The human body is full of fascinating reflexes—automatic responses that help us react quickly to different stimuli. While some, like the knee-jerk reaction, are well known, others are much less commonly discussed. These uncommon reflexes serve important biological purposes and can provide insights into neurological health. This article delves into rare human reflexes, explaining their mechanisms and significance.
1. Palmar Grasp Reflex
The palmar grasp reflex occurs in newborns when an object touches their palm, causing them to automatically grip it. This reflex is believed to be an evolutionary remnant from our primate ancestors who needed a strong grip to cling to their mothers. The reflex usually disappears by six months of age. If it persists beyond this period, it could indicate developmental or neurological concerns.
External Link: Stanford Children’s Health
2. Plantar Reflex
The plantar reflex involves the curling of the toes when the sole of the foot is stroked. In infants, an abnormal response known as the Babinski reflex causes the big toe to extend upward while the others fan out. This response is normal in infants but could indicate neurological issues if seen in adults.
Interesting Fact: This reflex is often tested by doctors to assess nerve function in the spinal cord and brain.
3. Galant Reflex
When the skin along a newborn’s back is stroked, they instinctively move toward the side being touched. This reaction, known as the Galant reflex, helps during birth and early motor development. It generally disappears by six months but, if retained, may contribute to posture or coordination issues.
4. Asymmetrical Tonic Neck Reflex (ATNR)
Often called the “fencing reflex,” the ATNR occurs when an infant turns their head to one side. In response, the arm on that side extends while the opposite arm bends. This reflex plays a role in early hand-eye coordination but should integrate into normal motor control by six months.
5. Symmetrical Tonic Neck Reflex (STNR)
The STNR is seen in infants when the head moves up or down, triggering corresponding arm and leg movements. This reflex is crucial for crawling development but should disappear by the first year. If retained, it may impact posture, balance, and coordination.
6. Tonic Labyrinthine Reflex (TLR)
The TLR causes changes in muscle tone based on head positioning. When an infant tilts their head back while lying down, their body stiffens. This reflex is important for balance and spatial awareness but should integrate within the first year of life.
7. Moro Reflex
Also known as the startle reflex, the Moro reflex occurs when an infant hears a loud sound or experiences sudden movement. The baby will extend their arms and legs outward, then quickly retract them. This reflex is a survival response that typically disappears by five months.
8. Babinski Reflex
The Babinski reflex is a variant of the plantar reflex, where stroking the foot results in the big toe extending upwards while the others fan out. While normal in infants, its presence in adults may indicate neurological disorders like multiple sclerosis or brain injury.
9. Parachute Reflex
The parachute reflex develops around six months of age and helps protect a baby from falls. When the infant is tilted forward, their arms extend outward as if preparing to catch themselves. This reflex remains throughout life and plays a crucial role in balance and motor development.
External Link: Cleveland Clinic
10. Swimming Reflex
Newborns instinctively perform swimming-like movements when placed in water. This primitive reflex, present at birth, disappears by six months. Although it may seem like an infant can swim, supervision is always required to prevent accidents.
Uncommon reflexes provide valuable insights into human development and neurological function. While these automatic responses generally integrate with age, their persistence can sometimes indicate underlying conditions. Understanding these reflexes can help parents and medical professionals monitor early development and neurological health.
By exploring these lesser-known reflexes, we can gain a deeper appreciation for the body’s natural instincts and the intricate connections between the brain, nerves, and muscles. If you notice unusual reflexes persisting beyond infancy, consulting a medical professional is always advisable.
READ MORE: Why Do We Get Goosebumps? The Science Behind Your Body’s Ancient Alarm System
