Which hereditary defect involves incomplete closing of the spine and the membranes around the spinal cord during early development?

Which hereditary defect involves incomplete closing of the spine and the membranes around the spinal cord during early development?

• A. Absence seizure
• B. Spina Bifida
• C. Trismus
• D. Delta Wave

Answer: (B)

When the neural tube in a developing embryo closes, it forms the spine and surrounding protective tissues. If that closure doesn’t happen completely, a neural tube defect can occur. Spina bifida is the classic example of this, involving incomplete fusion of the posterior vertebral arches. In more advanced forms, the membranes around the spinal cord (the meninges) may herniate through the opening, sometimes with the spinal cord involved. That’s why you hear terms like meninges protruding or, in more severe cases, myelomeningocele where both membranes and spinal cord tissue herniate. The result is varying degrees of impaired motor and sensory function below the defect, along with potential complications such as bladder or bowel dysfunction. There’s a hereditary and nutritional component to risk, notably folic acid deficiency during pregnancy, which is why supplementation helps reduce incidence. The other options describe conditions that aren’t related to spinal closure defects—absence seizures are a type of seizure, trismus is a jaw spasm, and delta waves are an EEG finding.

When the neural tube in a developing embryo closes, it forms the spine and surrounding protective tissues. If that closure doesn’t happen completely, a neural tube defect can occur. Spina bifida is the classic example of this, involving incomplete fusion of the posterior vertebral arches. In more advanced forms, the membranes around the spinal cord (the meninges) may herniate through the opening, sometimes with the spinal cord involved. That’s why you hear terms like meninges protruding or, in more severe cases, myelomeningocele where both membranes and spinal cord tissue herniate. The result is varying degrees of impaired motor and sensory function below the defect, along with potential complications such as bladder or bowel dysfunction. There’s a hereditary and nutritional component to risk, notably folic acid deficiency during pregnancy, which is why supplementation helps reduce incidence. The other options describe conditions that aren’t related to spinal closure defects—absence seizures are a type of seizure, trismus is a jaw spasm, and delta waves are an EEG finding.