Chapter 13 Vocabulary Flashcards
Contain the cell bodies of sensory neurons
Dorsal root ganglia
Axons of neurons which bring sensory information into the spinal cord
Dorsal root
Contains the axons of motor neurons that extend into the periphery to control somatic and visceral effectors
Ventral root
Sensory and motor roots are bound together into a single one of these
Spinal nerve
A series of specialized membranes surrounding the spinal cord which provide the necessary physical stability and shock absorption
Spinal meninges
The specialized membranes of the spinal cord are continuous with these, which begin at the foramen magnum
Cranial meninges
The tough, fibrous, outermost layer of the spinal cord
Dura mater
The middle layer of the meninges membranes
Arachnoid mater
The innermost meningeal layer
Pia mater
Fills the space between the two inner meningeal layers and acts as a shock absorber and a diffusion medium for dissolved gases, nutrients, chemical messengers, and wastes
Cerebrospinal fluid
A monosynaptic reflex that occurs a muscle is suddenly and unexpectedly stretched, the sensory neuron innervates a motor neuron directly. In this case, the motor neuron performs the information processing.
Stretch reflex
A reflex which moves affected body parts away from a stimulus
Withdrawal reflex
An example of a stretch reflex, which involves the kneecap
Patellar reflex
Reflexes that result from the connections that form between neurons during development, such as suckling or pulling away from pain
Innate reflex
More complex, learned motor patterns, such as stepping on the brakes to avoid hitting something
Acquired reflex
Provide a mechanism for the involuntary control of the muscular system, such as the “knee-jerk” reflex
Somatic reflex
Also called autonomic reflexes, they control other systems
Visceral reflex
Reflexes which involve the simplest reflex arc
Monosynaptic reflex
Reflexes processed in the spinal cord
Spinal reflex
The sensory receptors involved in the stretch reflex
Muscle spindles
A bundle of small, specialized skeletal muscle fibers
Intrafusal muscle fibers
Larger skeletal muscle fibers which surround the muscle spindles
Extrafusal muscle fibers
Motor neurons which innervate intrafusal fibers
Gamma motor neuron
