How do brain cells differ from other cells in the body?
The cells send signals to adjoining cells more quickly.
The cells function Independently from other cells in the region.
The cells do not store glucose as glycogen.
The cells are combined in concentric circles that increase with age.
The Correct Answer is C
Neurons, or brain cells, are highly specialized cells responsible for transmitting information throughout the nervous system. Unlike other cells in the body, neurons do not store glucose in the form of glycogen. This characteristic makes them heavily reliant on a continuous and stable supply of glucose from the bloodstream to meet their energy demands. Here's a detailed explanation:
The Role of Glucose in Neurons
- Energy Demand: Neurons have a high energy demand due to their role in maintaining electrical gradients, neurotransmitter synthesis, and signal transmission. The primary source of energy for neurons is glucose.
- Blood-Brain Barrier: Glucose is transported from the bloodstream to the brain through the blood-brain barrier, a selective barrier that regulates the passage of substances into the brain. Specialized glucose transporters, primarily GLUT1 and GLUT3, facilitate the uptake of glucose into neurons.
- Glycolysis and ATP Production: Once inside the neuron, glucose undergoes glycolysis, a metabolic pathway that breaks down glucose to produce ATP (adenosine triphosphate), the energy currency of the cell. The end product of glycolysis, pyruvate, enters the mitochondria where it is further oxidized in the Krebs cycle and oxidative phosphorylation to produce more ATP.
Lack of Glycogen Storage in Neurons
No Glycogen Reserves: Unlike liver and muscle cells, neurons do not have significant glycogen stores. Glycogen is a stored form of glucose that can be mobilized during periods of low blood glucose levels. Neurons lack this storage capacity, making them highly dependent on a continuous supply of glucose from the blood.
Importance of Continuous Blood Flow
Constant Supply Needed: Due to their inability to store glucose, neurons require a constant supply of glucose from the bloodstream. Any interruption in blood flow, such as during a stroke or hypoglycemia, can quickly lead to energy depletion and neuronal dysfunction or death.
Physiological Implications
Ischemia and Hypoglycemia: Conditions that disrupt the delivery of glucose to the brain, such as ischemia (reduced blood flow) or hypoglycemia (low blood glucose levels), can have severe effects on neuronal function and survival. This highlights the critical need for maintaining adequate cerebral blood flow and glucose levels.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
The body's ability to correct an excess or deficit of metabolic acids primarily depends on the normal function of the renal system. The kidneys regulate the acid-base balance by excreting excess acids or bases and reabsorbing bicarbonate from the urine, thus helping to maintain pH homeostasis.
Correct Answer is ["B","C","D"]
Explanation
Choice A reason:
Canceling Netflix by Internet service is not relevant to Mr. Jones’ discharge planning. While managing finances and subscriptions may be part of overall life management, it does not address the immediate safety and mental health needs of Mr. Jones.
Choice B reason:
Releasing information signed for family to secure Mr. Jones’ loaded gun or having the police secure the gun if needed prior to discharge is crucial for ensuring his safety. Removing access to firearms reduces the risk of self-harm and is an important step in discharge planning for someone with suicidal ideation.
Choice C reason:
Obtaining a psychiatric provider follow-up appointment as soon as possible and evaluating for PHP (Partial Hospitalization Program) or residential treatment with the treatment team is essential. Continuity of care and appropriate follow-up are critical for managing Mr. Jones’ depression and preventing relapse.
Choice D reason:
Assisting in developing a safety plan prior to discharge that is written with phone numbers and interventions is vital. A safety plan provides Mr. Jones with clear steps to take if he feels at risk of harming himself, including contact information for crisis services and supportive individuals.
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