The suckling reflex and infantile swallow normally disappear by the age of:
**Core Concept**
The suckling reflex and infantile swallow are primitive reflexes that are present in newborns. These reflexes are essential for feeding and are mediated by the brainstem. As infants grow and develop, these reflexes gradually mature and eventually disappear.
**Why the Correct Answer is Right**
The suckling reflex and infantile swallow normally disappear by the age of 3-4 months. This is because the maturation of the brainstem and the development of the cerebral cortex lead to the suppression of these primitive reflexes. The suckling reflex is mediated by the trigeminal nerve and the facial nerve, while the infantile swallow is mediated by the vagus nerve. As the infant's nervous system matures, the excitatory input from these nerves is gradually reduced, leading to the disappearance of these reflexes.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the suckling reflex and infantile swallow do not normally disappear in the first month of life.
**Option B:** This option is incorrect because the suckling reflex and infantile swallow do not normally disappear by the age of 6 months.
**Option C:** This option is incorrect because the suckling reflex and infantile swallow do not normally disappear by the age of 2 months.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the disappearance of the suckling reflex and infantile swallow is a normal developmental milestone. However, if these reflexes persist beyond the age of 4-6 months, it may indicate an underlying neurological disorder.
**Correct Answer: C. 2 months**