Bio 436 Lecture 4 (Concepts) Test
Questions and Correct Answers
Describe a neuron. What is a nerve? ✅Starts with the dendrites and goes to the cell
body then down the axon, which is covered in the myelin sheaths (dont forget nodes of
ranvier), then down to the axon terminal.
"Nerves" are bundles of neurons
What is different between sensory/afferent and motor/efferent neurons? Are both found
in nerves ✅Sensory/ afferent neurons conduct impulses in CNS
Motor/ Efferent neurons carry impulses out of CNS. (Somatic and autonomic)
How do cells signal one another? ✅With neurotransmitters
Why is a membrane potential important? ✅Because it makes sure the neurons can
spontaneously depolarize and conduct action potentials for no damn reason.
According to someone's quizlet it's an alternative source to atp
What is a membrane potential? ✅The difference in charge from one side of the
membrane to the other side. The inside of a cell is usually -75mV so the resting
membrane potential is said to be -75mV; is the alternative form of energy instead of
ATP so that ATP can be used for something else
How does a cell establish a membrane potential? ✅Membrane potentials change
because membranes become more or less permeable to ions, which is usually from an
ion channel being opened.
What is important inside of cells for the establishment of a membrane potential?
✅Potassium
and negative charged components
What ions are most involved?What channels? ✅Sodium and potassium, and the Na
and K channels. The potassium channel stays open after polarization to lead us to
hyperpolarization (leaky channel).
What is the name of the equation which allows us to calculate an equilibrium potential
for any individual ion? ✅Nernst Equation:
ENA = (RT/ZF) ln [(Na out)/(Na in)]
R= 2 cal/˚K-mole
T = 293˚K (20˚C)
Questions and Correct Answers
Describe a neuron. What is a nerve? ✅Starts with the dendrites and goes to the cell
body then down the axon, which is covered in the myelin sheaths (dont forget nodes of
ranvier), then down to the axon terminal.
"Nerves" are bundles of neurons
What is different between sensory/afferent and motor/efferent neurons? Are both found
in nerves ✅Sensory/ afferent neurons conduct impulses in CNS
Motor/ Efferent neurons carry impulses out of CNS. (Somatic and autonomic)
How do cells signal one another? ✅With neurotransmitters
Why is a membrane potential important? ✅Because it makes sure the neurons can
spontaneously depolarize and conduct action potentials for no damn reason.
According to someone's quizlet it's an alternative source to atp
What is a membrane potential? ✅The difference in charge from one side of the
membrane to the other side. The inside of a cell is usually -75mV so the resting
membrane potential is said to be -75mV; is the alternative form of energy instead of
ATP so that ATP can be used for something else
How does a cell establish a membrane potential? ✅Membrane potentials change
because membranes become more or less permeable to ions, which is usually from an
ion channel being opened.
What is important inside of cells for the establishment of a membrane potential?
✅Potassium
and negative charged components
What ions are most involved?What channels? ✅Sodium and potassium, and the Na
and K channels. The potassium channel stays open after polarization to lead us to
hyperpolarization (leaky channel).
What is the name of the equation which allows us to calculate an equilibrium potential
for any individual ion? ✅Nernst Equation:
ENA = (RT/ZF) ln [(Na out)/(Na in)]
R= 2 cal/˚K-mole
T = 293˚K (20˚C)
