Wk 6 Vocab Reproductive Flashcards
Acrosome
The caplike structure that partially covers the head of
a spermatozoon. It contains digestive enzymes that are activated
when the sperm enter the female reproductive tract. These
help the cell penetrate through the layers around the ovum to fertilize it.
Afterbirth
The name given to the placenta at parturition because
it is delivered after the newborn.
Allantoic sac
Part of the placenta. It is a fluid-filled sac formed
by the allantois that surrounds the amniotic sac.
allantois
Part of the placenta. It is the membrane that forms the
allantoic sac
Alveolar duct
The smallest air passageways in the lungs. The
alveolar ducts carry air to the alveolar sacs.
Alveoli
Microscopic, thin-walled sacs surrounded by networks of capillaries. The interface between the
wall of the alveoli and the wall of the capillary is where the actual
exchange of gases takes place in the lungs.
Amnion
Part of the placenta. It is the membrane that forms the
fluid-filled amniotic sac.
Ampulla
An enlargement in each semicircular canal that contains
the receptor structure (the crista).
Amniotic sac
Part of the placenta. It is the fluid-filled sac that
immediately surrounds the developing fetus.
Androgen
Hormones that promote the development of male
characteristics; male sex hormones. The principal androgen is
testosterone.
Antibody
Proteins produced by plasma cells (transformed B
lymphocytes) in response to the presence of an antigen. A specific serum antibody is generated for a specific antigen
Antrum
(1) The fluid-filled space within an ovarian follicle. (2)
The muscular part of the stomach that is responsible for grinding of food; located between the body of the stomach and the
pylorus.
blastocyst
The stage of development of a zygote that is ready for
implantation in the uterus. It is shaped like a tiny, hollow ball
of cells with a “bump” on one side that eventually develops into
the embryo
body of the penis
The largest portion of the penis. It contains
the majority of the erectile tissue of the organ.
broad ligaments
Paired sheets of connective tissue that suspend
the uterus from the dorsal part of the abdominal cavity and
attach it to the abdominal wall. They are often subdivided into
the mesovarium, which supports the ovary; the mesosalpinx,
which supports the oviduct; and the mesometrium, which supports the uterus.
bulb of the glans
An enlargement in the penis of the dog and
related species. It is made up of erectile tissue that slowly
engorges with blood during copulation. When muscles surrounding the vagina and vulva of the female clamp down on the
enlarged bulb, the male cannot withdraw the penis. He typically
dismounts and turns so that the two animals are tail to tail. This
position is known as the tie and usually lasts 15 to 20 minutes,
after which the animals can separate.
bulbourethral glands
Male accessory reproductive glands that
secrete a mucus-containing fluid just before ejaculation that
lubricates the urethra for the passage of semen and clears it of
urine. Bulbourethral glands are present in all common domestic
animals except dogs.
capacitation
The process spermatozoa undergo in the female
reproductive tract that increases their fertility before contact
with the ovum. Part of the process exposes the digestive enzymes
in the acrosome. This helps the cell penetrate through the layers
surrounding the ovum.
caruncle
Numerous mushroomlike structures in the lining of the
uterus of ruminant animals. They join with the cotyledons of
the placenta to form placental attachment sites called
placentomes.
cervix
The sphincter muscle “valve” between the uterus and the
vagina; controls access to the lumen of the uterus from the vagina.
It is normally closed except during breeding and parturition.
chorion
Part of the placenta; the outermost layer that attaches to
the uterine lining. The chorion is linked to the fetus by the
umbilical cord.
chromosome
Threadlike accumulations of DNA in the nuclei
of cells that are particularly visible during mitosis. The DNA of
the chromosomes contains the genetic material of the cell. The
number of chromosomes is constant within a given species
cleavage
The process of very rapid cell division after an ovum
has been fertilized. The cells divide so rapidly that they do not
have time to grow appreciably between divisions. The number
of cells increases rapidly, but the overall size of the cell mass does
not increase much.
clitoris
One of the structures of the vulva of the female. Homologous to the penis of the male, the clitoris contains erectile tissue
and is richly supplied with sensory nerve endings.
colostrum
The initial secretion of the mammary gland before
milk is produced. Colostrum is rich in nutrients, has a laxative
effect on the newborn, and contains antibodies to the diseases
the dam has been exposed to or vaccinated against. If the
newborn drinks the colostrum within the first few hours of
birth, the large antibody molecules will be absorbed intact by
the intestine and impart passive immunity to the young animal.
Common vaginal tunic
The outer connective tissue sac that surrounds the testis. It is derived from the layer of parietal peritoneum that was pushed ahead of the testis as it descended
through the inguinal ring. Also called the parietal vaginal tunic.
copulation
The act of breeding; consists of intromission of the
penis into the vagina, thrusting, and ejaculation.
cornification
formation of a layer of tough keratin on an epithelial surface
Corona glandis
The widest portion of the glans penis of
the horse.
corona radiata
A thin layer of granulosa cells that surrounds the ovum as it develops in the ovarian follicle and after it is released
by ovulation.
corpus cavernosum
penis
The larger of the two erectile tissue
structures in the body of the penis. It is located dorsal to the
smaller corpus cavernosum urethrae.
corpus cavernosum
urethrae
The smaller of the two erectile
tissue structures in the body of the penis. It forms a “sleeve”
around the urethra and is located ventral to the larger corpus
cavernosum penis.
corpus
hemorrhagicum
The blood-filled remnant of the ovarian
follicle immediately after ovulation.
corpus luteum
Literally “yellow body.”The solid endocrine structure that forms from the empty ovarian follicle after ovulation.
Under stimulation from luteinizing hormone from the anterior
pituitary gland, the granulosa cells left in the empty follicle
multiply to form the solid corpus luteum. It produces progestin
hormones, principally progesterone, that are necessary for the
maintenance of pregnancy
cotyledon
Numerous areas on the surface of the placenta of ruminant animals that join with the caruncles in the lining of the
uterus to form placental attachment sites called placentomes.
cotyledonary placental
attachment
The type of placental
attachment found in common ruminant animals. It consists of
numerous cotyledons on the surface of the placenta joining with
caruncles in the lining of the uterus to form attachment sites
called placentomes.
cremaster muscle
The bandlike muscle that raises and lowers the
testes in the scrotum to help control their temperature. The
testes must be maintained at a temperature slightly cooler than
body temperature to produce spermatozoa
crura
A portion of the roots of the penis. The connective tissue
bands that attach the penis to the brim of the pelvis.
cryptorchidism
The condition of one or both testes failing to
descend into the scrotum. Cryptorchidism in animals may be
unilateral (one side only) or bilateral (both sides).
cumulus oophorus
The small mound of granulosa cells on which
the oocyte sits as it develops in the ovarian follicle.
delivery of the
newborn
Passage of the newborn animal through
the vagina from the uterus to the outside world. Accomplished
by a combination of uterine and abdominal muscle
contractions.
delivery of the
placenta
Passage of the placenta through the
vagina from the uterus to the outside world after delivery of the
newborn. Accomplished by a combination of uterine and
abdominal muscle contractions.
retractor penis muscle
An elastic, bandlike muscle that pulls the
nonerect penis of animals with a sigmoid flexure back into its
S-shaped configuration.
roots of the penis
The structures that attach the penis to the
brim of the pelvis. They consist primarily of the two connective
tissue crura covered by the ischiocavernosus muscles.
round ligament of the
uterus
A cord of fibrous tissue and
smooth muscle contained in the free edge of a lateral fold of the
broad ligament in the female. Extends from the tip of the uterine
horn caudally and ventrally to the area of the inguinal ring.
scrotum
The sac of skin that houses the testes and, by raising or
lowering them, helps control their temperature.
seasonally
polyestrous
An animal that has continuous estrous
cycles during a certain portion, or portions, of the year and no
estrous cycles at other times.
seminal vesicle
Accessory reproductive glands that contribute
various materials to semen. Seminal vesicles are present in all
common domestic animals except the dog and cat.
seminiferous tubule
The site where spermatogenesis (spermatozoa production) takes place in the testis
sertoli cell
Large“nurse” cells which spermatozoa are attached
during their development. Sertoli cells normally produce small
amounts of estrogen hormones. If they grow abnormally and
form a Sertoli cell tumor, the unusually high amount of estrogens produced by the tumor can cause feminization of the
affected male animal.
sex chromosome
Two of the normal diploid chromosome
complement. The sex chromosomes determine the genetic sex
of the individual. If there are two X sex chromosomes, the individual is genetically female. If there is an X and a Y sex chromosome, the individual is genetically male.
sigmoid flexure
The S-shaped bend in the nonerect penis of the
bull, ram, and boar.
spermatic cord
Cordlike connective tissue structures that
enclose blood vessels, nerves, lymphatic vessels, and the vas
deferens as they pass between the testes and the abdominal
cavity through the inguinal rings.
spermatogenesis
The production of spermatozoa in the testis.
spermatic cord
Cordlike connective tissue structures that
enclose blood vessels, nerves, lymphatic vessels, and the vas
deferens as they pass between the testes and the abdominal
cavity through the inguinal rings.
spermatogenesis
The production of spermatozoa in the testis.
spermatozoon
(plural, spermatozoa) The male reproductive
cell. The male gamete.
diestrous
Animals that have two estrous cycles per year
diestrus
The active luteal stage of the estrous cycle. During this
period, the corpus luteum has reached maximum size and is
producing maximum amounts of progestin hormones.
diffuse placental
attachment
A loose form of placental attachment to the uterine wall; attachment sites are spread diffusively
over the whole surface of the placenta and the whole lining of
the uterus; found in horses, swine and camelids
Diploid chromosome number
The chromosome number in all
of an animal’s cells except for the gametes (reproductive cells).
It is always an even number
discoid placental
attachment
Attachment of the placenta to the
uterus in a single, disc-shaped area; found in primates, rabbits,
and many rodents.
Dystocia
A difficult birth. Dystocias usually result from a fetus
that is too large for the birth canal or one that is oriented inappropriately for delivery
efferent ducts of the
testes
The passageways that allow spermatozoa to move from the rete testis to the head of the
epididymis.
ejaculation
The reflex expulsion of semen from the penis.
embryo
The name generally given to the developing offspring
during the first trimester of pregnancy. During this period, the
newly implanted zygote and its placenta are getting themselves
organized and the body tissues, organs, and systems begin to
form
endometrium
the mucous membrane lining the uterus, which thickens during the menstrual cycle in preparation for possible implantation of an embryo
epididymis
The ribbonlike structure that lies along the surface
of the testis. It is actually one long, convoluted tube that links
the efferent ducts with the vas deferens. Spermatozoa are stored
in the epididymis as they await ejaculation.
erectile tissue
A spongy network of fibrous connective tissue and
blood sinuses. When more blood flows into erectile tissue than
leaves it, the sinuses engorge with blood and create hydraulic
pressure that enlarges and stiffens the organ in which the erectile
tissue is located.A spongy network of fibrous connective tissue and
blood sinuses. When more blood flows into erectile tissue than
leaves it, the sinuses engorge with blood and create hydraulic
pressure that enlarges and stiffens the organ in which the erectile
tissue is located.