Chapter 12 final Flashcards
What are the main parts of a neuron and what are their functions?
Soma- the control center of the neuron, has no centrioles, contents include a Nucleus, Cytoplasm, RER, neurofibrils, and Nissl bodies
Dendrite- Extension of a neuron that receives information from other cells or from environmental stimuli and conducts signals to the soma.
Axon- efferent nerve fiber
The lipofuscin accumulates with age and pushes the nucleus to one side of the cell. Lipofuscin granules are also called “wear and tear granules” because they are most abundant in old neurons.
What are
the different types of neurons based on functions and number of poles?
sensory (afferent) neurons= specialized to detect stimuli like light, heat, pressure and chemicals.
interneurons= lie within CNS (central nervous system), receive signals from other neurons and carry out the integrative function of the nervous sytem
motor neurons= send signals to muscle and gland cells
What are glial cells of the central and peripheral nervous system, know their functions?
Peripheral nervous system= two glial cells. Schwann cells (aid in regeneration of damaged nerve fibers). Satellite cells (provide electrical insulation and regulate chemical environment of neurons
Central nervous system= four glial cells. Oligodendrocytes (form myelin in brain and spinal cord). Epidenmal cells (secrete and circulate cerebrospinal fluid). Microglia (phagocytize and destroy microorganisms). Astrocytes (most abundant, many functions)
What is antigrade and
retrograde transport (role of kinesin and dynein)?
Anterograde transport: (kinesin) movement down the
axon away from soma
– Retrograde transport: (Dynein) movement up the axon
toward the soma
kinesin and dynein carry materials along their back while they crawl along microtubules
Why neurons do not undergo mitosis?
they have no centrioles
What are the causes of brain tumors?
arise from:
Meninges (protective membranes of CNS)
Metastasis from nonneuronal tumors in other organs
Often glial cells that are mitotically active throughout life
What are neurilemma, nodes of Ranvier, and
internodes? What causes MS and Tay-Sachs disease?
neurilemma= made by Schwann cells, thick outermost coil
nodes or Ranvier= gap between segments
internodes= myelin-covered segments from one
gap to the next
Multiple Sclerosis (MS)=
Tay-Sachs disease= is a hereditary disorder of infants of Eastern European Jewish ancestry, caused by abnormal accumulation of a glycolipid
MS and Tay-Sachs are degenerative disorders of the myelin sheath
What are the differences between
Local Potential and Action Potential?
Local potential= reversible, doesn’t follow all or none-law
action potential= is irreversible, follow all or none-law
what constitutes a synapse?
Synapse is the point where a neuron meets another neuron
What is declarative and
procedural memory?
declarative memory= things that can remember that can be written down
procedural memory= when you can remember a precision (tying a shoe)
What are the causes and symptoms of Alzheimer and Parkinson
disease?
Alzheimers= memory loss for recent events, moody, lose of ability to talk, eat, and walk. causes include a deficiency of acetylcholine ACh and nerve growth factor
Parkinsons’ disease= progressive loss of motor function, caused by degeneration of dopamine-releasing neurons, slurred speech, ineligible handwriting
