Nervous System Flashcards
What do receptors do?
detect changes or respond to stimuli
What are receptors made of?
neurons and specialized cells?
What are receptors classified as?
complex sensory organs
What do effectors do?
respond to efferent signals
What make up effectors?
cells and organs
What is included in effectors?
skeletal, cardiac, smooth muscles, and glands
What are the subdivisions of the nervous system?
central nervous system, peripheral nervous system, nerves, sensory receptors
What makes up the central nervous system?
brain and spinal cord
What makes up the peripheral nervous system?
all the neural tissue outside of the CNS
What are nerves?
bundles of axons with connective tissue and blood vessels
What do nerves do?
carry sensory information and motor information
What do the cranial nerves do?
connect to brain
What do spinal nerves do?
attach to spinal cord
What are the commands in the PNS?
cranial nerves and spinal nerves
What are the functions of the CNS?
to process and coordinate sensory and analytical data from inside and outside of the body, motor controls that control activities of peripheral organs, and higher functions of the brain like intelligence, memory, learning, and emotion
What are the functions of the nerves of the PNS?
to deliver sensory information to the CNS and carry motor commands to peripheral tissues and systems
What is the function of the receptors of the PNS?
to detect change or respond to stimuli
What are the functional divisions of the PNS?
afferent and efferent division
What does the afferent division of the PNS do?
carry sensory information from PNS sensory receptors to CNS
What does the efferent division of the PNS do?
carry motor commands from the CNS to PNS to muscles and glands
Give the order of a general neural circuit.
- skin receptor
- afferent or sensory neuron
- synapses on interneuron
- interneuron
- efferent or motor neuron
- striated muscles (effector)
What are the divisions of the ANS?
sympathetic division and parasympathetic division
What effect sympathetic division have?
has a stimulating effect
What kind of effect does parasympathetic division have?
Has a relaxing effect
What are the four structural classifications of neurons?
anaxonic neurons
bipolar neurons
unipolar neurons
multipolar neurons
Describe anaxonic neurons
no anatomic clues to distinguish dendrites from axons
Describe bipolar neurons
two distinct processes: one dendritic process and one axon with a cell body between them
describe unipolar neurons
fused dendrites and axon, cell body to one side
describe multipolar neurons
multiple dendrites, 1 axon
Name the 4 types of neural tissue.
ependymal cells, microganglia, astrocytes, oligodendrocytes
What do ependymal cells do?
they line central canal of spinal cord and ventricles of brain and secrete cerebrospinal fluid
What are micorganglia?
they are the wandering police force
What do astrocytes do?
They line the CNS capillaries and maintain the blood-brain barrier
What do oligodendrocytes do?
insulation, schwann cells (serve as the myelinating cell of the PNS and support cells of peripheral neurons), many axons of the CNS are completely sheathed in the process of oligodendrocytes (myelinated– internodes and nodes), regions dominated by myelinated axons constitute white matter of CNS, unmyelinated axons and densely packed neuron cell bodies with the concentration of NIssel bodies constitute the gray matter of the CNS
What are the neuroglia of the PNS?
satellite cells and schwann cells
What do satellite cells do?
surround the neuron cell bodies in the ganglia
What do schwann cells do?
form a sheath around every peripheral axon and a schwann cells can myelinate only one segment of a single axon, however, it can enclose segments of several unmyelinated axons
What are the three functional classifications of neurons?
sensory neurons, motor neurons, interneurons
What are sensory neurons?
afferent neurons of the PNS
What are motor neurons?
efferent neurons of the PNS
What are interneurons?
association neurons
What do sensory neurons do?
Deliver information from sensory receptors to the CNS
Where are sensory neurons located?
they are unipolar and the cell bodies are located in peripheral sensory ganglia
What is a ganglion?
A collection of neuron cell bodies in the PNS
What do the processes of the sensory neurons do?
processes (afferent fibers) extend from sensory receptors to CNS
What is the classification of sensory neurons?
somatic sensory neurons and visceral sensory neurons
What do somatic sensory neurons do?
monitor the effects of external environment
What do visceral sensory neurons do?
monitor the internal environment
What are sensory receptors?
the processes of specialized sensory neurons or cells monitored by sensory neurons
What do exteroceptors do?
sense external environment (touch, temperature, pressure, sight, smell, and hearing)
What do proprioceptors do?
sense the position and movement of skeletal muscles and joint
What do interoceptors do?
Monitor inside organ systems and sense taste, deep pressure, and pain
What do motor neurons do?
carry instructions from the CNS to peripheral effectors
How do motor neurons carry information?
via efferent fibers: axons traveling away from the CNS
What is the classification of motor neurons?
somatic motor neurons (somatic nervous system) and visceral motor neurons (autonomic nervous system)
What do somatic motor neurons do?
Innervate skeletal muscles (to supply with nerves)
What do visceral motor neurons do?
innervate all peripheral effectors other than skeletal muscles
