nervous system Flashcards
What is the axon hillock
origin of the icon from the cell body
What is the initial segment?
adjacent to the axon hillock, where an action potential is initiated
What is the axolemma?
specialized part of the plasma membrane that surrounds the cytoplasm of the axon
What is the perikaryon?
cytoplasm surrounding the nucleus: contains organelles that provide energy and synthesize the chemical neurotransmitters that are important in cell-to-cell communication
What are the neurofibrils?
bundles of neurofilament that extend into the dendrites and axon, providing internal support for these slender processes
What is a telodendria?
the branches at the end of the neuron
what is the location and structure of the axon terminals?
the end of the telodendria, where the neutron communicates with other cells
What are ependymal cells?
simple cuboidal/columnar epithelium that lines a fluid filled passageway within the spinal cord and brain,
What are microglia?
cells that migrate to the CNS as the nervous system forms, perform functions like removing debris, wastes and pathogens by phagocytosis
What are astrocytes?
- cells that maintain the blood-brain barrier
- provide support within nervous tissue
- regulate ion nutrient and dissolved gas concentrations in the interstitial fluid
- form scar tissue
What is the blood brain barrier
isolates the CNS from the chemicals and hormones circulating in the blood.
What are oligodendrocytes?
cells that provide structural framework within the CNS by stabilizing the positions of axons
what are somatic neurons?
innervate skeletal muscles
What are visceral motor neurons?
innervate all peripheral effectors other than skeletal muscles– smooth, glands, cardiac, adipose
What are autonomic ganglia?
second set of visceral motor neurons that innervate the peripheral effectors
What are efferent fibres?
axons that carry instructions from the CNS to peripheral tissues
What are afferent fibres?
axons that carry sensory information to the CNS
What is ganglion?
collection of neuron cell bodies in the PNS
What are sensory neurons?
unipolar neurons whose cell bodies are located in sensory ganglia in the PNS
What is the function of visceral sensory neurons?
TO monitor internal conditions and the organ systems
What are interoceptors?
monitor the digestive, respiratory, cardio, urinary, and reproductive systems
- provide sensations of stretching, deep pressure and pain
What are proprioceptors?
monitor the position and movement of skeletal muscles and joints
What are exteroceptors?
provide info about the eternal environment in the form of touch, temp or pressure sensations
- more complex senses of taste smell, sight, equilibrium and hearing
