stuff we did in neuro october 2nd 2024 Flashcards
What protects the brain from injury?
The skull, immune system, and blood-brain barrier protect the brain from internal and external forces.
What does the CNS rely on for its function?
The CNS relies on a continuous infusion of blood glucose and oxygen.
Can damaged brain tissue recover to its previous function?
Once brain tissue is damaged, it rarely recovers back to its previous level of function.
What are the two types of cells in the nervous system?
Neurons and supporting cells (neuroglial cells).
What is the function of neurons?
Neurons scan the environment, integrate systems at higher cognitive levels, and initiate responses to maintain homeostasis.
What is the role of neuroglial cells?
Supporting cells provide structural support, nutrition for neurons, and aid in processing and storing information.
What is the primary fuel source for neurons?
The primary fuel source for neurons is glucose.
Do neurons require insulin for glucose uptake?
No, insulin is not required for cellular uptake of glucose in the CNS.
What are dendrites?
Dendrites are extensions that carry nerve impulses TOWARD the cell body.
What are axons?
Axons are long, conductive projections from the cell body that carry nerve impulses AWAY from the cell.
What is myelin?
Myelin is an insulating lipid material that speeds conduction of nerve signals.
How do neuroglial cells compare in number to neurons?
There are 5-10 times more neuroglial cells than neurons.
When do nerves begin to regenerate after an injury?
Nerves begin to regenerate 1-2 weeks after injury, only if they are myelinated and in the peripheral nervous system.
Why is nerve regeneration limited in the CNS?
Regeneration in the CNS is limited due to increased scar formation and the different nature of myelin.
What factors influence nerve regeneration?
Factors include the location of the injury, type of injury, inflammatory responses, and the process of scarring.
Which type of nerve injury is more likely to regenerate: crushed or cut?
Nerves are more likely to regenerate if they were crushed rather than cut.
What happens to cut nerves?
Cut nerves often form connective tissue scars that block or slow nerve conduction.
How do neurons send and receive signals?
Neurons change the electrical state of their membranes and release chemicals (neurotransmitters) to communicate with nearby neurons.
What is the resting membrane potential?
The resting membrane potential is the state of a neuron when it is unexcited, maintaining a specific electrical charge.
What generates an action potential?
An action potential is generated when the membrane potential is raised sufficiently by a strong enough stimulus (all or nothing).
What are synapses?
Synapses are the regions between neurons where neurotransmitters convey impulses across.
What are presynaptic and postsynaptic neurons?
Presynaptic neurons conduct electrical impulses toward the synapse, while postsynaptic neurons conduct impulses away from the synapse.
What is the role of norepinephrine?
Norepinephrine regulates mood, sleep functions, and maintains arousal; it’s affected by cocaine and amphetamines.
How is acetylcholine related to Alzheimer’s disease?
A decrease in acetylcholine-secreting neurons is seen in patients with Alzheimer’s disease.
