moodle questions Flashcards
Ligand-gated ion channels exist for all of the following ions except: a. K+ b. Cl- c. Na+ d. Ca2+ e. H+
H+
Which is not a part of a neuron? a. axoplasm b. axon hillock c. synaptic vesicles d. interneuron e. presynaptic terminal
interneuron
In a myelinated axon, an action potential is conducted from one node of Ranvier to another by a process called saltatory conduction. The root word of saltatory is saltare. What does saltare mean? a. to dive b. to float c. to leap d. to grab e. to squeeze
to leap
The autonomic nervous system controls what activities: a. voluntary b. conscious c. quick d. slow e. unconscious
unconscious
Sensory neurons conduct action potentials towards the: a. legs b. central nervous system c. peripheral nervous system d. arms e. heart
CNS
The blood-brain barrier protects neurons from: a. insect bites b. radiation c. dust particles d. non-toxic substances e. toxic substances
toxins
Why do humans depend on electrical signals?
all nervous system activity is based on electrical signals from autonomic controls like food digestion to activities like mathematics and running
What is an action potential?
a change in electrical activity at the cellular membrane level that the body uses to communicate to other cells
How does hyperpolarization occur?
hyperpolarization occurs when the resting membrane potential that usually is around -85 mV moves more negative, that is, further away from 0 and further away from threshold. A stronger than normal stimulus would be required to create an AP in a hyperpolarized membrane
What are the two different types of summation and how does each occur?
spatial and temporal
spatial occurs when APs arrive simultaneously at 2 different presynaptic terminals that synapse with the same postsynaptic neuron (more than one AP at the same space)
temporal occurs when two or more APs arrive in quick succession at the same synapse
Name and describe 3 functional neurons.
sensory: conduct AP toward CNS
motor: conduct AP away from CNS
interneuron: conduct AP within the CNS
Which of the following is not a type of Neuroglia Cells? a. Ependymal Cells b. microglia cells c. satellite cells d. neurolemmocytes e. erythrocytes
erythrocytes are RBCs and not a type of neuroglia cell
During depolarization, which of the following occurs last? a. voltage-gated Na+ channels close b. voltage gated K+ channels open c. ligand gated K+ channels open d. neurotransmitter is released e. voltage gated Na+ channels open
b
Name two different types of channels and explain how they work.
ligand gated: NTC chemical binds to it to open it
v-gated: a change in the local voltage triggers opening
What is one similarity and difference between Schwann cells and Oligodendrocytes?
both wrap around axons to insulate from neighbors and APs
oligodendrocyte in CNS only, single cell can cover multiple axons
neurolemmocyte (schwann cells) in PNS only, each cell forms myelin sheath on only a portion of one axon
What has two processes: one dendrite and one axon? a. multipolar neurons b. bipolar neuron c. pseudo-unipolar neurons d. unipolar neurons e. quadra polar neurons.
bipolar neuron
What are neuroglia that are star-shaped because cytoplasmic processes extend from the cell body? a. ependymal cells b. oligodendrocytes c. astrocytes d. dendrites e. Schwann cells.
astrocytes
The peripheral nervous system does not include: a. spinal nerves b. efferent divisions c. afferent division d. cranial nerves e. it includes all of these things
e
Dendrites: a. receive input b. provide output c. insulate the cell d. contain the nucleus e. are found only in the brain
receive input and increase the surface area
What provides support and nutrients to the cell? a. satellite cell b. nodes of Ranvier c. axon
d. neurolemmocytes e. myelin sheath
a. satellite cell
Action potential consists of: a. local potential b. depolarization c. repolarization d. afterpotential e. all of the above
e
What is the function of the sodium potassium pump? a. Na+ inside, K+ outside b. Na+ inside, K+ inside c. Na+ outside, K+ inside d. Na+ outside, K+ outside e. Na+ outside, Na+ inside
c
Astrocytes: a. regulate what substances reach the CNS from the blood b. regulate extracellular brain fluid composition c. produce chemicals that demote tight junctions d. both a and b e. none of the above
d, a & b
graded potentials will result from
ligands binding to receptors changes in charge across the membrane mechanical stim T changes spontaneous change in permeability
What are the structural classes of neurons?
multipolar (many dendrites and an axon)
bipolar (dendrite and axon)
pseudo unipolar (axon and no dendrites)
What is white matter
bundles of parallel axons and their myelin sheaths (nerves in PNS, nerve tracts in CNS)
what are CNS nerve tracts?
white matter, a bundle of axons and their sheaths
what is gray matter?
groups of neuron cell bodies and their dendrites
very little myelin
in CNS called cortex or nuclei
in PNS, ganglion
