Lecture 3 Flashcards
What ions have a higher concentration inside the cell?
K
Potassium ions
What ions have a higher concentration in the outside of the cell?
Na, Ca, Cl
Sodium, Calcium, Chloride ions
What are the different channels?
non gated channel, gated channel
Channels that do not require a stimulus to open vs. channels that require a stimulus to open
What are the different stimulus to open gated channels?
voltage, chemical, mechanical, temperature
Voltage changes, chemical signals, mechanical force, temperature changes
How do the ions move once channels are open?
diffusion
Movement from high concentration to low concentration
What charge is a resting membrane potential?
(-70)
Negative seventy millivolts
How is the resting membrane potential maintained?
by active Na K pumps
Sodium-Potassium pumps actively transport ions to maintain resting potential
What is a graded potential?
membrane potential changes due to ion channels opening and can reach threshold for action potential
Small changes in membrane potential that can lead to action potential
Do all graded potentials reach action potential?
no, some hyperpolarize the cell body/ dendrites or are not very strong
Not all graded potentials lead to action potential
Can graded potentials piggy back off one another?
yes but it does not mean that the action potential will be greater. All action potentials are the same intensity
Graded potentials can summate but action potentials remain consistent in intensity
Where does the action potential begin?
trigger zone
Area where action potential is initiated
Where do action potentials occur?
axon hillock to axon
From the initial segment to the axon
What type of gates do graded potentials use?
Chemical, mechanical, temp, voltage
Chemical, mechanical, and temperature-sensitive gates
What type of gates do action potentials use?
Voltage
Voltage-gated channels
What fiber diameter travels faster: thin or thick?
thick
Thick fibers
What is the myelinated fibers conduction called?
saltatory conduction
Rapid conduction in myelinated fibers
What are the exposed axon areas between myelinated fibers called?
nodes of ranvier
Gaps in the myelin sheath
What is the neural junction?
between the pre and post synaptic neuron
Area where neurons communicate
What ion triggered the release of neurotransmitters by exocytosis?
Ca
Calcium ions
The binding of neurotransmitters from the pre synaptic neuron triggers what type of channels to open on the post synaptic neurons?
chemical gated channels and helps reach action potential
Channels that open in response to neurotransmitter binding
What neurotransmitters hyperpolarize the membrane?
gaba, glycine
Inhibitory neurotransmitters
Where can receptors be found?
dendrites unipolar or on cells that synapse with neurons
Receptors on dendrites or synapsing cells
What are phasic vs tonic receptors?
adapts to a stimuli ( clothes) vs. A continuous action potential response for the stimulus (posture)
Receptors that adapt to stimuli vs. receptors that maintain a response
Explain the 3 order neuron sensory pathway
the first neuron detects the signal and sends up the spinal cord to the medulla -> the second occurs in the medulla to the thalamus -> the third goes from the thalamus to the cerebral cortex area associated with the signal
Pathway of sensory information processing
