Introduction
A reflex is an involuntary or automatic action that your
body does in response to something without even
having to think aboutit
Neonatal reflexes – inborn reflexes present at birth &
occur in a predictablefashion
Normally developing newborn should respond to
certain stimuli with thesereflexes
Reflex arc
Anatomical pathway for a reflex is
called as reflex arc
It has 5 components :
Receptor
Afferent nerve
Center
Efferent nerve
Effectororgan
Classification of reflexes
Depending upon whether inborn or acquired
Unconditioned reflexes, inborn reflex
Conditioned reflexes/acquired reflexes
Depending upon the situation of the center
Cerebellar reflexes
Cortical reflex
Midbrain reflex
Bulbar or medullary reflexes
Spinal reflexes
Depending upon the purpose
Protective/flexor reflexes
Antigravity/extensor reflexes
Depending upon clinical basis
Superficial reflexes
Mucus membrane
Cutaneous reflex
Deep reflexes
Visceral reflexes
Pathological reflexes
Significance of reflexes
Helps to identify whether the child is developing
normally or not
Tells about what abnormalities the child may be
having if all reflexes are not proper
Knowledge of development of motor skills – helps to
identify whether development is going on at a proper
rate or not
General body reflexes
Moro reflex/ startle reflex
Begins at 28weeks of gestation
Initiated by any sudden movementof
the neck
Elicited by -- pulling the baby halfway
to sitting position from supine &
suddenly let the head fall back
Consists of rapid abduction & extension
of arms with the opening of hands,
tensing of the back muscles, flexion of
the legs and crying
• It is similar to moro reflex, but it is initiated by
sudden noise or any other stimulus
• In this, the elbows are flexed and the hands
remain closed, there is less of embrace, outward
and inward movement of arms.
STARTLE
REFLEX
Within moments, the arms come together again
Clinical significance
Its nature gives an indication of muscle tone
Failure of the arms to move freely or the hands toopen
fully indicates hypotonia.
It fades rapidly and is not normally elicited after 6
months of age.
Palmar/grasp reflex
Begins at 32weeks ofgestation
Light touch of the palmproduces
reflex flexion of the fingers
Most effective way -- slide the
stimulating object, such as afinger
or pencil, across the palm fromthe
lateral border
Disappears at 3-4months
Replaced by voluntary grasp at45
months
Clinical significance
Exceptionally strong grasp reflex -- spastic form of cerebral
palsy & Kernicterus
May be asymmetrical in hemiplagia & in cases of cerebral
damage
Persistence beyond 3-4months indicate spastic form of
palsy
Plantar/grasp reflex
Placing object or finger beneath the
toes causes curling of toes around the
object
Present at 32weeks ofgestation
Disappears at 9-12 months
• Clinical significance :
This reflex is referred to as the
"readiness tester".
Integrates at the same time that
independent gait first becomes
possible.
Walking/stepping
reflex
When sole of foot is pressed
against the couch, baby tries to
walk
Legs prance up & down as if baby
is walking or dancing
Present at birth, disappearsat
approx 2-4 months
With daily practice of reflex,
infants may walk alone at 10
months
Limb placement reflex
When the front of the leg below the
knee or the arm below the elbow is
brought into contact with the edge
of a table, child lifts the limbs over
the edge
Present at birth, fades awayrapidly
in early months of life
• Clinical significance
Reflex is readily demonstrable in the
newborn and persistent failure to
elicit it at this stage, is thought to
indicate neurological abnormality
Withdrawal reflex
Protective reflex
Stimulus :a pinprick or asharp
painful stimulus to sole of foot
Response :flexion & withdrawal of
stimulated leg
Present at birth, persists throughout
life
Clinical significance – Absence of
this is seen in neurologically impaired
infants.
Asymmetric tonic neck reflex
Most evident between 2-3months ofage
When the baby is at rest and not crying,
he lies at intervals with his head on one
side, the arm extended to the same side,
and often with a flexion of the contra
lateral knee.
• Clinical significance
This reflex normally disappears after 2
or 3 months, but may persist in spastic
children.
Symmetric tonic neck
reflex
Extension of the head causes
extension of the fore limbs and
flexion of the hind limbs
Evident between 2-3months ofage
Clinical significance
Not normally easily seen or elicitedin
normal infants
May be seen in an exaggerated form
in many children with cerebral palsy.
Babinski’s reflex
Stimulus consists of a firm painful stroke
along the lateral border of the sole fromheel
to toe
Response consists of movement (flexion or
extension) of the big toe and sometimes
movement (fanning) of the othertoes
Present at birth, disappears at approx9-10
months
Presence of reflex later may indicate disease
Babkin reflex
Deep pressure appliedsimultaneously
to the palms of both hands while the
infant is in supine position
Stimulus is followed by flexion or
forward bowing of the head, opening of
the mouth and closing of the eyes
Fades rapidly and normally cannot be
elicited after 4 months of age.
• Clinical significance
Reflex can be demonstrated in the newborn, thus showing
a hand-mouth neurological link, even at that early stage
It appears at
about 6-9
months and
persists
thereafter.
The reflex is elicited
by holding the child in
ventral suspension
and suddenly
lowering him to
couch. The arms
extend as defensive a
defensive reaction.
In children with
cerebral palsy,
the reflex may
be absent or
abnormal.
It would be
asymmetrical
in spastic
hemiplegia.
Landau reflex
Seen in horizontal suspension with the
head, legs & spine extended
If the head is flexed, hip knees &
elbows also flex
Appears at approximately 3months,
disappears at 12-24 months
• Clinical significance
Absence of reflex occurs in hypotonia,
hypertonia or mental abnormality
Trunk incurvation reflex
Stroking one side of spinal column
while baby is on his abdomencauses
Crawling motion with legs
Lifting head from surface
Present in utero, seen at
approximately 3rdor 4th day
Persists for 2-3 months
Gallant’s reflex
Firm sharp stimulation along sides of
the spine with the fingernails or a pin
produces contraction of the underlying
muscles and curving of the back.
Response is easily seen when theinfant
is held upright and the trunk
movement is unrestricted
Best seen in the neonatal period and
thereafter graduallyfades.
Tendon reflexes
Simple monosynaptic reflexes, which are elicited bya
sudden stretch of a muscletendon
Occurs when the tendon istapped
Present throughout life
Clinical significance
Useful diagnostically for :
Detection of upper motor neuron lesions(exaggerated
response)
Myopathic conditions (depressed or absentresponse)
Localization of the segmental lesions of thecord.
Tonic labyrinthine reflex
Labyrinths -- most importantorgans
concerned with the development of
anti-gravity postures and balance
Movement of the head in any
dimension stimulates the labyrinths;
and produces the appropriate
responses
Arms & legs extend when head moves
backwards, & will curl in when the
head moves forward
Emerges in utero until approximately
4 months postnatally
Facial reflexes
Nasal reflex
Stimulation of the face or nasal cavity with water orlocal
irritants produces apnea in neonates
Breathing stops in expiration with laryngeal closure in
infants – bradycardia & lowering of cardiac output
Blood flow to skin, splanchnic areas muscles & kidney
decreases
Flow to the heart & brain remains protected
Blink reflex
A bright light suddenly shone into the eyes, a puff ofair
upon the sensitive cornea or a sudden loud noise will
produce immediate blinking of the eyes
Purpose – to protect the eyes from foreign bodies &bright
light
May be associated tensing of the neck muscles, turning of
the head away from the stimulus, frowning and crying
Reflexes are easily seen in the neonate and continue to be
present throughout life
Clinical significance
Examination is a part of some neurological exams,
particularly when evaluatingcoma
Satisfactory demonstration of these reflexes indicate–
No cerebral depression
Contraction of appropriate muscles in response
Doll’s eye reflex
(Oculocephalic reflex)
Passive turning of the head of
the newborn leaves the eye
“behind”
A distinct time lag occurs before
the eyes move to a new position
in keeping with the head position
Disappears at within a weekor
two of birth
Failure of this reflex to appear
indicates a cerebral lesion
Head
Eye
Auditory orientingreflex
A sudden loud and unpleasant noise :
May produce the blink reflex
Infant may remain still and show increased alertness
Quieter sounds usually cause reflex eye and head turning tothe
side of the sound, as if to locate it
Seen first at about 4 months of age
Thereafter, head turning towards sound stimuli occurs and the
accuracy of localization increases rapidly by 9-10 months
Clinical significance
Reflex responses are made use of in tests of infants for
hearing loss
Pattern of the localization responses indicates the level of
neurological maturity
CORNEAL
REFLEX
• Consists of blinking
when cornea is
touched
PUPIL REFLEX
• Pupil reacts to light, but in
preterm baby and some
full term babies the
duration of exposure to
the light may have to be
prolonged to elicit the
reflex.
Oral reflexes
Rooting reflex
Baby’s cheek is stroked :
They respond by turning their head
towards the stimulus
They start sucking, thus allowingfor
breast feeding
When corner of mouth is touched, lower
lip is lowered, tongue moves towards the
point stimulated
When finger slides away, head turns to
follow it
When center of lip is stimulated, lip
elevates
Onset is 28
weeks IU
Disappears
by 3-4
months
Well-
establised
by 32-34
weeks IU
Sucking / Swallowing
reflex
Touching lips or placing something in
baby’s mouth causes baby to draw
liquid into mouth by creating vacuum
with lips, cheeks & tongue
Onset – 28weeks IU
Well established – 32-34weeks IU
Disappears around 12months
Clinical significance :
Persistence may inhibit voluntary sucking
Sigmund Freud - Any kind of deprivation of the
activity will lead to fixation resulting in oral habits
Gag reflex
(Pharyngeal reflex)
Seen in 19weeks of IU life
Reflex contraction of the back
of the throat
Evoked by touching the roof of
the mouth, the back of the
tongue, the area around the
tonsils and the back of the
throat
Functional significance
It, along with reflexive pharyngeal swallowing, prevents
something from entering the throat except as part of
normal swallowing and helps prevent choking
Clinical significance
Absence of the gag reflex -- symptom of a number of
severe medical conditions :
Damage to the glossopharyngeal nerve, the vagus nerve,
Brain death.
It is a non-
conditioned
reflex which
accounts for its
lack of individual
character and is
of sporadic
nature.
Starts as early as
21-29 weeks IU life.
Importance of cry
It is infant’s first verbal communication
Can be interpreted as a message of urgency ordistress
Indicates:
Hunger
Pain
Discomfort
Begins around 12 and half
weeks IU life.
Full swallowing and
sucking is established by
32-36 weeks of IU life.
Their absence in full-term
baby would suggest a
developmental defect.
INFANTILE
SWALLOW
•ACQUIRED
CONGENITAL REFLEX
•Until primary molars erupt,
infant swallows with jaws
separated and the tongue
thrust forward using facial
muscles.
•This is non-conditional
congenital reflex.
•After eruption of posterior
primary teeth, from18
months of age onwards, the
child tends to swallow with
teeth brought together by
masticatory muscle action,
without a tongue thrust.
Conclusion
Appropriate knowledge of reflexes enables apaedodontist
to identify whether the child is developing normallyor
not
to identify whether development is going on at a proper
rate or not
Knowledge of abnormalities if all reflexes are not proper