Chp. 7 nervous system
what is the correct sequence of events that follows a threshold potential
1- Na channels open, then Na+ diffuse inward 2- the membrane becomes depolarized 3- K channels open, K+ diffuse outward which Na is actively transported out of the cell 4- the membrane becomes repolarized
what are small collections of nerve cell bodies found in a small number oflocations outside the central nervous system called
Ganglia
which type of ion rapidly diffuses out of the cell into the tissue fluid immediately after an action potential is propagated
K+
what is the concentration of sodium and potassium ions on the inside and outside of the membrane when a nerve fiber is polarized
Na- higher on outside K+ higher on inside
What is the correct sequence ina typical reflex arc
Receptor-afferent neuron-integration center- efferent neuron-effector
what is essential for nerve impulse propagation
action potential
despite some neuronal loss, an unlimited number of neural pathways are available and ready to be developed; therefore, additional leaning can occur throughout life. what is the statement referring to
aging
what is a neuron with a cell body located in the CNS whose primary function is connecting other neurons called?
association neuron
which nervous system does the subdivisions sympathetic and parasympathetic nervous systems belong
autonomic nervous system
what must degenerate in order for parkinson's disease and huntington's diseaseto develop
basal ganglia
what is the type of neuron that is rarein adults and is found in some special sense organs (like eyes & ears)
bipolar neuron
which two structures is the term central nervous system referring to
brain and spinal cord
what is a traumatic brain injury called
cerebral edema
what is the correct sequence of nerves that exit the spinal cord, going from superior to inferior
cervical, thoracic, lumbar, sarcal
the sciatic nerve is the largest nerve in the body resulting from a combination of which two nerves
common fibular and tibial
what is the neuron processes that normally receive incoming stimuli called?
dendrites
what is the correct sequence from outermost to innermost layers of the meninges
dura mater,arachnoid layer, pia mater
where are bipolar neurons commonly found
eyes and nose
what is the lobe that contains the primary motor area that enables voluntary control of skeletal muscle movements
frontal
which lobes do the central sulcus separate
frontal and parietal lobes
what are elevated ridges located on the surface of the cerebral hemispheres called
gyri
control of temperature,endocrine activity, metabolism, andthirst are function associated with which part of the brain
hypothalamus
what is the thermostat of the body since it regulates body temperature
hypothalamus
what would cause a person who fell on their head to become lucid then confused and finally unresponsive
intracranial hemorrhage
what is the single deep groove separating the two cerebral hemispheres called
longitudinal fissure
which part of the brain is the vital center for the control of heart rate, breathing, blood pressure, swallowing, and vomiting located
medulla oblongata
what are the three major parts of the brain stem
medulla oblongata, pons, and mid brain
what is the most common structural classification of motor and association neurons?`
multipolar neuron
what is needed on neurons for impulse conduction to be fast
myelin sheaths
why does exposure to toxins have more devastating neural effects during early pregnancy than in late pregnancy
nervous system is formed during the first month of fetal development
what is the part of a Schwann cell that is external to the myelin sheath and forms a "neuron husk"
neurilemma
what is the substance that is released at axonal endings to start a nervous impulse called
neurotransmitter
what is the sensory receptor sensitive to deep pressure
pacinian corpuscle
what type of stimulation is when pupils dilate
parasympathetic stimulation
what is the area of the brain stem that plays a role in consciousness and the awake/sleep cycles
reticular activating system (RAS)
what are afferent nerves called? what are motor nerves called?
sensory, efferent
what type of effector organ is NOT directly controlled by the autonomic nervous system
skeletal muscle
if the specialized area of the cerebral hemisphere corresponding to Broca's area is damaged, what is the result
speech muscle is lost
what is a shallow groove located on the surface of the cerebral cortex called
sulcus
which nervous system division is responsible in preparing the body for the "fight-or-flight" response during threatening situations
sympathetic nervous system
what is the structural feature that is not part of a neuron, but plays a critical role as a functional junction between neurons
synaptic cleft
what is a type of sensory neuron, such as those found in PNS ganglia
unipolar neuron