-5) - FSH
- Pre-ovulatory (day 6-13) - Oestrogen
- Ovulation day 14 - LH
- Post-ovulatory phase (day 15-28) - progesterone
What hormones control the ovaries
Pituitary hormones following the release of GnRH - FSH & LH
What hormones control the uterus
Ovarian hormones - oestrogen & progesterone
What prevents the corpus luteum to degenerate into corpus albicans during pregnancy
human chorionic gonadotropin (hCG) hormone maintains & stimulates the corpus luteum to carry on producing hormones & after a few a weeks the placenta takes over rold of producing hCG & progesterone to maintain the pregnancy
What hormones occur during onset of female puberty
Occurs between 10-14 yrs
Onset of puberty is marked by pulses of LH & FSH, each triggered by a burst of GnRH
As puberty advances, the hormone pulses start to occur during the day as well as night, increasing over 3-4 yrs
Internal reproductive organcd reach maturity at the menarche
What does menarche mean
A females first menses indicating puberty
What is the menopause
The permanent cessation of menstruation for 12 consecutive months
Naturally occurs at 45-55yrs
due to ovarian aging whereby number of follicles become exhausted
Can be surgically induced following hysterectomy
Drop in oestrogen & progesterone affects negative feedback leading to high FSH & LH levels
What are common signs & symptoms of menopause
- hot flushes & increased sweating
- vaginal dryness & atrophy of mucosal lining leads to painful intercourse
- increase risk of UTIs due to urogenital atrophy
- mood changes, irritability, anxiety
- decreased libido & sleep disturbances
- breast shrinkage, sparse pubic & axillary hair
- osteoporosis (loss of oestrogen)
What is the epididymis
Two structures which cover the testicles and is the area where sperm is stored & matured
What duct does the sperm travel through from the epididymis
Which is cut during a vasectomy
The vas deferens ducts
What are the spermatic cords
The vas deferens which supply the testicles with oxygenated blood as well as vein that drain the testes
What are the seminal vesicles in males
Input key secretions into male ejaculate before entering the ejaculatory duct
What key gas erects the penis
Parasympathetic nervous system produces nitric oxide which stimulates vasodilation
Where do the testes develop during foetal growth
In the pelvic cavity near to the kidneys and then descend into the scrotum via the inguinal canals
Where does spermatogenesis occur
Testes divide into 200-300 lobules and im each Contains the seminiferous tubules
Which is regulated by FSH
Where is testosterone produced & secreted
Produced by GnRH in the hypothalamus triggers release of LH by pituitary which binds to ‘Leydig cells’ on the semniferous tubules of the testes
This produces a cascade effect converting LDL cholesterol to testosterone
What is the acrosome of spermatozoa
A vesicle that contains lysozomal enzymes that help to penetrate into the egg
What two glands produce seminal fluid
The seminal vesicles — (60% alkaline seminal fluid & some nutrients such as fructose to nourish sperm)
Prostate gland — milky fuild makes 30% semen which is nutrient rich for sperm, proteolytic enzymes, anticoagulants (to increase fluidity), what is PSA
What is prostate specific antigen
Is an enzyme that determines the functionality of the prostate
Can be identified in blood tests
Why is seminal fluid alkaline
To prevent sperm from urethral & vaginal acidity
What are the cowper’s glands
Secrete high alkaline mucosal fluid that neutralises urinary acids in the urethra & lubricates penis prior to ejaculation
What is hirsutism
Male pattern hair growth in females
What is metorrhagia
Mid-cycle bleeding
Menorrhagia
Very heavy menstrual bleeding
Polymenorrhea
Short cycle, frequent periods
Oligomenorrhea
Infrequent cycles
Galactorrhea
Lactation without pregnancy
Dyspareunia
Pain on intercourse
What are the common causes of primary amenorrhea
Failure of menses to occur by expected onset
Mostly caused by congenital defects: failure of ovarian follicles to develop
What are the common causes of secondary amenorrhea
Lack of menstruation for 3 months in previously menstrual women
Pituitary tumour, PCOS, hypothyroidism, stress, anorexia, excessive exercise (endorphins inhibit GnRH), uterine obstruction, medications
PCOS vs polycystic ovaries
PCOS = endocrine metabolic condition with multifaceted symptoms
Polycstic ovaries = 12 or more follicles / increased ovarian volume
What is the process of IVF
Artificial fertilisation of the ovum by sperm outside the body ‘in vitro’
Success rate around 30%
Drug ‘clomiphene’ causes oocytes to develop
Eggs retrieved from ovaries, examined & incubated with sperm on a petri dish to allow fertilisation to occur (or injected directly into egg)
Embryo is then transferred to the uterus with intent to establish a successful pregnancy
What is the oestrogen boosting allopathic treatment for menopause
HRT
Used to relieve menopausal symptoms & reduce risk of osteoporosis but only delays menopause whilst increasing risk of breast & endometrial cancer, heart disease, stroke & DVT
What is metformin
A form of allopathic med offered for PCOS
A harmful amino acid = homocysteine which increases risk of athersclerosis
What is the pathophysiology of endocrine mediated PCOS
Dysfunction of the hypothalamic-pituitary axis = imbalance of LH & FSH ratios
Higher LH promotes increased ovarian androgen formation (testosterone) which suppresses ovulation
Why does insulin resistance increase risk of PCOS
Insulin suppresses Sex Hormone-Binding Globulin (SHBG) which raises free circulating androgens (testosterone) thus suppressing ovulation
What is acanthosis nigricans
A sign of insulin resistance
Tough, dry, thickened dark skin often around skin folds eg neck, elbows, knuckles etc
What is clomiphene
An allopathic med that induces ovulation
Mammography v thermography
Mammo = radiation & has to be a considerably large & usually calcified tumour to spot
V
Thermo = more blood vessels show change in physiological/temperate so easier to spot lump in breast
What can be injected to help undescended testi drop
hCG acts like LH, increasing testosterone
This surgery usually occurs between 6-18 months of birth
Pathophysiology of BPH
Enlargemnt of prostate can occur from an increase in 5-alpha-reductase
This enzyme converts testosterone to DHT which has twice the effect on the prostate
What are 5-a-reductase inhibitors
Allopathic = finasteride
Alternative = zinc & saw palmetto herb
