1 / 14

Hypothalamus and the anterior pituitary

Hypothalamus and the anterior pituitary. The Hypothalamus pituitary axis synthesize. Hypothalamus, TRH , CRH Ant. PIT. Produce : ACTH TSH FSH LH G.H Post.Pitu. produce : ADH Oxytocin. Control: Through Hypothalamic releasing , inhibitor factors Stress . Hypoglycaemia.

cardea
Download Presentation

Hypothalamus and the anterior pituitary

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hypothalamus and the anterior pituitary

  2. The Hypothalamus pituitary axis synthesize • Hypothalamus, TRH , CRH Ant. PIT. Produce : • ACTH • TSH • FSH • LH • G.H Post.Pitu. produce : ADH Oxytocin

  3. Control: Through Hypothalamic releasing , inhibitor factors • Stress . • Hypoglycaemia. Disorders of Anti- pitruitary Hormones secretion :

  4. Excess Def. ACTH Cushing (rare) Hypoadrenalism TSH Hyperthyroidism 2nd hypothyroidism LH/FSH early puberty 2nd hypogonaidism infertility Excess GH: Gigantism. Acromegaly. Excessive hair growth. Compression of the optic chiasma may cause visual field defects.

  5. Diagnosis of the hypothalamic pituitary axis disorders : • Clinical presentation . • Radiological findings. • Plasma GH is increased. • Raised plasma glucose. • Diganosis is confirmed by: • Demonstrating Raised plasma GH not suppressed by a rise in plasma glucose concentration. • In normal subjects plasma GH falls to low levels.

  6. hypopituitarism Causes: • Destruction or damage to the gland by tumour • Infarction :post partum haemorrhage (Sheehan’s syndrome) • Pituitary surgery or irradiation. • Head injury or granuloma.

  7. Effects: • Secondary hypogonadism presenting as :amenorrhea, infertility , atrophy of secondary sexual characteristics. • Growth retardation in children . • Secondary hypothyroidism. • Secondary hypoadrenalism and hyperpigmentation . • Prolactin deficiency with failure to lactate .

  8. Adrenal disorders Adrenal hormones and their effects : • Cortisol controlled by ACTH through –ve feed back mechanism . • Stress . Effects : • CHO metabolism disorder causing hyperglycemia since it is hyperglycemic hormone. • Aldosterone controlled by rennin - angiotensin system. • Effects: reabsorption of Na and excretion of K

  9. Disorders of adrenal cortex1 Cushing ‘s syndrome: Due to excessive cortisol and ACTH. Effects: Obesity. Impaired glucose intolerance. Increased protein catabolism. Hypertension. Psychiatric disturbances.

  10. Cushing’s Syndrome

  11. Causes of Cushing’s syndrome : 1.Adrenal hyperplasia : • Morning and evening plasma cortisol raised. and not suppressed by dexamethasone. • ACTH level is very law . 2.Ectopic ACTH : • Plasma cortisol raised day and evening. • Plasma ACTH is high. • Not suppressed even after 8 mg dexamethasone.

  12. Investigation of suspected cushing’s syndrome: • Plasma cortisol morning raised . • Plasma cortisol evening raised . • Urinary free cortisol raised . • After 2mg dexamethasone no suppression .

  13. Adrenocortical hypofunction Addison’ disease : • Caused by: 1.Bilateral destruction of all zones of the adrenal cortex because of auto immune process. 2.T.B 3. Amyloid. 4. secondary deposit. 5.Haemorrhage into adrenal glands following meningitis.

  14. Clinical presentation : • Acute hypo function :adrenal crisis . • Shock • Features due to hyponatraemia and hyperkalaemia . • Hypoglycemia • Androgen deficiency . • Pigmentation.

More Related