Summary

This document provides an overview of the endocrine system, including the functions of different glands, hormones, and how they work together to regulate bodily functions. It explains various signaling mechanisms and how hormones interact with target cells.

Full Transcript

‭product to a body surface‬ ‭ENDOCRINE SYSTEM‬ ‭Internal Communication‬ ‭Endocrine Glands‬ ‭‬ ‭Nervous‬ ‭(axon)‬ ‭and‬ ‭endocrine‬ ‭(blood)‬ ‭systems‬ ‭facilitate‬ ‭‬ ‭Include‬ ‭the‬ ‭pituitary‬ ‭(anterior...

‭product to a body surface‬ ‭ENDOCRINE SYSTEM‬ ‭Internal Communication‬ ‭Endocrine Glands‬ ‭‬ ‭Nervous‬ ‭(axon)‬ ‭and‬ ‭endocrine‬ ‭(blood)‬ ‭systems‬ ‭facilitate‬ ‭‬ ‭Include‬ ‭the‬ ‭pituitary‬ ‭(anterior‬ ‭n‬ ‭posterior),‬ ‭thyroid,‬ ‭parathyroid,‬ ‭long-distance communication‬ ‭adrenal, and pineal glands‬ ‭‬ ‭Nervous system uses electrical signals‬ ‭‬ ‭Mainly secrete hormones‬ ‭○‬ ‭Neurotransmitters‬ ‭used‬ ‭for‬ ‭communication‬ ‭between‬ ‭one‬ ‭○‬ ‭Some have non-endocrine functions‬ ‭cell and another‬ ‭‬ ‭Do not have a duct for secretion‬ ‭‬ ‭Endocrine system uses hormones‬ ‭‬ ‭Secretions enter blood or interstitial fluid‬ ‭○‬ ‭Chemical signaling molecules that travel in blood‬ ‭‬ ‭Hormones affect target cells‬ ‭○‬ ‭Reach most cells of the body‬ ‭○‬ ‭Cells with receptors for that specific hormone‬ ‭○‬ ‭Have widespread effects‬ ‭Other Organs that Have Endocrine Function‬ ‭Functions of the Endocrine System‬ ‭‬ ‭Contains cells that have endocrine functions‬ ‭‬ ‭Helps maintain homeostasis by regulating:‬ ‭‬ ‭Includes‬‭the‬‭hypothalamus,‬‭thymus,‬‭heart,‬‭kidneys,‬‭stomach,‬‭small‬ ‭○‬ ‭Use of calories and nutrients‬ ‭intestine, liver, adipose tissue, ovaries, and testes‬ ‭○‬ ‭Secretion of wastes‬ ‭○‬ ‭Blood pressure and blood osmolarity‬ ‭Target Cells‬ ‭○‬ ‭Growth/Fertility and sex drive‬ ‭‬ ‭Receptor for‬‭certain‬‭hormones‬ ‭○‬ ‭Lactation‬ ‭‬ ‭Hormones travel through the bloodstream‬ ‭○‬ ‭Sleep‬ ‭○‬ ‭They can reach almost any cell in the body‬ ‭‬ ‭Hormones only affect target cells‬ ‭Chemical Signalling‬ ‭○‬ ‭Cells with a receptor for a particular hormone‬ ‭‬ ‭Hormones:‬‭chemical messengers used by endocrine system‬ ‭‬ ‭Binding‬ ‭of‬‭hormone‬‭to‬‭receptor‬‭on‬‭target‬‭cell‬‭initiates‬‭intracellular‬ ‭○‬ ‭Most are released into blood‬ ‭signaling‬ ‭○‬ ‭Paracrine‬ ‭signaling‬‭:‬ ‭hormone‬ ‭affects‬ ‭neighboring‬ ‭cells‬ ‭(katabi)‬ ‭Nervous vs Endocrine System‬ ‭○‬ ‭Autocrine‬ ‭signaling‬‭:‬ ‭hormone‬ ‭affects‬ ‭same‬ ‭cell‬ ‭that‬ ‭‬ ‭Both‬ ‭nervous‬ ‭and‬ ‭endocrine‬ ‭systems‬ ‭allow‬ ‭control‬ ‭and‬ ‭released it (sarili)‬ ‭communication of the body‬ ‭○‬ ‭Endocrine‬ ‭signaling‬‭:‬ ‭hormone‬ ‭travels‬ ‭through‬ ‭blood‬ ‭to‬ ‭‬ ‭They accomplish this in different ways:‬ ‭affect cells throughout body (lahat w the help of bloof)‬ ‭○‬ ‭Neurotransmitters versus hormones‬ ‭‬ ‭Neurotransmitters-used by neurons and the nervous system‬ ‭○‬ ‭Nervous system is generally faster to make a change‬ ‭○‬ ‭Endocrine system has more widespread effects‬ ‭Endocrine and Exocrine Glands‬ ‭○‬ ‭Endocrine‬ ‭system‬ ‭effects‬ ‭generally‬ ‭last‬ ‭longer‬ ‭(unless‬ ‭‬ ‭Chemical secretions exit glands via exocytosis (lumalabas sa cell)‬ ‭ma-catalyze, they will ano their function)‬ ‭‬ ‭Endocrine‬ ‭gland‬ ‭secretion‬ ‭releases‬ ‭product‬ ‭into‬ ‭bloodstream‬ ‭or‬ ‭extracellular fluid‬ ‭‬ ‭Exocrine‬ ‭gland‬ ‭secretion‬ ‭releases‬ ‭product‬ ‭into‬ ‭duct‬ ‭that‬ ‭carries‬ ‭Hormones‬ ‭molecules‬ ‭Types of Hormones‬ ‭○‬ ‭Cannot be stored (no reserve)‬ ‭‬ ‭Based on chemical structure‬ ‭○‬ ‭Not soluble in blood‬ ‭○‬ ‭Steroid hormones-‬‭cross cell membrane easily‬ ‭‬ ‭Travel bound to transport proteins when in blood‬ ‭‬ ‭Lipid-based hormones‬ ‭‬ ‭Peptide hormones‬‭-translated like other proteins‬ ‭‬ ‭nonpolar‬ ‭○‬ ‭Modified and stored in vesicles until release (w reserve)‬ ‭‬ ‭always need carrier (protein) (lipoprotein)‬ ‭○‬ ‭Soluble in blood‬ ‭‬ ‭via LDL, HDL, VLDL‬ ‭‬ ‭ Travel free" state‬ ‭○‬ ‭Amine-based hormones‬‭-modified amino acids‬ ‭‬ ‭Water-soluble; cannot cross cell membranes‬ ‭Hormone Receptors‬ ‭○‬ ‭Peptide‬ ‭and‬ ‭Protein‬ ‭hormones‬‭-made‬ ‭from‬ ‭chains‬ ‭of‬ ‭‬ ‭Receptors can be intracellular or on the cell surface‬ ‭amino acids‬ ‭‬ ‭Lipid-soluble‬‭hormone‬‭receptors‬‭are‬‭usually‬‭intracellular‬‭(cytosol‬‭or‬ ‭‬ ‭Water-soluble; cannot cross cell membranes‬ ‭nuclear)‬ ‭○‬ ‭This‬‭is‬‭because‬‭lipid-soluble‬‭hormones‬‭can‬‭pass‬‭through‬ ‭Steroid Hormone‬ ‭cell membrane‬ ‭‬ ‭Produced from cholesterol molecules‬ ‭‬ ‭Water-soluble hormone receptors usually on surface of cell‬ ‭‬ ‭Lipid-soluble hormones‬ ‭○‬ ‭This‬ ‭is‬ ‭because‬ ‭these‬ ‭hormones‬ ‭are‬ ‭usually‬ ‭unable‬ ‭to‬ ‭○‬ ‭Can pass through cell membranes‬ ‭cross cell membrane‬ ‭‬ ‭Require‬ ‭transport‬ ‭proteins‬ ‭to‬ ‭travel‬ ‭in‬ ‭blood‬ ‭(carrier‬ ‭protein)‬ ‭(albumin is the most common carrier sa blood)‬ ‭‬ ‭Examples include testosterone and estrogens‬ ‭Amine Hormones‬ ‭‬ ‭Made from individual amino acids‬ ‭‬ ‭Water-soluble hormones‬ ‭○‬ ‭Cannot freely pass through the cell membrane‬ ‭‬ ‭Do not require transport proteins in blood‬ ‭‬ ‭Examples include melatonin, epinephrine and norepinephrine‬ ‭Peptide and Protein Hormones‬ ‭‬ ‭Chains of amino acids‬ ‭Intracellular Hormone Receptors‬ ‭‬ ‭Water-soluble hormones‬ ‭‬ ‭Associated‬ ‭with‬ ‭steroid‬ ‭and‬ ‭thyroid‬ ‭hormones‬ ‭(t3:‬ ‭water‬‭soluble,‬ ‭○‬ ‭Cannot freely pass through the cell membrane‬ ‭t4: thyroglobular protein)‬ ‭‬ ‭Do not require transport proteins in blood‬ ‭○‬ ‭Hormone‬ ‭must‬ ‭be‬ ‭lipid-soluble‬ ‭to‬ ‭pass‬ ‭through‬ ‭‬ ‭Examples include antidiuretic hormone and insulin‬ ‭membrane‬ ‭‬ ‭May be in cytosol or nucleus‬ ‭Production of Hormones‬ ‭‬ ‭Results in increased transcription and increased protein synthesis‬ ‭‬ ‭Steroid‬ ‭hormones‬‭-made‬ ‭on‬ ‭demand‬ ‭by‬ ‭modifying‬ ‭cholesterol‬ ‭Membrane-bound Hormone Receptor‬ ‭‬ ‭Associated with water-soluble hormones‬ ‭Anatomy of Steroid Hormone‬ ‭○‬ ‭Amine and peptide hormones‬ ‭‬ ‭Steroid hormones are made on demand in endocrine cell‬ ‭‬ ‭Hormone serves as first messenger in the pathway‬ ‭○‬ ‭Enzymes modify cholesterol during synthesis‬ ‭○‬ ‭An‬‭intracellular‬‭second‬‭messenger‬‭relays‬‭message‬‭inside‬ ‭‬ ‭Secreted into blood and travel bound to a transport protein‬ ‭the cell‬ ‭‬ ‭Reach target cells where they are released from transport protein‬ ‭‬ ‭Bind to intracellular receptors within the target cell‬ ‭Second Messenger System‬ ‭1.‬ ‭Hormone binds to receptor in cell membrane‬ ‭Anatomy of Protein Hormone‬ ‭2.‬ ‭G protein is activated‬ ‭‬ ‭Protein‬ ‭hormones‬ ‭are‬ ‭made‬ ‭by‬ ‭rough‬ ‭ER‬ ‭or‬ ‭ribosomes‬ ‭in‬ ‭the‬ ‭3.‬ ‭G protein activates adenylyl cyclase‬ ‭endocrine cell‬ ‭4.‬ ‭Adenylyl‬ ‭cyclase‬ ‭converts‬ ‭ATP‬ ‭to‬ ‭cyclic‬ ‭adenosine‬ ‭‬ ‭Secreted into blood and travel in a "free" state‬ ‭monophosphate (cAMP)‬ ‭○‬ ‭Do not need transport proteins‬ ‭5.‬ ‭CAMP activates protein kinases‬ ‭‬ ‭Reach target cells and bind to receptors on surface of cell‬ ‭6.‬ ‭Protein kinases phosphorylate proteins‬ ‭○‬ ‭Initiate second messenger systems‬ ‭7.‬ ‭Phosphorylated proteins cause change‬ ‭8.‬ ‭Amplification‬ ‭allows‬ ‭a‬ ‭small‬ ‭amount‬ ‭of‬ ‭hormone‬ ‭to‬ ‭cause‬ ‭Factors affecting target cell response‬ ‭significant change‬ ‭‬ ‭The‬‭number‬‭of‬‭receptors‬‭a‬‭target‬‭cell‬‭has‬‭influences‬‭the‬‭strength‬‭of‬ ‭9.‬ ‭Phosphodiesterase (PDE)‬‭breaks down cAMP‬ ‭response‬ ‭10.‬ ‭Quickly stops internal cellular changes‬ ‭‬ ‭Downregulation‬‭-decrease in receptor number‬ ‭11.‬ ‭Other‬ ‭second‬ ‭messenger‬ ‭systems‬ ‭may‬ ‭use‬ ‭calcium‬ ‭ions‬ ‭as‬ ‭a‬ ‭○‬ ‭Occurs‬ ‭when‬ ‭hormone‬ ‭level‬ ‭is‬ ‭chronically‬ ‭higher‬ ‭(T2‬ ‭second messenger‬ ‭diabetes)‬ ‭‬ ‭bc the receptors are inhibited‬ ‭○‬ ‭Cells become less sensitive to hormone‬ ‭‬ ‭Upregulation‬‭-increase in receptor number‬ ‭○‬ ‭Occurs‬ ‭when‬ ‭hormone‬ ‭levels‬ ‭are‬ ‭chronically‬ ‭low‬ ‭(T1‬ ‭diabetes)‬ ‭‬ ‭may receptors, pero wala insulin‬ ‭○‬ ‭Cells become more sensitive to hormone‬ ‭Regulation of Hormone Secretion‬ ‭‬ ‭Most hormones regulated via negative feedback loops‬ ‭○‬ ‭As hormone level rises, secretion will slow down or stop‬ ‭‬ ‭Oxytocin‬ ‭(love‬ ‭hormone)‬ ‭(hypothalamus‬ ‭produce‬ ‭but‬ ‭stored‬ ‭in‬ ‭posterior pituitary gland) is regulated by a positive feedback loop‬ ‭○‬ ‭Suckling, sex, and labor leads to oxytocin release‬ ‭○‬ ‭Higher levels of oxytocin will increase rate of release‬ ‭‬ ‭Other factors influence hormone release:‬ ‭A.‬ ‭Chemical levels within blood‬ ‭hypophyseal portal vein to the anterior pituitary‬ ‭‬ ‭Levels of nutrients or ions.‬ ‭‬ ‭Posterior pituitary contains nervous tissue‬ ‭B.‬ ‭Endocrine‬ ‭system-tropic‬ ‭hormones‬ ‭(master‬ ‭chief:‬ ‭○‬ ‭Axons‬ ‭from‬ ‭hypothalamus‬ ‭project‬ ‭through‬ ‭infundibulum‬ ‭hypothalamus) control release of other hormones‬ ‭Hormones‬‭stored‬‭and‬‭released‬‭into‬‭blood‬‭at‬‭the‬‭posterior‬ ‭C.‬ ‭Nervous system stimulation‬ ‭pituitary‬ ‭Posterior Pituitary‬ ‭‬ ‭Stores and releases two hormones‬ ‭○‬ ‭Oxytocin and antidiuretic hormone (ADH)‬ ‭○‬ ‭Hormones‬‭are‬‭produced‬‭in‬‭hypothalamus‬‭and‬‭transported‬ ‭to posterior pituitary‬ ‭‬ ‭Oxytocin (for contractions in labor)‬ ‭○‬ ‭Release regulated by positive feedback loop‬ ‭○‬ ‭Responsible for milk ejection reflex (let down reflex)‬ ‭○‬ ‭Promotes uterine contractions‬ ‭○‬ ‭Contributes social bonding behavior‬ ‭Antidiuretic Hormone‬ ‭‬ ‭Released in response to high blood osmolarity‬ ‭○‬ ‭The solute concentration of blood (solvent is plasma)‬ ‭‬ ‭Conserves body fluids by increasing water reabsorption by kidney‬ ‭○‬ ‭Urine becomes darker‬ ‭Endocrine Control by the Hypothalamus and Pituitary Gland‬ ‭‬ ‭Can also cause constriction of blood vessels‬ ‭The Hypothalamus and the Pituitary Gland‬ ‭‬ ‭Leads to overall increase in blood pressure‬ ‭‬ ‭Hypothalamus:‬ ‭‬ ‭Release inhibited by drugs like alcohol‬ ‭‬ ‭Part of diencephalon of the brain‬ ‭○‬ ‭Higher amounts of urine produced‬ ‭○‬ ‭Regulates secretion of hormones from pituitary gland‬ ‭‬ ‭!! - alak inhibits antidiuretic hormone‬ ‭○‬ ‭Connected to posterior pituitary gland by infundibulum‬ ‭○‬ ‭Connected‬ ‭to‬ ‭anterior‬ ‭pituitary‬ ‭by‬ ‭Diabetes Insipidus‬ ‭hypothalamic-hypophyseal‬ ‭portal‬ ‭system‬ ‭(connects‬ ‭apg‬ ‭‬ ‭Results‬ ‭from‬ ‭chronic‬ ‭underproduction‬ ‭of‬ ‭anti-diuretic‬ ‭hormone‬ ‭and ppg)‬ ‭(ADH)‬ ‭○‬ ‭APG (8 hormones), PPG (2 hormones)‬ ‭‬ ‭Without ADH, kidneys do not reabsorb adequate amounts of water‬ ‭‬ ‭DI leads to excessive thirst and increased water consumption‬ ‭!! - ppg is from brain apg is from dila‬ ‭○‬ ‭Osmotic imbalance persists, however, due to lack of ADH‬ ‭‬ ‭lonic imbalances can occur in severe cases of D‬ ‭Anterior and Posterior Pituitary Gland‬ ‭‬ ‭primary‬‭:‬‭hormone‬‭di‬‭nagpproduce,‬‭secondary:‬‭receptors‬‭(to‬‭test:‬ ‭‬ ‭Anterior pituitary is composed of glandular tissue‬ ‭give artificial ADH)‬ ‭○‬ ‭Blood‬ ‭from‬ ‭hypothalamus‬ ‭travels‬ ‭through‬ ‭the‬ ‭natural; vasopressin, artificial; desmopressin‬ ‭‬ ○ I‭ncreased lipolysis catabolic‬ ‭○‬ ‭Increased blood glucose levels catabolic‬ ‭Anterior Pituitary Gland‬ ‭‬ ‭Produces six hormones‬ ‭Growth Hormone Disorder‬ ‭○‬ ‭Secretion‬ ‭is‬ ‭regulated‬ ‭by‬ ‭tropic‬ ‭hormones‬ ‭from‬ ‭‬ ‭In‬ ‭general,‬ ‭growth‬ ‭hormone‬ ‭promotes‬ ‭growth‬‭of‬‭epiphyseal‬‭plate‬ ‭hypothalamus‬ ‭during childhood‬ ‭‬ ‭growth hormone‬ ‭○‬ ‭Leads to elongation of bones‬ ‭‬ ‭thyroid‬ ‭stimulating‬ ‭hormone‬‭(t3‬‭t4)‬‭(to‬‭stimulate:‬ ‭‬ ‭Pituitary dwarfism‬ ‭need iodine)‬ ‭○‬ ‭Decreased‬ ‭stature‬ ‭due‬ ‭to‬ ‭decreased‬ ‭secretion‬ ‭of‬ ‭GH‬ ‭‬ ‭adrenocorticotropic hormone‬ ‭during childhood‬ ‭‬ ‭follicle-stimulating hormone‬ ‭‬ ‭Gigantism‬ ‭‬ ‭luteinizing hormone‬ ‭○‬ ‭Substantially‬ ‭increased‬ ‭height‬ ‭due‬ ‭to‬ ‭excessive‬ ‭GH‬ ‭‬ ‭prolactin‬ ‭secretion during childhood‬ ‭○‬ ‭Tropic‬ ‭hormones‬ ‭travel‬ ‭from‬ ‭hypothalamus‬ ‭to‬ ‭anterior‬ ‭‬ ‭Acromegaly‬ ‭pituitary in hypothalamic- hypophyseal portal system‬ ‭○‬ ‭Excessive GH secretion during adulthood‬ ‭○‬ ‭Causes‬ ‭increased‬ ‭growth‬ ‭of‬ ‭cartilage‬ ‭leading‬ ‭to‬ ‭larger‬ ‭Anterior Pituitary Hormones‬ ‭hands, feet, and ears.‬ ‭‬ ‭Growth‬ ‭hormone-‬‭anabolic‬ ‭(buildup)‬ ‭hormone‬ ‭that‬ ‭promotes‬ ‭○‬ ‭May‬ ‭cause‬ ‭cardiovascular‬ ‭complications‬ ‭due‬ ‭to‬ ‭protein synthesis and tissue building‬ ‭diabetogenic effect‬ ‭!! - cataabolic, breakdown‬ ‭!! - APG: production and secretion, PPG: secretion only‬ ‭‬ ‭ hyroid-stimulating‬ ‭hormone‬‭-causes‬ ‭release‬ ‭of‬ ‭thyroid‬ T ‭Major Hormones of the Body‬ ‭hormones from thyroid gland (metabolism)‬ ‭The Thyroid Gland (1)‬ ‭‬ ‭Adrenocorticotropic‬ ‭hormone-‬‭stimulates‬ ‭release‬ ‭of‬ ‭cortisol‬ ‭‬ ‭Located anterior to trachea and inferior to larynx‬ ‭(stress hormone) from adrenal cortex‬ ‭‬ ‭Two lateral lobes connected by isthmus‬ ‭‬ ‭Follicle-stimulating hormone-‬‭promotes gamete production‬ ‭‬ ‭Histology:‬ ‭‬ ‭Luteinizing‬ ‭hormone-‬‭promotes‬ ‭release‬ ‭of‬ ‭sex‬ ‭hormones‬ ‭and‬ ‭○‬ ‭Thyroid follicles-‬‭spherical units of thyroid‬ ‭initiates ovulation‬ ‭‬ ‭Internal cavity filled with colloid‬ ‭‬ ‭Prolactin-‬‭promotes milk production‬ ‭Growth Hormone‬ ‭‬ ‭Release‬‭regulated‬‭by‬‭GHRH‬‭(Growth‬‭hormone‬‭regulating‬‭hormone)‬ ‭and GHIH (somastostatin) from hypothalamus‬ ‭‬ ‭(stimulates‬ ‭liver)Causes‬ ‭production‬ ‭of‬ ‭insulin-like‬ ‭growth‬ ‭factors‬ ‭(IGFs) in target tissue‬ ‭‬ ‭Causes growth via:‬ ‭○‬ ‭Increased protein synthesis anabolic‬ ‭Calcitonin‬ ‭Synthesis and Release of Thyroid Hormone‬ ‭‬ ‭More sa children‬ ‭‬ ‭Thyroid hormone (TH) made by follicular cells‬ ‭‬ ‭Secreted and produced by parafollicular cells‬ ‭○‬ ‭Stimulated by TSH from anterior pituitary gland‬ ‭‬ ‭Secreted in response to elevated blood calcium levels‬ ‭‬ ‭Follicular cells bind iodine to thyroglobulin proteins in colloid‬ ‭‬ ‭Decreases blood calcium levels‬ ‭‬ ‭Intermediaries‬ ‭are‬ ‭combined‬ ‭to‬ ‭form‬ ‭T3‬ ‭(triiodothyronine)‬ ‭and‬ ‭Ta‬ ‭○‬ ‭Inhibits‬ ‭osteoclast‬ ‭activity‬ ‭and‬ ‭stimulates‬ ‭osteoblast‬ ‭(tetraiodothyronine)‬ ‭activity‬ ‭○‬ ‭T4 commonly known as thyroxine, T3 is thyronine‬ ‭○‬ ‭Decreases calcium absorption by the intestine‬ ‭‬ ‭Hormones remain in colloid until needed‬ ‭○‬ ‭Increases calcium loss in urine‬ ‭‬ ‭TSH‬ ‭stimulates‬ ‭release‬ ‭of‬ ‭T3‬ ‭and‬ ‭T₄‬ ‭from‬ ‭follicular‬ ‭cells‬ ‭when‬ ‭necessary‬ ‭Calcium Regulation‬ ‭‬ ‭Calcium plays a role in many biological processes‬ ‭Regulation of Thyroid Hormone Synthesis‬ ‭‬ ‭Levels are regulated by hormones‬ ‭‬ ‭Negative feedback regulates TH secretion‬ ‭‬ ‭Calcitonin‬ ‭from‬ ‭thyroid‬ ‭and‬ ‭parathyroid‬ ‭hormone‬ ‭(PTH)‬ ‭from‬ ‭the‬ ‭‬ ‭Low levels of TH stimulate TRH.release from hypothalamus‬ ‭parathyroid glands work antagonistically to regulate calcium levels‬ ‭‬ ‭TRH stimulates release of TSH from anterior pituitary‬ ‭‬ ‭TSH stimulates release of TH from thyroid gland‬ ‭Parathyroid Glands (2)‬ ‭‬ ‭Located on posterior of thyroid gland‬ ‭Functions of Thyroid Hormones‬ ‭‬ ‭Oxyphil cell function is unknown‬ ‭‬ ‭Increase basal metabolic rate (BMR)‬ ‭‬ ‭Chief cells secrete parathyroid hormone (PTH)‬ ‭○‬ ‭Cause every cell to increase production of ATP‬ ‭○‬ ‭Secreted in response to low calcium levels‬ ‭‬ ‭Promote protein synthesis‬ ‭○‬ ‭Increases blood calcium levels‬ ‭‬ ‭Increase effectiveness of epinephrine and norepinephrine‬ ‭‬ ‭Stimulates‬ ‭osteoclasts‬ ‭that‬ ‭breakdown‬ ‭bone‬ ‭○‬ ‭Increase body temperature‬ ‭matrix releasing calcium‬ ‭‬ ‭Heat given off due to ATP production‬ ‭○‬ ‭Inhibits osteoblasts‬ ‭‬ ‭Required‬ ‭for‬ ‭adequate‬ ‭growth‬ ‭and‬ ‭development‬ ‭of‬ ‭skeletal‬ ‭and‬ ‭○‬ ‭Stimulates‬ ‭calcitriol‬ ‭production‬ ‭to‬‭increase‬‭absorption‬‭of‬ ‭nervous tissue in childhood‬ ‭dietary calcium‬ ‭Thyroid Disorders‬ ‭‬ ‭Goiter‬‭enlarged thyroid.‬ ‭○‬ ‭Caused by accumulation of colloid‬ ‭‬ ‭Hypothyroidism‬‭= insufficient production of thyroid‬‭hormones‬ ‭○‬ ‭May lead to weight gain and cold intolerance‬ ‭‬ ‭Hyperthyroidism‬‭= excessive production of thyroid‬‭hormones‬ ‭○‬ ‭May lead to weight loss and increased body temperature‬ ‭Parathyroid Disorders‬ ‭‬ ‭Main mineralocorticoid is aldosterone‬ ‭‬ ‭Hyperparathyroidism‬ ‭=‬ ‭excessive‬ ‭secretion‬ ‭of‬ ‭PTH‬ ‭leads‬ ‭to‬ ‭○‬ ‭Increases sodium and water reabsorption by kidney‬ ‭excessive bone resorption‬ ‭○‬ ‭Increases blood pressure‬ ‭‬ ‭Leads to increased blood levels of calcium resulting in:‬ ‭‬ ‭Involved in renin-angiotensin-aldosterone system (RAAS)‬ ‭○‬ ‭Decreased bone density, leading to increased fractures‬ ‭○‬ ‭Reduced responsiveness of nervous system‬ ‭The Hormones in Zona Fasciculata‬ ‭○‬ ‭Increased calcium deposits in tissues and organs‬ ‭‬ ‭Intermediate region of adrenal cortex‬ ‭‬ ‭Hypoparathyroidism‬‭= insufficient production or secretion‬‭of PTH‬ ‭‬ ‭Secretes glucocorticoids‬ ‭○‬ ‭Leads‬ ‭to‬ ‭low‬ ‭blood‬ ‭levels‬ ‭of‬ ‭calcium,‬ ‭causing‬ ‭muscle‬ ‭‬ ‭Main glucocorticoid is cortisol‬ ‭twitching, cramping, convulsions, or paralysis‬ ‭○‬ ‭Released in response to stress‬ ‭○‬ ‭Release stimulated by ACTH‬ ‭Adrenal Glands (3)‬ ‭○‬ ‭Suppresses immune system‬ ‭‬ ‭Triangular glands on top of each kidney‬ ‭○‬ ‭Stimulates breakdown of stored nutrients for energy‬ ‭‬ ‭Covered by capsule‬ ‭‬ ‭Glycogenolysis‬ ‭‬ ‭Divided into adrenal cortex (superficially) and medulla (deeper)‬ ‭‬ ‭Lipolysis‬ ‭‬ ‭Adrenal cortex has three zones:‬ ‭‬ ‭Gluconeogenesis‬ ‭1.‬ ‭Zona glomerulosa‬ ‭2.‬ ‭Zona fasciculata‬ ‭The Hormones in Zona Reticularis‬ ‭3.‬ ‭Zona reticularis‬ ‭‬ ‭Deepest region of adrenal cortex‬ ‭‬ ‭Secretes androgens‬ ‭○‬ ‭These are male sex hormones‬ ‭‬ ‭Main androgen secreted is dehydroepiandrosterone (DHEA)‬ ‭‬ ‭Supplements testosterone in males‬ ‭‬ ‭Promotes libido in females‬ ‭The Adrenal Medulla‬ ‭‬ ‭Releases epinephrine and norepinephrine; collectively called‬ ‭‬ ‭catecholamines‬ ‭○‬ ‭Produced by chromaffin cells‬ ‭○‬ ‭Considered hormones when released into the blood‬ ‭‬ ‭Considered neurotransmitters at locations where‬ ‭they are released into a synapse‬ ‭‬ ‭Release results in fight-or-flight responses of the sympathetic‬ ‭nervous system‬ ‭The Hormones in Zona Glomerulosa‬ ‭‬ ‭Most superficial region of adrenal cortex‬ ‭‬ ‭Secretes mineralocorticoids‬

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