Fundamentals of the Nervous System and Nervous Tissue I

These flashcards cover key concepts and definitions related to the nervous system, including its structure, functions, types of cells, and classification of neurons.

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

The endocrine system and the nervous system.

What is the primary role of the endocrine system?

To deliver chemical messengers (hormones) to the bloodstream.

How many basic steps are involved in the functioning of the nervous system?

Three basic steps: sense organs receive information, the brain and spinal cord determine responses, and issue commands to glands and muscles.

What are the main functions of the nervous system?

Sensory input, integration, homeostasis, mental activity, and control of muscles and glands.

What does 'sensory input' refer to in the context of the nervous system?

Monitoring internal and external stimuli.

What is integration in the nervous system?

The processing of sensory input and initiation of responses by the brain and spinal cord.

What does the central nervous system (CNS) consist of?

The brain and spinal cord.

What are tracts in the context of the CNS?

Bundles of axons.

What are ganglia?

Clusters of cell bodies in the peripheral nervous system (PNS).

What are the two major divisions of the nervous system?

The central nervous system (CNS) and the peripheral nervous system (PNS).

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

To transmit action potentials from receptors to the CNS.

What does the motor (efferent) division of the PNS do?

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

What components make up the somatic nervous system?

Somatic (voluntary) motor nerve fibers that conduct impulses from the CNS to skeletal muscles.

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

Controls involuntary functions such as those of cardiac muscle, smooth muscle, and glands.

What are the two divisions of the autonomic nervous system and their functions?

Sympathetic division (fight or flight) and parasympathetic division (rest & digest).

What are neuroglia?

Supporting cells in the nervous system that hold neurons together and provide insulation and protection.

Name the four types of neuroglia found in the CNS.

Astrocytes, microglia, ependymal cells, and oligodendrocytes.

What are the functions of astrocytes?

They provide structural support, maintain the blood-brain barrier, and regulate the chemical environment around neurons.

What is the role of microglial cells?

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

Where are ependymal cells found and what is their function?

They line the internal cavities of the brain and spinal cord, secreting cerebrospinal fluid and helping to move it with cilia.

What do oligodendrocytes do?

They form myelin sheaths around axons in the CNS.

How do Schwann cells differ from oligodendrocytes?

Schwann cells form myelin sheaths around a single axon in the PNS, while oligodendrocytes can myelinate portions of several axons in the CNS.

What is myelin and its primary components?

An insulating layer around nerve fibers consisting of approximately 20% protein and 80% lipid.

What is the difference between gray matter and white matter?

White matter consists of myelinated fibers, while gray matter mostly contains neuron cell bodies and unmyelinated fibers.

Define 'nucleus' in the context of the CNS.

A collection of neuron cell bodies in the CNS.

What is a ganglion?

A collection of neuron cell bodies in the PNS.

What are the three structural types of neurons?

Multipolar, bipolar, and unipolar neurons.

What is the primary function of sensory (afferent) neurons?

To detect changes in the body and transmit information toward the CNS.

What do interneurons do?

They process, store, and retrieve information between sensory and motor pathways.

What are motor (efferent) neurons responsible for?

Sending signals out from the CNS to muscles and gland cells.

What are the two main components of neuron anatomy?

The cell body and processes (dendrites and axon).

What role do dendrites play in a neuron?

They are the receptive regions that convey incoming messages toward the cell body.

In which direction does axonal transport occur?

In both directions: anterograde (away from the cell body) and retrograde (towards the cell body).