Reproduction Flashcards
What is the structure of the testes?
Fibrous tissue divided into 250 columns
What does each lobule in the testes contain?
1-4 coiled seminiferous tubules (manufacture sperm)
Where is testosterone made?
In interstitial cells / Leydig cells
What is the function of the prostate?
Secretions activate sperm
e.g. spermine
What is a test for prostate cancer?
Prostate-Specific Antigen
High blood levels of enzymes in prostate cancer
What is the function of the seminal vesicles?
Secrete nutrients and enzymes into ejaculate and increase sperm mobility
What is the percentage of nutrients and enzymes in semen?
60%
What is Spermatogenesis?
Formation of sperm in seminiferous tubules regulated by sex hormones
What is the function of the blood-testes barrier?
Prevent immune system from killing sperm cells
What is a Spermatid?
A spermocyte that contains DNA but is not motile due to lack of a tail
What is Spermiogenesis?
Formation of a tail on a spermatid
What is the Acrosome?
- Around the head of a sperm cell
- Has enzymes that allow it to enter a female egg
How long does it take for spermatogenesis to occur and at what temperature?
64-72 days at 32°C
What are the TWO hormones made during Spermatogenesis?
Testosterone and Inhibin
What hormone stimulates Sertoli Cells?
Follicle Stimulating Hormone
(FSH)
What do Sertoli cells release?
- Androgen Binding Protein (stimulates spermatogenesis)
- Inhibin (inhibits FSH release)
What is the function of Lutenising Hormone?
Stimulates Leydig cells
(release testosterone)
What are the functions of testosterone?
- Stimulates spermatogenesis
- Inhibits hypothalamic release of GnRh
What hormone provides SECONDARY sex characteristics such as hair growth?
Testosterone
How many eggs do females have at birth, during puberty and reproductive years respectively?
- Birth: 2million
- Puberty: 400,000
- Reproductive years: 400 oocytes ovulated
What is an oocyte?
Immature egg surrounded by follicle cells
What are the TWO phases of the ovarian cycle?
- Follicular phase
- Luteal phase
What happens during ovulation?
Ovary wall ruptures and follicle is released
What is the name of the clotted blood the ruptured follicle fills with?
Corpus luteum
What are the hormones secreted by the corpus luteum?
Progesterone & Oestrogen
How does the corpus luteum know if fertilisation has occured or not?
Through the bloodstream, if chemicals are secreted or not
What is the protein produced by fat cells?
Leptin
Why is the level of leptin important?
If blood leptin is low then puberty is delayed
What hormone does LH stimulate in the female reproductive system?
Oestrogen
What inhibits FSH and LH and where are they produced?
Progesterone and Oestrogen produced by the corpus luteum
What structures transfer the ovum to the womb/uterus?
Fallopian Tubes
Describe the structure of the Uterus
Hollow, thick walled muscle that supports the developing ovum
What is the surface smooth muscle of the uterus called?
Endometrium
Makes placenta and gets bigger during pregnancy
What is the underlying smooth muscle of the uterus called?
Myometrium
What hormones maintain the endometrium with blood supply?
Oestrogen & Progesterone
What happens during menstruation?
- Endometrium is shed
- Oestrogen and progesterone are low
What happens during proliferation?
- Endometrium begins rebuilding
- Growing follicles
- Oestrogen produced
- Endometrial progesterone receptors appear
What happens on day 14 of the uterine / menstrual cycle?
Ovulation
What is the last phase of the uterine / mentrual cycle?
Secretory phase
What happens if the egg is not fertilised?
- Corpus luteum degenerates
- Progesterone decreases
- Endometrium breaks down
What happens to the arteries if no fertilisation occurs?
- They constrict due to lack of O2 and nutrients reaching the endometrium
- Arteries then relax, blood surges into the weakened capillaries and they break apart
What is the hormone produced during pregnancy that tells the endometrium to stay?
Human Chorionic Gonadotropin
(HCG)
What do pregancy tests detect in the urine?
Antibodies to Human Chorionic Gonadotropin
What are the THREE occuring oestrogens?
- 17β-Oestradiol (active)
- Oestrone
- Oestriol
How are steroid hormones transported in the blood?
60% bound to albumin and 38% bound to Gonadal Steroid Binding Globulin (GBG)
What are the effects of steroid hormones in females?
Induces and maintain female secondary sex characteristics
What produces progesterone and how is it transported in the blood?
From corpus luteum
80% bound to albumin and 18% bound to GBG
What are the effects of progesterone?
- Responsible for changes in the endometrium
- Most effects exhibited during pregnancy
What is Menopause?
Ovarian function declines from late 20s and ovulation ceases in late 40s / early 50s
What happens when oestrogen is lost?
- Atrophy of sex organs
- Depression
- Vasodilation of blood vessels
- Thining of skin
- Loss of bone mass
- Increase in blood cholesterol
What is the Dormitory Effect?
Olfactory system sending activity to hypothalamus in response to pheromones
Humans don’t release pheromones
