Reflexes + postural reactions Flashcards
What is a reflex
Automatic movement without conscious volition, usually initiated by sensory stimulation
Protective reflexes
Reflex with a purpose of protecting us from noxious stimuli (DTR, withdrawal, cross extension)
Components of a protective reflex
Stimulus
Predictable response
Limited modulation of response
Lifelong
Neonatal reflexes
Building blocks of movement
Provide 1st change in distribution of muscle tone
Adaptive utility
Can be used to determine gestational age in premature infants
Become less apparent over time
How can neonatal reflexes be used to determine gestational age in premature infants
Premies can have missing reflexes
How can neonatal reflexes be used to evaluate CNS health?
By knowing expected time frames of when they start to when they stop
Can evaluate if reflexes don’t go away when expected or come back
Similarities between protective reflexes and neonatal reflexes
Both have stimulus + response
Both have a protective/useful function
Differences between protective and neonatal reflexes
Neonatal reflexes become less pronounced over time
Neonatal reflexes get replaced by something more volitional + sophisticated
What are examples of neonatal reflexes
Rooting
Sucking
Stepping
Grasp
Startle (Morrow)
Galant
Attitudinal reflexes
Influence tone; opportunities for movement
Not protective in nature
Examples of attitudinal reflexes
ATNR (asymmetric tonic neck reflex(
STNR (symmetric tonic neck reflex)
Clinical relevance of neonatal reflexes
Failure of neonatal reflexes to appear at the appropriate age, or to assist beyond a certain age implies abnormal functioning of the nervous system
Stereotypical + obligatory neonatal reflexes
Abnormal at every age
Lack of variability in response to repeated stimulus (across multiple reflexes typically)
When are neonatal skills at their strongest?
At term (40 weeks)
How does strength of neonatal reflex change over time
Bell curve: weaker before 40 weeks, and weaker after 40 weeks
Relationship between strength of neonatal reflexes and postural reactions + volitional movement
Inverse
As the baby ages, neonatal reflexes decrease as postural reactions and volitional movements increase
Postural reactions
Motor skills that develop over first years of life and form basis for attainment of functional motor skills
Postural reactions vs reflexes
Postural reactions are learned, developed and last for a lifetime
Reflexes are born with and lost
Roll of postural reactions
Maintaining the body in an upright position in response to the position of the body
Last a lifetime to support movement + balance
What type of stimuli do postural reactions respond to in comparison to neonatal reflexes?
More global stimuli
Neonatal righting reactions
Neonatal neck righting
Body righting
Head/body follow each other while rolling
When do key head righting reactions happen?
Prone: 2-3 months
Side lying/lateral: 4 months
Supine: 5-6 months
Main goal of head righting reaction
Keep face vertical and mouth horizontal