Lab Quiz #9 Material (04/03/2025) Flashcards
This organ system enables the body to respond to changes in its external environment and controls the functions of internal organs and systems.
What is the nervous system?
This ANATOMICAL division of the nervous system includes the brain and spinal cord.
What is the central nervous system (CNS)?
This ANATOMICAL division of the nervous system includes peripheral nerves, cranial nerves, and ganglia.
What is the peripheral nervous system (PNS)?
This FUNCTIONAL division of the nervous system is under conscious voluntary control.
What is the somatic nervous system (SNS)?
This FUNCTIONAL division of the nervous system is under involuntary control.
What is the autonomic nervous system (ANS)?
List the 3 subdivisions of the autonomic nervous system (ANS).
1) Sympathetic
2) Parasympathetic
3) Enteric
This subdivision of the autonomic nervous system (ANS) serves the alimentary canal and regulates the function of internal organs by innervating smooth and cardiac muscle cells as well as glandular epithelium.
What is the enteric division?
What are the 2 main types of peripheral neuroglia?
Schwann & satellite cells
In MYELINATED nerves, {…} cells produce the {…} sheath from compacted layers of their own cell membranes that are wrapped concentrically around the nerve cell process.
1) Schwann
2) Myelin
This junction found between 2 adjacent Schwann cells is the site where the electrical impulse is regenerated for high-speed propagation along the axon.
What is the node of Ranvier?
In UNMYELINATED nerves, nerve processes are enveloped in the cytoplasm of these cells.
What are Remak Schwann cells?
These cells maintain a controlled microenvironment around the nerve cell bodies in the ganglia of the peripheral nervous system (PNS).
What are satellite cells?
This type of central neuroglial cell provides physical and metabolic support for neurons of the CNS.
What is an astrocyte?
This type of central neuroglial cell produces and maintains the myelin sheath in the CNS.
What is an oligodendrocyte?
This type of central neuroglial cell possesses phagocytotic properties and mediates neuroimmune reactions.
What is a microglia?
This type of central neuroglial cell forms the epithelial-like lining of the ventricles of the brain and spinal cord.
What is an ependymal cell?
This principal type of nerve tissue cell consists of specialized cells that conduct impulses.
What are neurons?
This principal type of nerve tissue cell consists of nonconducting cells in close proximity to nerve cells (neurons) and their processes.
What are supporting cells?
The structural and functional unit of the nervous system is called this.
What is the neuron (nerve cell)?
Do neurons divide?
NO
In certain brain regions, these cells may divide and differentiate into new neurons.
What are neural stem cells?
This type of neuron carries impulses from receptors to the CNS.
What is the sensory neuron?
This type of neuron carries impulses from the CNS or ganglia to effector cells.
What is the motor neuron?
This type of neuron communicates between sensory and motor neurons.
What is the interneuron?
Each neuron consists of a cell body, or {…} (contains the nucleus, Nissl bodies, and other organelles), an {…} (usually the longest process of the cell body; transmits impulses away from the cell body), and several {…} (shorter processes that transmit impulses toward the cell body).
1) Perikaryon
2) Axon
3) Dendrites
These are collections of nerve cell bodies outside the CNS.
What are ganglia?
Interactions between sensory (afferent) nerves that receive stimuli, the CNS that interprets them, and motor (efferent) nerves that initiate responses create these pathways.
What are neural pathways?
Neural pathways mediate reflex actions referred to as these.
What are reflex arcs?
What is so special about the function of the enteric division of the autonomic nervous system as it pertains to the central nervous system (CNS)?
NOTE: Mention how it interacts with the sympathetic and parasympathetic nervous systems.
The enteric division communicates with the CNS via parasympathetic & sympathetic nerve fibers but can function independently of the parasympathetic & sympathetic divisions
Specialized contacts between neurons that provide for transmission of information from one neuron to the next are called these.
What are synapses?
What are 2 other terms to describe supporting cells?
Neuroglial cells OR glia
The CNS contains four types of glial cells: oligodendrocytes, astrocytes, microglia, and ependymal cells. Collectively, these cells are called this.
What are central neuroglia?
These are the supporting cells of the peripheral nervous system (PNS) and include Schwann cells, satellite cells, and a variety of other cells associated with specific structures.
What are peripheral neuroglia?
This type of peripheral neuroglia surrounds the processes of nerve cells and isolates them from adjacent cells and extracellular matrix (ECM).
What is the Schwann cell?
Satellite cells surround the nerve cell bodies and are analogous to these nonmyelinating cells.
What are Remak Schwann cells?
The supporting cells of the ganglia in the wall of the alimentary canal are called these.
What are enteric neuroglial cells?
Are enteric neuroglial cells more morphologically & functionally similar to central or peripheral neuroglia?
Central neuroglia
What 2 structures separate the blood vessels from the nerve tissue?
1) Basal laminae
2) Variable amounts of connective tissue
This boundary between blood vessels and nerve tissue in the CNS excludes many substances that normally leave blood vessels to enter other tissues. It is the reason for the selective restriction of blood-borne substances in the CNS.
What is the blood-brain barrier?
Does the nervous system allow for a slow or rapid response to external stimuli?
Rapid
List 3 specific effectors in the internal organs that respond to the information carried by the autonomic nervous system.
1) Smooth muscle
2) Cardiac-conducting cells (i.e., Purkinje fibers)
3) Glandular epithelium
The regulation of the function of internal organs involves close cooperation between the nervous system and the endocrine system. Neurons in several parts of the brain and other sites behave as secretory cells and are referred to as this type of tissue.
What is neuroendocrine tissue?
These nerve fibers convey sensations of pain, temperature, touch, and pressure from the body surface.
What are somatic afferent fibers?
Somatic afferent fibers also convey this nonconscious sensation from the organs within the body to provide the brain with information related to the orientation of the body and limbs.
What is proprioception?
These nerve fibers transmit pain impulses and other sensations from internal organs, mucous membranes, glands, and blood vessels.
What are visceral afferent fibers?
This type of efferent neuron sends voluntary impulses to the skeletal muscles.
What is the somatic efferent neuron?
This type of efferent neuron transmits involuntary impulses to smooth muscle, cardiac-conducting cells (i.e., Purkinje fibers), and glands.
What is the visceral efferent neuron?
Interneurons, also called {…} neurons, form a communicating and integrative network between the sensory and motor neurons.
Intercalated
What (approximate) percentage of all neurons are considered interneurons?
More than 99.9%
Most neurons have only one {…}, usually the longest process extending from the cell, which transmits impulses away from the cell body to a specialized terminal (synapse).
Axon
A neuron usually has many {…}, shorter processes that transmit impulses from the periphery (i.e., other neurons) toward the cell body.
Dendrites
How are neurons anatomically characterized?
By the number of processes extending from the cell body
This is an anatomical term to describe neurons with an axon and 2 or more dendrites.
What is multipolar?
Which 2 types of neurons consistute most of the multipolar neurons in the nervous system?
Motor neurons & interneurons
This is an anatomical term to describe neurons with an axon and only 1 dendrite.
What is bipolar?
Between multipolar, bipolar, and pseudounipolar (unipolar) neurons, which type is most often associated with the receptors for the special senses (i.e., taste, smell, hearing, sight, & equilibrium)?
Bipolar neurons
This is an anatomical term used to describe neurons with one process, a single axon that divides close to the cell body into 2 long axonal branches.
What is pseudounipolar (unipolar)?
For pseudounipolar neurons, the branch that extends to the periphery is called this.
What is the peripheral dendritic branch?
For pseudounipolar neurons, the branch that extends to the central nervous system (CNS) is called this.
What is the central axonal branch?
The majority of pseudounipolar neurons are {…} (sensory, motor, or inter?) neurons located close to the CNS.
Sensory
What are the 2 types of ganglia in which the cell bodies of sensory neurons are situated?
Dorsal root & cranial nerve ganglia
This structure is the dilated region of the neuron that contains a large, euchromatic nucleus with a prominent nucleolus and surrounding perinuclear cytoplasm.
What is the cell body?
Under a light microscope (LM), the ribosomal content of neurons appears as these small bodies.
What are Nissl bodies?
In what 2 ways do Nissl bodies stain?
NOTE: Be sure to include the types of dyes along with how the stain looks, if that makes sense.
1) Intensely w/ basic dyes
2) Metachromatically w/ thionine dyes
Does each Nissl body correspond to a stack of rough ER or smooth ER? Why?
Rough ER because Nissl bodies are ribosomal content
This area of the cell body lacks large cytoplasmic organelles and serves as a landmark to distinguish between axons and dendrites in both LM and TEM preparations.
What is the axon hillock?
Where will you find the microtubule-organizing center (MTOC - i.e., the centrosome)?
In the perinuclear cytoplasm corresponding to the site of the axon origin (i.e., the axon hillock)
Newly synthesized protein molecules are transported to distant locations within a neuron in a process referred to as this.
What is neuronal transport?
Why does neuronal transport occur? Relate this to the fact that neurons do not replicate.
Although neurons don’t replicate, the subcellular components are consistently renewed via neuronal transport
In what 2 brain regions will you find neural stem cells?
1) Olfactory bulb
2) Dentate gyrus of the hippocampus
Neural stem cells are characterized by continuous expression of a 240-kDa intermediate filament protein called {…}, which is used to identify these cells by histochemical methods.
Nestin
How can neural stem cells be useful for treating neurodegenerative disorders, such as Alzheimer’s & Parkinson’s diseases?
Neural stem cells can migrate to sites of injury (i.e., sites of neurodegeneration) and differentiate into new, functional nerve cells
What is the main function of the dendrite?
To receive stimuli from the external environment or other neurons and carry that information to the cell body
Dendrites form these extensive arborizations that significantly increase the receptor surface area of a neuron.
What are dendritic trees?
Most excitatory neurons possess this type of dendritic structure.
What is a dendritic spine?
