Chapter 16, Problem 1P

Summary Introduction

To match: The given terms with the endocrine glands depicted in the diagram.

Introduction: The endocrine system is a chemical signaling system that uses the blood vessels as information channels. The endocrine glands are ductless organs located within the organ systems and contain groups of endocrine cells that secrete their hormones directly into their surroundings. Hormones are signaling molecules that help in regulating physiology and behavior.

Answer to Problem 1P

Pictorial representation: Fig. 1 represents the different types of endocrine gland.

Fig.1: Different types of endocrine gland

Explanation of Solution

1. A.    Pituitary gland: The pituitary gland is located at the base of the brain and produce thyroid and follicle stimulating hormones, luteinizing hormone, and adrenocorticotropic hormone.
2. B.     Pineal gland: Pineal gland is a small, cone-shaped structure of the endocrine gland. It is composed of pinealocytes and glial cells (cells of nervous system) and connects the nervous system with the endocrine system. The hormone melatonin is secreted by the pineal gland.
3. C.     Parathyroid glands: Parathyroid hormone (PTH) is an important hormone secreted by the parathyroid glands.
4. D.    Thyroid gland: Thyroid gland is a butterfly-shaped endocrine gland and is enclosed within a connective tissue capsule. The thyroid gland is located near the neck.
5. E.     Thymus: The thymus gland is located behind the sternum and between the lungs. Thymosin, thymulin, thymopoietin, and thymosin are secreted by thymus.
6. F.      Adrenal gland: The adrenal glands are paired and pyramid-shaped endocrine glands. They are located on the superior surface of the kidneys.
7. G.    Pancreas: Pancreas is a glandular organ present in the abdominal cavity of a vertebrate, which helps for the regulation of sugar levels in the body.
8. H.    Kidney: The kidney is the major excretory organ present in human beings. It is a bean-shaped organ located at the back of the abdomen. The nephron is the functional unit of the kidney.
9. I.        Ovary in female: The ovary is an organ that is present in the reproductive system of females and it produces ovum. Females have a pair of ovaries. Ovary is important in the reproduction, as it is responsible for the production of female reproductive cells.
10. J.       Testis in male: Testis is the male reproductive gland. Testosterone is a steroid hormone produced by testes in males. This hormone is responsible for the development of secondary sexual characters.