Ninja nerd Embryology | Fertilization, Cleavage, Blastulation video

"What is the anatomical term for the ""sheath"" or birth canal in the female reproductive system?"

Vagina 🛡️

"What is the lower- narrow portion of the uterus that connects to the vagina?"

Cervix 🚪

"What is the rounded- top-most portion of the uterus called?"

Fundus 🏰

In which specific part of the fallopian tube is fertilization intended to occur?

Ampulla 🎯

What are the finger-like projections at the end of the fallopian tubes that catch the egg?

Fimbriae 🖐️

Which brain structure initiates the reproductive cycle by releasing $GnRH$?

Hypothalamus 🧠

What does the abbreviation $GnRH$ stand for?

Gonadotropin-Releasing Hormone 🚀

Which gland is stimulated by $GnRH$ to secrete Luteinizing Hormone ($LH$)?

Anterior Pituitary 💡

"Besides $GnRH$- what other hormone provides positive feedback to trigger the $LH$ surge?"

Estrogen ✨

What effect does $LH$ have on the graafian follicle in the ovary?

It increases fluid and pressure to trigger ovulation 🎈

Which enzymes are activated to break down connective tissue so the egg can pop out of the ovary?

Metalloproteinases ✂️

"At the time of ovulation- the egg is technically at what developmental stage?"

Secondary oocyte 🥚

The secondary oocyte is arrested in which specific phase of meiosis until fertilization?

$Metaphase\ II$ 🛑

What is the name of the cellular layer surrounding the secondary oocyte during ovulation?

Corona radiata 👑

What must sperm undergo to remove cholesterol and prep for meeting the egg?

Capacitation 🚿

What specific protein on the egg's surface acts as a receptor for sperm?

$ZP3$ receptor 🔑

Which part of the sperm head releases hydrolytic enzymes to burrow through the egg's layers?

Acrosome 🧨

How many paternal chromosomes are delivered by the sperm cell?

$23$ 🧬

How many total chromosomes are found in a human zygote?

$46$ (Diploid) 👨‍👩‍👧

What is the single-cell stage called immediately after the fusion of sperm and egg?

Zygote 🌱

The process of the zygote rapidly dividing into multiple smaller cells is known as _____.

Cleavage ✂️

What is the name of the stage when the developing embryo consists of exactly two cells?

Two-cell stage 👯

How many cells are present in the embryo after the third round of cleavage division?

$8$ cells 🎱

"What is the name for the ""hollow ball of cells"" containing $16$ or more cells?"

Morula ⚽

What are the individual cells that make up the morula called?

Blastomeres 🔵

The process of the morula developing into a blastocyst is called _____.

Blastulation 🎈

What is the fluid-filled space inside a blastocyst called?

Blastocyst cavity 💧

Which part of the blastocyst consists of a clump of cells at one end?

Inner Cell Mass 🧶

The Outer Cell Mass of the blastocyst eventually differentiates into the _____.

Trophoblast 🛡️

The Inner Cell Mass of the blastocyst differentiates into the _____.

Embryoblast 👶

Which part of the blastocyst is responsible for helping form the placenta?

Trophoblast 🌳

The Embryoblast eventually develops into which two-layered structure?

Bilaminar disk 🥞

The Trophoblast differentiates into the Syncytiotrophoblast and the _____.

Cytotrophoblast 🧱

What are the two layers of the bilaminar disk?

Epiblast and Hypoblast ↔️

Approximately how long does the journey from ovulation to the specialized blastocyst take?

One week 📅

Term: Zona Pellucida

Definition: The protective protein membrane surrounding the oocyte and zygote 🛡️

What is the primary role of the Hypothalamus in the menstrual cycle?

Releasing neuro-peptides like $GnRH$ to signal the pituitary 📡

Why is it important that the oocyte stays in $Metaphase\ II$?

It is waiting for the sperm to trigger the completion of meiosis ⏳

Concept: Diploid Cell

Definition: A cell like the zygote that contains two full sets of chromosomes ($46$ total) 🧬

Where does the sperm travel immediately after passing through the cervix?

Body of the uterus 🗺️

What happens to the $ZP3$ receptors once a sperm cell successfully touches them?

They activate the sperm to release enzymes and fuse membranes 💥

Which specific hormone tells the ovary to pressurized the follicle with fluid?

Luteizing Hormone ($LH$) 🌊

"During the first week- the embryo moves from the fallopian tube toward the _____."

Uterus 🏠

What is the chronological first step in the embryology timeline discussed?

Ovulation 🥚

What is the chronological second step in the embryology timeline?

Fertilization 🤝

Step three of the first week involves rapid cell division called _____.

Cleavage 📈

The fourth major stage of the first week where the morula changes shape is _____.

Blastulation 🏗️

The outer layer of the blastocyst is the _____ Cell Mass.

Outer ⭕

The inner clump of the blastocyst is the _____ Cell Mass.

Inner 📍

What will the Epiblast and Hypoblast eventually form together?

The embryo 👶