Reflexes and Reflex Arc
Gag Reflex
A normal reflex mechanism that causes retching; activated by touching the soft palate or the back of the throat. TESTS THE SOMATIC MOTOR RESPONSES OF CRANIAL NERVES IX AND X. WHEN THE ORAL MUCOSA IS STROKED EACH SIDE OF THE UVULA SHOULD RISE.
Ipsilateral Response
A reflex occurring on the same side stimulated.
Reflex Arc
A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.
Somatic Reflexes
Activate skeletal muscle
Consensual Reflex
Allows both eyes to respond when you shine a light in one eye
Corneal Reflex
Closure of eyelids resulting from direct corneal irritation MEDIATED THROUGH THE TRIGEMINAL NERVE (CRANIAL NERVE V)
Integration center
Decodes signal
Ciliospinal
Handle of hammer to back of neck reaction of pupil on same side.
Plantar Flexion
Handle of mallet to bottom of foot.
Learned reflexes
Or Acquired reflexes Come from experience
Innate reflexes
Or Intrinsic reflexes A super fast motor response to a startling stimuli
Pupillary
Pen light in pupil, look at opposing pupil as well.
Cross-Extension
Pin prick arm, opposing hand, or Lift one leg observe the other.
Autonomic Reflexes
Pupillary Reflexes Ciliospinal Reflex Contraction of smooth or cardiac muscles or secretion of glands
Reflex
Rapid, predictable involuntary response to stimuli.
Superficial Cord Reflex
Reflexes that result from pain and temperature changes
Effector
Respond by contracting or secreting
Patellar/ Knee-Jerk
Rubber Mallet to Patellar ligament, crossed leg.
Achilles/ Ankle-jerk
Rubber mallet to Achilles tendon
Motor neuron
Sends directions back to site of stimulus
Receptor
Senses a stimulus (EX: Step on tack)
Spinal Reflexes
Stretch reflexes, Patellar, Achilles(activity 1, L2-L4 of the spinal cord), Reciprocal Inhibition. Crossed extensor reflexes (activity 2, at spinal cord level) Plantar reflexes: (activity 3, pyramidal tract). Babinski's Sign- Toes flaring or spreading, abnormal, except in babies.
Reciprocal Inhibition
The relaxation of the antagonist muscle in response to an agonist contraction is known as
Contralateral Response
The response observed on one side of the body when the opposite side has been stimulated.
Stretch Reflex
What reflex is initiated by stretching of muscle spindles and causes a contraction of the stimulated muscle and inhibits its antagonist
Cranial Nerve Reflex
corneal & lacrimation (ipsilateral CN V1 → bilateral CN VII), jaw jerk (CN V3 → V3), pupillary (ipsilateral CN II -LGN-to-pretectal-to-EW nucleus→ bilateral CN III), gag (CN IX → CN X)
Ciliospinal Reflex
dilation of the pupil on the painful side of stimulation. if absent there may be a lesion of the cervical sympathetics
Cremaster Reflex
male reflex in which brushing the skin in the superior aspect of the upper thigh causes the cremaster muscle to contract, causing the scrotum to elevate.
Abdominal Reflex
reflex that checks the integrity of the spinal cord and ventral rami from T8 to T12 brush along abs & umbilicus deviates toward stimulus = abnormal response (positive reflex)
Polysynaptic reflex arc
sensory neuron may fire onto a motor neuron as well as interneurons that fire onto other motor neurons
Monosynaptic reflex arc
single synapse between the sensory neuron that receives the stimulus and the motor neuron that responds to it Knee jerk reflex
Salivary Reflex
stimulate saliva production
Sensory neuron
transmits signal up to PNS