Fertilisation Process

Study Notes

Process: Fertilisation occurs when a sperm penetrates the outer layer of the egg (zona pellucida) and fuses with the egg's nucleus.
Location: Fertilisation typically takes place in the ampulla of the fallopian tube.
Timing: Fertilisation usually occurs within 24 hours after ovulation.
Sperm capacitation: Sperm must undergo capacitation, a process that enables them to penetrate the egg's zona pellucida.
Fusion of gametes: The sperm's nucleus fuses with the egg's nucleus, resulting in a single cell with a complete set of chromosomes (zygote).

Process: Implantation is the process by which the fertilised egg (blastocyst) attaches to the uterine lining (endometrium).
Timing: Implantation typically occurs 6-10 days after fertilisation.
Location: Implantation usually takes place in the upper part of the uterus.
Hormonal regulation: The hormone progesterone prepares the uterine lining for implantation by thickening the endometrium and promoting blood vessel growth.
Adhesion molecules: The blastocyst produces adhesion molecules that facilitate attachment to the uterine lining.
Trophectoderm: The outer layer of the blastocyst (trophectoderm) invades the uterine lining, establishing a connection between the embryo and the mother's bloodstream.
Establishment of pregnancy: Successful implantation marks the establishment of a pregnancy, and the embryo begins to receive essential nutrients and oxygen from the mother's bloodstream.

Fertilisation occurs when a sperm penetrates the outer layer of the egg (zona pellucida) and fuses with the egg's nucleus, resulting in a single cell with a complete set of chromosomes (zygote).
The process typically takes place in the ampulla of the fallopian tube.
Fertilisation usually occurs within 24 hours after ovulation.
Sperm must undergo capacitation, a process that enables them to penetrate the egg's zona pellucida.
Capacitation is necessary for the sperm to fuse with the egg's nucleus.

Implantation is the process by which the fertilised egg (blastocyst) attaches to the uterine lining (endometrium).
The process typically occurs 6-10 days after fertilisation.
Implantation usually takes place in the upper part of the uterus.
The hormone progesterone prepares the uterine lining for implantation by thickening the endometrium and promoting blood vessel growth.
The blastocyst produces adhesion molecules that facilitate attachment to the uterine lining.
The outer layer of the blastocyst (trophectoderm) invades the uterine lining, establishing a connection between the embryo and the mother's bloodstream.
Successful implantation marks the establishment of a pregnancy, and the embryo begins to receive essential nutrients and oxygen from the mother's bloodstream.