Chap12/16 Flashcards
What are the classifications of nerve fibers?
Classified by diameter, conduction speed, and myelination (e.g., A, B, C fibers)
Larger, myelinated fibers conduct signals faster than smaller, unmyelinated ones.
What is the function of ependymal cells?
Produce and circulate cerebrospinal fluid (CSF)
Ependymal cells line the ventricles of the brain and the central canal of the spinal cord.
What do astrocytes do?
Support neurons, form the blood-brain barrier
Astrocytes are star-shaped glial cells in the brain and spinal cord.
What is the role of oligodendrocytes?
Myelinate axons in the central nervous system
Oligodendrocytes provide support and insulation to axons.
What do Schwann cells do?
Myelinate axons and form the neurolemma for axon regeneration
Schwann cells are the principal glial cells of the peripheral nervous system.
What occurs during the absolute refractory period?
Another action potential cannot be initiated regardless of stimulus strength
This is due to inactivation of sodium channels.
What are the main functions of the parasympathetic nervous system?
Rest-and-digest (e.g., slows heart rate, promotes digestion)
The parasympathetic system conserves energy.
What are the main functions of the sympathetic nervous system?
Fight-or-flight (e.g., increases heart rate, dilates pupils)
The sympathetic system prepares the body for stressful situations.
What do adrenergic neurons release?
Norepinephrine as their neurotransmitter
Adrenergic neurons are part of the sympathetic nervous system.
What is a receptor agonist?
A molecule that mimics a natural neurotransmitter or hormone, activating the receptor to produce a response
Example: epinephrine acting on adrenergic receptors.
What are general senses?
Include touch, temperature, pain, pressure, vibration, and proprioception
These senses provide information about the external and internal environment.
Where does integration of conscious sensations occur?
In the cerebral cortex
The cerebral cortex is responsible for awareness, perception, and decision-making.
What are proprioceptors?
Specialized sensory receptors that detect body position, movement, and muscle tension
Found in muscles (muscle spindles), tendons (Golgi tendon organs), and joints.
Define learning.
A process of acquiring new knowledge, behaviors, or skills through experience, practice, or study
Learning is essential for adaptation and growth.
