Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 25

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  embryonic period
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The anlage of the subarachnoid space is seen in embryos at stage 14 (33 days) in the innermost zone of the primary meninx as irregular spaces on the ventral surface of the spinal cord. At first this space is only on the ventral surface of the spinal cord. From stage 18 (44 days) on, when the dura mater proper is formed, the reticular tissue of the primary meninx and spaces are around the circumference of the spinal cord. These spaces gradually coalesce and contain many blood vessels.
The aim of study is to investigate the development of the anal canal in human embryos and foetuses. In embryos at stage 19 the boundary between the ectodermal and endodermal linings of the anal canal is located just below the level of the internal anal sphincter muscle. Histological sections showed that the first signs of anal columns are observed in embryos at stage 21 (51 days).
Investigations were made on .serial sections of human embryos at developmental stage 23 (56 days). The oculomotor complex in embryos at this stage consists of lateral, median, and accessory nuclei. The lateral (chief) nucleus forms the greatest part of the oculomotor complex and it is subdivided into ventromedial and dorsolateral groups. Between the posterior portions of lateral nuclear groups is the median nucleus. Dorsally and medially to the lateral nucleus is the accessory (parasympathetic) nucleus.
Investigations were made on serial sections of human embryos at developmental stages from 13 to 23 (32-56 postovulatory days). The trochlear nucleus appears in the posterior region of the basal plate of the midbrain at stage l3. It is composed of large neurons, the processes of which are sharply defined. Since stage l5 the trochlear fibers can be followed through the alar region to their decussation in the mid-dorsal part of the midbrain. The trochlear nerve emerges from the dorsal surface of the lowest part of the midbrain.
Study was carried out on serial section of 45 human embryos of stages 13 to 23. The urorectal septum develops from three folds: single superior and two lateral ones. Development of the urorectal septum begins at stage 13 when the superior fold between the hindgut and allontois appears. At stage 15, all three folds unite to from complete septum, reaching the cloacal membrane and dividing the cloaca into anterior compartment, the primary urogenital sinus and the posterior compartment rectum.
The length of the humerus was measured in 69 staged human embryos at developmental stages 18–23 (7 and 8 weeks). It was found that the length of the humerus increases from 2.0 mm at stage 18 to 5.4 mm at stage 23. There were slight variations at certain of the stages investigated. Asymmetry between limb lengths was not found during the embryonic period under examination.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.