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Flashcards in Intro Deck (25):

Define the following:

-Prenatal period: 

-Perinatal period: 

-Postnatal period: 

-Neonatal period: 



-Puberty(girls &boys are dif.): 


A.Prenatal period: the period of gestation that is prior to birth

B. Perinatal period: 22 Weeks gestation to 28 days after birth

C. Postnatal period: after birth

•  Neonatal period: up to 1 month after birth

•  Infancy: first postnatal year

•  Childhood: 12 months to 12-13 years

•  Puberty: 10-15 years (girls); 12-17 years (boys)

•  Adolescence: 3-4 years post-puberty


A clinician might say a pregnancy lasts for how long? what would a patient say?

-40 weeks

-9 months


To an embryologist, what are the stages of fetal development?




  1. preimplantation

  2. embryonic

  3. fetal stage


Describe what happens during the Prenatal weeks:

•Week 1: 

•Week 2: 

•Week 3: 

•Weeks 3-8: 

•Week 9 to term: 

•Week 1: Preimplantation stage: zygote, morula, blastocyst

•Week 2: Inner cell mass forms bilaminar embryo

•Week 3: Bilaminar embryo becomes trilaminar embryo

•Weeks 3-8: Embryonic period – organogenesis (all organs are made)

•Week 9 to term: Fetal period - Growth and differentiation


The first 2 weeks after fertilization are the ____ _ ____ period which means?

What is common in this phase?

“all or nothing”

If something goes wrong, the embryo will not survive.

Miscarriages/spontaneous abotions


The ______ stage starts at week 3 and goes until week 8, _____ will be formed. This is a _____ period; what does this mean?

  • embryonic
  • organs
  • critical period
  • harmful agent of any sort (physical, chemical, radiation) can cause then a major anomally. This is where things can go very wrong. 


Weeks 9-38 are called the _____ _____. what would happen if an injury were to occur during this time?

  • fetal period
  • the injury is most likely to produce minor structural defects or functional abnormalities


what is Gestational age (GA)? 

the age of the embryo/fetus from the presumed first day of the last menstrual period – clinical notion


what is Fertilization age?

Which is longer Fertilization age or GA? Why?


The age of the embryo/fetus from the fertilization day – not used as such

GA is approximately 2 weeks longer than the fertilization age because the oocyte is not fertilized until about 2 weeks after the last Menstrual Period (around ovulation time) when gestational age is counted.


EDD is what? 

What is the Naegele's rule?

___% of women deliver on their due date while 60-70% deliver within 13 days from their due date. Why the variation?


Expected Delivery Date

  • first day of LMP – 3 months +1 year +1 week
  • 5%
  • different time length of the period prior to ovulation; after ovulation, the period between ovulation and menstruation is fairly constant, at 14 days


What is an Abortion? An abortion happens before what time in development?

expulsion/removal of the embryo/fetus from uterus prior to age of viability- does not matter how it happens

22-23 weeks gestation


What is a misscarriage?

What is it a synonym for?

What are the majority caused by?


Miscarriage is spontaneous expulsion from uterus of embryo/fetus relatively early (usually < 20 weeks);

synonym = spontaneous abortion

à majority are caused by chromosomal abnormaliti


Premature infants are born between stage of _____ and ___ weeks. A majority are caused by ______ _____ of the pregnancy.

What is a still born?

viability (22-23 wks) and 37 weeks

Maternal complications

A baby that is born dead but after 22 wks?


what are PGCs?

These are Identified during the ___ week in the ____ ____ and are important for ______. During week 4-6, they migrate to the ____ ____ ___ area. PGCs wil then continue to multiply by _______ during their migration.

Primordial Germ cells


yolk sac


future genital ridge

mitosis during their migration


After moving to the primitive genital ridge, PGCs stimulate the surrounding ______ to create the ____ ____ ___. The swelling becomes the ______ _____. The PGCs are now called _____ (same cells w/ new name). In females the somatic support cells will become ____ ____ while in males they will become ____ ____ .

  • epithelium
  • somatic support cells
  • Primitive Gonad
  • gonocytes
  • ovarian follicles (female)
  • Sertoli cells (male)


Gonocytes will undergo _____. In a female, they will become _____ and they will become ____ in males. The basic chromosomal events of the process are the same in the two sexes afterwards. Both will undergo Several ______ divisions and two _____ divisions. However, the timing of the _______ of germ cells is different in the male and female

  • mitosis
  • oogonia
  • spermatogonia
  • mitotic
  • meiotic
  • maturation


•Gonocytes  have ____ pairs of chromosomes for a total of ___ chromosomes this makes them _____ cellls. One chromosome from of each pair comes from each parent. There are __ pairs of matching, homologous chromosomes called ______ and two ____ ______ that determine sex of the individual. 


  • 23
  • 46
  • diploid
  • 22
  • autosomes
  • sex chromosomes (X&Y)


Mature gametes are ____ cells which means they have ___ copy(ies) of each chromosome(s). This is because during _______, the number is _____ by____ during the _____ division. 










Describe Gametogenisis. Label the process in each blue box and label the teal box and say if diploid or haploid

Q image thumb

A image thumb

Oogonias divide by MITOSIS by the ___ week of pregnancy& the number of germ cells in the ovary reaches its max (7 mil); Most of them ________. Surviving cells have entered _______ of ____ ___ and each is tightly enclosed in a ______ ________. By ____, only 700,000 to 2 million oogonias remain and even more degenerate. By puberty, only about ________ remain

  • 20
  • degenerate
  • prophase of meisis 1
  • primary follicle
  • birth
  • 400,000


Before birth, all primary oocytes are suspended in _____ of ____ ____ . ____ primary oocytes form after birth

•The primary oocytes remain dormant in the _____ _____ until _____. At puberty,  __-___ _____ develop/month, but one is _____. The primary oocyte will _____ in ___ and shortly before _______ completes the first _____ division. It now is a ______ ____ and a ____ ____ that are both _____, but the secondary follicle takes almost all of the _____.  At ovulation, the nucleus of the secondary oocyte begins the second _____ division, but progresses only to ______, when division is arrested. If a _____ penetrates the secondary oocyte, the second meiotic division is completed

prophase of meiosis I


ovarian follicles until puberty

5-12 follicles


increase in size



secondary follicle 

polar body











______ inside the embryonic male gonad remain dormant from 6th week until ______ and does not end until _____. 200-300 million sperms are produces per ___.  Simpler process that is prone to less errors! The entire spermatogenesis process takes about ___ _____.

  • Spermatogonias
  • puberty
  • death
  • day
  • 2 months


In spermatogenesis, at puberty, _____ will cause _____ ____ differentiate into _____ ______. _______ (which are still PGC's) resume development and divide several times through _____ to become primary _____ which are ___ cells. The cells are gradually translocated from the basal to the ____ side of the _______ ______ while spermatogenesis takes place. Primary spermatocytes complete, without interruption,  ___  _____ divisions  to form 2 ___ ____ followed by 4 ______. As they migrate, the spermatids undergo maturation and go through _______ or the differention of the ___ ___.

  • testosterone
  • sertoli cells
  • seminiferous tubules
  • spermatogonias
  • mitosis
  • spermatocytes
  • diploid
  • luminal
  • seminiferous epithelium
  • 2 meiotic 
  • secondary spermocytes
  • spermatids
  • spermiogenesis
  • sperm cell. 


In the Embryp....

  1. Proximal and distal mean?
  2. Superior and inferior are equivalent to ____(____) and _____
  3.  A median plane is ____ section down the _____
  4. Anterior and posterior are equivalent to_____ and___

Q image thumb

  1. close or far away from center
  2. Cranial (rostral) and caudal
  3. logitudinal,middle
  4. Dorsal and ventral