When adrenaline is secreted into the blood, our body undergoes a rapid response often termed the “fight or flight” reaction. Heart rate and blood pressure increase, providing more oxygen and nutrients to muscles. Blood sugar levels rise, enhancing energy availability. Pupils dilate for better vision, and blood flow to non-essential systems like digestion reduces, focusing the body’s resources on immediate physical response.

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Activation of the “Fight or Flight” Response

When adrenaline is secreted into the bloodstream, it triggers the body’s innate “fight or flight” response. This reaction is an evolutionary mechanism that prepares the body to either confront or flee from perceived threats. Adrenaline, also known as epinephrine, is released by the adrenal glands, typically in response to stress, fear, or excitement.

Increased Heart Rate and Blood Pressure

One of the primary effects of adrenaline is the increase in heart rate and blood pressure. This surge ensures that more oxygenated blood is pumped to the muscles, preparing them for rapid and strenuous activity. The increased heart rate also helps to transport glucose and oxygen throughout the body more efficiently, providing the energy needed for a quick response.

Elevation of Blood Glucose Levels

Adrenaline stimulates the liver to break down glycogen, a stored form of glucose, into glucose itself. This increases blood sugar levels, providing an immediate energy source for the body. This energy boost is crucial for physical exertion, as it allows muscles to work harder and longer in response to a threat.

Dilation of Airways and Pupils

Adrenaline causes the airways to dilate, allowing for increased airflow into the lungs. This enhances oxygen intake, which is vital during physical exertion. Additionally, the pupils dilate, improving vision and perception, which is essential for quickly assessing and responding to the environment during stressful situations.

Redistribution of Blood to Essential Organs

In response to adrenaline, blood flow is redirected from non-essential systems, like the digestive system, to more critical organs and muscles. This redistribution of blood ensures that the body’s resources are focused on responding to the immediate threat or challenge. It also temporarily suppresses functions like digestion and reproduction, which are not essential in a fight or flight situation.

In summary, the secretion of adrenaline into the blood prepares the body for a rapid response to perceived threats or stress. This involves increasing heart rate and blood pressure, elevating blood glucose levels, enhancing oxygen intake and vision, and prioritizing blood flow to essential organs and muscles. These physiological changes enable the body to react quickly and effectively in demanding situations.

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List of Questions of Class 10 Science Chapter 6

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What is the role of the brain in reflex action?
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Give an example of a plant hormone that promotes growth.
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Design an experiment to demonstrate hydrotropism.
How does chemical coordination take place in animals?
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How does our body respond when adrenaline is secreted into the blood?
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Draw the structure of a neuron and explain its function.
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How does chemical coordination occur in plants?
What is the need for a system of control and coordination in an organism?
How are involuntary actions and reflex actions different from each other?
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?