Chapter 10: Conception, Pregnancy, and Childbirth R7-12 Flashcards
Conception
union of a sperm cell and an ovum
Y chromosomes
Creates a boy
-faster swimming sperm than X (why more boys than girls)
Male fetuses are more likely to be lost in spontaneous _____
abortions
-which often occur in the first month
Upon ejaculation, ___ to ___ million sperm are released and only ___ in ___ get in the vicinity of an ovum
200-400 million
1 in 1000
Sperm cells are apparently attracted by
Sperm cells are apparently attracted by
zona pellucida
A gelatinous layer that surrounds an ovum
hyaluronidase
An enzyme that briefly thins the zona pellucida, enabling one sperm to penetrate
Physicians often recommend that couples try to conceive on their own for ___ months before seeking medical assistance
six
Infertility
Inability to conceive a child
-failed to conceive for over a year
In vitro fertilization can cost up to
$15 000
About __% of infertility lies in men, while ___% lies in both partners
40% men
20% both
Motility
Self-propulsions. Motility is a measure of the viability of sperm cells
Autoimmune responses
The production of antibodies that attack naturally occuring substances that are (incorrectly) recognized as foreign or harmful
Problems in producing normal, abundant sperm may be caused by:
genetic factors, advanced age, hormonal problems, diabetes, injuries to the testes, varicose veins in the scrotum, drugs (alcohol, narcotics, marijuana, and/or tobacco), antihypertensive medications, environmental toxins, excess heat, and emotional stress
Low sperm count (or the absence of sperm)
the most common problem
To be considered normal, sperm must be able to:
- To be considered normal
- sperm must be able to
artificial insemination
The introduction of sperm into the reproductive tract through means other than sexual intercourse
Women encounter the following major fertility problems:
Irregular ovulation, including failure to ovulate (MOST COMMON)
Obstructions or malfunctions of the reproductive tract, often caused by infections or diseases involving the reproductive tract
Endometriosis
Declining hormone levels of estrogen and progesterone that occur with aging and may prevent the ovum from becoming fertilized or remaining implanted in the uterus
The following fertility problems are found in men:
Low sperm counts
Irregularly shaped sperm (e.g., malformed heads or tails)
Low sperm motility
Chronic diseases such as diabetes
Infections such as sexually transmitted infections
Injuries to the testes
Autoimmune responses, in which the man produces antibodies that deactivate his sperm
A pituitary imbalance and/or thyroid disease
Ovulation can often be induced by fertility drugs such as
- clomiphene (sold as Clomid), which stimulates the pituitary gland to secrete FSH and LH, which in turn stimulate the maturation of ova.
- Pergonal, contains a high concentration of FSH, which directly stimulates maturation of ovarian follicles
Endometriosis (1 in 6 cases)
A condition caused by the growth of endometrial tissue in the abdominal cavity, or elsewhere outside the uterus, and characterized by menstrual pain
Laparoscopy
A medical procedure in which a long, narrow tube (a laparoscope) is inserted through an incision in the naval, permitting visual inspection or organs in the pelvic cavity
In Vitro Fertilization (IVF)
A method of conception in which mature ova are surgically removed from an ovary and placed in a laboratory dish with sperm
gamete intrafallopian transfer GIFT
sperm and ova are inserted together into a fallopian tube for fertilization. Conception occurs in a fallopian tube, rather than in a laboratory dish.