What is the endoplasmic reticulum?
A network of membranes involved in protein and lipid synthesis.
What do neurons typically have?
Many dendrites.
Which type of glia guide the migration of neurons during embryonic development?
Radial glia.
What is necessary to change the amount of polarization of a neuron?
Change the difference in voltage between the inside and outside of the cell membrane.
What does the concentration gradient refer to?
The difference in the distribution of ions across the cell membrane.
What does Nettie need to do to get the sodium channels to open?
Depolarize the neuron to reach threshold so the voltage-gated sodium channels open.
Why did Terrance not feel pain after receiving Novocain?
It blocks sodium channels, preventing action potentials.
What would Charles Sherrington likely agree about reflexes?
Reflexes involve communication between neurons at synapses, leading to a delayed but coordinated response.
What is the primary difference between temporal summation and spatial summation?
Temporal summation = multiple signals from the same presynaptic neuron over time. Spatial summation = simultaneous signals from multiple presynaptic neurons.
What should Toshia do to produce an IPSP in her cultured neurons?
Open potassium (K⁺) or chloride (Cl⁻) channels to hyperpolarize the neuron.
What did Loewi discover when he transferred fluid from one frog’s heart to another?
The second heart rate also decreased, showing that neurotransmitters (like acetylcholine) are chemical messengers.
What do dopamine, norepinephrine, and epinephrine have in common?
They are all catecholamines derived from the same precursor, tyrosine.
What happens when an action potential reaches the end of an axon?
Voltage-gated calcium (Ca²⁺) channels open, and calcium enters the presynaptic terminal.
What type of effect does glutamate have when it opens sodium gates?
An excitatory postsynaptic potential (EPSP).
How do hormones exert their effects?
By traveling through the bloodstream and influencing activity in target cells or tissues.
How can small, charged molecules cross the cell membrane?
Through protein channels or ion channels.
What is another name for a presynaptic terminal?
An end bulb or bouton.
Which type of glia builds myelin sheaths around axons in the periphery of the body?
Schwann cells.
What is Korsakoff’s syndrome associated with?
Severe memory problems caused by thiamine (vitamin B1) deficiency, often due to chronic alcoholism.
Under which conditions is the sodium-potassium pump less effective?
When the cell is low on ATP (energy).
What should Dr. O’Reilly do to produce hyperpolarization in neurons?
Open potassium (K⁺) channels to let K⁺ exit or open chloride (Cl⁻) channels to let Cl⁻ enter.
What causes potassium ions to leave the cell just after the peak of the action potential?
The concentration gradient and the opening of voltage-gated potassium channels.
What evidence did Sherrington use to deduce that synaptic transmission is slower than axon conduction?
Reflexes took longer than expected if communication were purely electrical, suggesting a delay at the synapse.
What produces an IPSP?
The selective flow of potassium (K⁺) out of the cell or chloride (Cl⁻) into the cell.
