內(nèi)分泌生殖系統(tǒng)教學課件：總論

1、 Introduction to the endocrine system Part 1 Introduction Endocrinology 1. Definition: the study of hormones and their functions. 2. History: (1) Ancient China (2) 1849, Berthold (3) 1855, Addisons disease (4) Ernest Starling 1902, Hormone, 1905, “Endocrine system” Ernest Starling (1866-1927) Endocr

2、ine vs. exocrine Characteristic of endocrine gland Without duct The endocrine cells arranged in cluster, follicle or cords Rich in capillaries The secretion is hormone which transported by blood circulation Endocrine system 1. Endocrine glands (1) Classical endocrine glands (2) Extensive endocrine g

3、lands 2. Endocrine cells Classical endocrine glands Hormones Definition - chemical messengers - secreted by endocrine gland or cells - released into the blood - effect on target cells through receptors Major Hormones Hormones Functions to control the regulatory systems in the body (1) homeostasis (2

4、) metabolism (3) growth and development (4) reproduction Neural regulation -exerts point-to-point -control through nerves -electrical in nature and fast Endocrine regulation -broadcasts its hormonal messages to essentially all cells -by secretion into blood and extracellular fluid -requires a receiv

5、er to get the message -slow and wider Neuroendocrine regulation: 1928, Scharrer Transportation of Hormones Endocrine (Telecrine, hemocrine) Paracrine Transportation of Hormones Types of hormones 1.Peptide hormones 2. Steroids 3.Amine hormones (derivatives of the amino acid tyrosine) Synthesis of hor

6、mones Synthesis of steroid hormones Synthesis of amine hormones Synthesis of peptide hormones The comparison of hormones ReceptorsCarrier protein Orally active storage PeptidesCell membrane NoNot usuallyHormone SteroidsCytoplasm /nucleus YesYes, mostlyPrecursor Thyroid hormone nucleusYesYesPrecursor

7、 CatecholaminesCell membrane NoNoHormone The transport of hormones 1. Peptide and CA: water-soluble 2. Steroids and thyroid hormone: bound to proteins Eg. Thyroid hormones binding globulin (THBG) Cortisol binding globulin (CBG) Sex hormones binding globulin (SHBG) Effects of hormone binding proteins

8、: (1) Increase the solubility (2) Create an accessible reserve (3) Increase the biological half time The metabolism of hormones 1. Peptide hormones: degradation in a lysosome 2. Steroids: excreted in an unchanged form 3. Catecholamines: COMT and MAO 4. Thyroxine: removing the iodine residues Results

9、 of metabolism (1) Inactivation (2) Activation Properties of the hormone effect 1. Specificity 2. Signal transmission 3. High biological efficiency Properties of the hormone effect 1.Specificity: target, receptor Properties of the hormone effect 2. Signal transmission Properties of the hormone effec

10、t 3. High Biological Efficiency Low plasma concentration (nmol pmol/L) great regulatory function Part 2 Important concepts in endocrine regulation Patterns of hormone secretion Different hormones have markedly different patterns of secretion. 1. Set point regulation 2. Episodic secretion 3. Diurnal

11、variation Regulation of hormone secretion: endocrine axis Endocrine axis 1. Long-loop feedback: (1) Classical negative feedback (2) Regulated by the end product 2. Short-loop feedback Regulated by the intermediate product 3. Ultrashort-loop feedback Regulation of hormone secretion: negative feedback

12、 Regulation of hormones secretion 1. Synergistic effects 2. Permissive effect 3. Antagonist effects Interaction Between the Hormones 1. Synergistic effects (1) Additive: same effect of the hormones on one target organ (2) Complementary: work on different stages of a physiological procedure Interacti

13、on Between the Hormones 2. Permissive effect A hormone enhances the responsiveness of a target organ to the second hormone, and increases the activity of the second hormone. Interaction Between the Hormones 3. Antagonist effects One hormone antagonize the effects of another. Eg. The regulation effec

14、t of glucagon and insulin on blood glucose metabolism Interaction Between the Hormones Part 3 Endocrine disorders Endocrine disorders Normal amount of hormones are essential for the body. Either excessive or insufficient hormones secretion are disorders. Excessive secretion: hyper- Insufficient secr

15、etion: hypo- Endocrine disorders Secondary: Hypothalamus or pituitary disorder Primary: endocrine glands disorder Endocrine disorders Part 4 Endocrine investigations General principles 1. Purposes: diagnosis/monitoring 2. After clinical pattern recognition or understanding of physiology and anatomy

16、3. Blood test maybe basic or dynamic. 1) Basic test : 9:00h, fasted 2) Dynamic test: (1) stimulation test :when suspect a hormone is too low. (2) suppression test: when suspect a hormone is too high. Measurement of hormones 1. Biological sample (1) Blood (2) Urine (3) Biopsy 2. Image: radiological i

17、maging is vital. Ectopic hormone secretion 1. Definition: The inappropriate secretion of hormones by tissues that do not usually produce that hormones. 2. Clinical significance: as a feature of endocrine tumors. 3. Diagnosis: combined methods. Receptors and hormone action The first step of a hormone

18、s action is to bind to specific receptors at the target cell. Protein in nature (may contain carbohydrate or phospholipid moieties) Classification by location: 1.Cell surface receptors 2.Intracellular receptors: (1) cytoplasm receptors (2) nucleus receptors Receptors of hormones Classification by mechanisms: Receptors of hormones 1.Second messenger mechanisms: Peptide hormones and CA -bind the receptors on the membrane -activate some e