Biology 30 - Chapter 14

Gonads

organ that produces reproductive cells (gametes); the ovary produces eggs (ova), and the testes produces sperm

sex hormones

one of several chemical compounds that control the development and function of the reproductive system or secondary sex characteristics

primary sex characteristic

any structure (organ, duct, or gland) that plays a direct role in reproduction; compare secondary sex characteristic

secondary sex characteristic

any of the physical manifestations that distinguish male from female but are not required for reproduction, such as distribution of body fat, female breasts, change of voice pitch in adolescent males, differences in muscularity, etc.

sperm cells

male reproductive cell (gamete)

Testes

in mammals, a pair of male reproductive organs (gonads) that produces sperm

Scrotum

pouch that contains the testes in most mammals

seminiferous tubule

long, coiled tube inside the testes in which sperm are produced

Sertoli cells

cells within the seminiferous tubules that support and nourish developing sperm

Epididymis

in human males, a narrow, tightly coiled tube connecting the seminiferous tubules to the ductus deferens; within, the sperm mature and become motile

ductus deferens

a storage duct from the epididymis leading to the penis via the ejaculatory duct; formerly known as vas deferens

ejaculatory duct

tube connecting the ductus deferens to the penis

Penis

male copulatory organ; in humans, the male organ of sexual intercourse; its primary reproductive function is to transfer sperm from the male to the female reproductive tract

seminal vesicle

in human males, gland behind the bladder that is connected to the ductus deferens; produces a mucus-like fluid containing the sugar fructose, which provides energy for the sperm

prostate gland

in male mammals, a mass of glandular tissue at the base of the urethra that secretes mucus-like, alkaline fluid that neutralizes the acids from urine in the urethra

Cowper’s gland

gland in human males that secretes mucus-like fluids into the urethra

Semen

fluid released from the penis during ejaculation; combination of sperm and glandular secretions

Urethra

the tube through which urine exits the bladder and the body

Ejaculation

release of semen from the penis

Ovary

in mammals, one of a pair of female reproductive organs (gonads); is suspended in the abdominal cavity and produces eggs (ova)

Ova

female reproductive cell (gamete)

Follicle

in the female reproductive system, specialized cell structure within the ovaries; each one contains an ovum (egg) that will be released

Ovulation

in females, the process by which a single follicle in an ovary matures and then ruptures, releasing the ovum (egg) into the oviduct; usually occurs at the midpoint (day 14) of a 28-day menstrual cycle

Fimbriae

thread-like projections that sweep the released ovum from the ovary into the cilia-lined oviduct

Oviduct

one of a pair of cilia-lined tubes in the body that transport an egg (ovum) from the ovary to the uterus; also known as Fallopian tube

Uterus

in mammals, expanded muscular organ in the female reproductive tract through which eggs pass to the environment or in which an embryo develops and is nourished before birth

Endometrium

the mucous membrane that lines the uterus and increases in thickness in the latter part of the menstrual cycle; is richly supplied with blood vessels to provide nutrients for the fetus

Cervix

in females, the narrow opening of the uterus that connects to the vagina

Vagina

a muscular tube that leads from outside the female’s body to the uterus; serves as an entrance for the erect penis to deposit sperm during sexual intercourse and as an exit for the fetus during childbirth

Menstruation

initial phase in the menstrual cycle, in which the endometrium disintegrates and is expelled from the uterus of females who are not pregnant

Vulva

the external parts of the genital organs of female mammals; includes the labia majora and labia minora, as well as the glans clitoris

sexually transmitted infection (STI)

infection such as AIDS, chlamydia, or genital herpes that is normally passed from one person to another through sexual activity; also known as sexually transmitted disease (STD)

AIDS

Acquired Immunodeficiency Syndrome; a disease that compromises the body’s capacity for immunity; caused by a group of related viruses collectively called human immunodeficiency virus, or HIV, which are transmitted through body fluids; results in susceptibility to other diseases, often resulting in death

HIV

human immunodeficiency virus; a group of related viruses that destroy the body’s capacity for immunity, and so cause AIDS

Hepatitis

inflammation of the liver tissue; the three types are hepatitis A, B, and C

genital herpes

a sexually transmitted infection caused by one of two herpes viruses

human papilloma virus (HPV)

virus responsible for a condition known as genital warts; transmitted by skin-to-skin contact

Chlamydia

a sexually transmitted infection caused by the bacterium Chlamydia trachomatis; symptoms may include discharge from the penis or vagina, burning pain while urinating, or fever; left untreated, the disease can lead to pelvic inflammatory disease (PID)

pelvic inflammatory disease (PID)

infection of the female uterus, oviducts, and/or ovaries; can result in a build-up of scar tissue causing infertility; may occur as a result of undetected chlamydia or gonorrhea infection

Gonorrhea

a sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae; can result in infection of the urethra, cervix, rectum, and throat; left untreated, the disease can lead to PID and may spread through the bloodstream to the joints, heart, or brain

Syphilis

a sexually transmitted infection caused by the bacterium Treponema pallidum; if untreated, can cause bones, muscles, and nerve tissue to degenerate

chromosomal sex

genetic sex of an individual, as determined by the type of sex chromosomes within the gametes at fertilization

Puberty

period in which the reproductive system completes its development and becomes fully functional, and reproductive hormones begin to be formed

gonadotropin releasing hormone (GnRH)

hormone produced by the hypothalamus; acts on the anterior pituitary gland to cause it to release two different sex hormones

follicle-stimulating hormone (FSH)

reproductive hormone produced by the anterior pituitary gland; stimulates the development of the sex organs and gamete production in males and females

luteinizing hormone (LH)

reproductive hormone produced by the anterior pituitary; in the ovaries, triggers ovulation, stimulates the formation of the corpus luteum, and (with follicle-stimulating hormone) stimulates estrogen production; in the testes, stimulates the release of testosterone

Testosterone

reproductive hormone produced in the testes; stimulates the development of the male reproductive tract and secondary sex characteristics; only minor effects in females

Inhibin

hormone released from the seminiferous tubules; acts on the anterior pituitary to inhibit the production of follicle-stimulating hormone (FSH); produces a negative feedback loop that controls the rate of sperm formation

Andropause

in men, a gradual decline in their testosterone level beginning around age 40; symptoms include fatigue, depression, loss of muscle and bone mass, and a drop in sperm production

Estrogen

female sex hormone produced in the ovary; helps maintain sexual organs and secondary sexual characteristics

Progesterone

female sex hormone produced first by the corpus luteum of the ovary to prepare the uterus for the fertilized egg (ovum), and later by the placenta to maintain pregnancy

menstrual cycle

in a human female, period of 20–45 days during which hormones stimulate the development of the uterine lining, and an egg (ovum) is developed and released from an ovary; if the egg is not fertilized, the uterine lining is shed as the cycle begins again; can be divided into the ovarian cycle and the uterine cycle

corpus luteum

yellowish, gland-like structure that develops from a follicle that has matured and released its egg (ovum); it produces progesterone and some estrogen; if pregnancy doesn’t occur, it degenerates

follicular stage

the first stage of the ovarian cycle (part of the menstrual cycle), during which increased levels of FSH stimulate the follicles to release increased quantities of estrogen and some progesterone into the bloodstream, leading to the release of an egg (ovum) from the follicle

luteal stage

the second stage of the ovarian cycle (part of the menstrual cycle), beginning with ovulation; during this stage, luteinizing hormone (LH) stimulates the formation of the corpus luteum, which secretes progesterone and some estrogen, which stimulate in the thickening of the endometrium for implantation of the embryo

Menopause

period in a woman’s life during which a decrease in estrogen and progesterone results in an end of menstrual cycles, usually occurring around age 50

hormone replacement therapy (HRT)

administration of low levels of estrogen and/or progesterone to alleviate symptoms of menopause in females