Chapter 5: Sex Hormones, Sexual Differentiation, and the Menstrual Cycle Flashcards
Prenatal Period
The time from conception to birth.
Hormones
Chemical Substances secreted by the endocrine glands into the bloodstream.
Testosterone
A hormone secreted by the testes in males (and also present at lower levels in females)
Androgens
A group of sex hormones, one of which is testosterone.
Estrogens
A group of sex hormones, one of which is estradiol.
Progesterone
A sex hormone secreted by the ovaries as well as the testes.
Pituitary Gland
A small endocrine gland located on the lower side of the brain below the hypothalamus; it is important in regulating levels of sex hormones.
Hypothalamus
A small region of the brain that is important in regulating many body functions, including the functioning of the sex hormones.
Follicle-Stimulating Hormones (FSH)
A hormone secreted by the pituitary; it stimulates follicle development in females and sperm production in males.
Luteinizing Hormone (LH)
A hormone secreted by the pituitary; it regulates estrogen secretion and ovum development in females and testosterone production in males.
Gonadotropin-Releasing Hormone (GnRH)
A hormone secreted by the hypothalamus that regulates the pituitary’s secretion of gonad-stimulating hormones.
Hypothalamus-Pituitary-Gonad (HPG) Axis
The negative feedback loop that regulates sex-hormone production.
Inhibin
A hormone secreted by the testes and ovaries that regulates FSH levels.
Prolactin
A pituitary hormone that stimulates milk production by the mammary glands.
Oxytocin
A pituitary hormone that stimulates milk ejection from the nipples and contractions of the uterus during childbirth.
SRY
Stands for sex-determining region, Y chromosome.
Mullerian Ducts
Ducts found in both male and female fetuses; in males they degenerate, and in females they develop into the fallopian tubes, the uterus, and the upper part of the vagina.