Lab Exercise 19 Flashcards
What are reflexes?
rapid, involuntary motor responses to an environmental stimulus detected by sensory receptors
What is a reflex arc?
a pathway to an effector from a receptor that a nerve impulse travels along
What is a somatic reflex?
the motor response is contraction of skeletal muscle
What is an autonomic (visceral) reflex?
the motor response involves cardiac muscle, smooth muscle, or glands
What is a spinal reflex?
reflexes mediated by spinal nerves
What is a cranial reflex?
reflexes mediated by cranial nerves
What are the five components of a reflex arc?
sensory receptor, sensory neuron, integrating center, motor neuron, and effector
What does a sensory receptor do?
if the stimulus to the sensory receptor is strong enough, an action potential is generated in the sensory neuron
What does a sensory neuron do?
the sensory neuron propagates the action potential and synapses with neurons in the spinal cord or brain stem
What does the integrating center do?
located within the gray matter of the CNS; transfers information from the sensory neuron to the motor neuron; the integrating center of a monosynaptic reflex arc is a single synapse between a sensory and motor neuron; the integrating center in a polysynaptic reflex arc consists of multiple synapses involving one of more interneurons between a sensory and a motor neuron
What does a motor neuron do?
carries the action potential initiated by the integrating center to the effector
What does an effector do?
can be skeletal muscle, cardiac muscle, smooth muscle, or glands; responds to stimulation by the motor neuron of the reflex arc
What are ipsilateral reflex arcs?
involve sensory receptors, sensory nerve neurons, motor neurons, and effectors all on the same side of the body
What are contralateral reflex arcs?
involve sensory receptors and neurons on one side of the body and motor neurons and effectors on the opposite side
What are bilateral (consensual) reflex arcs?
involve both sides of the body simulataneously
