Stretch Reflex
Transcript of Stretch Reflex
STRETCH STRETCH REFLEXREFLEX
Group 3ConsunjiCuaDe LeonDolencio
ObjectivesObjectives
To elicit and observe examples of stretch reflexes
To analyze abnormal reflex responses from a knowledge of the reflex pathways.
TheoryTheoryReflexReflexReflex is an involuntary response to
a stimulus by the animal organism. It consists of the stimulation of an afferent nerve through a sense organ, or receptor, followed by transmission of the stimulus to an efferent motor nerve, resulting in action of a muscle or gland, called the effector.
Stretch Reflex ( Deep Tendon Stretch Reflex ( Deep Tendon Reflex)Reflex)
Brisk contraction of a muscle when stimulated by a sharp tap by the rubber reflex hammer on the part where the muscle is inserted is the deep tendon reflex(DTR) or the stretch reflex.
How is a Stimulus Detected? Some cells are specialized to react to
a specific stimulus.These are called receptors.
When the receptor is stimulated, it sends a message to a
part of your body that effects the correct response. This is
called the effector.
How the Message Travels How the Message Travels From theFrom theReceptor to the Effector.Receptor to the Effector.
How is the Hammer Tap How is the Hammer Tap Detected?Detected?
◦Stretch receptor: muscular spindles -Provide the central nervous system with sensory
information regarding the muscle length and the rate of change in the muscle length
Each muscle spindle measures about 1 to 4 mm in length and is surrounded by a fusiform capsule of connective tissue.
Within the capsule are the Intrafusal muscle fibers and outside the muscular spindles are the Extrafusal muscle fibers.
Types of Intrafusal Fibers Types of Intrafusal Fibers and Its Sensory Endingsand Its Sensory Endings
Nuclear bagNuclear chain
Two types of sensory Two types of sensory innervation of muscle innervation of muscle spindles:spindles:
Annulospiral endings
Flower-spray endings
How the Message Travels How the Message Travels From theFrom theReceptor to the Effector.Receptor to the Effector.
Stretch ReflexStretch Reflex
Response ReflexesResponse Reflexes
STATIC RESPONSE-primary and secondary endings-slowly stretched
DYNAMIC RESPONSE-primary endings-rapid change in spindle length
Dynamic ReflexDynamic Reflex-elicited by dynamic signal from
primary endings of muscle spindle
-instantaneous, strong reflex contraction
Purpose of Stretch Purpose of Stretch ReflexesReflexesThe stretch reflexes (often called
deep tendon reflexes) provide information on the integrity of the central and peripheral nervous system.
Generally, decreased reflexes indicate a peripheral problem, and lively or exaggerated reflexes a central one.
ProcedureProcedureANKLE JERK KNEE JERK
TRICEPS JERK BICEPS JERK
RESULTSRESULTSREFLEX RESPONSE (Movement Elicited) NATURE OF RESPONSE (Brisk, Weak)
1)Achilles Tendon Reflex (Ankle jerk)
Right Left Relaxed (Right and Left)
Monkey Grip (Right and Left)
Plantar flexion of ankle joint on tapping the Achilles tendon
Plantar flexion of ankle joint on tapping the Achilles tendon
Weak plantar flexion of ankle joint
Brisk plantar flexion of ankle joint
2) Patellar Tendon Reflex (Knee Jerk) Extension of knee
joint on tapping the patellar tendon
Extension of knee joint on tapping the patellar tendon
Weak extension of knee joint
Brisk extension of knee joint
3) Triceps Tendon ReflexExtension of the elbow joint
Extension of the elbow joint
Weak extension of the elbow joint
Clenched Teeth (Right and Left)
brisk extension of the elbow joint
4) Biceps Brachii Tendon Reflex Flexion of the elbow
joint by tapping the biceps tendon
Flexion of the elbow joint by tapping the biceps tendon
Weak flexion of the elbow joint
Brisk flexion of the elbow joint
JENDRASSIK MANEUVERJENDRASSIK MANEUVERA reinforcement of the reflexMonkey gripUsed to distract the patient to
enhance the chances of obtaining the reflex.
DiscussionDiscussion REFLEX ARC
-refers to the neural pathway that a nerve impulse follows. The reflex arc typically consists of five components (5):
1. The receptor at the end of a sensory neuron 2. The sensory (afferent) neuron 3. The integration center consists of one or more
synapses in the CNS. 4. A motor (efferent) neuron 5. An effector
Muscle Spindle (Stretch Muscle Spindle (Stretch Reflex)Reflex)
Monosynaptic and Monosynaptic and Polysynaptic reflex arcPolysynaptic reflex arc
MONOSYNAPTIC◦-consists of single sensory and motor◦-presence of a single chemical synapse
POLYSYNAPTIC◦-one or more interneurons connect
sensory and motor signals◦-number of synapse in each branch
varies
Receptors of ReflexReceptors of Reflex
Muscle spindle Golgi Tendon Organ
Roles of Muscle Spindle Roles of Muscle Spindle ( Stetch Reflex)( Stetch Reflex)A muscle spindle is a small cluster of
specialized muscle fibers within a muscle. Also called stretch receptors, they detect stretch (changes in the length) in the muscle.
When a muscle stretches, the muscle spindle detects how much and how fast the muscle is stretching and sends signals to the spine with this information.
The purpose of muscle spindles stretch reflex is to help maintain muscle tone and to protect your body from injury caused by overstretching.
Superficial and Deep Superficial and Deep reflexesreflexesDEEP REFLEX
-involuntary muscular contraction following percussion of a tendon or bone-also called “jerk”
SUPERFICIAL REFLEX-any withdrawal reflex elicited by noxious or tactile stimulation of the skin, cornea, or mucous membrane-
SUPERFICIAL SUPERFICIAL REFLEXESREFLEXES
ABDOMINAL REFLEXCREMASTER REFLEXNORMAL PLANTAR
RESPONSEANAL WINK
CORNEA REFLEX
Example of superficial reflex cornea reflex
Pathologic reflexPathologic reflexThe Snout reflex
-This reflex is tested in a neurological exam and if present, is a sign of brain damage.
Babinski response - appearance of this reflex suggests the
presence of an upper motor neuron lesion
Hoffman response- affecting upper extremity
Guideline in Accurate Guideline in Accurate reflex testreflex test0 – absence+ - weak Hyporeflexive++- Normoreflexive+++ - Hyperreflexive without
clonus++++- hyperreflexive with
clonus
ReinforcementsReinforcementsThe muscle that would be tested
should be supportedThe muscle should also be
relaxed
Importance to OT Importance to OT professionprofessionTo determine the spasticity or
flaccidity of the muscle tone.
To know the abilities and capacities of the patient before giving an activity