BIO 1201 Final QUESTIONS AND ANSWERS
What are first messengers?
Hormones
CNS-Central Nervous System
brain and spinal cord
Cell Body
most of a neuron's organelles including nucleus
Dendrites
branched extensions- recieve signals from other cells
Axon
transmits signals to other cells
Synaptic terminals
axon branch that transmits info to another cell at a synapse
Support Cells
Glia, radial Glia, astocytes, Schwann Cells, Nodes of Ranvier, oligodendrocytes
Glia
nourish cells, insulate axons of neurons, regulate extracellular fluid surrounding neurons
Radial Glia
form tracks along which newly formed neurons migrate from the neural tube
Astocytes
facilitate info transfer at synapses- release neurotransmitters
Oligodendrocytes
myelinated axons in the CNS; type of glia
Schwann Cells
produces myelin sheaths in the PNS; type of glia
Nodes of Ranvier
In myelinated axons, voltage-gated sodium channels are restricted to gaps in the myelin
sheath; the extracellular fluid is in contact with the membrane here only
, Sodium
high outside the resting cell and low inside
Potassium
low outside the resting cell and high inside
Membrane Potential
charge diff outside and inside the cell; attraction of opposite charges (voltage)
Resting Potential
not sending a signal; maintained by ungated channels
Refractory period
the "downtime" when a second action potential cannot be initaited; ensures that all
signals in an axon travel in one direction, from the cell body to the axon terminals; due
to the inactivation of sodium channels
Graded Potential
the response to hyperpolarization and depolarization is a shift in membrane potential
Action Potential
massive change in membrane voltage
Depolarization
opens most sodium channels, while the potassium channels remain closed; rising
phase of action potential; LESS negative intracellular membrane
Hyperpolarozation
open potassium channels, while sodium channels remain closed; falling phase of action
potential; MORE negative intracellular membrane
Threshold
membrane voltage to a particular value
Excitabe cell
a cell that has ion channels that open or close in response to a stimuli
Refractory Period
unidirectionality of propagation of an action potential due to this
Saltatory Conduction
action potential appaers to jump along the axon from node to node
Types of First Chemical Messengers
What are first messengers?
Hormones
CNS-Central Nervous System
brain and spinal cord
Cell Body
most of a neuron's organelles including nucleus
Dendrites
branched extensions- recieve signals from other cells
Axon
transmits signals to other cells
Synaptic terminals
axon branch that transmits info to another cell at a synapse
Support Cells
Glia, radial Glia, astocytes, Schwann Cells, Nodes of Ranvier, oligodendrocytes
Glia
nourish cells, insulate axons of neurons, regulate extracellular fluid surrounding neurons
Radial Glia
form tracks along which newly formed neurons migrate from the neural tube
Astocytes
facilitate info transfer at synapses- release neurotransmitters
Oligodendrocytes
myelinated axons in the CNS; type of glia
Schwann Cells
produces myelin sheaths in the PNS; type of glia
Nodes of Ranvier
In myelinated axons, voltage-gated sodium channels are restricted to gaps in the myelin
sheath; the extracellular fluid is in contact with the membrane here only
, Sodium
high outside the resting cell and low inside
Potassium
low outside the resting cell and high inside
Membrane Potential
charge diff outside and inside the cell; attraction of opposite charges (voltage)
Resting Potential
not sending a signal; maintained by ungated channels
Refractory period
the "downtime" when a second action potential cannot be initaited; ensures that all
signals in an axon travel in one direction, from the cell body to the axon terminals; due
to the inactivation of sodium channels
Graded Potential
the response to hyperpolarization and depolarization is a shift in membrane potential
Action Potential
massive change in membrane voltage
Depolarization
opens most sodium channels, while the potassium channels remain closed; rising
phase of action potential; LESS negative intracellular membrane
Hyperpolarozation
open potassium channels, while sodium channels remain closed; falling phase of action
potential; MORE negative intracellular membrane
Threshold
membrane voltage to a particular value
Excitabe cell
a cell that has ion channels that open or close in response to a stimuli
Refractory Period
unidirectionality of propagation of an action potential due to this
Saltatory Conduction
action potential appaers to jump along the axon from node to node
Types of First Chemical Messengers
