Chapter 11 & 12 Flashcards
Functions of the nervous system
maintains homeostasis receives sensory input integrating information controlling muscles and glands establishing and maintaining mental activity
What makes up the central nervous system (CNS)
brain and spinal cord
What makes up the peripheral nervous system (PNS)
sensory receptors and nerves
What are ganglia in the peripheral nervous system
collection of neuron cell bodies outside CNS
How many neurons are in series in the autonomic nervous system
2
Dendrites
short often highly branched
Axons
branch to form colcollaterals
Nissl Bodies
chromatopilic substance
Presynaptic Terminal
regulates resting or vegetative function
Motor (efferent) interneuron
action potential away from CNS
Sensory (afferent) interneuron
action potential toward CNS
Bipolar neuron
sensory in retina of the eye and nose
What determines resting membrane potential and potassium pumps
K+
Epinephrine is
adrenaline
What cells do not action potentials
neuroglia
Astrocytes
regulate substance that reach CNS from the blood
Ependymal Cells
line brain ventricles and spinal cord central canal
Satellite Cells
surrounds neuron cell bodies in sensory ganglia
Where do unmylinated axons rest
invagination of schwann cells or oligodendrites
What matter is composed of of bundles of mylinated axons
white
The plasma membrane is more permeable to ___ than to ___ ions because there are more leak channels for the former type of ion
K+, Cl-
Na+
If potassium membrane permeability is increased you would expect the cell to be
hyperpolarized
An increase in what leads to depolarization
pottasium
If the charge difference across the cell membrane is decreased, the membrane potential?
decreases
Voltage gated sodium channels are sensitive to change in what
extracellular calcium
Local Potential
a small change in the resting membrane potential of a neuron caused by a stimulus that opens a ligand-regulated sodium gate in the membrane of a neuron
When does an action potential occur
when local potential reaches threshold
What is the all or none principle
mo matter how strong the stimulus, as long as it is greater than threshold, then action potential will occur
Absolute refractory period
no matter how large 2nd action potential cannot be produced
Relative refractory period
can initiate another action potential