Chapter: ? Development Flashcards
(30 cards)
What is the difference between male and female gametes?
The size and amount produced
What is the prenatal period?
Time between conception and birth
o Formation of a zygote, up to birth
What is the embryonic period?
Conception to the first 8 weeks
What is the fetal period?
8 weeks to birth
What is the uterus?
where organisms will develop
What are the ovaries?
where female gametes are produced and then released
What is the Oviduct (Fallopian tube)?
- Lateral third of the fallopian tube: where the sperm “attack”
- Where the female gamete finally finishes meiosis
What are the fimbria?
cilia that “catch” the eggs between ovary and fallopian tube
What is a zygote?
a diploid cell produced by the interaction between male and female gametes
o Sperm brings 23 chromosomes. Egg brings 23 chromosomes
What happens by the fifth day?
o As you divide, the zygote makes its way down the fallopian tube
By the 5th day, the zygote has split into 4 cells
What is a morula?
A collection of 12-16 cells
What is a blastocyst?
Blastocyst was differentiated from the morula
o (inner cell mass, blastocyst cavity, trophoblast)
o Reaches uterus around day 4
o Implantation of blastocyst on day 7
Into the uterine wall (endometrium)
What happens to the inner wall around the 7/8th day?
Differentiates into the epiblast and the hypoblast
What is the epiblast layer?
o Organism and the amniotic sac (water cushion that surrounds the uterus)
Single layer of cells
Primitive streak, tail, and node
•(Gastrulation)
What is the hypoblast layer?
Yolk sac
What does the tropoblast become after 7 or 8 days?
Placenta
What happens during gastuaration?
o Formation of the three primary germ layers Ectoderm: become skin Mesoderm: become heart, bones Endotherm: become lungs, gut o Formation of Primitive streak
What happens around day 14-15?
Migration of cells from the Epiblast on the dorsal surface through the primitive streak displace underlying hypoglast cells (will become the endotherm)
What happens during day 16?
Mesoderm later forms through movement of the epiblast cells through primitive streak
What happens to left over cells after the mesoderm forms from the primitive streak?
Left over cells become ectoderm
Describe the formation of the notochord
o Is a stiffening rod (located under ectoderm) that is later modified into cartilage in the vertebrate
Runs towards the head of the embryotic disc
o Sends signals the ectoderm
Cells under the notochord differentiate into the neural plate to make our nervous system
Forms the nervous system/ nervous tissue
o Neural folds have closed forming the neural tube
Neuralation: neural tube is invaginated down to the mesoderm, forming the neural groove
Folic acid prevents problems with neural tube
• Top portion will become cortex, other part will become spinal cord
What happens to the ectoderm during day 24?
• Ectoderm will fold to form a cylindrical shape, like folding paper into a tube (Day 24)
o Can start to see the adult body plan
When can the human body plan be seen?
day 28
What is the function of the yolk sac?
To provide nutrients until week 4