Lesson 4 Part 3 Germ Layers and Organogenesis

University:
California State University, Northridge
Course:
BIOL 211 | Human Anatomy
Academic year:

2022
Views:

476

Pages:

1
Author:

Accinkiquicpqw

Part 3: Germ Layers and Organogenesis Q: What are the 3 germinal layers that will germinate the organs of the body? A: Ectoderm, mesoderm, endoderm. Q: The germination process involves cellular ____ and _____. A: Rearrangements; migrations. Q: What is the primitive streak? A: A raised dorsal groove that establishes the longitudinal axis of the embryo. Q: What sets the stage for organogenesis? A: Gastrulation. Q: By what week are all organ systems recognizable? A: By the 8th week. Q: Organogenesis is the series of organized _____ processes that transforms a ____ mass of cells into a complete organ in the developing embryo. The cells of an ________ region undergo differential development and movement to form an organ _______ or ____. A: Integrated; amorphous; organ-forming; primordium; anlage. Q: What is the time frame for the first trimester? A: 0–3 months. Q: What developmental events occur during the first trimester? A: Fertilization, cleavage, implantation, gastrulation, neurulation, organogenesis; all major organ systems are formed; fetus begins to move, but movements cannot be felt. Q: What changes occur during the second trimester? A: Skin and hair grow; eyes blink; fetal movements can be felt; arms and legs reach final proportions; heartbeat can be heard. Q: What changes occur during the third trimester? A: Substantial increase in size; skin is red and wrinkled; development of the lungs is completed; fingernails and toenails grow; fetus can survive if born during this stage.