Problem 138 - Objective Biology for NEET

Question

Select the correct statement: (a) Neural system co-ordinates and integrates functions as well as metabolic and homeostatic activities of all organs (b) Chemical involved in the transmission of impulse at chemical synapses are always proteins (c) The electrical potential difference across the resting neural membrane is called the action potential (d) Organ of Corti influenced by gravity and movement and helps in maintaining balance of the body and posture

Step-by-Step Solution

Answer

The correct statement is (a) Neural system co-ordinates and integrates functions as well as metabolic and homeostatic activities of all organs.

Step 1: Analyse Option A

The neural system indeed co-ordinates and integrates functions as well as metabolic and homeostatic activities of all organs. This statement is correct.

Step 2: Analyse Option B

While chemicals are indeed involved in the transmission of impulse at chemical synapses, they are not always proteins. This statement is incorrect as the chemicals involved are mostly neurotransmitters, which can be amino acids, peptides, and monoamines.

Step 3: Analyse Option C

Whilst there is an electrical potential difference across the resting neural membrane, it is called the resting potential not the action potential. Thus, this statement is incorrect.

Step 4: Analyse Option D

The organ of Corti does play a crucial role in hearing but it doesn’t directly influence gravity and maintaining balance. The sense of balance is primarily controlled by the vestibular system in the human ear. Therefore, this statement is also incorrect.

Key Concepts

Neural Integration

Neural integration is a critical function of the neural system that allows coordination and synthesis of various signals throughout the body. Essentially, the neural system works like a sophisticated network that sends and receives messages to ensure different body parts work in harmony. These messages are conveyed through neurons, which are specialized cells designed to transmit information rapidly.
The purpose of neural integration is to ensure that all vital activities such as movement, thought processes, and sensory perceptions are well-coordinated. It means the brain and the spinal cord, which make up the central nervous system (CNS), work together with peripheral nerves to regulate these functions seamlessly.

• The CNS acts as the processing center.
• Peripheral nerves carry signals to and from the CNS.
• Neurons communicate via synapses, where integration happens.

The integration is not just about sending signals; it involves complex processes that include combining different sensory inputs and coordinating them to produce a coherent response.

Metabolic Activities

Metabolic activities refer to the biochemical processes that occur within living organisms to maintain life. These processes include breaking down nutrients to produce energy, synthesizing necessary molecules, and eliminating waste. The neural system plays an essential role in managing these activities.
The brain, as part of the neural system, needs a significant amount of energy to function properly. This energy is derived from metabolic processes, mainly through the metabolism of glucose, the brain's primary fuel.

• The brain consumes approximately 20% of the body's energy.
• Glucose is a principal energy source for neural activities.
• Neurotransmitters facilitate the regulation of metabolic pathways in response to the body’s energy demands.

Thus, neural integration is not just about communication but also about ensuring that the metabolic demands of the body meet our cognitive and physical activities.

Homeostasis

Homeostasis is the body's ability to maintain a stable internal environment despite changes in external conditions. This stability is crucial for the proper functioning of cells and organs. The neural system is a primary player in maintaining homeostasis through constant monitoring and adjustments.
In homeostasis, signals are sent to organs to regulate functions such as temperature, pH, blood pressure, and glucose levels.

• The nervous system detects internal changes via sensory receptors.
• It integrates this information to decide on a response.
• Effector mechanisms are activated to correct any imbalances.

For instance, when body temperature rises, the nervous system triggers sweating to cool the body down. Similarly, in the cold, it stimulates responses like shivering to generate heat.

Neurotransmitters

Neurotransmitters are chemicals that facilitate communication between neurons. They are crucial in the neural integration process at synapses, which are junctions where neurons connect. These chemicals are diverse and include amino acids, peptides, and monoamines, not just proteins.
Neurotransmitters have specific roles depending on the receptor they bind to and the effect they generate.

• Excitatory neurotransmitters, such as glutamate, promote action potentials.
• Inhibitory neurotransmitters, like GABA, prevent actions and maintain balance in neural circuits.
• Modulatory neurotransmitters, like dopamine, influence entire brain areas over longer periods.

The efficient functioning of neurotransmitters is essential for processes like mood regulation, learning, and movement. Imbalances or dysfunctions in neurotransmitter systems can lead to disorders such as depression, anxiety, and Parkinson’s disease.