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The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, dentin, peripheral and enteric ...
Epidermal thickenings called Rete ridges (or rete pegs) extend downward between dermal papillae. [7] Blood capillaries are found beneath the epidermis, and are linked to an arteriole and a venule. The epidermis itself has no blood supply and is nourished almost exclusively by diffused oxygen from the surrounding air. [8]
In neuroanatomy, a gyrus (pl.: gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg. : sulcus ). [ 1 ] Gyri and sulci create the folded appearance of the brain in humans and other mammals .
The lobes are large areas that are anatomically distinguishable, and are also functionally distinct. Each lobe of the brain has numerous ridges, or gyri, and furrows, sulci that constitute further subzones of the cortex. [2] The expression "lobes of the brain" usually refers only to those of the cerebrum, not to the distinct areas of the ...
Generally speaking, the ectoderm differentiates to form epithelial and neural tissues (spinal cord, nerves and brain). This includes the skin, linings of the mouth, anus, nostrils, sweat glands, hair and nails, [3] and tooth enamel. Other types of epithelium are derived from the endoderm. [3]
The apical ectodermal ridge (AER) is a structure that forms from the ectodermal cells at the distal end of each limb bud and acts as a major signaling center to ensure proper development of a limb. After the limb bud induces AER formation, the AER and limb mesenchyme —including the zone of polarizing activity (ZPA)—continue to communicate ...
The cerebrum (pl.: cerebra), telencephalon or endbrain [1] is the largest part of the brain, containing the cerebral cortex (of the two cerebral hemispheres) as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system.
After formation of the tube, the brain forms into three sections; the hindbrain, the midbrain, and the forebrain. The types of neuroectoderm include: Neural crest. pigment cells in the skin; ganglia of the autonomic nervous system; dorsal root ganglia. facial cartilage; aorticopulmonary septum of the developing heart and lungs; ciliary body of ...