What is hyperactive stretch reflex?
Hyperactive stretch reflexes are seen when there is interruption of the cortical supply to the lower motor neuron, an “upper motor neuron lesion.” The interruption can be anywhere above the segment of the reflex arc. Analysis of associated findings enables localization of the lesion.
Is the stretch reflex excitatory or inhibitory?
Both extensor and flexor motor neurons are firing to maintain the arm at its location. When the pitcher is placed on the tray, the stretch reflex activates the flexor and inhibits the extensor.
What is the stretch reflex for?
The stretch reflex (myotatic reflex), or more accurately “muscle stretch reflex”, is a muscle contraction in response to stretching within the muscle. The reflex functions to maintain the muscle at a constant length.
What is an exaggerated stretch reflex?
Definition and Clinical Features. The core feature of spasticity is the exaggeration of stretch reflexes. The result is the velocity-dependent increase in resistance of a passively stretched muscle or muscle group.
What are the two types of stretches?
Stretches are either dynamic (meaning they involve motion) or static (meaning they involve no motion). Dynamic stretches affect dynamic flexibility and static stretches affect static flexibility (and dynamic flexibility to some degree). The different types of stretching are: ballistic stretching.
What is an example of a stretch reflex?
For example, this reflex occurs is when a person is standing in an upright position then begins to lean on one side. Some of the stretch reflexes are jaw jerk reflex, biceps reflex, brachioradialis reflex, triceps reflex, patellar reflex, and ankle jerk reflex. Synonyms: myotatic reflex.
What are the major components of a stretch reflex?
The pathway can be described as a ‘reflex arc’ which is made up of 5 components:
- A receptor – muscle spindle.
- An afferent fibre – muscle spindle afferent.
- An integration centre – lamina IX of spinal cord.
- An efferent fibre – α-motoneurones.
- An effector – muscle.
What are the symptoms of Hyperreflexia?
- anxiety and apprehension.
- irregular or slow heartbeat.
- nasal congestion.
- high blood pressure with systolic readings often over 200 mm Hg.
- a pounding headache.
- flushing of the skin.
- profuse sweating, particularly on the forehead.
Why are my reflexes so sensitive?
Brisk reflexes may develop when neurons deteriorate. These neurons are also known as the upper motor nerve cells. Other causes of brisk reflexes are associated with neurological conditions, including: Hyperthyroidism: This condition can cause too much thyroid hormone to be released in your body.
Which is the best description of the stretch reflex?
Finally we have brainstem reflexes, e.g. the eye movement reflexes. The stretch reflex is also referred to as the deep tendon reflex or myotatic reflex. It is a simple pre-programmed response by the human body in response to the muscle being passively stretched e.g. by a tendon hammer, or a sudden change in the ground surface.
Which is an example of an overactive reflex?
Hyperreflexia (or hyper-reflexia) is defined as overactive or overresponsive reflexes. Examples of this can include twitching or spastic tendencies, which are indicative of upper motor neuron disease as well as the lessening or loss of control ordinarily exerted by higher brain centers of lower neural pathways (disinhibition).
What causes an attenuated muscle stretch reflex ( MSR )?
Attenuated muscle stretch reflexes (MSRs) suggest lower motor neuron problems, most commonly of the spinal nerve roots (i.e. radiculopathy). Hyperactive muscle stretch reflexes can present an increased single response and/or repetitive response (clonus).
What does hyperreflexia mean in terms of reflexes?
Hyperreflexia refers to hyperactive or repeating (clonic) reflexes. These usually indicate an interruption of corticospinal and other descending pathways that influence the reflex arc due to a suprasegmental lesion, that is, a lesion above the level of the spinal reflex pathways.