* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download The Hypothalamo-Pituitary- Adrenal Axis
Survey
Document related concepts
Neuroendocrine tumor wikipedia , lookup
Endocrine disruptor wikipedia , lookup
Menstrual cycle wikipedia , lookup
Mammary gland wikipedia , lookup
History of catecholamine research wikipedia , lookup
Xenoestrogen wikipedia , lookup
Bioidentical hormone replacement therapy wikipedia , lookup
Breast development wikipedia , lookup
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency wikipedia , lookup
Hormone replacement therapy (menopause) wikipedia , lookup
Hyperthyroidism wikipedia , lookup
Hyperandrogenism wikipedia , lookup
Hypothalamic–pituitary–adrenal axis wikipedia , lookup
Hormone replacement therapy (male-to-female) wikipedia , lookup
Transcript
The Hypothalamo-PituitaryAdrenal Axis Table 10.1 Factors Influencing Evaluation of Endocrine Function in Aging Physiologic Metabolism Body Composition Nutrition Exercise Stress Hormone Metabolism ÇÈ Activity T4 Î T3 T Î DHT Inter-endocrine Relations Secretory Rate Transport to target site Number & Affinity Of Receptors CNS Figure 10.1 ↓ GLA N D ↓ TROPIC HORMO N E ↓ CLEA RA NC E GLA N D ↓ BLOO D -HORMO N E ↓ BO UN D A N D FREE IRCULA C TOR Y A CTIV E MET A BO LITE ↓ TA RGET CELL ↓ RECEPTOR BIN D IN G TRA NS D UCTION A CTIV A TION ↓ RESPO NS E Hypophysiotropic hormones CRH: corticotropic releasing hormone GHRH: growth hormone releasing hormone GHIH: growth hormone inhibitory hormone Somatostatin PRH: prolactin releasing hormone GnRH: gonadotropin releasing hormone TRH thyrotropin (TSH)-releasing hormone Pituitary Hormones ACTH: adrenocorticotropin hormone LH: lutenizing hormone FSH: follicle stimulating hormone PL: prolactin TSH: thyroid stimulating hormone GH: growth hormone **Please see Figures 10.7-10.9 in text** Aorta Figure 10.2 Right Kidney Vena Cava Rt. Adrenal Lf. Adrenal Left Kidney Figure 10.3 Diagram of a section of the adrenals illustrating the various zones and hormones Zona Fasciculata Zona Glomerulosa Zona Reticularis Capsule Medulla Cortex all layers z. fasciculata & reticularis z. glomerulosa Medulla corticosterone cortisol & sex hormones aldosterone epinephrine & norepinephrine Figure 10-6 Figure 10.6 C N S LIMBI C SYSTEM ↓ (-) (-) HYPO THA LA M US CRH ↓ PITUITA RY ↓ CLEA RA NC E A CTH ↓ A D REN A L CO RTEX Reminder CRH: corticotropic releasing hormone ACTH: adrenocorticotropic hormone ↓ GLUCO CO RTICO ID S EX S STERO ID S ↓ TA RGET CELLS ↓ IN TRA CELLULA R BIN D IN G A CTIV A TIO N TRA NS LO CA TIO N ↓ MET A BO LIC RESPO NS E FREE & BOU N D Cortiso l Epinep hrine Nore pine phr ine TARGET ACTIONS Actions Of Glucocorticoids Liver cellular absorption of glucose glycogenesis Muscle cellular celluar absorption of amino acids Actions of Adrenaline/Noradrenaline TARGET ACTIONS Target Blood Vessel vasoconstriction vasodilatation Intestine relaxation of motility constriction of sphincters of GI tract and bladder Heart White Blood Cells anti inflammatory action Brain excitability (EEG) behavioral changes Hypothalamus/Anterior Pituitary negative feedback of CRH, ACTH, GCs excitation contraction } Lungs brochial dilation Liver activation of glycogenolysis mobilization of metabolic energy Adipocytes activation of lipolysis Kidney Sodium reabsorption (especially by aldosterone) Bone bone resorption osteoporosis Pancreas inhibition of insulin secretion stimulation of insulin secretion Brain vigilance anxiety, fear, rage functions of emergency Figure 10.5 Schematic diagram of corticosteroid action in target cell Corticosteroid Hormone-receptor complex Intracellular receptor Biological Response Proteins mRNA Hormone-receptor complex bound to DNA mRNA Nucleus •Gene expression & new protein synthesis •Activation/repression of preexisting cell proteins •Relatively long latency of onset •Rapid onset of action •Medium & long term cell program •Rapid adaptation to changes in the milieu •Organization of cell networks for complex functions •Dynamic modifications of long term cell programs Figure 10.7 Diagrammatic representation of the anterior pituitary estrogens thryroid hormones corticosteroids androgens ovary LH FSH PL mammary gland PL thyroid TSH adrenal cortex ACTH skeleton, muscles, liver GH testis ISCH FSH PL Anterior Pituitary Figure 10.8 Diagrammatic representation of the posterior pituitary Posterior Pituitary Oxytocin uterine smooth muscle and mammary gland Vasopressin Kidney function Changes with Aging in the Hypothalamo-Pituitary-Adrenal Axis No significant changes in healthy, non-stressed, elderly The few changes that occur are rapidly compensated for (e.g. decreased secretion of GCs from the adrenal cortex) but also less rapid metabolism in the liver & less urine excretion Therefore the circulating levels remain constant Also, normal ACTH & cortisol responses to CRH administration Some alterations of the circadian rhythm STRESS Cortisol, norepinephrine, and epinephrine Figure 10.4 Corticosterone titers in young (3-5 mo) and aged (24-28 mo) rats 40 Corticosterone µg/100 ml Old youngrats rats old rats rats Young 20 * 0 Stress 0 Recovery 1 2 Hours 3 4 Exposure to Stress Generates: • Specific responses: vary with the stimulus (specialized responses) and generate different responses with each different stimulus. • Nonspecific responses: (also called nonspecialized) are always the same – regardless of the stimulus – mediated through stimulation of neural, endocrine, and immune axis