Notes On The Endocrine System

Submitted By mkaranxha
Words: 5220
Pages: 21
Open Document
Chapter 18
The Endocrine System
The body contains roughly 30 chemical messengers known as hormones, which regulate activities such as sleep, body temperature, hunger, and stress management.
Intracellular communication like direct communication which occurs between two cells of the same type-- Through Gap Junctions.
Gap junctions: 1. Coordinates ciliary movement among epithelial cells 2. Coordinate contractions of cardiac muscle cells 3. Facilitate the propagation of action potentials from one neuron to the next at electrical synapses

Paracrine communication-the use of chemical messengers to transfer information from cell to cell within a single tissue 1. Chemicals involved are called paracrine factors or local hormones 2. Example is prostaglandins 3. Enter bloodstream but with low concentrations
Difference between paracrine factors and hormones is a matter of degree. Paracrine factors can diffuse out of their tissue of origin and have widespread effects. Hormones can affect their tissues of origin as well as distant cells

Target cells-specific cells that have the receptors needed to bind and read the hormonal message when it arrives.

Hormone may: 1. Stimulate the synthesis of an enzyme or a structural protein not already present in the cytoplasm by activating appropriate genes in the cell nucleus 2. Increase or decrease the rate of synthesis of a particular enzyme or other protein by changing the rate of transcription or translation; or 3. Turn an existing enzyme or membrane channel “on” or “off” by changing its shape or structure

A single hormone can alter the metabolic activities of multiple tissues and organs at the same time. These effects may be slow to appear, but they typically persist for days.
Hormonal regulation is quite suitable for directing gradual, coordinating processes, but cannot handle situations requiring split-seconds responses (That type of crisis management is handled by the nervous system)
The nervous system sends messages through action potential propagation. Synaptic communication

Mechanisms of Intercellular Communication | Mechanism | Transmission | Chemical Mediators | Distribution of Effects | Direct communication | Through gap junctions | Ions, small solutes, lipid-soluble materials | Usually limited to adjacent cells of the same type that are interconnected by connexons | Paracrine communication | Through extracellular fluid | Paracrine factors | Primarily limited to a local area, where paracrine factor concentrations are relatively high. Target cells must have appropriate receptors | Endocrine communication | Through the bloodstream | Hormones | Target cells are primarily in other tissues and organs and must have appropriate receptors | Synaptic communication | Across synaptic clefts | Neurotransmitters | Limited to very specific area, target cells must have appropriate receptors |

* The nervous and endocrine system share many chemical messengers. For example, norepinephrine and epinephrine are called hormones when released into the bloodstream, but neurotransmitters when released across synapses. * Both systems are regulated mainly by negative feedback control mechanisms * The two systems share a common goal: to preserve homeostasis by coordinating and regulating the activities of other cells, tissues, organs and systems

Endocrine cells are glandular secretory cells that release their secretions into the extracellular fluid differently from exocrine cells which secrete their products onto epithelial surfaces, generally by way of ducts

Classes of Hormones
We divide hormones into three groups on the basis of their chemical structure 1. Amino acid derivatives
Amino acid derivatives, sometimes known as biogenic amines, are relatively small molecules that are structurally related to amino acids, the building blocks of proteins.
These hormones are synthesized from the amino acids tyrosine and
Show More

Related Documents: Notes On The Endocrine System

The Endocrine System

The endocrine system plays a significant role in the development of resistance training. The endocrine system integrates physiologic responses and plays an important role in maintaining homeostatic conditions at rest and during exercise. The type of resistance training workout used dictates the hormonal responses that cause increases in muscle mass. These tissue adaptations are influenced by changes in circulating hormonal concentrations after exercise. Long-term heavy resistance training causes…

Words 362 - Pages 2

Essay On Endocrine System

Endocrine system is a set-up of glands, which produces and releases hormones that help us in the regulation of many significant body functions, especially with the body’s ability to convert the calories into energy that powers cells and the organs. This system influences how our heart beats, how our bones and tissues grow, even the ability to make a baby. It preforms an important role in whether or not we develop diabetes, thyroids disease, growth disorders, sexual dysfunction, and a host of other…

Words 1217 - Pages 5

Diseases Of The Endocrine System

Diseases of the Endocrine System Mollie Rubin 1. The steroid hormones are all derived from cholesterol. Moreover, with the exception of vitamin D, they all contain the same cyclopentanophenanthrene ring and atomic numbering system as cholesterol.The particular steroid hormone class synthesized by a given cell type depends upon its complement of peptide hormone receptors, its response to peptide hormone stimulation and its genetically expressed complement of enzymes. 2. Endocrine System 3. Hormones…

Words 1176 - Pages 5

Endocrine system Essay

The Anatomy and Physiology: The Endocrine System, Assignment 3 Task 1 A) Pineal gland – secretes melatonin and its role is to regulate the body’s circadian rhythm (the usual fluctuation of physiology over the day-night cycle) (Norris and Siegfried 2011), body temperature, cardiovascular function, and reproduction (Springhouse 2009). B) Posterior pituitary gland (PPG) – releases hormones which are synthesized in the nerve cell bodies of the hypothalamus. Antidiuretic hormone targets the kidney…

Words 446 - Pages 2

The Endocrine System Essay

Study guide for quiz 1 on chapter 16’ answers Describe structural and functional relationships between the hypothalamus and the pituitary gland. Structural relationship: The pituitary gland is a pea-sized gland located immediately beneath the hypothalamus connected by the pituitary stalk, or more technically, the infundibulum. Posterior Pituitary Lobe is a down growth of hypothalamic neural tissue. Anterior Pituitary Lobe has vascular connection to hypothalamus. Functional relationship: The…

Words 1221 - Pages 5

Endocrine System and Cortisol Essay

Husson University: Lisa Mazzarelli, Instructor Lab 1: Anatomy and Physiology Lab II Study Guide Endocrine System Anatomy and Physiology; Dissection Ex 3, pg. 721, and PhysioEx #4. 1 Introduction This week begins your study of the endocrine system. You will perform a dissection of a cat specimen to identify the major organs of the endocrine system. You will be using the same cat specimen for the duration of the semester, so it is important to start off on the right track. A good, clean…

Words 695 - Pages 3

Endocrine System Lab Report

of the completed tables. Label each component of the endocrine, cardiovascular (circulatory), and respiratory systems and their functions in the following tables. When your lab report is complete, submit this document to your instructor in your assignment box. 1. Endocrine System: Observe the diagram showing the major organs of the endocrine system. Using the textbook and Virtual Library resources, fill in the following table: Endocrine System Number Name of the Organ or Part Hormone(s) Produced…

Words 638 - Pages 3

Endocrine system Essay

[Introduction. The zodiac is believed to be developed in Egypt but later adopted by the Babylonians. - The ancient Greeks divided the heavens into 12 groups known as constellations. Each of these groups is named after a personification (zodiac) that correlates with the nature of each constellation. Attention Getter What are you? Are you a Cancer, a Leo, or maybe even a Taurus? Those are just 3 of the different types of Zodiac signs. Personally, I have never really paid attention to the meaning…

Words 669 - Pages 3

Essay about Endocrine System

MLT 116 Mader Chapter 10: The Endocrine System I. Introduction Endocrine system = endocrine glands & their hormones Hormones = chemical messengers; released directly into bloodstream (or extracellular fluid) ( target tissue ( effect Response is slower & longer lasting than nervous system Endocrinology = study of endocrine glands & their hormones A. Hormone action Two basic types hormones: 1. peptides: amino acids, polypeptides, proteins Ex: T4, FSH, LH…

Words 1534 - Pages 7

Essay on Endocrine System and Maisto

September, 2012 The endocrine system and the glands that are within it are there to help people become the individuals that they are. Chemical substances are released into the bloodstream from the endocrine glands, these are called hormones. Hormones function as messengers that are also quite similar to neurotransmitters. Norepinephrine can serve as both a hormone and a neurotransmitter. (Maisto & Morris, 2005) There are a few differences between the nervous system and the endocrine system, but the main…

Words 776 - Pages 4