HSCI 100 Lecture 22: HSCI 100 (4)
Document Summary
Human chorionic gonadotrop (hcg) is secreted maintain the corpus luteum and the endometrium. The inner cell mass detaches itself and becomes the embryonic disk that will go through a strulation to become 3 primary germ layers (endoderm, mesoderm, and ectoderm) Morula: solid ball of cells formed as the zygote undergoes cleavage. Early blastocyst: hollow ball of cells with a fluid filled cavity. Late blastocyst: pre embryo with the embryonic disk, two layers of cells that becomes the embryo proper. Gastrula: embryo with 3 primary germ layers (ectoderm, mesoderm, and endoderm) Ectoderm (out)- epidermis of skin, epithelial lining of oral cavity and rectum: nervous system. Mesoderm (middle)- skeleton, muscular system, dermis of skin, cardiovascular system, urinary system, reproductive system, outerlayers of respiratory and digestive system. Endoderm (inner)- epithelial lining of digestive tract and respiratory tract; associate glands of those systems; epithelial lining of urinary bladder. The neural tube will become the spinal cord and brain.