Reflex

Definition

A stereotyped (involuntary) motor response elicited by a defined stimulus. Template:Fn

Explanation

A reflex action or reflex is a biological control system linking stimulus to response and mediated by a reflex arc. Reflexes can be built-in or learned.

Reaction time

For a reflex, reaction time is the time from the onset of a stimulus until the organism responds.

Mechanism

A reflex mechanism involves a receptor organ, and effector organ, and some type of communication network.

Ivan Pavlov unintentionally launched the study of conditioning by establishing a way of producing what he called "conditional reflexes", i.e. reflexes that would only be seen conditional on previous experiences of the subject.

Reflex actions seen in adult humans include:

• Accommodation reflex
• Achilles reflex
• Anocutaneous reflex
• Babinski reflex
• Biceps stretch reflex
• Brachioradialis reflex
• Crossed extensor reflex
• Mammalian diving reflex
• Gag reflex
• Gastroc-Soleus reflex
• Patellar reflex (knee-jerk reflex)
• Photic sneeze reflex
• Pupillary reflex
• Quadriceps reflex
• Salivation
• Sneeze
• Triceps stretch reflex
• Vestibulo-ocular reflex
• Withdrawal reflex

Processes such as breathing, digestion and the maintenance of the heartbeat can also be regarded as reflex actions, according to some definitions of the term.

Newborn babies have a number of other reflexes which are not seen in adults, including:

• suckling
• hand-to-mouth reflex
• Moro reflex, also known as the startle reflex

See also

• Autonomic nervous system
• Sensory system
• Spinal nociceptive reflex

External links

• Reflexes in newborn babies

References

Template:Fnb Purves (2004). Neuroscience: Third Edition. Massachussets, Sinauer Associates, Inc.