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Both the nervous and the endocrine systems are involved when a person is in a dangerous situation - NSC Life Sciences - Question 4 - 2019 - Paper 1
Question 4
Both the nervous and the endocrine systems are involved when a person is in a dangerous situation. Describe the path of an impulse in a reflex arc during a reflex a... show full transcript
Worked Solution & Example Answer:Both the nervous and the endocrine systems are involved when a person is in a dangerous situation - NSC Life Sciences - Question 4 - 2019 - Paper 1
Step 1
Describe the path of an impulse in a reflex arc during a reflex action.
Answer
The reflex arc begins with the receptor that receives the stimulus and converts it into an impulse. This impulse is then transmitted by the sensory neuron, which travels through the dorsal root of the spinal nerve and enters the spinal cord.
Within the spinal cord, the impulse is transferred via an interneuron, which relays the signal to the motor neuron. The motor neuron then carries the impulse away from the spinal cord through the ventral root to the effector, which is typically a muscle or gland. The entire process allows for a rapid response to the stimulus, minimizing the response time.
Step 2
Describe the role of different glands of the endocrine system in providing the body with extra energy during the dangerous situation.
Answer
In a dangerous situation, the endocrine system plays a crucial role in enhancing the body's ability to respond by secreting various hormones:
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Adrenal glands secrete adrenaline, which increases blood glucose, heart rate, and breathing rate while dilating blood vessels to essential organs, ensuring they receive adequate oxygen and nutrients.
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Pancreas (specifically the islets of Langerhans) secretes glucagon, which raises blood glucose levels, providing energy for muscles during the fight-or-flight response.
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The pituitary gland releases Thyroid-Stimulating Hormone (TSH) to stimulate the thyroid gland.
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The thyroid gland itself secretes thyroxin, increasing the body’s metabolic rate and facilitating higher energy production, which is vital in stressful situations to prepare the body for physical exertion.