Unit B - Contraception and Embryonic Development Flashcards
What are the contraception options available to males?
- Vasectomy
- Ca2+ blocker → inhibition of the maturation of sperm in the epididymis.
- Condoms
- Abstinence
What are the contraception options available to females?
- Birth control pills (estrogen and progesterone)
- Barrier methods
- IUD
- Chemical → spermicides
- Abstinence
- Tubal ligation → clamp fallopian tube
What is Vitro Fertilization (IVF)?
Eggs are retrieved from the ovaries and fertilized with sperm in a laboratory setting. The resulting embryos are then transferred into the uterus.
What happens in the Embryonic Period of Development? When is it?
- Cells divide and become redistributed
- Tissues and organs form
- Structures that support and nourish the embryo form
First 8 weeks
What happens in the Fetal Period of Development? When is it?
- Body grows rapidly
- Organs begin to function and coordinate to form organ systems
9th → birth
What is a zygote?
When sperm and ovum unite in the fallopian tube to form a single fertilized cell.
How does the sperm find the egg?
Because sperm are chemically attracted to the ovum, it follows its attraction.
If not close enough, it will just wonder forward until atraction
Define copulation.
Intercourse.
How many sperm fertilize an egg?
Only one.
What does the process Cleavage do?
Process of cellular division without the enlargement of cells.
What is a morula?
A 16-cell zygote, found before implantation
What is a Blastocyst?
A morula that has absorbed fluid from the endometrium BUT doesn’t have to be IMPLANTED
What is the Trophoblast?
The outer layer of the blastocyst.
What does the trophoblast develop into?
A chorion
What helps embed the blastocyst into the endometrium?
Enzymes from the trophoblast.
What helps maintain the corpus luteum? Where is this chemical produced?
HCG produced by the Trophoblast?
What is the Inner cell mass?
The cells of the morula forming the inner cell mass.
What happens to hCG production over the three trimesters?
It diminishes over time.
What does the inner cell mass turn into?
It develops into the embryo.
What produces Estrogen and progesterone in the third trimester?
Only the placenta.
in what trimester is progesterone and estrogen production shared with the placenta and ovary
Second Trimester However, the placenta now takes the dominant role in producing the hormones.
How long is the journey for the fertilized ovum to reach the uterus?
3-5 days
What happens in implantation in embryonic development?
The embedding of the blastocyst into the endometrium.
Enzymes secreted by the trophoblast digest tissues and blood vessels of the endometrium.
Trophoblast secretes HCG to maintain the corpus luteum (helps to make progesterone and estrogen.
In the second trimester, what takes over the secretion of estrogen and progesterone?
mostly the placenta
What is the Gastrulation process?
Turning the blastocyst into a gastrula through the formation of the Ectoderm, Endoderm, and Mesoderm.
During the Gastrulation process, what is the embryo called?
A gastrula
What are the names of the different stages of egg development in order?
Zygote → morula → blastocyst → gastrula →embryo, fetus
What is morphogenesis? When does this start?
A series of events that form distinct structures of the developing organism. Starts at gastrulation.
What is differentiation in embryonic development?
Embryonic cells ability to become different types of cells.
The ectoderm helps to create what part of the body?
Brain, spinal cord, & epidermis.
The mesoderm helps to create what part of the body?
Muscles, Skeleton, and reproductive organs.