Biology Test Review: Unit 1-Chapter 13

Testes

Testes

Male reproductive organ that produces sperm and male hormones. 

Luteal Stage

Days 15-28. Begins after ovulation. Increased LH causes the follicle to develop into a corpus luteum. Corpus luteum secretes progesterone and some estrogen. Increased progesterone and estrogen inhibit FSH and LH production. The corpus luteum will disintegrate, leading to a gradual decrease in progesterone and estrogen. Decrease in progesterone and estrogen causes an increase in FSH, which restarts the cycle. 

Parturition

Is the process of giving birth. There are three stages: Dilation, Expulsion, and Placental. 

Scrotum

Pouch of skin that contains the testes and helps regulate the temperature of the testes for optimal sperm production. 

Corpus Luteum

An increased LH causes the follicle to develop into this. 

Oxytocin

Hormone that stimulates uterine contractions. 

Seminiferous Tubules

Long, coiled tubes in the testes where sperm are produced. 

Menstruation

If fertilization does not occur, estrogen and progesterone drop, and the endometrium breaks down.

Lactation

Is the formation and secretion of breast milk. 

Interstitial Cells

Hormone secreting cells that release testosterone.   

Sterile

A condition in which a man or woman is unable to have children.

Prolactin

Is the hormone needed for milk production. Following birth the pituitary begins to produce and secrete it so milk can be produced. 

Epididymis

Duct where sperm mature and become motile. 

Infertile

A condition when a man or woman have been unsuccessful for over a year trying to conceive a child.

Home Preg. Test

Work by checking urine for Human Chorionic Gonadotropin (HCG). 

Vas (Ductus) Deferens

Storage duct that is connected to the penis. Sperm cells move out of each epididymis through this.

Artificial Insemination

Sperm are collected and placed in the woman’s vagina. 

Ultrasound

Uses sound waves to create a cross-sectional image of the fetus. Provides information about physical abnormalities. Non-invasive.

Penis

Male organ for sexual intercourse, its primary function is to transfer sperm into the female reproductive system.

In Vitro Fertilization

Eggs and Sperm are collected and fertilization is induced outside of the body. The embryo is placed in the uterus. 

Amniocentesis

Cannot be done before the 14th week of pregnancy. A needle is used to draw amniotic fluid from the uterus. Cells from the fetus are collected, can be screened genetically. Invasive. 

Seminal Vesicles

Secretes mucus-like fluid that contains sugar as energy source for sperm.

Surrogacy 

Contracting another woman to carry the baby to term.

Prostate Gland

Secretes an alkaline fluid that increases the pH in the female reproductive tract, aiding in protection for sperm.

Chorionic Villi Sampling 

Can be done earlier than amniocentesis - around the 9th week of pregnancy. Cells from the chorion are removed. Cells can be used to create a karyotype. Invasive.

Superovulation

Hormone treatment that stimulates follicle development and ovulation of multiple eggs.

Cowper's Gland

Secretes a mucus-like fluid that aids in lubrication and neutralizing the acidity of any urine in the urethra. 

Cryopreservation

The use of very low temperatures to preserve structurally intact living cells and  tissues.

Semen

The combination of sperm cells and fluid.

Fertilization

The action or process involving the fusion of male and female gametes to form a zygote.

Ovaries

Female gonads which produce eggs and female hormones. 

Zygote

Is the fusion of male sperm and female egg. Resulting single cell.

Follicles

Structures that develop and mature in the ovaries and are responsible for containing an egg. 

Cleavage

Following fertilization, the zygote divides rapidly by mitosis. Despite cell division, the zygote doesn’t grow in size. The process of cell division without growth. 

Fimbriae

Thread-like projections that sweep the egg from the ovary to the oviduct (fallopian tube).

Morula

By the time the zygote is a sphere of 16 cells.

Oviduct (Fallopian Tube)

Tube that connects the ovary to the uterus. Is ciliated which helps move the egg towards the uterus. 

Blastocyst

Once the morula enters the uterus, it develops into a hollow ball of cells. 

Uterus

Muscular organ that holds and nourishes a developing fetus.

Trophoblast

The outer cellular layer. Develops into the chorion, which develops into the placenta. 

Endometrium

Vascular membrane that lines the wall of the uterus, it supplies nutrients for the fetus.

Inner Cell Mass

Mass of cells that develops into the embryo itself.  

Cervix

Muscular tissue that forms the opening of the uterus to the vagina.

Implantation

Between the fifth and seventh day, the blastocyst embeds itself into the endometrial lining of the uterus. 

Vagina

Tube that leads from the exterior to the uterus and acts as the entrance for an erect penis to deposit sperm. Additionally, it acts as the birthing canal. 

Human Chorionic Gonadotropin (HCG)

A hormone for the maternal recognition of pregnancy produced by trophoblast cells. The presence of it is detected in some pregnancy tests.

Spermatogenesis

The process by which sperm cell production occurs.

Gastrulation

Is the formation of the three primary germ layers.  

Puberty

The period during which adolescents reach sexual maturity and become capable of reproduction.

Primary Germ Layers

The first layer of cells that form during embryonic development. They’re called: Ectoderm, Mesoderm, and Endoderm.

Andropause

When the production of testosterone and other male hormones slowly decline.

Differentiation

Is the process that allows specialization of cell function. 

Gonadotropin Releasing Hormone (GnRH)

Produced by the hypothalamus. Acts on the pituitary gland, causing it to release FSH and LH.

Follicle-Stimulating Hormone (FSH)

 Males - Produced by the pituitary gland. Stimulates the testes to begin producing sperm. Females - Produced by the pituitary gland. Stimulates the ovaries to begin egg production.

Luteinizing Hormone(LH)

 Men - Produced by the pituitary gland. Stimulates the testes to release testosterone. Women - Produced by the pituitary gland. Triggers ovulation and stimulates the production of female sex hormones.  

Morphogenesis

When distinct structures start to form. 

Testosterone

Male sex hormone produced by the testes. Stimulates the male reproductive tract and secondary sex characteristics. 

Neurulation

At two weeks,this process begins - the developing embryo becomes a neurula. Mesodermal cells will form the backbone. Ectodermal cells form the brain and spinal cord. 

Inhibin

Produced by the testes. Acts on the pituitary gland to inhibit FSH production.

Notochord

The backbone.

Oogenesis

The production or development of an ovum (egg).

Neutral Tube

The brain and spinal cord.

Menopause

A hard stop to the end of monthly menstruation due to loss of ovarian follicular function. This means that the ovaries stop releasing eggs for fertilization.

Extra-Embryonic Membranes

System of membranes external to the embryo, used for protection, nutrition, respiration, and excretion. There are four: Allantois, Amnion, Chorion, and Yolk Sac. 

Estrogen

Female sex hormone produced by the ovaries. Stimulates the female reproductive tract and secondary sex characteristics.

Allantois

Forms the umbilical cord.

Progesterone

Female sex hormone produced by the ovaries. It causes uterine wall thickening.

Amnion

Fluid-filled sac used for protection.

Ovarian Cycle

Is divided into two stages: the follicular stage and the luteal stage. Begins with an increase of FSH. FSH stimulates a follicle to mature. As the follicle matures, it releases estrogen and progesterone. Increased estrogen levels inhibit the release of FSH. Additionally, increased estrogen levels stimulates a sharp increase in LH which triggers ovulation. Increased LH causes the follicle to develop into a corpus luteum. Corpus luteum secretes progesterone and some estrogen. Increased progesterone and estrogen inhibit FSH and LH production. The corpus luteum will disintegrate, leading to a gradual decrease in progesterone and estrogen. Decrease in progesterone and estrogen causes an increase in FSH, which restarts the cycle.

Chorion

Forms the placenta.

Uterine Cycle

When a new follicle matures and releases estrogen, the endometrial wall begins thickening. After ovulation, when the corpus luteum produces progesterone, a more rapid thickening occurs. If fertilization does not occur, estrogen and progesterone drop, and the endometrium breaks down - menstruation. If fertilization does occur, estrogen and progesterone remain high, which maintains the endometrium for the developing fetus.

Yolk Sac

Site of the first blood cell production.

Follicular Stage

Days 1-14. Begins with an increase of FSH. FSH stimulates a follicle to mature. As the follicle matures, it releases estrogen and progesterone. Increased estrogen levels inhibit the release of FSH. Additionally, increased estrogen levels stimulates a sharp increase in LH which triggers ovulation. 

Placentia

Formed from the chorion, it attaches the fetus to the uterine wall. The site of metabolic exchange. Nutrients and oxygen diffuse from the mother’s circulatory system to the baby, and waste products leave the baby’s circulation.

Umbilical Cord

Forms around the end of the eighth week. Connected from the navel of the fetus to the placenta. Is made of two arteries which remove oxygen poor blood, and one vein which transports oxygen rich blood.

Ovulation

The process in which a mature egg is released from the ovary.

Menstrual Cycle

Hormonal regulation of the female reproductive system. 

Fraternal Twins

Dizygotic Twins. Two eggs, two sperm - separate fertilizations. Twins are not genetically identical. 

Identical Twins

Monozygotic Twins. One egg, one sperm, one fertilization - the zygote splits. Twins are genetically identical.

Dilation Parturition

Uterine contractions cause the cervix to dilate. Amniotic sac breaks, fluid is released.

Expulsion Parturition

The baby is born. It pushes through the cervix to the birth canal. 

Placental Parturition

After the birth, the placenta and umbilical cord are expelled from the uterus. The afterbirth. 

Maternal Blood Tests (Aka. Maternal Serum Screening)

Done during the second trimester of pregnancy. Measures substances of blood to determine the risk that the baby may have a chromosomal disorder.

Cell-free DNA Prenatal Screening

Cell-free DNA fragments found in the placenta are screened. They represent the genetic profile of the fetus. Non-invasive but a positive test result must be confirmed with an invasive method.

Fetoscopy

Observation of the fetus in the womb using an endoscope. Allows us to see physical features.