CLICHM2 Lecture Notes PDF - Endocrinology

CLICHM2 - LECTURE 1ST Semester | A.Y. 2024-2025 | PALCON, GIA JEZERRI T. UB BSMLS3 - LCH CLINICAL ENDOCRINOLOGY ENDOCRINE SYSTEM ➔ It is the study of glands that produce the ➔ From the Greek words “Endo” means hormones and effects of...

CLICHM2 - LECTURE 1ST Semester | A.Y. 2024-2025 | PALCON, GIA JEZERRI T. UB BSMLS3 - LCH CLINICAL ENDOCRINOLOGY ENDOCRINE SYSTEM ➔ It is the study of glands that produce the ➔ From the Greek words “Endo” means hormones and effects of hormones on “within”, and “crino” means ‘“secrete” organs ➔ It is composed of: (1) Endocrine glands and ➔ Study of hormones and where it is synthesize (2) Specialized endocrine cells located and their effects/actions on organs throughout the body ➔ Scientific study of the function and ➔ Components of endocrine system: pathology of the endocrine glands a. Endocrine Glands ➔ Major target glands: b. Endocrine Cells a. Gonads ➔ Endocrine cells secrete minute amounts of b. Thyroid chemical messengers (aka Hormones) c. Adrenal ➔ Once the hormones will be synthesize, they will be traveling into the bloodstream going OUTLINE to the circulation I. ENDOCRINOLOGY ➔ After circulation, why are hormones ➔ Overview of the Endocrine System directly going/specific to Adrenal glands? ➔ Mechanisms that regulate hormone ANSWER: secretion a. For each target cell, there are receptors ➔ Hormones from the major target present glands b. A hormone is specific to a type of cell ➔ Test procedures because of presence of receptors ➔ Clinical Significance HORMONES CHECKPOINT!!! ➔ Comes from the Greek word “Hormon” means “to set into motion” Which of the following glands/organs is not an ➔ Also called as the CHEMICAL MESSENGER endocrine gland? secreted by Endocrine glands A. Hypophysis ➔ Substances that acts a site distant from their B. Eccrine point of origin C. Parathyroid ➔ In general, it is produce at one site of the D. Pancreas body and exert their action at a distant cell Hypophysis - aka Pituitary Gland, Endocrine ➔ Examples of Endocrine hormones: Parathyroid - located within thyroid gland, a. Cortisol Endocrine b. Oxytocin Pancreas - can be Endocrine (hormones) or c. Thyroid Hormones (T3 and T40 Exocrine (digestive enzymes) d. Insulin Hormones under Pancreas a. Insulin b. Glucagon CHARACTERISTICS OF HORMONES c. Somatostatin ➔ Each hormone is produced by specific tissue or gland ➔ Release directly from tissue into the OVERVIEW OF THE ENDOCRINE SYSTEM bloodstream and carried to a specific site of action ENDOCRINE EXOCRINE Specific site of action is called as Target organs or Target Cell Ductless With ducts/ ➔ It acts at specific site/sites to induce certain Into the bloodstream or passageways characteristics by chemical changes circulation Examples: The response should be what it’s Secretes and stored in a. Sweat supposed to do (exact) granules inside the cells b. Sebaceous Examples: c. Pancreas FUNCTIONS OF HORMONES a. Pancreas ➔ Categories: b. Pituitary GLAND - cluster I. Affecting growth, development, and c. Adrenal of cells/tissues maturation d. Renin (Kidneys) II. Control of systemic homeostasis, e. Erythropoietin ENDOCRINE CELL energy balance, and integrated (Important in - pwedeng kalat metabolism hematopoiesis) kalat/ cells only III. Regulation of reproduction CLICHM2 | Bachelor of Science in Medical Laboratory Science | PALCON, GIA JEZERRI T. Category I Category II Category III CLASSIFICATIONS OF HORMONES Direct Emergency Coordinate physical situation sexual POLYPEPTIDE/PROTEIN HORMONE growth of (fight or flight) hormones for ➔ Water soluble childhood Body reproduction ➔ Synthesize by Anterior Pituitary Gland Assist fetal processes (testosterone, ➔ From the Anterior Pituitary Gland, Placenta, development (metabolism) estrogen) Pancreas, Parathyroid ➔ Circulate freely in the plasma once they are secreted CHEMICAL NATURE OF HORMONES ➔ They can be secreted as complete (no ➔ Classify based on solute or water soluble activation) or inactive form (will be activated) ➔ They do not require carrier proteins to enter HORMONES the blood ➔ Half life: Short, relatively short Lipid Soluble VS Water Soluble ➔ Synthesis of these hormones are regulated by the following: Non-polar Polarity Polar a. Change in analyte concentration Concentration in the blood; induce Requires Transport Does not certain gland to synthesize a carriers or require a hormone EXAMPLE: Binding CHON binding CHON Enzyme from Degradation Easily the lungs, degraded bec liver or they are water b. Negative feedback mechanism It will only work once enough excreted in soluble, easily Parathyroid Hormone in the blood the urine washout EXAMPLE: Few days to Life-span Short period of several time weeks EXAMPLES OF POLYPEPTIDE HORMONES: Steroid Examples Protein Thyroid Hormones GLYCOPROTEIN HORMONES Fatty Acid Amino Acid ➔ Luteinizing hormone, Follicle-stimulating Derived Derived hormone, L-Thyroid-stimulating hormone, Human chorionic gonadotropin ➔ They have alpha and beta subunits EXPLANATION: hehehehehehehehe ➔ Identical alpha, different beta ➔ All of them have the same alpha subunits but different beta subunits ➔ B-hCG = present when there is pregnancy PEPTIDE HORMONES ➔ Cleave to produce certainty hormone ➔ INSULIN, ACTH ➔ Stored in secretory granules once synthesize ➔ Once needed, they will be released into the circulation ➔ INSULIN -> INSULIN PROPER (functional) ➔ POMC -> ACTH (synthesize in Anterior Pituitary gland) AMINO ACID-DERIVED HORMONES ➔ Synthesize by Thyroid and Adrenal glands ➔ Water soluble hormones ➔ Some of them may require carriers CLICHM2 | Bachelor of Science in Medical Laboratory Science | PALCON, GIA JEZERRI T. ➔ Some may not require carriers Site of Adrenal APG, Thyroid REQUIRE CARRIERS Production glands, placenta, and gonads, parathyroid adrenal ➔ T3 and T4 (Thyroid) placenta gland gland ➔ T3 and T4 - intracellular receptor ➔ Serum protein: Thyroxine Binding Globulin, Examples Cortisol FSH, LH, Epinephrine Transthyretin, Albumin Aldosterone TSH, hCG, Norepineph ➔ Low Albumin = Increase T3 and T4 Testosterone Glucagon, rine, T3 and Estrogen PTH, hGH, Thyroxine DO NOT REQUIRE CARRIERS Progesterone Prolactin ➔ Catecholamine, Norepinephrine (Adrenal) ➔ Catecholamine - receptor present in cell surface TYPES OF HORMONE SIGNALING ➔ Synthesis of these hormones are regulated ➔ Once the hormone is synthesize, it will be by the following: released and it will act on the cells a. NERVE STIMULATION surrounding it or act on itself b. ANOTHER HORMONE 1. Autocrine c. NEGATIVE FEEDBACK act directly on themselves exert its action to its set of origin It will go out of the cell STEROID/VITAMIN DERIVED HORMONES 2. Paracrine ➔ Synthesize from Cholesterol, Adrenal glands, produce by wide variety of tissues Gonads, Placenta and secreted into the extracellular ➔ Hydrophobic; insoluble in water fluid ➔ Require carriers or binding proteins exerts its action locally/adjacent to ➔ Specific transport proteins: the cell of origin a. Adrenal gland - cortisol binding EXAMPLES: neurotransmitters and protein neurohormones b. Gonads - sex hormone binding 3. Intracrine proteins Synthesize by the cell and will be ➔ Half-life: 30-90 minutes used by the cell ➔ Synthesis of these hormones are regulated It will never go out of the cell by the following: a. NEGATIVE FEEDBACK Examples: Cortisol/Aldosterone, CONTROL OF HORMONE SECRETION Estrogen, Testosterone, Progesterone 1. Stimulation of Hormone Release “STER” 2. Inhibition of Hormone Release STEP BY STEP ON HOW HORMONES WORK: ➔ Secretion and Inhibition have the same set ➔ Once the hormone is synthesize its present in of stimuli the circulation, it will travel to its target organ ➔ For the released of hormone to be or specific site stimulated or inhibited, these are the ➔ It will meet the receptor forming a Hormone following stimuli: Receptor Complex 1. Humoral ➔ Once a complex is formed, it will go inside Change in analyte concentration (in the cell and go inside the nucleus the blood) ➔ The nucleus will redirect to create a mRNA The release of hormone will be ➔ mRNA - synthesis of protein regulated if there is a change in concentration in the body fluid Inhibit if reach insufficient amount of 3 GENERAL CLASSES OF HORMONES hormone Steroid Protein Amine 2. Neural Hormones Hormones Hormones Presence of action potentials Example: As the nipples are suckled Chemical Cholesterol Protein Amino Acid by the young, action potentials are Component being generated. These action Solubility Lipid Water Water potentials will travel one neuron to another. As it reaches the Carrier Protein N/A May or hypothalamus, it will send/secrete a may not hormone to command the pituitary require a gland to release another hormone. carrier protein From the pituitary gland will travel to the breast. CLICHM2 | Bachelor of Science in Medical Laboratory Science | PALCON, GIA JEZERRI T. As the young keeps on suckling the nipples, it will continue to stimulates hormone 3. Hormonal Is from another hormone and that other hormone will stimulate the release of a particular hormone REGULATION OF HORMONE LEVELS IN THE BLOOD 1. Negative Feedback 2. Positive Feedback Stimulus improved = improved synthesis of hormone Oxytocin = contraction of cervix Prolactin = sucking action of bby Feedback Mechanism NEGATIVE FEEDBACK POSITIVE FEEDBACK When a stimulus When a stimulus causes an increase occurs, the response in a hormone's level, enhances or the resulting effects increases the trigger a response original effect, that reduces the leading to an even hormone’s greater response until production, a specific outcome is effectively reversing achieved the initial change