Central Nervous System Overview

These flashcards cover key concepts related to the central nervous system, neural reflexes, and their functional organizations.

What are the two main components of the Central Nervous System (CNS)?

The brain and spinal cord.

How many sensory neurons are approximately found in the human body?

About 10 million sensory neurons deliver information to the CNS.

What is the function of motor neurons in the CNS?

Motor neurons deliver commands to peripheral effectors.

What type of neurons interpret, plan, and coordinate signals in the CNS?

Interneurons, also known as association neurons.

What are the three main types of sensory inputs associated with the spinal cord?

Interoceptors, exteroceptors, and proprioceptors.

What is the role of the dorsal root of each spinal nerve?

Carries sensory information to the spinal cord.

What is the significance of the reflex arc?

It is the wiring of a single reflex starting from a receptor and ending at a peripheral effector.

What are the five steps in a neural reflex?

1) Arrival of stimulus and activation of receptor; 2) Activation of sensory neuron; 3) Information processing in the CNS; 4) Activation of motor neuron; 5) Response of peripheral effector.

What characterizes a monosynaptic reflex?

It involves a direct synapse between sensory and motor neurons.

What type of reflexes require interneurons for their response?

Polysynaptic reflexes.

What are muscle spindles?

Receptors in stretch reflexes that respond to changes in muscle stretch.

What is cerebrospinal fluid (CSF) and its primary function?

CSF cushions the brain and spinal cord, provides buoyancy, and transports nutrients and waste.

What is meningitis?

Inflammation of the meninges, often resulting from bacterial or viral infection.

What is the primary difference between white matter and gray matter in the CNS?

Gray matter consists of neuron cell bodies and dendrites, while white matter consists of bundles of axons.

What does the sympathetic nerve innervate?

Structures in the thoracic cavity through preganglionic and postganglionic fibers.

What causes reciprocal inhibition in reflex responses?

Inhibition of antagonistic muscle through interneurons during reflex action.