Week 4- Reproductive Systems Flashcards
What 3 organs provide seminal fluid components?
Seminal vesicles
Bulbourethral glands
Prostate
What does the seminal fluid comprise of?
Fructose Citric acid Bicarbonate Fibrinogen Fibrinolytic enzymes
Where is the spermatic chord located?
At the deep inguinal ring
What are the 2 layers of the penis?
Corpora cavernosa and corpora spongiosum
What type of stimulation is required for erection and ejection?
Erection: parasympathetic
Ejaculation: sympathetic
How is the arterial blood supplied to the testes?
Via testicular arteries from the aorta via the spermatic chord
How is lymph drained from the testes?
Para- aortic lymph nodes
What is cut to make males sterile?
Vas deferens
What part of the female reproductive tract is in the peritoneal cavity?
Ovaries
What type of muscle do the fallopian tubes contain?
Spiral muscle
What muscles and ligaments is the uterus supported by?
Muscles: levator ani and coccygeus
Ligaments: broad, round, uterosacral
Where does fertilisation occour?
Ampulla
What parts of the female system are sterile?
Everything above the cervix
How is sterility in the female system maintained?
Shedding, thick mucus, narrow, ph less than 4.5
How is the arterial blood supplied to the ovaries?
Ovarian arteries from aorta
How is lymph drained from the ovaries, uterus and vagina?
Ovaries: para aortic lymph nodes
Uterus/vagina: iliac, sacral, aortic, inguinal lymph nodes
What is gametogenesis in males called?
Spermatogenesis
What specialised cells are found inside and outside the seminiferous tubules?
Inside: sertoli cells
Outside: leydig cells
What hormones do the testes produce?
Androgens (testosterone, dihydrotestosterone, androstenedione)
Inhibin
Oestrogens
What is the main function of sertoli cells?
Support developing germ cells (assist movement to tubular lumen, transfer nutrients from capillaries to developing germ cells, phagocytosis of damaged germ cells)
Hormone synthesis
What is the main function of leydig cells?
Hormone synthesis
What hormones do the ovaries produce?
Oestrogens (oestradiol, oesterone, oestriol)
Progesterone
Androgens (testosterone, androstenedione, DHEA)
Relaxin
Inhibin
What is menarche?
Beginning of the female period
What can be tested if it is suspected a female is infertile?
Progesterone levels or look for a corpus luteum via ultrasound (both display wether or not a female is ovulating)
What are the 2 main cell types of the ovary?
Theca (outer part of follicle)
Granulosa (inner part of follicles)
What happens in women if there is overproduction of androgens?
PCOS
What enzyme converts testosterone to oestradiol?
Aromatase
Describe the hypothalamic pituitary gland axis for production of oestrogen/progesterone/androgens
Kisspeptin, GnRH, LH/FSH, gonads then hormones
What is hyperprolactinaemia and what physiological changes does it cause?
Too much proclactin due to pituitary tumor, prolactin binds to kisspeptin neurone inhibiting kisspeptin release so lower GnRH/LH/FSH/Test/oestr
What are symptoms of hyperprolactinaemia?
Oligo-amenorrhea, low libido, infertility, osteoporosis
What is oligomenorrhea?
Periods that are more than 35 days apart
A drop in what hormone causes bleeding on day one of the period?
Progesterone
What does the spermatic chord contain?
Testicular artery Pampiniform plexus Autonomic and GF nerves Lymph vessels Vas deferens
How many seminiferous tubules are there and how many lobules?
1-4 tubules
300 lobules
Describe male gonads
Begins at puberty and continues for life, spermatoginia undergo differentiation and self renewal
Describe female gonads
Around 6 million oogonia per ovary
Primary oocytes form within ovarian follicles
At birth around 2 million per ovary
At puberty less than half a million remain
Describe spermatogenesis
Spermatogonium undergoes mitosis to form primary spermatocytes
1st meiotic division forms secondary spermatocytes
2nd meiotic division forms spermatids
Spermatids mature to spermatozoa
Spermatogonium and primary spermatocytes are diploid, secondary spermatocytes, spermatids and spermatozoa are haploid
What hormones do sertoli cells produce?
Inhibin and activin ( +ve/-ve on FSH)
Anti-mullerian hormone (AMH)
Androgen binding protein (ABP)
How hormones fo leydig cells produce? When do they produce these hormones?
Produce androgens:
Testosterone
Androstenedione
DHEA
These are produced in response to LH stimulation
Describe oogenesis
Oogonium undergoes mitosis to form primary oocytes
These undergo 1st meiotic division to form secondary oocytes and 2 first polar bodies
These undergo 2nd meiotic division to form ootids and 2 second polar bodies
Ootids differentiate to form ova
Oogonium and primary oocytes are diploid, secondary oocytes, ootids and ova are haploid
What happens to oogonia in the 2nd trimester of pregnancy?
They all develop into primary oocytes
Where is oogenesis halted before menarche?
Before the first meiotic division, this only happens after periods start
Describe folliculogenesis
- Premordial follicle (primary oocyte at birth)
- Primary follicle- primary oocyte and layers of granulosa cells and outer theca cells
- Secondary follicle- fluid filled cavity (antrum) develops, has FSH/LH receptors
- Mature follicle- forms due to LH surge, secondary oocyte formed
- Ruptures surface of ovary
- Corpus luteum
What is the function of theca cells?
Support folliculogenesis- structural and nutritional support of growing follicle
Hormone synthesis- LH stimulates synthesis of androgens
What is the function of granulosa cells?
Hormone synthesis- FSH stimulates granulosa cells to convert androgens to oestrogens via aromatase, also secrete inhibin and activin which have effects on FSH
After ovulation- turn into granulosa leutin cells that produce progesterone as negative feedback to allow maintenance of endometrium during pregnancy as well as relaxin that helps the the endometrium prepare for pregnancy and softens pelvic ligaments/cervix)
What is primary vs secondary amenorrhea?
Primary: when you’ve never had a period
Secondary: had a period and have not had a period for 6 months
What are some causes of amenorrhea?
Stress Poor nutrition Weight loss (Premature) menopause Any disruption of the hypothalamo-pituitary-gonado axis Pregnancy PCOS Hyperthyroid (maybe hypothyroid)
What is the most common cause of hyperprolactinemia?
Prolactinoma (tumor)
Where does steroidogenesis occour in males?
Leydig cells
Where does steroidogenesis occour in females?
Theca and granulosa cells
Describe the hypothalamic pituitary gland axis for reproduction
Kisspeptin is produced in the hypothalamus
Kisspeptin causes release of gonadotrophin releasing hormone
GnRH binds to receptors in the anterior pituitary gland causing release of LH/FSH
LH/FSH bind to gonads
Target hormones oestrogen/progesterone/androgen are released
How is GnRH released?
Via pulsar release
How does GnRH travel to the anterior pituitary?
Via hypophyseal portal circulation
How do testosterone and oestrogen undertake negative feedback in the HPG axis?
They stop release of LH/FSH from the anterior pituitary as well as kisspeptin release from kisspeptin neurones
What is the method by which testosterone and oestrogen are released?
Dional release ie released in the morning
What hormone has an effect on the HPG axis and how?
Prolactin- it binds to kisspeptin releasing neurones so kisspeptin release is inhibited. This decreases downstream GnRH/LH/FSH/Testosterone
Why does bleeding occour on day 1 of the menstrual cycle?
Due to a drop in progesterone levels
Around what day of the menstrual cycle does ovulation occour and why?
Day 14 due to an LH surge
How many days or longer does an average menstrual cycle have to be for a female to be considered to have oligomenarrhea?
35 days or more
What 2 subcycles does the ovarian cycle comprise of?
The ovarian cycle and the uterine cycle
Describe the ovarian cycle
Follicular phase (primary/secondary/mature follicle)
Ovulation
Luteal phase (corpus luteum dies if theres no pregnancy)
What are the 3 phases of the uterine cycle
Menstrual phase
Proliferative phase
Secretory phase
Why does body temp rise slightly after ovulation?
Due to progesterone
Where is testosterone synthesised?
Leydig cells
What cells is inhibin secreted from?
Sertoli cells
What cells does testosterone promote the action of?
Sertoli cells
