Spike Walker (2011) CIL:39092, Homo sapiens, egg, sperm, cumulus cell. CIL. Dataset

Light micrograph of human ovum (egg) and sperm. The ovum is much larger than the sperm and is surrounded by protective cumulus cells around the outside surface (yellow). The membrane surrounding the ovum (brown) is the zona pellucida. The head of the sperm carries special enzymes to dissolve the zona pellucida, which is required in order to fertilise the egg. This image was taken from a failed human IVF procedure. IVF is a widely used technique that allows infertile couples to have their own children by taking egg cells from the mother and fertilising with sperm cells from the father externally to the body, before implanting the resultant embryo back into the womb.

人卵（卵子）与精子之光学显微镜图像。卵子相较于精子体积显著较大，其外围被一层保护性的卵丘细胞所环绕（黄色）。环绕卵子的膜（棕色）即为透明带。精子的头部携带有溶解透明带的特殊酶，此过程对于受精卵子至关重要。该图像源自一次失败的人体试管婴儿（IVF）手术。试管婴儿技术是一种广泛应用于不孕夫妇，通过从母亲体内取出卵细胞，并与父亲提供的精子细胞体外受精，随后将形成的胚胎重新植入子宫的辅助生殖技术。