Endocrine System Quiz

Endocrine System Overview

• Invertebrates possess a simple endocrine system with a limited number of hormones.
• Vertebrates feature a complex endocrine system, characterized by a wide variety of hormones.

Endocrine Glands

• Endocrine glands are ductless and secrete hormones directly into the extracellular fluid (ECF).
• Hormones are non-nutrient chemicals acting as intercellular messengers, produced in trace amounts.
• Hormones are transported via blood and exert effects on specific target tissues only.

Hypothalamus

• The hypothalamus is located in the basal part of the diencephalon in the forebrain.
• It contains several nuclei made up of neurosecretory cells that produce hypothalamic hormones.
• Regulates the synthesis and secretion of pituitary hormones through:
  • Releasing hormones (RH): Stimulate pituitary hormone secretion (e.g., Gonadotropin-releasing hormone (GnRH)).
  • Inhibitory hormones (IH): Inhibit pituitary hormone secretion.

Pituitary Gland

• Situated in the sella turcica, a bony cavity, and attached to the hypothalamus via the infundibulum.
• Connected to the hypothalamus through a portal system.
• Pars distalis (anterior pituitary) is crucial for hormone production, with the pars intermedia often merged with it in humans.
• Produces adenohypophysis hormones like somatostatin.
• Regulates a wide range of body functions, including:
  • Growth Hormone (GH): Promotes overall body growth.
  • Prolactin (PRL): Targets mammary glands to stimulate milk growth and formation.
  • Thyroid Stimulating Hormone (TSH): Stimulates the thyroid gland to secrete thyroid hormones.
  • Melanocyte Stimulating Hormone (MSH): Regulates skin pigmentation by acting on melanocytes.
  • Gonadotrophins: Influence the function of gonads.

Disorders Related to Endocrine Function

• Acromegaly: A condition resulting from the overproduction of growth hormone (GH).

Test your knowledge on the endocrine system, focusing on the differences between invertebrates and vertebrates. Explore the functions of endocrine glands and the role of hormones as intercellular messengers. This quiz will cover essential concepts of hormone production and action.