Structure and Function of the Nervous System Flashcards

Flashcards covering the cellular components, invertebrate comparisons, human anatomical organization, and functional divisions of the nervous system as detailed in the Chapter 1 Study Guide.

Neurons

Cells of the nervous system that carry both electrical and chemical messages, consisting of three parts: cell body, axons, and dendrites.

Afferent

Sensory neurons or fibers that "arrive" at the Central Nervous System (CNS).

Efferent

Motor neurons or fibers that "exit" the Central Nervous System (CNS).

CNS

Central Nervous System; consisting of the brain and the spinal cord.

Glia

Connective glands that "glue" neurons together, regulate the amount and spread of signals, and provide nutrients to the neurons they surround.

Astrocytes

A type of glia that regulates energy and metabolism.

Microglia

A type of glia that serves as the immune system of the brain.

Oligodendrocytes

A type of glia associated with axons in the Central Nervous System (CNS).

Schwann cells

A type of glia associated with axons in the Peripheral Nervous System (PNS).

Eukaryotic Cells

Cells with a nucleus and other membrane-bound organelles that house DNA and mRNA.

Neural nets

A population of nerve cells connected by a synapse, found in animals like Cnidaria (Hydra, corals, jellyfish, and anemones).

Ganglia (General)

Nerve cords arranged in a ladder-like formation or a group of nerve cells.

Bilateral symmetry

An organism organization with one nerve cord and centralized ganglia.

Radial Symmetry

An organization that lacks a Central Nervous System and instead has radial nerves or nerve nets.

Centralization

The consolidation of neurons into a specific center or area; found only in nervous systems with bilateral symmetry.

Cephalization

The concentration of the nervous system at the anterior (back) part of the body or head; found only in bilateral symmetry.

Nuclei

A group of neurons within the Central Nervous System that function as one body.

PNS

Peripheral Nervous System; carries information from everything outside of the CNS (muscles, organs, nerves, and senses) to the spinal cord and brain.

Grey matter

Composed of somas and dendrites.

White matter

Composed of axons, which are covered in myelin.

Meninges

The three membranes that encase the Central Nervous System: dura mater, arachnoid mater, and pia mater.

Ventricles

Interconnected cavities or open spaces in the CNS that contain cerebrospinal fluid (CSF).

Cerebrospinal fluid (CSF)

Fluid produced in blood vessels in the ventricle lining; provides nutrients and acts as a barrier between the brain and skull.

Arteries (Brain)

Vessels that carry blood away from the heart to the brain, consisting of the anterior, middle, and posterior cerebral arteries.

Neural Circuits

The functional arrangement of afferent and efferent neurons.

Dorsal

Referencing both the back of the spinal cord and the top of the brain.

Ventral

Referencing the bottom of the brain or the front of the spinal cord.

Superior

Directional orientation meaning above the structure.

Inferior

Directional orientation meaning below the structure.

Anterior

Directional orientation towards the face and head.

Medial

Directional orientation meaning toward the middle.

Ectoderm

The outer tissue of the embryo that thickens to form the neural plate.

Neural plate

A flat structure formed from the ectoderm at 3 weeks that invaginates into a groove to form the neural tube.

Neural tube

Formed in the 3rd and 4th week of development; it elongates to form the spinal cord and then the brain.

Spinal Cord Regions

The five major regions consisting of Cervical, Thoracic, Lumbar, Sacral, and Coccyx.

Telencephalon

An embryological division of the forebrain that develops into the cerebral hemispheres, hippocampus, and amygdala.

Diancephalon

An embryological division of the forebrain that develops into the posterior pituitary, thalamus, and hypothalamus.

Mesencephalon

The embryological division for the midbrain, consisting of the tectum and tegmentum.

Metencephalon

An embryological division of the hindbrain that develops into the cerebellum and pons.

Myelencephalon

An embryological division of the hindbrain that develops into the medulla.

Cerebrum

The largest part of the brain, divided into left and right hemispheres.

Basal ganglia

A group of nuclei including the caudate nucleus, putamen, globus pallidus, and subthalamic nucleus.

Hypothalamus

Part of the diancephalon that regulates the release of hormones.

Brainstem

Structure that connects the cerebrum to the spinal cord and the cerebellum.

Cerebellum

Known as the "little brain;" used for motor coordination and some forms of simple learning.

Somatic Nervous System

The conscious or voluntary division of the PNS involved in relaying sensory and motor information to and from the CNS.

Autonomic Nervous System (ANS)

The unconscious or involuntary division of the PNS involved in the function of internal organs and glands.

Sympathetic Nervous System

A subdivision of the ANS characterized by "Fight, Flight or Freeze" responses to stressful activity.

Parasympathetic Nervous System

A subdivision of the ANS characterized by "Rest and Digest" functions, responsible for relaxation and systems like digestion.