1 / 11

Endocrinology

Endocrinology. A quick review Sam Craik. What is endocrinology. B. Paracrine. B. A. The transmission of a hormone message from one cell... Transports via the blood stream. Arrives at a distant cell elsewhere in the body. Triggering a response from this cell. A. Autocrine.

venice
Télécharger la présentation

Endocrinology

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. Endocrinology A quick review Sam Craik

  2. What is endocrinology B. Paracrine B A • The transmission of a hormone message from one cell... • Transports via the blood stream. • Arrives at a distant cell elsewhere in the body. • Triggering a response from this cell. A. Autocrine C. Endocrine C

  3. Hormone Types - Peptide • Synthesised from one or more amino acid. • Peptides often produced as inactive pro-hormones. • Can be stored in vesicles for quick release. • Act at target’s plasma membrane. • Second messengers activated. • Rapid response. Examples: Serotonin (amino acid derived) T3, T4 (dipeptide) Insulin (polypeptide)

  4. Hormone Types - Lipid • Derived from lipids: often cholesterol, sometimes fatty acids. • Cholesterol converted to pregnalone. • From here it is converted to steroid hormones. • Slow fluctuations in steroid homone levels. • Lipid soluble - Act on intracellular receptors. • This affects gene expression, slow response. Examples: Testosterone, Oestrogen, Progesterone. Cortisol Prostaglandins (Fatty Acid)

  5. Anterior Pituitary

  6. Posterior Pituitary • Oxytocin – Induction of childbirth, milk ejection. • Vasopressin – Increased water absorption in kidney. • Both are produced in the Hypothalamus and transported down a nerve axon in vesicles to the posterior pituitary where it is released into the blood. This is Neuroendocrine action. A D D. Neuroendocrine

  7. Hypothalamus Hypothalamus GnRH GnRH Ant Pituitary Ant Pituitary FSH FSH Ovary Ovary Oestrogen Oestrogen Feedback • Postive and negative feedback can occur where a hormone within a series acts back on the earlier hormones to activate or inhibit their release. +ve Feedback -ve Feedback

  8. Growth Hormone Hypothalamus • Excess • Gigantism in children, excessive long bone growth. • Acromegaly in adults, epiphyseal fusion occurred already. • Growth in soft tissues and flat bones. • Deficiency • Short Stature • Loss of growth stimulation (bone and muscle growth, fat brakdown) GHRH Ant Pituitary Growth Hormone Liver IGF-1

  9. Thyroid Hormones Control rate of cellular metabolism • Deficiency • Hypothyroidism • Congenital • Iodine Deficiency • Hashimotos (AI) • Tiredness • Weight Gain • Memory problems • Depression • Goitre Hypothalamus • Excess • Hyperthyroidism • Graves Disease (AI) • Restlessness • Weight Loss • Irritability • Goitre TRH Ant Pituitary TSH Thyroid T3 + T4

  10. Glucocorticoids Hypothalamus • Deficiency • Addison’s Disease • Destruction of Adrenal Cortex causes reduction in production of glucocorticoids (eg: Cortisol), mineralocorticoids and sex steroids. • Often autoimmune • Sometimes Tubercolosis • Weight loss • Anorexia • Weakness CRH Ant Pituitary ACTH Adrenal Cortex Cortisol

  11. Glucocorticoids Hypothalamus • Excess • Cushing Syndrome • Can be at hypothalmic, pituitary or adrenal level. • Cortisol has a negative feedback on ACTH. • Can use ACTH levels to detect where problem is. • High ACTH = Hypothalamus or Pituitary, excess ACTH produced. • Low ACTH = Adrenal Cortex, excess Cortisol independent of ACTH, feeds back to inhibit. • Thin limbs (fat/muscle breakdown) • Central weight gain (storage of released fats/glucose) CRH Ant Pituitary ACTH Adrenal Cortex Cortisol

More Related