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What is the role of astrocytes in the CNS?
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Astrocytes are abundant glial cells that support and anchor neurons.
What are the types of glial cells in the CNS and their functions?
Astrocytes (support and anchor neurons), Microglial cells (immune defense), Ependymal cells (produce and circulate cerebrospinal fluid), and Oligodendrocytes (create myelin sheath around neurons).
Why are neurons described as having a 'high metabolic rate'?
Neurons require a continuous supply of oxygen and glucose to function properly.
Describe the functional types of neurons.
Sensory (afferent) neurons transmit impulses from sensory receptors to CNS, Motor (efferent) neurons transmit impulses from CNS to muscles/glands, and Interneurons transmit impulses within CNS, predominantly multipolar.
Identify the components of the Central Nervous System (CNS).
The brain and spinal cord.
Describe the types of glial cells in the PNS and their functions.
Satellite Cells (support neuron cell bodies) and Schwann Cells (create myelin sheath around axons).
Explain the structure and function of neurons.
Neurons respond to stimuli and transmit signals. They consist of the soma (cell body), dendrites (receive messages), and axon (sends messages).
What are the two divisions of the Autonomic Nervous System (part of the Motor Division in PNS), and what are their functions?
Sympathetic (mobilizes the body into action) and Parasympathetic (calms the body down).
What is the function of the myelin sheath, and which cells create it in the CNS and PNS?
The myelin sheath insulates neurons and speeds up signal transmission. In the CNS, oligodendrocytes create it, and in the PNS, Schwann cells create it.
What proportion of nervous tissue is made up of cells versus extracellular space?
Nervous tissue is densely packed with cells, comprising less than 20% of the extracellular space.
Define the three main functions of the nervous system.
Sensory input (detection of stimuli), integration (processing and decision making), and motor output (execution of response).
Differentiate between the sensory (afferent) and motor (efferent) divisions of the Peripheral Nervous System (PNS).
The sensory division picks up sensory stimuli and sends it to the brain, while the motor division sends instructions from the brain to muscles and glands.
What makes the nervous system superior to the endocrine system?
The nervous system controls all organs, physiological, and psychological reactions.
How does the Nervous System detect and respond to a spider on the knee?
Sensory neurons detect the spider, signals travel to spinal cord via Schwann cells, interneurons process the signal, and motor neurons execute the response.
Compare the structural types of neurons.
Multipolar neurons have many processes (one axon, multiple dendrites), Bipolar neurons have two processes (one axon, one dendrite), and Unipolar neurons have one process (mostly in sensory receptors).
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