Lecture One Flashcards
What is the foundation of cellular communication
The Ability of all living cells to maintain an electrical membrane potential
What are nerve cells 4 specialized regions
Cell body, dendrites, axon, presynaptic terminals
What is the cell body
Contains cells components. It is the portion surrounding the nucleus
What are the dendrites
Main areas for receiving information. They have neurotransmitter receptors
What are the axons
Message sending portion of the neuron
What is the point of origin on the axon
Axon hillock
What is the un myelinated region of the axon known as and what does it do?
Initial segment and it is where the action potential occurs
What is the presynaptic terminal?
Multiple endings that are the rapid conversion of neurone electrical signal into chemical signal
What contributes to the shape of action potentials
It is dependent on the different channels
What is conductance
Opposite to resistance. If a Channel is open you have conductance
What is an action potential
Transient depolarization triggered by depolarization beyond the threshold
How do cells communicate
They communicate through action potentials but action potentials are just one letter
Why did scientists use a squid
In a squid there is a long axon even a naked eye can see
What do changes in a membrane potential depend on
The flow of positive or negative ions in or out of a cell
What is the flow caused by
The opening of ion channels
What are Ion channels
Proteins that form pores through the cell membrane
What does the term gated mean
Ion channels can be open or closed
Who won the novel prize in 1963 for action potentials
Hodgkin and Huxley
How do different neuronal types respond to a continuous depolarization
Neurones can transform a simple input of information into a variety of output patterns
What are rhythmically bursting cells
Cells that participate in central circuits that generate rhythmic motor outputs such as locomotion and respiration
Who won the Nobel prize in 1991 for work on the function of a single ion channel
Neher and sackman
How are open/ closed states observed
Detecting the flow of current conducted by the receptors
What is a patch clamp
A tool for recording current flowing through a single ion channel
What is ligand gating
Channels open when the energy from ligand binding drives channel toward open state
What is phosphorylation gating
Protein phosphorylation and dephosphorylation regulates open/ close
Energy to do so comes from the transfer of high energy phosphate 1 (p1)
What is voltage gated
Energy from change in electrical potential difference across the membrane causes conformational changes
What is stretch or pressure gated
Energy comes from mechanical forces that are passed to the channel through the cytoskeleton
How does a change in membrane potential close or inactivate channels
The refractory(inactivated state) comes after the Transition from resting or close to to open up on membrane depolarization
How does calcium binding close or inactivate channels
The internal increase of calcium due to activity of a channel may inactivate a channel due got binding of ca2+
How does dephosphorylation close or inactivate a channel
The increase of calcium internal concentration in voltage gated calcium channels may produce inactivation through dephosphorylation of a channel
