Chapter 26 Hormones and the Endocrine System - Coggle Diagram
Chapter 26 Hormones and the Endocrine System
The Nature of Chemical Regulation
Chemicals signals of the endocrine system (hormones) regulate gradual changes in the body. In contrast, electrical signals of the nervous system coordinate immediate responses.
The endocrine system is a group of interacting glands and tissues that produce and secrete chemicals to initiate and maintain body functions.
Endocrine cells release chemical signals called hormone, which travel in the bloodstream to all parts of the body.
Hormones are made and secreted mainly by organs called endocrine glands.
Hormonal signaling has 3 stages: reception, signal transduction, and response.
Reception of a signal occurs when a hormone binds to a specific receptor protein on or in the target cell
The binding of a signal molecule to a receptor protein triggers events within the target cell - signal transduction - that convert the signal from one form to another.
Response is a change in the cell's behavior
Water-Soluble Hormones bring cellular changes with out entering their target cells. The receptors proteins for most water soluble hormones are embedded in the plasma of target cells.
A water-soluble hormone molecule binds to the receptor protein, activating it.
The initiates a signal transduction pathway, a series of changes in cellular proteins that converts an extracellular chemical signal to a form that can bring about a response inside the cell.
The final relay molecule activates a protein that carries out the cell's response, which may occur in the cytoplasm or in the nucleus
A widely used weed killer demasculinizes male frogs
Endocrine disruptors, substances that interfere with the endocrine system's normal functions.
The Vertebrate Endocrine System
The vertebrate endocrine system consists of more than a dozen major glands.
Hypothalamus, which is closely tied to pituitary, connects the nervous and endocrine system
Hypothalamus is the main control center of the endocrine system. It receives information from nerves about the external environment and the internal condition of the body.
Pituitary gland consists of two part
Posterior pituitary composed of nervous tissue and is actually an extension of the hypothalamus.
Anterior pituitary is an endocrine gland that both synthesizes and secretes hormones.
A releasing hormone stimulates the anterior pituitary to secrete one or more specific hormones and an inhibiting hormone induces the anterior pituitary to stop secreting one or more specific hormones.
Thyroid hormone performs several important homeostatic functions and stimulates metabolism in virtually all the tissues of the body.
Thyroid hormones regulate an animal’s development and metabolism. Negative feedback maintains homeostatic levels in the blood.
The gonads, or sex glands secrete sex hormones in addition to producing gametes.
estrogens maintain the female reproductive system and promote the development of female features
progesterone is primarily involved in preparing and maintaining the uterus to support an embryo.
androgens stimulate the development and maintenance of the male reproductive system; the main androgen is testosterone.
The pancreas is a gland with dual functions: It secretes digestive enzymes into the small intestine, and it secretes two protein hormones, insulin and glucagon, into the blood.
Diabetes mellitus results from a lack of insulin or a failure of cells to respond to it.
The result of diabetes is an elevated level of blood glucose, or hyperglycemia.
The endocrine system includes two adrenal glands
a central portion called the adrenal medulla and an outer portion called the adrenal cortex.
reactions are triggered by two hormones secreted by the adrenal medulla, epinephrine (adrenaline) and norepinephrine (noradrenaline).
Diverse functions have evolved for hormones.
Hormones can promote social behaviors.