Fertilization Process

What is the primary function of the removal of membrane proteins during capacitation?

What is the term for the condition where multiple sperm fuse with the oocyte?

During which stage of fertilization does the sperm lose its tail?

What is the resulting product of the fusion of sperm with the oocyte?

What is the primary characteristic of the cell divisions during cleavage?

Where does the process of capacitation occur?

What is the purpose of the corona radiata and zona pellucida?

What is the stage of fertilization that occurs immediately after sperm deposition in the vagina?

What is the main purpose of the abundant cytoplasm in the conceptus during pre-embryonic cleavages?

What would happen to the endometrium if the implanted blastocyst did not secrete human chorionic gonadotropin (hCG)?

What is the primary function of the syncytiotrophoblast cells during implantation?

What is the main benefit of a small surface area-to-volume ratio for the zygote?

What is the typical duration of the implantation process?

What structures are formed as the pre-embryo floats to the uterus?

What is the role of the LH-like hormone human chorionic gonadotropin (hCG) during implantation?

How does the blastocyst obtain nutrients during its journey to the uterus?

Fertilization is the process of forming a fertilized egg, resulting from sperm deposition in the vagina during copulation.
Sperm must undergo capacitation, a gradual process of membrane protein removal and release, to penetrate the egg.
Capacitation occurs as sperm travel through cervical mucus, uterus, and uterine tubes, enabling them to penetrate the oocyte.
Hundreds of capacitated sperm must break through the corona radiata and zona pellucida to fuse with the oocyte plasma membrane.
Once fused, the sperm loses its tail and migrates to the center of the oocyte, completing meiosis II and forming a diploid zygote.

Cleavage is the process of rapid mitotic divisions in the zygote, occurring as it travels down the uterine tube towards the uterus.
Cell growth periods between divisions are very short, resulting in smaller daughter cells.
Pre-embryonic cleavages utilize the abundant cytoplasm of the conceptus, dividing rapidly without changing the total volume.
A small surface area-to-volume ratio is beneficial to the zygote, allowing for efficient diffusion of nutrients and waste.

Implantation begins around day 6-7 after ovulation, as the blastocyst floats to the uterine cavity.
The endometrium's special glycoproteins aid in blastocyst implantation, and the trophoblast cells attach to the endometrium.
Syncytiotrophoblast cells invade and digest the endometrium, covering and sealing off the implanted blastocyst within a short time.
Implantation takes about a week and is completed by the 14th day after ovulation, maintained by human chorionic gonadotropin (hCG) secreted by the trophoblast cells.