Developmental Anatomy Flashcards
Study of developmental events occurring prior to birth?
Embryology
Development can be broken down into two functions. What are these two functions?
Differentiation and Reproduction
Formation and organization of all diverse cell types.
Differentiation
New individuals are produced from generation to generation.
Reproduction
The first 38 weeks of human development that begins with the fertilization and ends with birth is the _______ period?
Prenatal period
What 3 periods separate the prenatal period?
- Pre-embryonic period
- Embryonic period
- Fetal period
How long is the pre-embryonic period?
The first 2 weeks of development
How long in the embryonic period?
The 3rd - 8th week of development
How long is the fetal period?
The last 30 weeks of development.
What are the developmental processes called that occur in preembryonic and embryonic periods?
Embryogenesis
The embryonic process where the zygote undergoes mitotic cell division to form blastocyst.
Cleavage
The embryonic process where blastocyst forms 3 primary germ layers.
Gastrulation
The embryonic process where 3 primary germ layers
arrange themselves to give rise to all organs in the body.
Organogenesis
What is the process whereby two sex cells fuse to
form a new cell containing genetic material derived from both parents?
(Haploid sperm reaches haploid secondary oocyte)
Fertilization
Where does fertilization occur?
In ampulla of uterine tube
What path does sperm take to achieve fertilization?
- Sperm swim from the vagina to the cervix
- Mainly pass through the uterus and uterine
tubes due to contraction of the walls of
these structures
What is gametogenesis?
Production of sex cells (gametes)
What are gametes?
Sex cells
What is produced in gametogenesis? (Hint: Chromosomes, autosomes).
23 pairs of chromosomes, 22 autosomes, and 1 sex cell
In gametes, these contain genetic information for characteristics.
Autosomes
What determines sex?
Sex chromosomes
Male =_____ vs Female =_____
Male = XY Female = XX
Are gametes diploid or haploid?
Haploid
What cellular division produces 2 diploid cells that
are identical to the parent cell?
Mitosis
What cellular division produces 4 haploid cells that are genetically different from the parent cell?
Meiosis
What combines genes from both parents onto one homologous chromosome?
Meiosis
A single secondary oocyte is produced – 22
autosomes and 1 X chromosome
• Parent cells = oogonia in ovaries
• Oogonia go through mitosis to produce up to
two million cells in the embryo
• Oogonia differentiate into primary oocytes that
will start meiosis
• Primary oocytes will arrest in prophase I of
meiosis until puberty
• At puberty some primary oocytes will begin to
complete meiosis each month
Meiosis results in unequal division with
one cell receiving most of the cytoplasm and organelles – this is the secondary oocyte, the other cell is a
polar body
• The secondary oocyte is arrested in
metaphase II
• At ovulation, the secondary oocyte will
be released and travel to the uterus
Oogenesis
The secondary oocyte is ovulated…… True or False?
True
What surrounds the secondary oocyte?
Corona radiata - cuboidal cells
Zona pellucida - A thin ring of proteins and glycoproteins
What is the male sex cell?
Sperm
What is the parent cell in spermatogenesis?
Spermatogonia
What does spermatogonia give rise to?
Two primary spermatocytes (exact copies of parent)
Each primary spermatocyte gives rise to?
Two secondary spermatocytes
How many chromosomes does the primary spermatocyte have?
43 chromosomes
How many chromosomes does the secondary spermatocyte have?
23 chromosomes
What is spermiogenesis?
The maturation of sperm
What happens following spermiogenesis?
Sperm is transported through seminiferous tubules and stored in epididymis of testes.
Which of the following will occur during the pre-embryonic period? a. Gastrulation b. Organogensis c. Implantation d. Neurulation e. None of the above
c. Implantation
Which of the following is true of meiosis? a. It produces genetically identical cells b. It produces diploid cells c. It produces cells with 46 chromosomes d. It produces cells with 23 chromosomes e. None of the above
___________ represent the first haploid stage of spermatogenesis.
a. Spermatogonia
b. Primary spermatocytes
c. Secondary spermatocytes
d. Spermatids
e. Spermatozoa
d. Spermatids
Fertilization generally occurs in the:
a. Ampulla of uterine tube
b. Ovary
c. Fimbriae of uterine tube
d. Cervix
e. Uterus
a. Ampulla of uterine tube
What happens once sperm reaches female reproductive tract?
Undergo capacitation
What happens to the acrosome in capacitation?
Glycoprotein coat and some proteins are removed from the plasma membrane that covers acrosome.
What process allows the sperm to respond to chemotropic signals, gain hyper
motility, interact with zona pellucida, undergo acrosome react and fuse with oocyte plasma membrane?
Capacitation
What does the sperm motility penetrate?
The corona radiata
Membrane proteins in the sperm head
bind to ZP3, and acrosomal enzymes are
released to digest a path in the ___________.
Zona pellucida
In fusion, what happens when the sperm meets the oocyte?
The membranes fuse
Only the sperm _______ enters the oocyte cytoplasm.
nucleus
The secondary oocyte completes meiosis to form ______.
ovum
What are the nuclei of the sperm and ovum called?
pronuclei
During fusion, what do the pronuclei fuse to form?
A single diploid nucleus (a zygote)
After fertilization, the zygote begins rapid mitotic division. What is this called?
Cleavage
Does cleavage increase total volume? Yes or No
No
During cleavage, what is each daughter cell called?
blastomere
What is the 8-cell stage called where cells
become tightly compacted into ball?
Compaction
What is it called when cells divide again, forming a 16-cell stage?
Morula
What happens when morula enters uterine cavity?
Blastocyst forms
What is the blastocyst cavity?
A large fluid filled space
When the blastocyst forms, what two populations of cells arise?
- Trophoblast
2. Embryoblast