Chapter 7 Flashcards
What are the three types of ion channels
Leak channels, ligand-gated, voltage-gated
When is a leak channel open
Always
What causes a ligand-gated channel to open
When a specific chemical binds to it
What causes a voltage-gated channel to open
When a specific voltage is reached
The central nervous system is composed of what
Brain and spinal cord
What are the 2 parts of the autonomic nervous system
Sympathetic and parasympathetic
What are the 5 main parts of a neuron
Cell body, dendrites, axon, axon hillock and axon terminal
What direction goes an action potential travel down the axon
From the axon hillock to the axon terminal
What are the 3 functional classifications of neurons
Afferent, efferent, interneuron
What is the difference between a graded potential and an action potential
Graded potential is a small change in membrane potential that degrades. An action potential will be sent down the entire axon
What are the 3 stages of an action potential
Depolarization, repolarization, hyperpolarization
What gates are the first to open when threshold is reached
Sodium activation gates
What causes hyperpolarization
Slow closing of potassium gates
What is resting membrane potential in a neuron
-70 mV
What is the threshold potential in a neuron
-55 mV
What is the all-or-none principle
Once threshold is reached, an action potential will occur
What is the difference between relative and absolute refractory periods?
Relative - A stronger than normal stimulus will cause an action potential
Absolute - No matter what, another action potential can not occur
The absolute refractory period occurs during what stages of an action potential
Depolarization and repolarization
When does the relative refractory period occur
Hyperpolarization
What 2 characteristics of a neuron will speed up transmission?
Increased size and myelination
What are the 4 primary contributors to membrane potential and what do they do to membrane potential
Na+/K+ ATPase pump - More negative
K+ leak channels - More negative
Proteins in the cell - More negative
Na+ leak channels - Less negative
What are the two types of graded potentials
Depolarizing, hyperpolarizing
What is happening to membrane potential during depolarization
Less negative
