Diseases of the Endocrine System

What is glucocorticoids

Is a class of corticosteroids that regulate metabolism and immune response

How does cortisol control its own release

By reducing the levels of CRH and ACTH

What is the function of the glucocorticoids

Metabolic functions: Raise blood glucose by increasing gluconeogenesis in the liver

Breakdown fats and protein to supply energy in stress

Immune Effects: Reduce inflammatory signals and lower immune activity

What is the consequence of deficiency and excess of cortisol

Deficiency: Addison’s Disease- fatigue low BP

Excess: Cushing’s Disease- obesity, high BP, hyperglycaemia

What are the main thyroid hormones

T3- triiodothyronine

T4- thryoxine

They set your energy use, heat production, and metabolic rate

How are thyroid hormones made

Thyroglobulin acts as a scaffold for T3 and T4

Iodine is required for to produce thyroid hormones

What does the parathyroid hormone do?

Synthesize and secrete Parathyroid hormone which increases blood calcium levels

What does Parafollicular cells located in the thyroid tissue do

Produce calcitonin which lowers blood calcium

How does the feedback mechanism work for thyroid hormones

Initiation- The hypothalamus releases TRH which stimulates the anterior pituitary to release TSH. TSH tells thyroid to make T4 and T3

Rising T3 and T4 signal the hypothalamus to lower the TRH and TSH

How does the thyroid hormone act in the cell

T4 enters the the cell and is changed to T3

T3 enters the nucleus and binds to the thryroid hormone receptor

The receptor turns certain genes on and off

his changes the protein production in the cellThe new protein causes the metabolic effects of T3

Name some of the Thyroid Disorders

Hyperthyroidism- often caused by Graves disease, too much T3 and T4 in the blood

Hypothyroidism- Low T3 and T4

Nontoxic Goitre

Thyroid carcinoma