Free Chemical Coordination and Hormones MCQs with Answers

• A. Liver
• B. Pancreas
• C. Thyroid gland
• D. Adrenal gland

Explanation: Insulin is produced by the beta cells of the islets of Langerhans in the pancreas, and it lowers blood glucose.

• A. converting glycogen in the liver into glucose
• B. increasing the uptake of glucose by cells and its storage as glycogen in the liver and muscle
• C. increasing the excretion of glucose in the urine
• D. stopping the digestion of carbohydrate in the gut

Explanation: Insulin from the beta cells of the islets of Langerhans makes cell membranes more permeable to glucose and stimulates the enzymes that…

• A. iodine is needed to make insulin
• B. iodine destroys the thyroid gland directly
• C. the thyroid cannot make enough thyroxine and enlarges under continued stimulation by the pituitary
• D. excess iodine accumulates in the neck

Explanation: Thyroxine contains iodine, so a shortage means output falls, and the low blood level removes the negative feedback on the pituitary, which…

• A. Increased heart rate
• B. Conversion of glycogen to glucose in the liver
• C. Dilation of the bronchioles
• D. Increased peristalsis and secretion in the gut

Explanation: Adrenaline prepares the body for fight or flight, so it diverts blood and resources to the heart, muscles and lungs and slows digestion…

• A. Thyroid
• B. Adrenal
• C. Pituitary
• D. Pancreas

Explanation: The pituitary gland is called the master gland because its hormones regulate other endocrine glands.

• A. Alpha cells
• B. Beta cells
• C. Delta cells
• D. Acinar cells

Explanation: Beta cells of the pancreatic islets produce insulin in response to high blood glucose.

• A. Only growth
• B. Basal metabolic rate
• C. Only blood pressure
• D. Only digestion

Explanation: T3 and T4 regulate basal metabolic rate (BMR), growth, development, and body temperature.

• A. Adrenal medulla
• B. Adrenal cortex
• C. Anterior pituitary
• D. Thyroid

Explanation: Cortisol (a glucocorticoid) is produced by the adrenal cortex, especially in response to stress.

• A. GH and TSH
• B. ADH and oxytocin
• C. ACTH and FSH
• D. Prolactin and LH

Explanation: The posterior pituitary stores and releases ADH and oxytocin, which are produced in the hypothalamus.

• A. Excess iodine
• B. Iodine deficiency
• C. Excess calcium
• D. Vitamin D deficiency

Explanation: Iodine deficiency causes goiter (enlarged thyroid) as the gland tries to compensate for insufficient T3/T4 production.

• A. Binding cell surface receptors
• B. Binding intracellular receptors
• C. Opening ion channels
• D. Activating second messengers

Explanation: Steroid hormones (lipid-soluble) diffuse through membranes and bind intracellular receptors that regulate gene transcription.

• A. Insulin resistance
• B. Autoimmune destruction of beta cells
• C. Excess insulin
• D. Pituitary tumor

Explanation: Type 1 diabetes is an autoimmune disease where beta cells are destroyed, requiring insulin injections.

• A. Increasing bone resorption
• B. Decreasing bone resorption
• C. Increasing calcium absorption
• D. Decreasing calcium excretion

Explanation: Calcitonin from the thyroid inhibits osteoclasts, decreasing bone resorption and lowering blood calcium.

• A. Increased heart rate
• B. Bronchodilation
• C. Glycogenolysis
• D. Decreased blood pressure

Explanation: Adrenaline increases (not decreases) blood pressure through vasoconstriction and increased cardiac output.

• A. Nervous system
• B. Endocrine system
• C. Respiratory system
• D. Both A and B

Explanation: Animals coordinate body activities through both the nervous system, which uses rapid electrical signals, and the endocrine system, which…

• A. Glucagon
• B. Insulin
• C. Gastrin
• D. TSH (Thyroid Stimulation Hormone)

Explanation: Insulin lowers blood glucose by promoting glucose uptake by cells and its storage as glycogen in the liver and muscles.

• A. STH
• B. TSH
• C. ACTH
• D. Thyroxin

Explanation: Acromegaly results from excess secretion of somatotropic hormone, also called growth hormone or STH, after the growth plates have closed.

• A. Acidic
• B. Basic
• C. Neutral
• D. All of these

Explanation: Secretin is released by the duodenal mucosa when acidic chyme from the stomach enters the small intestine, and it stimulates bicarbonate…

• A. Alpha cells
• B. Delta cells
• C. Nerve cells
• D. Beta cells

Explanation: Beta cells in the islets of Langerhans secrete insulin, which lowers blood glucose by promoting glucose uptake and storage.

• A. Thyroid
• B. Pancrease
• C. Pineal
• D. Pituitary

Explanation: The pineal gland is a very small endocrine gland that secretes melatonin and helps regulate biological rhythms such as the sleep-wake…