The tissues derived from the ectoderm are: some epithelial tissue (epidermis or outer layer of the skin, the lining for all hollow organs which have cavities open to a surface covered by epidermis), modified epidermal tissue (fingernails and toenails, hair, glands of the skin), all nerve tissue, salivary glands, and …

amniotic egg. A shelled, water-retaining egg with four membranes that enables reptiles, birds, and egg-laying mammals to complete their life cycles on dry land. amnion. thin innermost membranous sac that surrounds the developing embryo of higher vertebrates (reptiles, birds and mammals) that secretes amniotic fluid.

Which of the following INCORRECTLY matches the primary germ layer with the formed structures? All of the above are correct. Organogenesis gives rise to recognizable adult organ systems from the three primary germ layers by the end of the embryonic period at 8 weeks.

Germ layer, any of three primary cell layers, formed in the earliest stages of embryonic development, consisting of the endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer).

The mesoderm gives rise to the skeletal muscles, smooth muscle, blood vessels, bone, cartilage, joints, connective tissue, endocrine glands, kidney cortex, heart muscle, urogenital organ, uterus, fallopian tube, testicles and blood cells from the spinal cord and lymphatic tissue (see Fig.

The extraembryonic mesoderm supports the epithelium of the amnion and yolk sac as well as the villi, which arise from the trophoblastic tissue. It also is involved in the development of the fetal blood. On day 12 of human development, the extraembryonic mesoderm splits to form the chorionic cavity.

The resulting cavity between the somatopleure and splanchnopleure is called the intraembryonic coelom. This space will give rise to the thoracic and abdominal cavities….

There are three types of structural body formation present in animals related to coelom:

• Acoelomate: Coelom is absent. The blastocoel is completely occupied by mesoderm.
• Pseudocoelomate: True coelom is not present. The blastocoel is partly filled by mesodermal cells.
• Eucoelomate: Animals that have a true coelom.

The fetal membrane surrounds the fetus during pregnancy and is a thin tissue composed of two layers, the chorion and the amnion. While rupture of this membrane normally occurs at term, preterm rupture can result in increased risk of fetal mortality and morbidity, as well as danger of infection in the mother.

An extraembryonic membrane is one of the membranes which assist in the development of the embryo. Such membranes occur in a range of animals from humans to insects. They originate from the embryo, but are not considered part of it. They typically perform roles in nutrition, gas exchange, and waste removal.

Four embryonic membranes form to support the growing embryo: the amnion, the yolk sac, the allantois, and the chorion. The chorionic villi of the chorion extend into the endometrium to form the fetal portion of the placenta.

First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst. Inside the uterus, the blastocyst implants in the wall of the uterus, where it develops into an embryo attached to a placenta and surrounded by fluid-filled membranes.

During the second week of human development, the blastocyst attaches to the wall of the uterus. The cells in the blastocyst’s outer layer are called trophoblast cells, and they penetrate into the uterus, establishing a connection between the blastocyst and the mother.