Chapter 3 - Anatomy of the Nervous System Flashcards
Central nervous system (CNS)
The portion of the nervous system within the skull and spine
Peripheral nervous system (PNS)
The portion of the nervous system outside the skull and spine
Somatic nervous system (SNS)
The part of the peripheral nervous system that interacts with the external environment
Afferent nerves
Nerves that carry sensory signals to the central nervous system
Efferent nerves
Nerves that carry motor signals from the central nervous system to the skeletal muscles or internal organs
Autonomic nervous system (ANS)
The part of the peripheral nervous system that participates in the regulation of the body’s internal environment
Sympathetic nerves
Those motor nerves of the autonomic nervous system that project from the central nervous system in the lumbar and thoracic region areas of the spinal cord
Parasympathetic nerves
Those autonomic motor nerves that project from the brain to the sacral region of the spinal cord
Cranial nerves
The 12 pairs of nerves extending from the brain (e.g., optic nerves, olfactory nerves, and vagus nerves)
Glial cells
Several classes of nonneural cells of the nervous system
Oligodendrocytes
Glial cells that myelinate axons of the central nervous system; also known as oligodendroglia
Myelin
A fatty insulating substance
Myelin sheaths
Coverings on the axons of some neurons that are rich in myelin and increase the speed and efficiency of axonal conduction
Schwann cells
The glial cells that compose the myelin sheaths of PNS axons and promote the regeneration of PNS axons
Microglia
Glial cells that respond to injury or disease by engulfing cellular debris and triggering inflammatory responses
Astrocytes
Large, star-shaped glial cells that play multiple roles in the central nervous system
Golgi stain
A neural stain that completely darkens a few of the neurons in each slice of tissue, thereby revealing their silhouettes
Niss1 stain
A neural stain that has an affinity for structures in neuron cell bodies
Electron microscopy
A microscopy technique used to study the fine details of cellular structure
Anterior
Toward the nose end of a vertebrate
Posterior
Toward the tail end of a vertebrate or toward the back of the head
Dorsal
Toward the surface of the back of a vertebrate or toward the top of the head
Ventral
Toward the chest surface of a vertebrate or toward the bottom of the head
Medial
Toward the midline of the body
Lateral
Away from the midline of the body of a vertebrate, toward the body’s lateral surfaces
Superior
Toward the top of the primate head
Inferior
Toward the bottom of the primate head or brain
Proximal
Close to something
Distal
Far from something
Horizontal sections
Any slices of brain tissue cut in a plane that are parallel to the top of the brain
Frontal sections
Any slices of brain tissue cut in a plane that is parallel to the face; also termed coronal sections
Sagittal sections
Any slices of brain tissue cut in a plane that is parallel to the side of the brain
Cross section
Section cut at a right angle to any long, narrow structure of the central nervous system
Gray matter
Portions of the nervous system that are gray because they are composed largely of cell bodies and unmyelinated interneurons
White matter
Portions of the nervous system that are white because they are composed largely of myelinated axons
Dorsal horns
The two dorsal arms of the spinal gray matter
Meninges
The three protective membranes that cover the brain and spinal cord (singular meninx)
Dura mater
The tough outer meninx
Arachnoid membrane
The meninx that is located between the dura mater and the pia mater and has the appearance of a gauzelike spiderweb
Subarachnoid space
The space beneath the arachnoid membrane, which contains many large blood vessels and cerebrospinal fluid
Pia mater
The delicate, innermost meninx
Cerebrospinal fluid (CSF)
The fluid that fills the subarachnoid space, the central canal, and the cerebral ventricles
Central canal
The small cerebrospinal fluid-filled channel that runs the length of the spinal cord
Cerebral ventricles
The four cerebrospinal fluid-filled internal chambers of the brain: the two lateral ventricles, the third ventricle, and the fourth ventricle
Choroid plexuses
The networks of capillaries that protrude into the ventricles from the pia mater and produce cerebrospinal fluid
Blood-brain barrier
The mechanism that impedes the passage of toxic substances from the blood into the brain
Ventral horns
The two ventral arms of the spinal gray matter