Week 2 of human development: The “week of twos”
Trophoblast goes wild Early in the second week, some trophoblast cells lose their cell membranes and coalesce into a mass of cytoplasm with many scattered nuclei (= a syncytium). Called the syncytiotrophoblast, this invasive mass burrows into the spaces between endometrial cells, pulling the blastocyst into the endometrium. The trophoblast cells internal to the syncytiotrophoblast […]
Week 1 of human development
The zygote undergoes mitotic divisions About 24 hours after fertilization, the zygote begins to move down the uterine tube toward the uterine cavity while undergoing a series of mitotic cell divisions called cleavage. Each division produces daughter cells called blastomeres. No cell growth occurs during early cleavage, so each mitotic division produces smaller and smaller […]
2. Early embryology: Weeks 1–4
In this chapter Optional Reading Embryology resources Langman’s Medical Embryology, 15th ed., chapters 3, 4, 5, and 6. There are a number of good Internet sites dealing with human embryology, some with animations. We have included a few here: Medical Animations: YouTube channel devoted to embryology animations. Embryology: G’day! Dr. Hill’s site in Australia has […]
1. Introduction to anatomy
Anatomy is the study of the structure of the human body, from the molecular to the macroscopic, and includes the examination of development and functional significance. It is the structural setting in which function occurs. Philosophy of teaching and learning anatomy Anatomy is much more than knowing “the hip bone is connected to the thigh […]