Neuro Flashcards
What is the definition of homeostasis?
Dynamic constancy
What does negative feedback do?
An increase or decrease in a variable causes a response that moves variables in the opposite direction
What is positive feedback?
An accelerated, explosive system, and the feedback stops when the stimulus does
Birth, blood clotting, and sexual orgasm are examples of what type of feedback?
Positive
Responses to Na+ change, temperature change, and blood pressure changes are what type of feedback?
Negative
The stimulus strength affects spike height in action potentials or local potentials?
Local potentials
Stimulus strength affects frequency in action potentials or local potentials?
Action potential
What triggers local potentials?
Ligand binding
Which can sum, between action potentials and local potentials?
Local potentials
What causes voltage-gated ion channels to open?
Membrane depolarization
What opens the voltage gated Ca2+ channel of the presynaptic terminal?
The action potential and Na+ entry
What does calcium do in the pre-synaptic axon?
Helps synaptic vesicles fuse with the pre-synaptic membrane and release neurotransmitters
Which type of receptor is a receptor and a channel?
Ionotropic
Which receptor type is slow and longer lasting?
Metabotropic
What activates a metabotropic receptor?
Neutrotransmitter binds, activates g-proteins, g-proteins activate the receptor
What do G-proteins do?
Activate metabotropic receptors when stimulated by neurotransmitters
What does cocaine inhibit the reuptake of?
Dopamine
Which medication hyperpolarizes excited cells?
Anti-anxiety medication
Which medication acts like GABA towards excited cells?
Anti-anxiety medication
Which drug blocks the modulatory interneuron?
Dopamine
Inhibitory or excitatory? NT binds to ionotropic receptor, chlorine flux. Chlorine high outside compared to inside
Inhibitory - negative ions coming in
Excitatory or inhibitory? NT binds to metabotropic receptor, second messenger cascade closes a calcium channel
Inhibitory, loss of positive ion flux
Calcium is high inside or outside cells?
Very high outside
What is happening at rest at the sarcomere?
Tropomyosin is covering the myosin binding site on the actin
Where is the myosin binding site?
Actin
What causes tropomoysin to pull off the myosin binding site?
Calcium binds to troponin
Acetylcholine binds to what receptor on the muscle cell endplate?
Nicotinic receptor
What type of receptor is a nicotinic receptor?
Metabotropic
What does the nicotinic receptor do on the muscle cell endplate?
Opens channels, Na+ influx
The action potential propagates down the muscle cell membrane and hits what?
DHP membrane
How is the Ryanodine receptor opened?
DHP changes conformation, communicates with and opens the Ryanodine receptor
Where is calcium being held in the muscle cell?
Sarcoplasmic reticulum (SR)
How does calcium exit the SR?
Ryanodine receptor on the SR opens to allow calcium into the muscle cell cytoplasm
What is the calcium source for muscle excitation?
Extracellular
