Developmental Anatomy
Stage 4: Lab Manual - Horizon 4
- Length 0.1 -0.2 mm.
- The above specimen is the blastocyst of the Macaque monkey.
- Stage 4, the onset of implantation, is reserved for the attaching blastocyst.
- Implantation includes:
- a. Dissolution of the zona pellucida, and contact and attachment (adhesion) between the blastocyst and endometrium.
- b. Penetration.
- c. Migration of the blastocyst through the endometrium.
- Ovulation age: 5 - 6 days
Developmental Stages in Human Embryos by Ronan O'Rahilly and Fabiola Müller.
Published by Carnegie Institution of Washington, Publication 637. 1987.
Stage 4 (PDF 27 KB)
QUESTION: What are the three parts of implantation?
