Download Plantar reflex or Babinski reflex

Practical Physiology
REFLEXES
Prepared and presented By
Dr. Mohammed chyad Al-Noaemi
NERVOUS SYSTEM
Reflex, is an involuntary and nearly instantaneous
movement in response to a stimulus.
Monosynaptic Reflex as stretch reflexes (knee jerk reflex).
Multisynaptic Reflex as withdrawal reflex (nociceptive R.)
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Types of Reflexes:
Superficial Reflexes.
Deep Reflexes.
Eye Reflexes.
Superficial Reflexes
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Abdominal reflexes (T6-L1)
Plantar reflex or Babinski reflex (L5, S1, S2)
Anocutaneous reflex (S2-S4)
Cremasteric reflex (L1-L2)
Abdominal Reflex (T6-L1)
Plantar reflex or Babinski reflex (L5, S1, S2)
In normal adults the plantar reflex causes a downward
response of the hallux (flexion). An upward response
(extension) of the hallux is known as, Babinski response
or Babinski sign,
Its presence can
identify disease
of the spinal cord
and brain in adult
and also exists as
a primitive reflex
in infants
Plantar reflex or Babinski reflex
(L5, S1, S2)
The lateral side of the sole of the foot is rubbed with a
blunt instrument or device so as
not to cause pain, discomfort, or
injury to the skin; the instrument
is run from the heel along a curve
to the toes.
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Plantar reflex or Babinski reflex
(L5, S1, S2)
Babinski's Sign in
a healthy newborn
Pathological Babinski's
sign in adult
Plantar reflex or Babinski reflex
(L5, S1, S2)
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Normal
Adult
Abnormal
Infant
Normal
Cremasteric Reflex (L1-L2)
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The cremasteric reflex is a superficial reflex
observed in human males.
This reflex is elicited by lightly stroking the
superior and medial (inner) part of the thigh.
The normal response is a contraction of the
cremaster muscle that pulls up the scrotum and
testis on the side stroked.
Stretch reflexes
(Monosynaptic Reflexs)
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The stretch reflexes (often called deep tendon reflexes).
Generally, decreased reflexes indicate a peripheral
problem (PNS), and lively or exaggerated reflexes a
central problem (CNS).
Biceps reflex (C5, C6)
Brachioradialis reflex (C5, C6, C7)
Extensor digitorum reflex (C6, C7)
Triceps reflex (C6, C7, C8)
Patellar reflex or knee-jerk reflex L2, L3, L4)
Ankle jerk reflex (Achilles reflex) (S1, S2)
Stretch reflexes
(Monosynaptic Reflexs)
Patellar reflex or knee-jerk reflex
(L2, L3, L4)
Patellar reflex or knee-jerk reflex
(L2, L3, L4)
Patellar reflex or knee-jerk reflex
(L2, L3, L4)
Patellar reflex or knee-jerk reflex
(L2, L3, L4)
Patellar reflex or knee-jerk reflex
(L2, L3, L4)
Ankle jerk reflex (Achilles reflex)
(S1, S2)
Triceps Reflex
Neuro-Brachial-Radialis Reflex
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Supination Reflex
The jaw jerk reflex or the
masseter reflex
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is a reflex used to test the status of a patient's
trigeminal nerve (CN V). The mandible—or
lower jaw—is tapped at a downward angle just
below the lips at the chin while the mouth is
held slightly open. In response, the masseter
muscles will jerk the mandible upwards.
Normally this reflex is absent or very slight.
However in individuals with upper motor
neuron lesions the jaw jerk reflex can be quite
pronounced
Withdrawal reflex
(nociceptive or flexor withdrawal R.)
is a spinal reflex intended to protect the body
from damaging stimuli. A classic example is
when a person touches something hot and
withdraws their hand from the hot object
without thinking about it. The heat stimulates
temperature and pain receptors in the skin,
triggering a sensory impulse that travels to the
central nervous system. The sensory neuron
then synapses with interneurons that connect to
motor neurons.
Vestibulo–ocular reflex
is a reflex eye movement that stabilizes images on the
retina during head movement by producing an eye
movement in the direction opposite to head
movement, thus preserving
the image on the center of
the visual field. For example,
when the head moves to the
right, the eyes move to the
left, and vice versa
Vestibulo–ocular reflex
Withdrawal reflex (cont.)
Some of these send motor impulses to the flexors
to allow withdrawal; some motor neurons send
inhibitory impulses to the extensors so flexion is
not inhibited - this is referred to as reciprocal
innervation. While all of this occurs, other
interneurons relay the sensory information up to
the brain so that the person becomes aware of
the pain and what happened
Withdrawal reflex (cont.)
Crossed Extensor reflex
Crossed extensor reflex is a withdrawal reflex.
 When the reflex occurs the flexors in the
withdrawing limb contract and the extensors
relax, while in the other limb, the opposite
occurs.
 An example of this is when a person steps on a
nail, the leg that is stepping on the nail pulls
away, while the other leg takes the weight of the
whole body
Crossed extension reflex
following withdrawal reflex
Crossed extension reflex
following withdrawal reflex
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Once a pain receptor has been stimulated, the
signal travels via the sensory nerve to the
posterior horn of the spinal cord. The nerve
synapses with ipsilateral motor neurons that exit
the anterior horn of the spinal cord and work to
pull the injured body part away from danger. At
the same time the sensory neuron synapses with
the ipsilateral motor neuron, it also synapses
with the motor neuron in the contralateral
anterior horn. This motor neuron stabilizes the
Crossed extension reflex
following withdrawal reflex
cont.
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This motor neuron stabilizes the uninjured side of the
body (for instance, preparing the opposite leg to
support the entire body weight when the other foot has
stepped on a tack). At the same time as these two
synapses, the sensory neuron also sends signals up the
spinal cord to get motor neurons to contract muscles
that shift the center of gravity of the body to maintain
balance. This contralateral stimulation of motor
neurons to stabilize the body is called the crossed
extension reflex, and is a result of the withdrawal reflex
(usually in the lower extremities
Grading
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In medicine, reflexes are often used to assess the
health of the central nervous system. Doctors
will typically grade the activity of a reflex on a
scale from 0 to 4:
Grade
Description
0
Absent
1+ or +
Hypoactive
2+ or ++
"Normal"
3+ or +++
Hyperactive without clonus
4+ or ++++
Hyperactive with clonus
Eye Reflexes
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1. Conjunctiva Reflex.
2. Pupillary Light Reflex.
3. Accommodation Reflex (Convergence reflex).
4. Vestibulo-ocular reflex.
Blink Reflex (CR: V&VII)
(Corneal reflex), (conjunctiva reflex).
Blinking of both eyes when the cornea of
either eye is touched, to protect the eye.
it is an involuntary blinking of the eyelids elicited
by stimulation (such as touching of a foreign body)
of the cornea. Stimulation should elicit both a
direct and consensual response (response of the
opposite eye). The reflex consumes a rapid rate of
0.1 second. The blink reflex also occurs when sounds
greater than 40-60 dB are made
Accommodation Reflex
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It is a reflex action of the eye, in response to focusing
on a near object, then looking at distant object (and
vice versa), comprising coordinated changes in
vergence, lens shape and pupil size. It is dependent on
cranial nerve II (afferent limb of reflex), superior
centres and cranial nerve III.
Accommodation to near vision
 Convergence of eyes
 Pupillary constriction
 Increase lens convexity.
Accommodation Reflex
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Light from a single point of a distant object and
light from a single point of a near object being
brought to a focus.
The Pupillary Light Reflex
(C.R.II&III)
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is a reflex that controls the diameter of the pupil,
in response to the intensity (luminance) of light
that falls on the retina of the eye, thereby
assisting in adaptation to various levels of
darkness and light, in addition to retinal
sensitivity. Greater intensity light causes the
pupil to become smaller (allowing less light in),
whereas lower intensity light causes the pupil to
become larger (allowing more light in). Thus, the
pupillary light reflex regulates the intensity of
light entering the eye
Pupillary Light Reflex
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pupillary light reflex. When the light is turned
on, the pupil reacts by constricting
Pupillary Light Refelex
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Under normal conditions, the pupils of both
eyes respond identically to a light stimulus,
regardless of which eye is being stimulated.
Light entering one eye produces a constriction
of the pupil of that eye, the direct response, as
well as a constriction of the pupil of the
unstimulated eye, the consensual response.
Comparing these two responses in both eyes is
helpful in locating a lesion
Vestibulo-ocular reflex
Movement of the eyes to the right when the head
is rotated to the left, and vice versa
Reflexes involving cranial nerves
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Name
Pupillary light reflex
Accommodation reflex
Jaw jerk reflex
Corneal reflex, (blink reflex)
Vestibulo-ocular reflex
Gag reflex
Sensory
II
II
V
V
VIII
IX
Motor
III
III
V
VII
III, IV, VI
X
Reflexes usually only observed in
human infants
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Newborn babies have a number of other
reflexes which are not seen in adults, referred to
as primitive reflexes. These include:
Tonic neck reflex (TNR)
Grasp reflex
Hand-to-mouth reflex
Moro reflex, also known as the startle reflex
Rooting reflex
Sucking
Grasp reflex
Tonic neck reflex (TNR)
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is a primitive reflex found in newborn humans, but
normally vanishes around six months of age.
When the face is turned to one side, the arm and
leg on the side to which the face is turned
extend and the arm and leg on the opposite side
bend.
Tonic Neck Reflex
Moro Reflex
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It is normally present in all infants/newborns up to
4 or 5 months of age, and its absence indicates a
profound disorder of the motor system. An absent
or inadequate Moro response on one side is found
in infants with hemiplegia, brachial plexus palsy, or a
fractured clavicle. Persistence of the Moro response
beyond 4 or 5 months of age is noted only in infants
with severe neurological defects. It was discovered
and first described by Austrian pediatrician Ernst
Moro (1874-1951).
Moro reflex
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This reflex is a response to unexpected loud
noise or when the infant feels like it is falling. It
is believed to be the only unlearned fear in
human newborns
Moro Reflex
Rooting reflex
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The rooting reflex is present at birth; it assists in
breastfeeding, disappearing at around four
months of age as it gradually comes under
voluntary control. A newborn infant will turn his
head toward anything that strokes his cheek or
mouth, searching for the object by moving his
head in steadily decreasing arcs until the object
is found. After becoming used to responding in
this way (if breastfed, approximately three weeks
after birth), the infant will move directly to the
object without searching
Rooting reflex
Sucking reflex
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The sucking reflex is common to all mammals
and is present at birth. It is linked with the
rooting reflex and breastfeeding, and causes the
child to instinctively suck at anything that
touches the roof of their mouth and suddenly
starts to suck simulating the way they naturally
eat. There are two stages to the action:
Expressio: activated when the nipple is placed
between a child's lips and touches their palate.
They will instinctively press it between their
tongue and palate to draw out the milk.
Babkin Reflex
the application of pressure to both palms. Infants
may display head flexion, head rotation or
opening of the mouth, or a combination of
these responses.
Walking/stepping reflex
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The walking or stepping reflex is present at
birth; though infants this young can not support
their own weight, when the soles of their feet
touch a flat surface they will attempt to 'walk' by
placing one foot in front of the other
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