Fetal CNS Flashcards
(41 cards)
What is brachycephaly?
Short, broad head due to premature suture fusion
Commonly seen in certain craniosynostosis conditions.
What is dolichocephaly
Long, narrow head
Often associated with certain developmental conditions.
What is macrocephaly?
An overly large head
Defined as head circumference more than two standard deviations above average for age.
What is microcephaly?
A condition in which a baby’s head is smaller than expected for the baby’s age
Possible causes: Zika virus, rubella, Down syndrome, craniosynostosis, and bacterial menigintis
Can result from various factors including maternal infections and genetic disorders.
What is meningocele?
A defect of the posterior elements of the spine with extrusion of meninges and cerebrospinal fluid (CSF) without the involvement of neural elements
A type of spina bifida.
What is myelomeningocele
Protrusion of a sac from a spinal defect that contains the spinal cord and meninges
It is the most serious type of spina bifida.
What is a neuropore?
Either the rostral or caudal end of the neural tube
Important in the process of neurulation.
What is neurulation?
The process by which the neural tube is formed
Critical for proper CNS development.
What does ‘rostral’ mean?
Toward the cephalic or head end
Used in anatomical terminology.
What are somites?
Embryonic stages of vertebrates
They play a role in the development of the vertebral column and associated structures.
What is the vermis?
Central portion of the cerebellum between the hemispheres
Important for coordination and balance.
What are the stages of neurulation?
- Neural plate
- Neural groove
- Neural folds
- Neural tube final stage
These stages are essential for CNS development.
What happens during the fusion of the neural tube?
Begins in the mid-portion of the embryo and proceeds rostrally and caudally
The rostral end closes on Day 25 and the caudal end on Day 27.
What structures make up the CNS and how common are CNS abnormalities?
- Brain and spinal cord
- 1–2 per 1,000 births (or 1 in 100 by some sources)
What are the closure days for the rostral and caudal neuropores?
Rostral: Day 25, Caudal: Day 27
What happens if the neural tube fails to close?
Neural Tube Defects (NTDs) occur
List the three primary vesicles formed after the closure of the rostral neuropore
- Prosencephalon (forebrain)
- Mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
What brain structures develop from the Prosencephalon?
Cerebral hemispheres, lateral ventricles, thalamus
What brain structures develop from the Mesencephalon?
cerebral peduncles, corpora quadrigemina
What brain structures develop from the Rhombencephalon?
pons, cerebellum, medulla
List the five embryonic brain vesicles?
Forebrain: Telencephalon and Diencephalon
Midbrain: Mesencephalon
Hindbrain: Metencephalon and Myelencephalon
These structures evolve from the primary vesicles.
What is the Diencephalon?
Located between the cerebrum and midbrain, consists of thalamus (“interbrain”) and hypothalamus
The Diencephalon plays a key role in sensory and regulatory functions.
What is the function of the corpus callosum?
Large bundle of 200+ million myelinated nerve fibers that connects the left and right cerebral hemispheres.
What is the Cavum Septum Pellucidum (CSP), and why is it significant?
- It’s a thin membrane connecting the corpus callosum to the columns of the fornix and separating the lateral ventricles
- Its absence may indicate agenesis of the corpus callosum.
