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.
Wolffian Ducts
Ducts found in both male and female fetuses; in females they degenerate, and in males they develop into the epididymis, the vas deferens, and the ejaculatory duct.
Cryptorchidism
Undescended testes; the condition in which the testes do not descend to the scrotum as they should during prenatal development.
Epigenetics
A functional change to DNA that does not alter the genetic code itself but leads to changes in gene expression. Often an epigenetic change involves methylation, that is, a methyl group is attached to the base cytosine in the DNA.
Homologous Organs
Organs in the male and female that develop from the same embryonic tissue.
Analogous Organs
Organ in the male and female that have similar functions.
Intersex
A condition in which the individual has a mixture of male and female reproductive structures, so that it is not clear at birth whether the individual is a male or a female. Formally called a pseudohermaphrodite.
Disorders of Sex Development (DSD)
Another term for intersex conditions.
Congenital Adrenal Hyperplasia (CAH)
A condition in which a genetic female produces excess levels of androgens prenatally and therefore has male-appearing genitals at birth.
Androgen-Insensitivity Syndrome (AIS)
A genetic condition in which the body is unresponsive to androgens so that a genetic male may be born with a female-appearing body.
Puberty
The time during which there is sudden enlargement and maturation of the gonads, other genitalia, and secondary sex characteristics, so that the individual becomes capable of reproduction.
Menarche
First menstruation.
Leptin
A hormone related to the onset of puberty.
Kisspeptin
A hormone involved in the initiation of pubertal development.
Adrenal Glands
Endocrine glands located just above the kidneys; in females they are major producers of androgens.
Adrenarche
In childhood, the maturation of the adrenal glands, resulting in increased secretion of androgens.
Follicular Phase
The first phase of the menstrual cycle, beginning just after menstruation, during which an egg matures in preparation for ovulation.
Ovulation
Release of an egg from the ovaries; the second phase of the menstrual cycle.
Luteal Phase
The third phase of the menstrual cycle, following ovulation.
Corpus Luteum
The mass of cells of the follicle remaining after ovulation; it secretes progesterone.
Menstruation
The fourth phase of the menstrual cycle, during which the endometrium of the uterus is sloughed off in the menstrual discharge.
Dysmenorrhea
Painful menstruation.
Prostaglandins
Chemicals secreted by the uterus that cause the uterine muscles to contract; they are the cause of painful menstruation.
Endometriosis
A condition in which the endometrium grows abnormally outside the uterus; the symptom is unusually painful periods with excessive bleeding.
Amenorrhea
The absence of menstruation.
Premenstrual Syndrome (PMS)
A combination of severe physical and psychological symptoms, such as depression and irritability, occurring just before menstruation.
Premenstrual Dysphoric Disorder (PMDD)
A diagnostic category in DSM, characterized by symptoms such as sadness, anxiety, and irritability in the week before menstruation.
