With reference to the coordinated functions of the endocrine system and the nervous system in the human body, consider the following statements:
- 1. The hypothalamus produces 'releasing and inhibiting hormones' to control the secretions of the anterior part of the pituitary gland, and its neurosecretory neurons extend directly to the posterior pituitary gland from where oxytocin and vasopressin are stored and released.
- 2. The cortex part of the adrenal gland secretes 'corticosteroid' hormones, in which 'aldosterone' mainly maintains electrolyte balance in the body by controlling the reabsorption of sodium ions and water by the renal tubules.
- 3. The 'corpus callosum' located in the human brain is a band of tough nerve fibers that connects the two hemispheres of the brain, and it is mainly responsible for the processing of visual information.
- 4. The 'islets of Langerhans' of the pancreas perform endocrine functions, in which alpha cells secrete insulin which reduces the amount of glucose in the blood, while beta cells secrete glucagon which stimulates glycogenolysis.
Which of the above statement(s) is/are completely true?
Detailed Explanation & Solution
Statement 1 is true because the hypothalamus controls the functions of the pituitary gland and its neurons send oxytocin and vasopressin (ADH) to the posterior pituitary gland. Statement 2 is true because aldosterone secreted by the adrenal cortex controls the reabsorption of sodium and water by the kidneys. Statement 3 is false because the corpus callosum connects both cerebral hemispheres, but it primarily establishes communication between the two hemispheres, not exclusively for visual processing. Statement 4 is false because the 'alpha cells' of the pancreas secrete glucagon (glucose-increasing) and 'beta cells' secrete insulin (glucose-decreasing); the statement gives the reverse.