Fertilization

Fertilization begins when the ovum and sperm fuse together. Once the ovum is drawn into the fallopian tube it rest in the outer portion of the tube. Here it awaits a sperm to penetrate it. The ovum must be fertilized within 24 hours of entering the tube. If it is not fertilized it degenerates. The ovum then travels down through the fallopian tube and uterus into the vagina. This is when menstruation takes place.

   

1. The sperm: Click play to view a movie of sperm entering the vaginal canal.

2. The sperm penetrates the ovum.

3. Fusion takes place.

4. The sperm embeds itself into the uterus.

5. Embryo begins to grow.