The Endocrine System The Endocrine System Hormones control
- Slides: 24
The Endocrine System
The Endocrine System • Hormones control several major processes
The Endocrine System • Second-messenger system of the body • Uses chemical messengers (hormones) that are released into the blood
Hormone Overview • Hormones are produced by specialized cells • Cells secrete hormones into extracellular fluids
The Chemistry of Hormones • Amino acid–based, which includes (water soluble)
The Chemistry of Hormones • Steroids— • Prostaglandins—
Mechanisms of Hormone Action • Hormones affect only certain tissues or organs (target cells or target organs)
Effects Caused by Hormones • Changes in plasma membrane permeability or electrical state • Synthesis of proteins (such as enzymes)
The Chemistry of Hormones • Two mechanisms in which hormones act • Direct gene activation • Second-messenger system
Direct Gene Activation (Steroid Hormone Action) • Steroids – Lipid Soluble
Direct Gene Activation (Steroid Hormone Action)
Steroid hormone Nucleus Cytoplasm Receptor protein Hormone-receptor complex DNA m. RNA Plasma membrane of target cell Figure 9. 1 a, step 5
Steroid hormone Nucleus Cytoplasm Receptor protein Hormone-receptor complex DNA m. RNA New protein Plasma membrane of target cell Figure 9. 1 a, step 6
Second-Messenger System (Non-steroid Hormone Action) • Amino Acids - Water Soluble Hormones
Second-Messenger System (Non-steroid Hormone Action) • Target cells have receptors on outside
Amino Acids - Water Soluble Hormones
Nonsteroid hormone (first messenger) Cytoplasm Enzyme ATP c. AMP Receptor protein Plasma membrane of target cell Second messenger Effect on cellular function, such as glycogen breakdown Figure 9. 1 b, step 4
Control of Hormone Release • Hormone levels in the blood are mostly maintained by negative feedback • A stimulus or low hormone levels in the blood triggers the release of more hormone • Hormone release stops once an appropriate level in the blood is reached
Stimuli of Endocrine Glands • Hormonal • Humoral • Neural
Hormonal Stimuli of Endocrine Glands • Most common stimuli • Endocrine glands are activated by other hormones
Humoral Stimuli of Endocrine Glands • Changing blood levels of certain ions stimulate hormone release
Neural Stimuli of Endocrine Glands • Nerve impulses stimulate hormone release • Most are under the control of the sympathetic nervous system
- Chapter 45 hormones and the endocrine system
- Nontropic hormones
- Portal circulation
- Endocrine system and reproductive system
- Endocrine system vs nervous system
- Lymphatic system vs endocrine system
- Nervous system vs endocrine system venn diagram
- Endocrine system and nervous system
- Chapter 16
- Adenohypophysis
- The body's speedy electrochemical communication network
- Comparison of endocrine and nervous system
- Gonads glands
- Endocrine system fact
- External anatomy of a rat
- Metabolic action of growth hormone
- Exocrine glands are ductless
- Chapter 7 13 endocrine system
- Stimulus endocrine system
- Humoral stimulus
- Hypothal
- Biology 30 endocrine system
- Endocrine system function
- Chapter 23 the endocrine system
- Endocrine system analogy