Biology 1306- Chapter 46

Third Trimester

- Growth - Local regulators and hormones induce and regulate labor

Changes that occur in the mother during the 1st trimester

- Mucus plug to protect against infection - Growth of the placenta and uterus - Cessation of ovulation and the menstrual cycle - Breast enlargement - Nausea is also very common

Spermatogensis differes from oogenesis in 3 ways

- all 4 products of meiosis develop into sperm while only one of the four becomes an egg - spermatogensis occurs throughout adolescence - sperm are produce continuously without the prolonged interruptions in ooogenesis (periods)

______________ and _____________ are invasive techniques in which amniotic fluid or fetal cells are obtained for genetic analysis

Amniocentesis ; chorionic villus sampling

FSH promotes the activity of ________, which nourish developing sperm

Sertoli Cells

Spontaneous abortion/miscarriage occurs in __________ of all pregnancies

¹/₃

To ensure the survival of offspring, animals

- have eggs with calcium and protein containing shells (eggs) - retain embryo, which develops inside the female - enforce parental care to ensure survival

First trimester

- main period of organogenesis - major structures are present by 8 weeks (fetus) - Changes occur in the Mother

Plan B One Step (post sexual relation)

- may prevent or delay ovulation - interfere with fertilization of an egg - also possible to prevent implantation of a fertilized egg in the uterus by altering is lining - does not cause miscarriage or abortion because it cannot stop fetus development one the fertilized egg implants in the uterus - does not work if you are already pregnant

Second Trimester

-fetus grows and is very active - mother may feel fetal movements - uterus grows enough for the pregnancy to become obvious

3 methods of contraceptive

1. Preventing release of eggs and sperm 2. keeping sperm and egg apart 3. Preventing implantation of an embryo

Permanent Sterilization

1. Tubal Ligation: ties off the oviducts 2. Bipolar Coagulation: most popular method of laparoscopic female sterilization, method uses electrical current to cauterize sections of the fallopian tube 3. Vasectomy: ties off the vas deferens

Choose the pair of contraceptive methods that are the most similar in function. 1.oral contraceptives and condoms 2. tubal ligation and vasectomy 3. abortion and diaphragm 4. coitus interruptus and the rhythm method

2. Tubal Ligation and Vasectomy ; both disrupt the network of ducts needed to unite gametes

The combination of estrogen and progesterone in most oral contraceptive for women 1. stimulates LH and FSH secretion by the anterior pituitary, thus inhibiting follicle development. 2. enhances secretion of GnRH by the hypothalamus, thus overstimulating secretion of LH and FSH. 3. inhibits secretion of LH and FSH by the anterior pituitary, thus inhibiting follicle development. 4. tricks the body into responding as if a pregnancy were already underway

3.inhibits secretion of LH and FSH by the anterior pituitary, thus inhibiting follicle development.

An advantage of internal fertilization over external fertilization is that: 1. internal fertilization allows animals to reproduce sexually. 2. internal fertilization requires much less expenditure of resources. 3. internal fertilization produces more offspring, ensuring rapid population growth. 4. internal fertilization prevents the drying out of gametes in a dry environment

4. internal fertilization prevents the drying out of gametes in a dry environment

Each year, _________ women in the US have an abortion preformed by a physician

850K

Luteal Phase

After ovulation, follicular tissue left behind transforms into the coprus luteum

_____________ of the fetus poses ethical questions and can present parents with difficult decisions

Genetic Testing

Sequential Release of _________ then _______ and _____ stimulates follicle growth

GnRh; FSH; LH

An infant suckling on the breast of a woman who has recently given birth sends a nerve impulse to the pituitary gland. The pituitary gland then secretes oxytocin, which stimulates the mammary glands in the breasts to release milk. What type of hormonal feedback is this?

Positive

RU-486

abortion pill

Menopause may have evolved to

allow a mother to provide better care for her children and grandchildren

Syphilis

bacteria; multiple system damage and fatal; 4 out of 1000 infants infected

Gonorrhea

bacteria; scar tissue, blindness in infants, antiobiotic resistant

Chlamydia

bacteria; very common and often undetected; may cause sterility

Barrier Methods

block fertilization with a pregnancy rate of less than 10% 1- condom 2- diaphragm is inserted into vagina before intercourse

Menopause

cessation of ovulation and menstruation that occurs after about 500 cycles; unusual among animals

Hormones closely link to cycles of female reproduction

changes in the uterus define menstrual cycle (aka uterine cycle) & changes in the ovaries define the ovarian cycle

Most animals exhibit cycles related to

changing seasons

Estrous cycles

characteristics of most mammals; endometrium is reabsorbed by the uterus; sexual receptivity is limited to a "heat" period; length and frequency of estrus cycles vary from species to species

Corpus Luteum disintegrates, and the ovarian steroid hormones __________

decrease

Contraception

deliberative prevention of the pregnancy

Organogenesis

development of the body organs

Hermaphroditism

each individual has a male and female reproductive system; two hermaphrodites can mate and some can self fertilize

External Fertilization

eggs shed by the female are fertilized by sperm in the external environment

Fetus

embryo (at or around 8 weeks)

Menstrual Cycle

endometrium is shed from the uterus in a bleeding called menstruation

All fertilization requires

environmental cues; pheromones and/or courtship behavior

Follicle growth and an increase in the hormone estradiol characterize the ______________ of the ovarian cycle

follicular phase

To produce sexually, animals must produce

gametophytes

FSH and LH regulate processes in the________ and the production of _________________

gonads; sex hormones

Simple systems do not have _______ but form gametes from ______________

gonads; undifferentiated tissue

Birth Control Pills

hormonal contraceptives with a pregnancy rate of less than 1%

Human reproduction is coordinated by

hormones

Reproductive cycles are controlled by

hormones and environmental cues

Intrauterin Devices (IUDs)

inserted into uterus and interfere with fertilization and implantation; pregnancy rate is less than 1%

Eggs

larger and carry out their funcition within the female

LH regulates ____________, which secrete testosterone and other androgens, which in turn promote spermatogensis

leydig cells

In Vitro Fertilization (IVF)

mixes egg with sperm in culture dishes and returns the embryo to the uterus at the 8 cell stage

Sperm

motile and must pass from male to female

Ultrasound Imaging

noninvasive procedure to detect fetal condition

Mammary Galds

not a part of the reproductive system but are important to mammalian reproduction; within the glands, small sacs of epithelial tissue secrete milk

Menstrual cycles are characteristic of

only humans and some other primates;

Gonads

organs that produce gametes;

Follicular phase ends at _______, and the secondary ______ is released

ovulation; oocyte

Gametogenesis

production of gametes: sperm & eggs

Estrogens and androgens have multiple effects including

promotion of specific behaviors

Trichomoniasis

protozoan; parasite inhabits urogenital tract and spreads through intercourse or toilet facilities; can result in sterility

Monogamy is

rare among animals

Fraternal Twins

release and fertilization of two eggs

Gonadotropin - releasing hormone (GnRH)

secreted by the hypothalamus and directs the release of FSH and LH from the anterior pituitary

Secretory Phase

secretion of nutrients during the this phase coordinates with the luteal phase

A blood sample taken from a woman in her 40s showing high levels of estrogen, progesterone, hCG, and prolactin suggests that 1. she will ovulate within one week. 2. she has not been sexually active for several months. 3. she is pregnant. 4. she is undergoing early menopause.

she is pregnant; woman is probably pregnant and an embryo or fetus is producing HCG

Menstrual Flow Phase

shedding of the endometrium during this phase coordinates with the growth of the new ovarian follicles

Intracytoplasmic Sperm Injection (ICSI)

sperm are injected directly into an egg

Internal Fertilization

sperm is deposited in or near the female reproductive tract, and fertilization occurs within the tract; requires behavioral interactions and compatibility copulatory organs

Identical Twins

splitting of the embryo during the first month

Assisted Reproductive Technologies

technology that can treat infertility

Abortion

termination of pregnancy; RU-486 can result in abortion within the first 7 weeks of a pregnancy

Proliferative Phase

thickening of the endometrium during this phase coordinates with the follicular phase

Sexual receptivity is not limited to a __________.

time frame

Rhythm method/ Natural Family Planning

to refrain from intercourse when conception is most likely; it has a pregnancy of about 10-20%

Fertilization

union of egg and sperm

Hormones coordinate the _________ with the _________

uterine cycle; ovarian cycle

Genital Herpes

virus; may be implicated in cervical cancer

Coitus Interruptus

withdrawal of the penis before ejaculation (unreliable)