Flashcards in Hormonal control of reproduction Deck (61)
What does ICSH stand for?
Interstitial cell stimulating hormone
What are hormones?
Chemical messengers produced by the endocrine glands
Where are hormones directly released?
Into the bloodstream and travel to their target tissue or organ where they have their effect
What do hormones control?
The onset of puberty, sperm production and the menstrual cycle
At puberty what does the hypothalamus in the brain secret?
A releaser hormone that targets the pituitary gland
What is the pituitary gland stimulated to release?
One hormone called the follicle stimulating hormone (FSH) and a second hormone called luteinising hormone (LH) in women and interstitial cell stimulating hormone (ICSH) in men. By a releaser hormone produced in the hypothalamus. This triggers the onset of puberty.
In males what does FSH promote?
Sperm production in the seminiferous tubules of the testes
In males what does ICSH stimulate?
The interstitial cells in the testes to produce the male sex hormone called testosterone
What does testosterone stimulate?
Sperm production in the seminiferous tubules and also activates the prostate gland and the seminal vesicles to produce their fluid secretions
What happens if there is an overproduction of testosterone
Negative feedback mechanism controls FSH and LCSH
What does high levels of testosterone inhibit?
The secretion of FSH and LCSH from the pituitary gland, resulting in a decrease in the production of testosterone by the interstitial cells
What do seminiferous tubules unite to form?
Coiled tubes that connect to the sperm duct-free swimming sperm leave the testes in the sperm duct
what does semen contain?
Sperm and the fluid from the seminal vesicles and the prostate gland
what does seminal vesicles secrete?
A liquid rich in fructose to provide energy for sperm motility
What does the seminal vesicles liquid contain?
Hormone like compounds that stimulate contraction of the female reproductive tract
What does contractions of the seminal vesicles do?
Help the sperm reach the oviduct (where fertilisation takes place) quicker than 'swimming' alone
What does the prostate gland secrete?
Lubricating liquid containing enzymes of a thin consistency for the sperm to swim through the oviduct
what do the enzymes of the prostate gland do?
Maintain the fluid at optimum viscosity for sperm motility
Just before ovulation what do the cells lining the female cervox secret?
What can the watery mucus do?
Be easily penetrated by sperm
What does GRH stimulate ?
The pituitary gland
What is produced at puberty
Gonad Releasing hormones (GRH)
What hormone is produced from the pituitary gland?
After interstitial cells produces testosterone what does is help to do?
Helps FSH to produce sperm
What happens if there isn't a constant concentration of testosterone?
The pituitary monitors this to then make ICSH increase or decrease testosterone production
When is the hypothalamus stimulated?
When it produces GRH
When are males fertile?
All the time
Where are interstitial cells found ?
Surrounding the sperm producing tubules of the testes
How are sperm formed?
from germline cells in tiny tubes called seminiferous tubules