Chapter 21 - Reproductive System Flashcards
gamete
An organism’s reproductive cells. They are also referred to as sex cells. Female gametes are called ova (ovum) or egg cells, and male gametes are called sperm.
zygote
fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm)
diploid cell vs haploid cell
Diploid refers to the number of complete chromosome sets present in each cell of an organism:
Diploid cells contain two complete sets.
Haploid cells, on the other hand, only contain one complete chromosome set.
Gametes (male OR female sex cells) are haploid cells. When the gametes unite, they form a zygote, which is a diploid cell.
meiosis
a special type of cell division of germ cells in sexually-reproducing organisms used to produce the gametes, such as sperm or egg cells
urogenital tract
A reference to the fact that the male urethra has a dual urinary and reproductive function. The term urogenital tract is sometimes used in place of reproductive tract.
gonads
The essential organs of reproduction; the female gonads are the ovaries and the male gonads are the testes. Gonads are sometimes actually referred to as the “essential organs of reproduction”.
testes
The male gonads responsible for the production of sperm (spermatozoa).
Singular: testicle or testis
Plural: testes
accessory organs of reproduction
Organs that assist the gonads in their reproductive work. They tend to be ducts, sex glands other than the gonads, and the external sexual organs.
seminal vesicle
either of two small saclike glands, located on each side of the bladder in males, that add nutrient fluid to semen during ejaculation
scrotum
A sac of skin that hangs from the body at the front of the pelvis, between the legs, and that holds the testes.
vas deferens
(also called ductus deferens)
It is part of the male reproductive system of many vertebrates. There are two of them, and they are thick, smooth, very muscular, and movable tubes that can easily be felt or “palpated” through the thin skin of the scrotal wall. The tubes (also called ducts by some) transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation.
spermatic cord
A cord-like structure in the male reproductive system that contains nerves, blood and lymph vessels, and the vas deferens (a coiled tube that carries sperm out of the testicle). It runs from the abdomen to the testicle, and connects to the testicle in the scrotum (external sac).
prepuce
a term used as a synonym for either the foreskin or clitoral hood
clitoral hood
skin surrounding and protecting the head of the clitoris
epididymis
a tube that connects a testicle to a vas deferens in the male reproductive system
bulbourethral gland
also called Cowper’s gland
One of two small exocrine glands in the reproductive system of many male mammals. The bulbourethral glands are responsible for producing a pre-ejaculate fluid called Cowper’s fluid (known colloquially as pre-ejaculate or pre-cum), which is secreted during sexual arousal, neutralizing the acidity of the urethra in preparation for the passage of sperm cells.
homologous
- (of organs) similar in position, structure, and evolutionary origin but not necessarily in function
- having the same relation, relative position, or structure
- derived from or developed in response to organisms of the same species (e.g. a homologous tissue graft)
homologous graft
a graft of tissue obtained from the body of another animal of the same species but with a genotype differing from that of the recipient; called also allograft and homograft.
genotype
the genetic constitution of an individual organism
ejaculatory duct
either of the paired ducts in the human male that are formed by the junction of the duct from the seminal vesicle with the vas deferens and that pass through the prostate to empty into the urethra
ampulla
- a glass or earthenware flask with a globular body and two handles used especially by the ancient Romans to hold ointment, perfume, or wine
- a saccular anatomical swelling or pouch
tunica albuginea
a tough, whitish membrane that surrounds the testes
seminiferous tubules
any of the coiled threadlike tubules that make up the bulk of the testes and are lined with a layer of epithelial cells from which the spermatozoa are produced
interstitial cells
any cell that lies in the spaces between the functional cells of a tissue
testosterone
A hormone produced by the human body. It’s mainly produced in men by the testicles. Testosterone affects a man’s appearance and sexual development. It stimulates sperm production as well as a man’s sex drive. It also helps build muscle and bone mass. It is also responsible for the change in a male’s voice during puberty.
septum
A dividing wall or membrane, especially between bodily spaces or masses of soft tissue.
One example is the cartilage in the nose that separates the nostrils.
lobule
a small lobe or a subdivision of a lobe
spermatogenesis
the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis
germ cell
any biological cell that gives rise to the gametes of an organism that reproduces sexually
spermatogonia
singular: spermatogonium
primitive male germ cells that undergo spermatogenesis to become sperm cells
gonadotropin
A hormone that has a stimulating effect on the gonads—the testes and ovaries. It is secreted from the pituitary gland.
three parts of the sperm cell
The head of the sperm contains the nucleus. The nucleus holds the DNA of the cell.
The midpiece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy.
The tail of the sperm moves like a propeller, around and around.
acrosome
a cap-like structure on a sperm cell’s head containing enzymes that enable the sperm to break down the covering of the ovum and permit entry if contact occurs
cryptorchidism
It is a condition in which one or both of the testes fail to descend from the abdomen into the scrotum.
Early in fetal life the testes are located in the abdominal cavity but normally descend into the scrotum about 2months before birth. Failure of the testes to descend may be caused by hormonal imbalances in the developing fetus or by a physical deficiency or obstruction.
Regardless of cause, in the cryptorchid infant the testes remain “hidden” in the abdominal cavity. Because the higher temperature inside the body cavity inhibits spermatogenesis, measures must be taken to bring the testes down into the scrotum to prevent permanent sterility.
(The word cryptorchidism is from the Greek words kryptikos (hidden) and orchis (testis).)
semen
also called seminal fluid
a viscid whitish fluid of the male reproductive tract consisting of spermatozoa suspended in secretions of accessory glands (as of the prostate and Cowper’s glands)
viscid
- having an adhesive quality: STICKY
- having a glutinous consistency: VISCOUS
- covered with a sticky layer
benign prostatic hypertrophy (BPH)
also called prostate gland enlargement
It is a common problem in older men. The condition is characterized by an enlargement or hypertrophy of the prostate gland.
That the urethra passes through the center of the prostate after exiting from the bladder is a matter of considerable clinical significance in this condition. As the prostate enlarges, it squeezes the urethra, frequently closing it so completely that urination becomes very difficult or even impossible.
In some cases, drugs (Avodart, Flomax, others) may be used to improve urine flow and reduce symptoms of BPH. Surgical removal of part or all of the gland, a procedure called prostatectomy is also a treatment option.
prostate cancer
A cancer that occurs in the prostate.
Prostate cancer also causes hypertrophy of the gland and restricted or obstructed urine flow caused by malignant tumor growth.
In addition to surgery, cancerous prostatic growths may also be treated using systemic chemotherapy, cryotherapy (freezing) of prostatic tissue, microwave (heat) therapy, hormonal therapy, inserting radioactive “seeds” directly into the tumor, and the use of various types of external-beam radiation.