Test your knowledge of human endocrine system, hormones, and their functions with these multiple-choice questions.
First, read the main notes on Human Physiology, then try to answer the questions below without looking back!
Test Your Knowledge
Showing questions 21 - 40 of 47
21. Exopthalmic goitre, also known as Graves' disease, is a form of hyperthyroidism. Which of the following are characteristic symptoms of this condition?
**Exopthalmic goitre is a form of hyperthyroidism, characterised by enlargement of the thyroid gland, protrusion of the eyeballs, increased basal metabolic rate, and weight loss, also called Graves’ disease**.
22. Besides T4 and T3, the thyroid gland also secretes a protein hormone that regulates blood calcium levels. What is this hormone's primary action?
Thyroid gland also secretes a protein hormone called **thyrocalcitonin (TCT) which regulates the blood calcium levels**, specifically by decreasing them (implied by its opposition to PTH, which increases calcium).
23. How many parathyroid glands are typically found in humans, and where are they located?
In humans, **four parathyroid glands are present on the back side of the thyroid gland, one pair each in the two lobes of the thyroid gland**.
24. Parathyroid hormone (PTH) is a hypercalcemic hormone. What are its primary mechanisms for increasing Ca^2+ levels in the blood?
**Parathyroid hormone (PTH) increases the Ca^2+ levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/demineralisation). PTH also stimulates reabsorption of Ca^2+ by the renal tubules and increases Ca^2+ absorption from the digested food**.
25. The thymus gland plays a major role in the development of the immune system. Which of the following best describes the functions of thymosins, the peptide hormones secreted by the thymus?
**Thymosins play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity. In addition, thymosins also promote production of antibodies to provide humoral immunity**.
26. The adrenal medulla secretes two hormones commonly known as catecholamines, which are often called 'emergency hormones' or 'hormones of Fight or Flight'. What are these two hormones?
The **adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. These are commonly called as catecholamines**. They are rapidly secreted in response to stress and emergency situations and are called **emergency hormones or hormones of Fight or Flight**.
27. Which of the following physiological effects are NOT primarily associated with the action of catecholamines (adrenaline and noradrenaline)?
**Adrenaline and noradrenaline increase alertness, pupilary dilation, piloerection (raising of hairs), sweating etc. Both the hormones increase the heart beat, the strength of heart contraction and the rate of respiration. Catecholamines also stimulate the breakdown of glycogen resulting in an increased concentration of glucose in blood**. Regulation of water and electrolyte balance is primarily a function of mineralocorticoids from the adrenal cortex.
28. The adrenal cortex is divided into three layers. From outer to inner, what are these layers called?
The **adrenal cortex can be divided into three layers, called zona reticularis (inner layer), zona fasciculata (middle layer) and zona glomerulosa (outer layer)**.
29. What is the main glucocorticoid in the human body, and what are its key functions?
In our body, **cortisol is the main glucocorticoid**. Glucocorticoids **stimulate gluconeogenesis, lipolysis and proteolysis; and inhibit cellular uptake and utilisation of amino acids. Cortisol is also involved in maintaining the cardio-vascular system as well as the kidney functions. Glucocorticoids, particularly cortisol, produces anti-inflammatory reactions and suppresses the immune response**.
30. Underproduction of hormones by the adrenal cortex can lead to a disease characterised by altered carbohydrate metabolism, acute weakness, and fatigue. What is this condition called?
**Underproduction of hormones by the adrenal cortex alters carbohydrate metabolism causing acute weakness and fatigue leading to a disease called Addison’s disease**.
31. The endocrine part of the pancreas consists of specific cell clusters. What are these called, and what are the two main types of cells within them?
The **endocrine pancreas consists of ‘Islets of Langerhans’. The two main types of cells in the Islet of Langerhans are called $lpha$-cells and $eta$-cells.** The $lpha$-cells secrete glucagon, while the $eta$-cells secrete insulin.
32. Glucagon is a hyperglycemic hormone. Which of the following mechanisms does it primarily use to increase blood glucose levels?
**Glucagon acts mainly on the liver cells (hepatocytes) and stimulates glycogenolysis resulting in an increased blood sugar (hyperglycemia). In addition, this hormone stimulates the process of gluconeogenesis which also contributes to hyperglycemia.** Glucagon also reduces the cellular glucose uptake and utilisation.
33. Insulin is a peptide hormone crucial for glucose homeostasis. Which of the following is its primary action in regulating blood glucose?
**Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue), and enhances cellular glucose uptake and utilisation. As a result, there is a rapid movement of glucose from blood to hepatocytes and adipocytes resulting in decreased blood glucose levels (hypoglycemia). Insulin also stimulates conversion of glucose to glycogen (glycogenesis) in the target cells**.
34. Prolonged hyperglycemia, often associated with loss of glucose through urine and formation of ketone bodies, is a characteristic of which complex disorder?
**Prolonged hyperglycemia leads to a complex disorder called diabetes mellitus which is associated with loss of glucose through urine and formation of harmful compounds known as ketone bodies**.
35. In male individuals, the Leydig cells (interstitial cells) present in the testis are responsible for producing a group of hormones. What are these hormones primarily called?
The **Leydig cells or interstitial cells, which are present in the intertubular spaces (of testis) produce a group of hormones called androgens mainly testosterone**.
36. Androgens have anabolic effects on metabolism. What specific metabolic pathways do they influence?
These hormones (androgens) produce **anabolic (synthetic) effects on protein and carbohydrate metabolism**.
37. The ovary, serving as both a primary female sex organ and an endocrine gland, primarily produces which two groups of steroid hormones?
**Ovary also produces two groups of steroid hormones called estrogen and progesterone**. Estrogen is mainly synthesised by growing ovarian follicles, and progesterone mainly by the corpus luteum.
38. After ovulation, the ruptured ovarian follicle is converted into a structure that mainly secretes progesterone. What is this structure called?
After ovulation, the **ruptured follicle is converted to a structure called corpus luteum, which secretes mainly progesterone**.
39. Which of the following is NOT a primary action of estrogens in females?
**Estrogens produce wide ranging actions such as stimulation of growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters (e.g., high pitch of voice, etc.) and mammary gland development. Estrogens also regulate female sexual behaviour**. **Progesterone supports pregnancy** and stimulates milk secretion.
40. The atrial wall of the human heart secretes a peptide hormone that plays a role in regulating blood pressure. What is this hormone called, and how does it affect blood pressure?
The **atrial wall of our heart secretes a very important peptide hormone called atrial natriuretic factor (ANF), which decreases blood pressure. When blood pressure is increased, ANF is secreted which causes dilation of the blood vessels. This reduces the blood pressure**.