الغدد الصم

الغدد الصماء الرئيسية. (ذكر يسار, أنثى على اليمين.) 1. غدة صنوبرية 2. غدة نخامية 3. غدة درقية 4. ثيموس 5. غدة كظرية 6. بنكرياس 7. مبيض 8. خصية

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.

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

الهرمون المفرز اختصاره من خلايا تأثيره
Thyrotropin-releasing hormone TRH Parvocellular neurosecretory neurons Release thyroid-stimulating hormone from anterior pituitary (primarily)
Stimulate prolactin release from anterior pituitary.
Gonadotropin-releasing hormone GnRH Neuroendocine cells of the Preoptic area Release of FSH and LH from anterior pituitary.
Growth hormone-releasing hormone GHRH Neuroendocrine neurons of the Arcuate nucleus Release GH from anterior pituitary
Corticotropin-releasing hormone CRH Parvocellular neurosecretory neurons Release ACTH from anterior pituitary
Vasopressin Parvocellular neurosecretory neurons Release ACTH from anterior pituitary
Somatostatin, also growth hormone-inhibiting hormone SS or GHIH Neuroendocrince cells of the Periventricular nucleus Inhibit release of GH and TSH from anterior pituitary
Prolactin inhibiting hormone or Dopamine PIH or DA Dopamine neurons of the arcuate nucleus Inhibit release of prolactin and TSH from anterior pituitary
Prolactin-releasing hormone PRH Release prolactin from anterior pituitary

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:

  • (decreased reuptake in kidney but increased uptake from bones
  • activate vitamin D)

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)

Potassium and H+ secretion in kidney.

Androgens (including DHEA and testosterone) Zona fasciculata and Zona reticularis cells Virilization, anabolic

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:

Anti-inflammatory

Androstenedione Theca cells Substrate for estrogen
Estrogens (mainly estradiol) Granulosa cells Structural:

Protein synthesis:

  • Increase hepatic production of binding proteins

Coagulation:

Fluid balance:

Gastrointestinal tract:

  • Reduce bowel motility
  • Increase cholesterol in bile

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

  1. ^ Kosfeld M et al. (2005) Oxytocin increases trust in humans. Nature 435:673-676. PDF PMID 15931222
  2. ^ Scientific American Mind, "Rhythm and Blues"; June/July 2007; Scientific American Mind; by Ulrich Kraft
  3. ^ أ ب ت Kaushansky K. Lineage-specific hematopoietic growth factors. N Engl J Med 2006;354:2034-45. PMID 16687716.
  4. ^ The adipose tissue as a source of vasoactive factors. Frühbeck G. (Curr Med Chem Cardiovasc Hematol Agents. 2004 Jul;2(3):197-208.)
  5. ^ http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/otherendo/somatostatin.html Colorado State University - Biomedical Hypertextbooks - Somatostatin
  6. ^ 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)
  7. ^ أ ب Physiology at MCG 5/5ch4/s5ch4_17
  8. ^ 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
  9. ^ أ ب ت ث http://www.vivo.colostate.edu/hbooks/pathphys/reprod/placenta/endocrine.html
  10. ^ Physiology at MCG 5/5ch9/s5ch9_13
  11. ^ 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. 
  12. ^ http://www.breastcancer.org/tre_sys_hrt_idx.html
  13. ^ 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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