The rostral neuropore or anterior neuropore is a region corresponding to the opening of the embryonic neural tube

Neural tube

In the developing vertebrate, the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord...

 in the anterior portion of the prosencephalon

Prosencephalon

In the anatomy of the brain of vertebrates, the prosencephalon is the rostral-most portion of the brain. The prosencephalon, the mesencephalon , and rhombencephalon are the three primary portions of the brain during early development of the central nervous system...

. It closes on day 25 of embryogenesis giving rise to the lamina terminalis

Lamina terminalis

The median portion of the wall of the fore-brain vesicle consists of a thin lamina, the lamina terminalis, which stretches from the interventricular foramen to the recess at the base of the optic stalk and contains the organum vasculosum of the lamina terminalis, which regulates the osmolarity of...

 of the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

.

Failure to Close

Failure of closure of the anterior neuropore during embryogenesis

Embryogenesis

Embryogenesis is the process by which the embryo is formed and develops, until it develops into a fetus.Embryogenesis starts with the fertilization of the ovum by sperm. The fertilized ovum is referred to as a zygote...

 will lead to anencephaly

Anencephaly

Anencephaly is a cephalic disorder that results from a neural tube defect that occurs when the cephalic end of the neural tube fails to close, usually between the 23rd and 26th day of pregnancy, resulting in the absence of a major portion of the brain, skull, and scalp...

, the failure of the brain to develop.

Failure of closure of the posterior neuropore during embyrogenesis will lead to spina bifida

Spina bifida

Spina bifida is a developmental congenital disorder caused by the incomplete closing of the embryonic neural tube. Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to protrude through...

.