Fundamentals of the Nervous System and Nervous Tissue

These flashcards cover key concepts regarding the structure and function of the nervous system, including terminology, cell types, anatomical divisions, and functional classifications.

What are the two systems that maintain internal conditions in the body?

The endocrine and nervous systems.

What is the primary method of communication in the endocrine system?

Chemical messengers called hormones delivered via the bloodstream.

What are the three basic steps of the nervous system?

1. Sense organs receive information. 2. Brain and spinal cord determine responses. 3. Brain and spinal cord issue commands to glands and muscles.

List the five functions of the nervous system.

1. Sensory input 2. Integration 3. Homeostasis 4. Mental activity 5. Control of muscles and glands.

What constitutes the central nervous system (CNS)?

The brain and spinal cord.

What is a tract in the CNS?

A bundle of axons.

Define a nucleus in the context of the CNS.

Clusters of cell bodies in the CNS.

What constitutes the peripheral nervous system (PNS)?

Cranial nerves and spinal nerves.

What is the function of the sensory (afferent) division of the PNS?

Transmits action potentials from receptors to the CNS.

What do somatic sensory fibers convey?

Impulses from skin, skeletal muscles, and joints to the CNS.

What is the primary function of motor (efferent) division?

Transmits action potentials from the CNS to effectors like muscles and glands.

What does the sympathetic division of the ANS do?

Mobilizes body systems during activity (fight or flight).

What is the role of astrocytes in the CNS?

To support neurons, form the blood-brain barrier, and maintain ionic balance.

What unique feature do ependymal cells have?

They have no basement membrane.

What is the primary role of oligodendrocytes in the CNS?

To form myelin sheaths around axons.

What types of cells in the PNS are involved in myelination?

Schwann cells and satellite cells.

Characterize the structure of neurons.

Large, specialized cells that conduct impulses with a cell body, dendrites, and an axon.

What do dendrites do?

Convey incoming messages toward the cell body as graded potentials.

Describe axonal transport.

It is an efficient internal transport mechanism that moves molecules and organelles along the axon in both directions.

What are nodes of Ranvier?

Gaps between myelin segments along an axon.

What constitutes gray matter in the CNS?

Mostly neuron cell bodies and nonmyelinated fibers.

Define a ganglion.

A collection of neuron cell bodies in the PNS.

Explain the difference between a nerve and a tract.

A nerve is a bundle of axons in the PNS, while a tract is a bundle of axons in the CNS.

What are the types of structural neurons?

Multipolar neurons, bipolar neurons, unipolar neurons.

What are the three functional classifications of neurons?

1. Sensory (afferent) neurons 2. Interneurons 3. Motor (efferent) neurons.

What is the primary role of interneurons?

To process, store, and retrieve information in the CNS.

What is the anatomical position of the somatic motor division?

Conducts impulses from the CNS to skeletal muscles.

What is the main function of the autonomic nervous system (ANS)?

To control involuntary actions such as heart rate and digestion.

What are the two major divisions of the autonomic nervous system?

Sympathetic division and parasympathetic division.

Define neuron anatomy focusing on the axon and its function.

The axon generates nerve impulses and transmits them to the axon terminal.

What do microglial cells do in the CNS?

They act as defensive cells, responding to inflammation and removing debris.

What is myelination and its significance?

Myelination is the formation of a myelin sheath that insulates nerve fibers, increasing conduction speed.

What is the composition of myelin?

About 20% protein and 80% lipid.

What are the components of the nervous system control system?

Sensory receptors, afferent pathways, control (integrating) center, efferent pathways, and effector organs.