![]() Formation of the cranial flexures: Final configuration is shown. The roof of the mesencephalon becomes thinned as a result of the pontine flexure and produces the roof of the fourth ventricle.įormation of the flexures: Shown are the three flexures that have formed by the fifth embryonic week. Pontine flexure: A third flexure, the pontine flexure, occurs during the fifth embryonic week between the mesencephalic and cervical flexures and is concave ventrally. ![]() Cervical flexure: The cervical flexure occurs at the junction of the metencephalon and spinal cord.Mesencephalic flexure: The mesencephalic flexure occurs around the mesencephalon.From Larsen (12).Ĭoncave bending of the neuraxis (primary flexures) occurs during the fourth embryonic week. Myelencephalon: The myelencephalon develops into the medulla.įormation of the secondary vesicles: Shown are the five secondary vesicles that form during the fifth embryonic week. The sharp, ventrally concave bend in the developing midbrain of the embryo.Metencephalon: The metencephalon forms the pons and cerebellum.Mesencephalon: The mesencephalon remains unchanged and gives rise to the tectum (superior and inferior colliculi), midbrain tegmentum, and cerebral peduncles.Diencephalon: The diencephalon develops into the hypothalamus, thalamus, epithalamus, neural retina, and pineal body.Telencephalon: The telencephalon forms the cerebrum and basal ganglia.From Larsen (12).ĭuring the fifth embryonic week, five secondary vesicles develop from the primary vesicles: Prosencephalon – two secondary vesicles The cranial neural tube during the fourth embryonic week divides into three morphologically and histochemically distinct primary vesicles:įormation of the primary vesicles: Formation and progression of the mesencephalic and cervical flexures are shown. The spinal cord is caudal to the myelencephalon and remains unsegmented. At the top of the ascending colon, the colon abruptly bends to the left, forming the right colic flexure (also called the hepatic flexure).The formation of the cranial vesicles and flexures provides further development and segmentation of the brain and occurs in two phases ( 3, 10, 11, 12). It is usually located on the right side of the body, extending from the cecum upward. The ascending colon (or right colon) is the beginning part of the colon. In this regard, is the hepatic flexure part of the ascending colon? It lies more cranial than the right colic flexure. The phrenicocolic ligament attaches the splenic flexure to the left hemidiaphragm. called also right colic flexure.įurthermore, why is the left colic flexure higher than the right? Left colic flexure (or splenic flexure) is the bend in the large intestine in the left upper quadrant of the abdomen as the transverse colon continues as the descending colon. Medical Definition of hepatic flexure : the right-angle bend in the colon on the right side of the body near the liver that marks the junction of the ascending colon and the transverse colon. Likewise, what does hepatic flexure mean? It receives blood supply from the superior mesenteric artery. The hepatic flexure lies in the right upper quadrant of the human abdomen. The right colic flexure or hepatic flexure (as it is next to the liver) is the sharp bend between the ascending colon and the transverse colon.
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