Lab Exam 2: Chapter 29, Human Development Flashcards
What period occurs from fertilization through week 8?
Embryonic Period
What period is week 9 through birth?
Fetal Period
Neonatal refers to what?
The first 28 days (four weeks), of a child’s life.
How many trimesters are in the pre-natal period?
3 trimesters
What occurs during the 1st trimester?
Major organs are developing and a fetus is most susceptible to drugs, radiation and microbes.
What occurs during the 2nd trimester?
Anatomical and physiological systems are nearly developed and beginning to develop human-like features.
What occurs during the 3rd trimester?
A period of rapid fetal growth which the weight of the fetus doubles. Most organ systems become fully functional.
What occurs during capacitation (capacit= capable of)?
- Tail beats harder
- Sperm breakdown, releasing cholesterol, glycoproteins, and proteins.
- Acrosomal enzymes breakdown the corona radiata
- sperm receptors (zp3) form on the zona pellucida
What is fast blockage of polyspermia?
When the oocyte’s cell membrane depolarizes and blocks the sperm receptors
What is slow blockage of polyspermia?
When the oocyte releases Ca, and that Ca hardens the zona pellucida creating a hardened shell to prevent multiple sperm from fertilizing.
How do fraternal twins develop?
- Dizygotic
- Two oocytes and two sperm
- Two placentas
How do identical twins develop?
- Monozygotic
- One fertilized ovum
- Identical genome
- Developing cell splits into two by day 8, or conjoined twins will be the result.
How long does it take for mitosis to occur after ovulation? How long does it take to complete?
24 hours; 6 hours
Estrogen and Progesterone are produced by what during the first 3-4 months during pregnancy? Afterwards produced by what?
Corpus Luteum; placenta
What hormone will taper off, causing the corpus luteum to die off.
HCG
