Reproduction and Hormones Flashcards
What is the SRY gene?
The SRY gene is found on the sex-determing region of the Y chromosome and is responsible for causing the primitive gonads in males to become testes.
Define ‘Testes’?
Testes are the first part of male genitalia to form following the activation of the SRY gene. They produce sperm and androgens (testosterone).
What are ‘Wolffian ducts’?
All fetus’ start with both Wolffian and Mullerian ducts. The Wolffian ducts are precursors of the male reproductive organs.
They develop into seminal vesicles (sac-like structures that store semen) and the vas deferens (a duct from the testes into the penis) after testosterone exposure during prenatal development.
What are ‘Mullerian ducts’?
All fetus’ star with both Mullerian and Wolffian ducts. The Mullerian ducts are precursors to the female reproductive organs.
They develop into the fallopian tubes, ovaries and uterus after estrogen exposure during prenatal development
What are steroid hormones?
Sex influencing hormones that are derived from cholesterol.
What are Androgens and Estrogens?
Categories of chemicals - neither is a specific chemical itself.
Androgens promote the development of typically masculine features
Estrogens promote typically female features
What is Testosterone?
Testosterone is the most widely known Androgen
What is Estradiol?
Esradiol is the most prominent Estrogen
What is Progesterone?
Progesterone is a hormone which ready’s a females uterus for implantation of a fertilized ovum and promotes maintenance of pregnancy.
What is the Müllerian inhibiting hormone (MIH)?
A peptide hormone that degenerates the Müllerian ducts in males.
What are the three ways steroid hormones can exert their effects?
- They can bind to membrane receptors like protein or peptide hormones.
- They can enter cells and activate certain kinds of proteins in the cytoplasm.
- They can bind to chromosomes where they activate or inactivate specific genes.
What is Oxytocin?
It is a hormone, produced in the hypothalamus and relsased in the prosteria Pituitary gland.
It stimulates contractions for childbirth, mammary gland for milk, released during orgasm and stimluates relaxation as well as facilitates the bonding between mating partners and mother and baby (maternal behaviour).
What is Vasopressin?
A hormone, synthezised in the hypothalamus and found in the prosteria pituitary gland. Involved in long-term bonding.
What causes ‘intersex’?
A child born with an XX chromosome pattern where a SRY gene moves from the father’s Y chromosome onto another one.
An atypical hormone pattern or mutation of testosterone before brith.
What is the most common cause of intersex development?
Congenital adrenal hyperplasia (CAH) - the overdevelopment of the adrenal glands from birth (higher than normal levels of testosterone)
