الغدد الصم
جهاز الغدد الصماء أو الجهاز الصماوي (بالإنجليزية: Endocrine system) عبارة عن جهاز متكامل من الأعضاء الصغيرة التي تقوم بتحرير جزيئات إشارة خارج خلوية تدعى هرمونات. الجهاز الصماوي له دور أساسي في تنظيم الاستقلاب والنمو ووظائف الأنسجة، كما أن له دور في تحديد المزاج. العلم الطبي الذي يتعامل مع اعتلالات الغدد الصماء يسمى علم الغدد الصم وهو فرع من الطب الباطني.
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وظيفة جهاز الغدد الصماء
يقوم جهاز الغدد الصماء (بالإضافة للجهاز العصبي) بالتحكم في وظائف الجسم وهي غدد لاقنوية ductless تفرز مواد كيميائية تسمى هرمونات hormones تتجه إلى الدم مباشرة، ومن هنا تسمى الغدد ذات الإفراز الداخلي ، ولابد من إنتاج هذه الهرمونات بالكميات المطلوبة لكي تؤدي وظائفها على أحسن وجه. أما إذا زاد إفراز الهرمون عن حاجة الجسم أو نقص فهذا سوف يؤدي إلى إختلال في الوظيفة مما قد يسبب أعراضا مرضية تختلف من هرمون إلى آخر.
الغدد الصماء في الفقاريات
- الغدة النخامية pituitary gland.
- تحت المهاد hypothalamus.
- الغدة الصنوبرية pineal gland.
- الغدة الدرقية thyroid gland.
- الغدة الجاردرقية parathyroid glands.
- الغدة الكظرية (فوق الكلوية) adrenal (suprarenal).
- المناسل gonads (المبيض ovary في الأنثى و الخصية testis في الذكر).
- المشيمة (خلال فترة الحمل) (ويعتبر غدة صماء حيث يقوم بإفراز ثلاث هرمونات وأيضا يعتبر غدة قنوية لأنه يقوم بإفراز العصارة البنكرياسية).
- البنكرياس pancreas (ويعتبر غدة صماء حيث يقوم بإفراز ثلاث هرمونات وأيضا يعتبر غدة قنوية لأنه يقوم بإفراز العصارة البنكرياسية).
- مخاطية المعدة و الأمعاء gastrointestinal mucosa.
- الكليتان kidneys.
أمراض الغدد الصماء
هناك عدة طرق لإصابة الغدد بخلل في وظائفها هى : 1- نقص إنتاج الهورمون.
2- زيادة إنتاج الهورمون.
3- إنتاج هورمون غير طبيعي.
4- وجود خلل في أماكن استقبال الهورمون لإحداث تأثيره الفسيولوجي.
5- وجود خلل في نقل الهورمون أو تفاعله الكيميائي.
6- وجود أورام حميدة أو خبيثة في الغدة المصابة.
جدول الغدد الصم والهرمونات التي تفرزها
This is a table of the glands of the endocrine system, and their secreted hormones
الوطاء Hypothalamus
Pineal body
الهرمون المفرز | من خلايا | تأثيره |
---|---|---|
ملاتونين (أساساً) | الخلايا الصنوبرية Pinealocytes | مضاد للتأكسد antioxidant ويسبب النعاس |
الغدة النخامية Pituitary (النخامية hypophysis)
الفص الأمامي من الغدة النخامية النخامية الأمامية Anterior pituitary فص (adenohypophysis)
الهرمون المفرز | اختصاره | من خلايا | تأثيره |
---|---|---|---|
Growth hormone | GH | Somatotropes | stimulates growth and cell reproduction
Release Insulin-like growth factor 1 from liver |
Prolactin | PRL | Lactotropes | milk production in mammary glands sexual gratification after sexual acts |
Adrenocorticotropic hormone or corticotropin | ACTH | Corticotropes | synthesis of corticosteroids (glucocorticoids and androgens) in adrenocortical cells |
Lipotropin | Corticotropes | lipolysis and steroidogenesis, stimulates melanocytes to produce melanin | |
Thyroid-stimulating hormone or thyrotropin | TSH | Thyrotropes | stimulates thyroid gland to secrete thyroxine (T4) and triiodothyronine (T3) |
Follicle-stimulating hormone | FSH | Gonadotropes | In female: stimulates maturation of Graafian follicles in ovary.
In male: spermatogenesis, enhances production of androgen-binding protein by the Sertoli cells of the testes |
Luteinizing hormone | LH | Gonadotropes | In female: ovulation
In male: stimulates Leydig cell production of testosterone |
Posterior pituitary lobe (neurohypophysis)
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
اوكسيتوسين Oxytocin | Magnocellular neurosecretory cells | Contraction of cervix and vagina
Involved in orgasm, trust between people.[1] and circadian homeostasis (body temperature, activity level, wakefulness) [2]. يدر لبن الثدي | |
Vasopressin or antidiuretic hormone | AVP or ADH | Magnocellular neurosecretory cells | retention of water in kidneys
moderate vasoconstriction |
Intermediate pituitary lobe (pars intermedia)
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Melanocyte-stimulating hormone | MSH | Melanotroph | melanogenesis by melanocytes in skin and hair. |
الدرقية Thyroid
الهرمون المفرز | اختصاره | من خلايا | تأثيره |
---|---|---|---|
Triiodothyronine | T3 | Thyroid epithelial cell | potent form of thyroid hormone: increase the basal metabolic rate & sensitivity to catecholamines,
affect protein synthesis |
Thyroxine or tetraiodothyronine | T4 | Thyroid epithelial cells | less active form of thyroid hormone: increase the basal metabolic rate & sensitivity to catecholamines,
affect protein synthesis, often functions as a prohormone |
Calcitonin | Parafollicular cells | Construct bone
reduce blood Ca2+ |
الجار درقية Parathyroid
الهرمون المفرز | اختصاره | من خلايا | تأثيره |
---|---|---|---|
Parathyroid hormone | PTH | Parathyroid chief cell | increase blood Ca2+: *indirectly stimulate osteoclasts
(Slightly) decrease blood phosphate: |
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القلب
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Atrial-natriuretic peptide | ANP | Cardiac myocytes | Reduce blood pressure by:
reducing systemic vascular resistance, reducing blood water, sodium and fats |
Brain natriuretic peptide | BNP | Cardiac myocytes | (To a minor degree than ANP) reduce blood pressure by:
reducing systemic vascular resistance, reducing blood water, sodium and fats |
Striated muscle
Secreted hormone | From cells | Effect |
---|---|---|
Thrombopoietin | Myocytes | stimulates megakaryocytes to produce platelets[3] |
البشرة
Secreted hormone | From cells | Effect |
---|---|---|
Calcidiol (25-hydroxyvitamin D3) | Inactive form of Vitamin D3 |
نسيج شحمي Adipose tissue
الهرمون المفرز | From cells | Effect |
---|---|---|
لپتين Leptin (أساساً) | Adipocytes | decrease of appetite and increase of metabolism. |
Estrogens[4] (mainly Estrone) | Adipocytes |
المعدة
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
گاسترين Gastrin (أساساً) | G cells | Secretion of gastric acid by parietal cells | |
Ghrelin | P/D1 cells | Stimulate appetite,
secretion of growth hormone from anterior pituitary gland | |
Neuropeptide Y | NPY | increased food intake and decreased physical activity | |
سكرتين Secretin | خلايا S | افراز البيكربونات من الكبد, البنكرياس و غدد برونر Brunner's gland الاثنى عشرية
Enhances effects of cholecystokinin يوقف انتاج العصارة المعدية | |
سوماتوستاتين Somatostatin | D cells | Suppress release of gastrin, cholecystokinin (CCK), secretin, motilin, vasoactive intestinal peptide (VIP), gastric inhibitory polypeptide (GIP), enteroglucagon
Lowers rate of gastric emptying Reduces smooth muscle contractions and blood flow within the intestine [5] | |
هستامين Histamine | ECL cells | stimulate gastric acid secretion | |
Endothelin | X cells | Smooth muscle contraction of stomach [6] |
الإثنى عشر
الهرمون المفرز | من خلايا | تأثيره |
---|---|---|
Cholecystokinin | I cells | Release of digestive enzymes from pancreas
Release of bile from gallbladder hunger suppressant |
الكبد
الهرمون المفرز | الاختصار | من خلايا | تأثيره |
---|---|---|---|
Insulin-like growth factor (or somatomedin) (Primarily) | IGF | Hepatocytes | insulin-like effects
regulate cell growth and development |
Angiotensinogen and angiotensin | Hepatocytes | vasoconstriction
release of aldosterone from adrenal cortex dipsogen. | |
Thrombopoietin | Hepatocytes | stimulates megakaryocytes to produce platelets[3] |
البنكرياس
Secreted hormone | من خلايا | Effect |
---|---|---|
Insulin (Primarily) | ß Islet cells | Intake of glucose, glycogenesis and glycolysis in liver and muscle from blood
intake of lipids and synthesis of triglycerides in adipocytes Other anabolic effects |
Glucagon (Also Primarily) | a Islet cells | glycogenolysis and gluconeogenesis in liver
increases blood glucose level |
Somatostatin | d Islet cells | Inhibit release of insulin [7]
Inhibit release of glucagon[7] Suppress the exocrine secretory action of pancreas. |
Pancreatic polypeptide | PP cells | Unknown |
الكلية
Secreted hormone | من خلايا | Effect |
---|---|---|
Renin (Primarily) | Juxtaglomerular cells | Activates the renin-angiotensin system by producing angiotensin I of angiotensinogen |
Erythropoietin (EPO) | Extraglomerular mesangial cells | Stimulate erythrocyte production |
Calcitriol (1,25-dihydroxyvitamin D3) | Active form of vitamin D3
Increase absorption of calcium and phosphate from gastrointestinal tract and kidneys inhibit release of PTH | |
Thrombopoietin | stimulates megakaryocytes to produce platelets[3] |
Adrenal glands
Adrenal cortex
Secreted hormone | From cells | Effect |
---|---|---|
Glucocorticoids (chiefly cortisol) | zona fasciculata and zona reticularis cells | Stimulation of gluconeogenesis
Inhibition of glucose uptake in muscle and adipose tissue Mobilization of amino acids from extrahepatic tissues Stimulation of fat breakdown in adipose tissue anti-inflammatory and immunosuppressive |
Mineralocorticoids (chiefly aldosterone) | Zona glomerulosa cells | Increase blood volume by reabsorption of sodium in kidneys (primarily) |
Androgens (including DHEA and testosterone) | Zona fasciculata and Zona reticularis cells | Virilization, anabolic |
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Adrenal medulla
Secreted hormone | From cells | Effect |
---|---|---|
Adrenaline (epinephrine) (Primarily) | Chromaffin cells | Fight-or-flight response:
|
Noradrenaline (norepinephrine) | Chromaffin cells | Fight-or-flight response:
|
Dopamine | Chromaffin cells | Increase heart rate and blood pressure |
Enkephalin | Chromaffin cells | Regulate pain |
الخصيتان
Secreted hormone | من خلايا | Effect |
---|---|---|
Androgens (chiefly testosterone) | Leydig cells | Anabolic: growth of muscle mass and strength, increased bone density, growth and strength,
Virilizing: maturation of sex organs, formation of scrotum, deepening of voice, growth of beard and axillary hair. |
Estradiol | Sertoli cells | Prevent apoptosis of germ cells[8] |
Inhibin | Sertoli cells | Inhibit production of FSH |
Ovary
These originate either from the ovarian follicle or the corpus luteum.
Secreted hormone | From cells | Effect |
---|---|---|
پروجسترون Progesterone | Granulosa cells, theca cells | Support pregnancy[9]:
غيره:
|
Androstenedione | Theca cells | Substrate for estrogen |
Estrogens (mainly estradiol) | Granulosa cells | Structural:
Protein synthesis:
Fluid balance:
Gastrointestinal tract:
Melanin:
Cancer:
Lung function: |
Inhibin | Granulosa cells | Inhibit production of FSH from anterior pituitary |
المشيمة (أثناء الحمل)
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Progesterone (أساساً) | Support pregnancy[9]:
Other effects on mother similar to ovarian follicle-progesterone | ||
Estrogens (mainly Estriol) (Also Primarily) | Effects on mother similar to ovarian follicle estrogen | ||
Human chorionic gonadotropin | HCG | Syncytiotrophoblast | promote maintenance of corpus luteum during beginning of pregnancy
Inhibit immune response, towards the human embryo. |
Human placental lactogen | HPL | Syncytiotrophoblast | increase production of insulin and IGF-1
increase insulin resistance and carbohydrate intolerance |
Inhibin | Fetal Trophoblasts | suppress FSH |
الرحم (when pregnant)
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
پرولاكتين Prolactin | PRL | Decidual cells | milk production in mammary glands |
Relaxin | Decidual cells | Unclear in humans |
وصلات خارجية
المصادر
- ^ Kosfeld M et al. (2005) Oxytocin increases trust in humans. Nature 435:673-676. PDF PMID 15931222
- ^ Scientific American Mind, "Rhythm and Blues"; June/July 2007; Scientific American Mind; by Ulrich Kraft
- ^ أ ب ت Kaushansky K. Lineage-specific hematopoietic growth factors. N Engl J Med 2006;354:2034-45. PMID 16687716.
- ^ The adipose tissue as a source of vasoactive factors. Frühbeck G. (Curr Med Chem Cardiovasc Hematol Agents. 2004 Jul;2(3):197-208.)
- ^ http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/otherendo/somatostatin.html Colorado State University - Biomedical Hypertextbooks - Somatostatin
- ^ Diabetes-related changes in contractile responses of stomach fundus to endothelin-1 in streptozotocin-induced diabetic rats Journal of Smooth Muscle Research Vol. 41 (2005) , No. 1 35-47. Kazuki Endo1), Takayuki Matsumoto1), Tsuneo Kobayashi1), Yutaka Kasuya1) and Katsuo Kamata1)
- ^ أ ب Physiology at MCG 5/5ch4/s5ch4_17
- ^ Pentikäinen V, Erkkilä K, Suomalainen L, Parvinen M, Dunkel L. Estradiol Acts as a Germ Cell Survival Factor in the Human Testis in vitro. The Journal of Clinical Endocrinology & Metabolism 2006;85:2057-67 PMID 10843196
- ^ أ ب ت ث http://www.vivo.colostate.edu/hbooks/pathphys/reprod/placenta/endocrine.html
- ^ Physiology at MCG 5/5ch9/s5ch9_13
- ^ Hould F, Fried G, Fazekas A, Tremblay S, Mersereau W (1988). "Progesterone receptors regulate gallbladder motility". J Surg Res. 45 (6): 505–12. PMID 3184927.
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: CS1 maint: multiple names: authors list (link) - ^ http://www.breastcancer.org/tre_sys_hrt_idx.html
- ^ Massaro D, Massaro GD (2004). "Estrogen regulates pulmonary alveolar formation, loss, and regeneration in mice". American Journal of Physiology. Lung Cellular and Molecular Physiology. 287 (6): L1154-9. PMID 15298854 url=http://ajplung.physiology.org/cgi/content/full/287/6/L1154.
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انظر أيضاً
- Releasing hormones
- Neuroendocrinology
- الجهاز العصبي
- Endocrine disruptor
- Major systems of the human body
وصلات
- Journals Designed for Clinical Endocrinologists
- Islet cell antibody
- Binding of antibody to pancreas
- Kidshealth.org
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