Chapter 14: Nervous Tissue Flashcards
What are the three functions of the nervous system?
- Collect information: sensory input
- Process and evaluate information: the brain and spinal chord interprets stimuli
- Response to information: motor output
What are the structural classifications of the nervous system?
- central nervous system (CNS)
- peripheral nervous system (PNS)
What are the functional classifications of the nervous system?
- sensory (afferent)
- somatic
- visceral - motor (efferent)
- somatic
- visceral (autonomic)
The CNS includes the …
- brain
- spinal cord
The PNS includes the …
- cranial nerves
- spinal nerves
- ganglia
List the functional characteristics of the sensory nervous system.
- afferent
- sensory input
- sensory receptors receive stimuli and nerves transmit this information to the CNS
- unipolar
List the functional characteristics of the motor nervous system.
- efferent
- motor output
- the CNS sends information by the way of nerves to effector organs (muscles, glands)
- multipolar
What are the two functional organizations of the sensory nervous system?
- somatic: receives stimuli from the skin, joints, skeletal muscles, and special sense organs
- visceral: receives stimuli from the viscera
Match the following:
- somatic
- visceral
a. voluntary
b. involuntary
- Somatic (voluntary)
- Visceral (involuntary)
What are the two functional organizations of the motor nervous system?
- somatic: sends information to skeletal muscle
- visceral (autonomic): sends information to cardiac muscle, smooth muscle, and glands
Nervous tissue is composed of which type of cells?
1, Neurons
2. Glial cells
Which cells in the nervous tissue are excitable and receive neuron impulses?
Neurons
Which cells in the nervous tissue are non-excitable cells and are support for the neuron?
Glial cells
List the four characteristics of neurons.
- Excitability: response to stimuli
- Conductivity: propagate electrical signal
- Extreme longevity
- Amniotic
What are the main structures of the presynaptic neuron?
- Dendrites
- Cell body
- Axon hillock
- Axon
- Axon collaterals
- Nodes of Raniver
- Telodendria (synaptic knobs)
Name the structure and function.
- receives input
- graded potential
-multiple branching of unmyelinated processes
Name the structure and function.
- interprets the input from dendrites
- neuron’s control center
- contains chromatophilic substances (nissl bodies)
Name the structure and function.
- sends action potential away from cell body to neurons, muscle cells, glands
- long process from cell body
Name the structure.
Axon hillock: connection between axon and cell body
Name the structure.
Axon collaterals: side branch of axon
Name the structure.
Telodendria: branches at the end of axon (synaptic knobs)
List the three structural classifications of neurons.
- multipolar
- unipolar
- bipolar
List the three functional classifications of neurons.
- Sensory (afferent) neurons
- Motor (efferent) neurons
- Interneurons neurons
This structural classification of neurons:
- has many dendrites, one axon
- is the most common type
- are motor neurons and interneurons
Multipolar
This structural classification of neurons:
- has one process from the cell body (peripheral and central)
- are somatic and sensory neurons
Unnipolar
This structural classification of neurons:
- has one dendrite, one axon
- are special sensory neurons
Bipolar
In a multipolar neuron, what do the central and peripheral processes lead to?
Peripheral process: splits into dendrites (graded potential)
Central process: leads to synaptic knobs (action potential threshold)
List the functional characteristics of the interneurons.
- receive, process, integrate
- communicate between sensory and motor neurons
- in the CNS
- multipolar
What are the two characteristics of glial cells?
- more numerous than neurons
- actively mitotic
Name the 4 glial cells of the CNS.
- Astrocyte
- Ependymal
- Microglial
- Oligodendrocyte
Where is this glial cell located?
What are its functions?
Give the name.
Astrocyte
Located: CNS
Function: helps the blood-brain barrier
Where is this glial cell located?
What are its functions?
Give the name.
Epedymal
Located: CNS
Functions:
- lines ventricles of brain and central canal of the spinal chord
- assists production of cerebrospinal fluid
Where is this glial cell located?
What are its functions?
Give the name.
Microglial
Located: CNS
Functions:
- phagocytic cell
- protection, engulfs infectious agents (immunity)
Where is this glial cell located?
What are its functions?
Give the name.
Oligodendrocyte
Located: CNS
Functions:
- myelinates and insulates axons
- allows for faster action potential propagation
What are the two glial cells of the PNS?
- Satellite
- Neurolemmocyte
Where is this glial cell located?
What are its functions?
Name: Satellite
Location: PNS
Functions:
- electrically insulates cell bodies
- regulates nutrients and waste exchange
Where neurolemmocyte glial cells located?
What are its functions?
- myelinates and insulates axons
- allows for faster action potential propagation
The myelin sheath of the CNS and PNS are composed of which glial cells?
A. oligodendrocytes and neurolemmocytes
B. astrocytes and satellites
C. oligodendrocytes and satellites
D. neurolemmocytes and microglials
A. oligodendrocytes and neurolemmocytes
What are the two main functions of the myelin sheath?
- insulates axons
- allows for faster action potential propagation
The gaps between myelin sheaths on the axon are called…
Neurofbril nodes (nodes of Ranvier)
Fill in the blank. Nerve impulses “____” from node to node.
“jump”
The junction from which a nerve impulse passes from axon to another neuron or effector is a:
A. dendrite
B. action potential
C. synapse
C. synapse
Name this structure of the chemical synapse and all its contents.
Presynaptic neuron (synaptic knob)
- nerve impulse
- Calcium (Ca2+) ions
- voltage-gated Ca2+ channels
- synaptic vesicles containing Acetylcholine (ACh)
Name the contents of of the chemical synapse and what is below it.
Synaptic cleft
- Acetylcholine (red)
- ligand-gated receptor proteins
- Sodium (Na+) ions
Postsynaptic neuron
- postsynaptic membrane
Describe in 3 steps what occurs at the presynaptic neuron.
- Action potential propagates down axon to the synaptic knob
- Action potential causes voltage-gated Ca2+ channels to open (Ca2+ enters)
- Ca2+ causes synaptic vesicles to release ACh into the synaptic cleft
Describe in 3 steps what occurs at the postsynaptic neuron.
- Neurotransmitters bind to ligand-gated ion channels on the postsynaptic membrane (receptor protein)
- Sodium ions enter postsynaptic neuron
- Nerve transmission converts from electrical to chemical to electrical ….
Identify the parts of the nerve structure and the type of connective tissue.
Nerve
- epineurium (dense irregular CT)
Fascicle
- perineurium (dense irregular CT)
Axon
- endoneurium (areolar CT)
Match the phrase to the definition.
1. collection of cell bodies in CNS
2. collection of axons in CNS
3. collection of cell bodies in PNS
4. collection of axons in PNS
-ganglion
- nuclei
- tract
- nerve
- Nuclei: collection of cell bodies in CNS
- Tract: collection of axons in CNS
- Ganglion: collection of cell bodies in PNS
- Nerve: collection of axons in PNS
Fill in the blanks of the CNS glial cells.
- Astrocytes - Satellites
- Help produce cerebrospinal fluid
- Immune cells
- Oligodendrocytes
Fill in the blanks of the PNS glial cells.
- Regulate exchange - Astrocytes
- Neurolemmocytes - myelin sheath
Identify 1-6.
- Satellite
- Microglial
- Astrocyte
- Neurolemmocytes
- Oligodendrocyte
- Ependymal
Identify the functional and structural characteristics of afferent and efferent neurons.
Afferent (red)
Structural: unipolar
Functional: sensory
Efferent (blue)
Structural: multipolar
Functional: motor
