Endocrine System Flashcards
What are the main homeostatic imbalances and diseases of the endocrine glands
- endocrine hyper secretion (excess hormone production)
- endocrine hypo secretion (hormone deficiency)
- tumours of the endocrine glands
Discuss the pathophysiology of Grave’s Disease
Autoimmune disease
- overactive thyroid due to thyroid antibodies binding to TSH-receptor and stimulating thyroid hormone synthesis, secretion and goitre formation
Autoimmune disorder where thyroid-stimulating immunoglobulins bind to the thyroid cells and stimulates the production of too much thyroid hormone.
Identify the tests and signs/symptoms of Grave’s Disease
- Grave’s opthalmopathy
- Overactive metabolism
- Rhythm irregularities
- psychiatric problems
Test: blood test for levels of TSH
Discuss the pathophysiology of Hashimoto’s thyroiditis
Autoimmune disease
- inflammation damages the gland leading to decreased thyroid hormone production
- thyroid gland is attacked by a variety of cell and antibody mediated immune responses
Identify the tests and signs/symptoms of Hashimoto’s thyroiditis
- weight gain
- sensitivity to cold and heat
- fatigue
- Myxoedematous psychosis
Discuss the pathophysiology of type 1 diabetes
Autoimmune destruction of the pancreatic beta cells. As a result, they produce insufficient amounts of insulin - leads to hyperglycaemia
Discuss the pathophysiology of type 2 diabetes
encompassed by a poor response to insulin, or insulin-resistance
often in type 2 diabetes the pancreas progressively stops producing a sufficient amount of insulin due to declining beta cell function - occurs due to chronic hyperglycaemia, where beta cells eventually become overworked and unable to produce insulin, as they are constantly forced to produce an excess of insulin in response to the abnormal levels of glucose
Identify the signs/symptoms of diabetes
- polyuria
- polydipsia
- polyphagia
- hyperglycaemia
Discuss the pathophysiology of Cushing’s syndrome
Hypercortisolism - excessive cortisol
Causes: May be from exogenous administration of glucocorticoids for asthma, immunosuppression etc.
Identify the signs/symptoms of Cushing’s syndrome
- weight gain (central obesity)
- buffalo hump
- moon face
- baldness
Discuss the pathophysiology of Addison’s disease
Cortisol deficiency
Causes – adrenal insufficiency, secondary adrenal insufficiency caused by ACTH deficiency e.g. removal of the pituitary, tuberculosis which can destroy the adrenal glands, cancer and chronic fungal infection
Identify the signs/symptoms of Addison’s disease
- chronic fatigue
- muscle weakness
- weight loss
- loss of appetite
Discuss the pathophysiology of diabetes insipidus
imbalance of fluids in the body
caused by abnormality in the functioning or levels of antidiuretic hormone (ADH), also known of as vasopressin. Manufactured in the hypothalamus and stored in the pituitary gland, ADH helps to regulate the amount of fluid in the body
Signs/symptoms: increase thirst
Discuss the cardiovascular effects of increased insulin secretion
Increased insulin = hypoglycaemia
Hypoglycaemia can have various effects on the cardiovascular system. Hypoglycaemia often stimulates the release of epinephrine which in turn increases the workload of the heart .
Explain what diabetic ketoacidosis is
Diabetic ketoacidosis is a serious complication characterised by extreme hyperglycaemia and usually occurs following a stress such as infection, or omission of insulin.
related to a deficiency of insulin and an increase in the insulin counter-regulatory hormones (adrenaline, cortisol, glucagon, growth hormone). In response to these hormones, hepatic glucose production increases and peripheral glucose usage decreases, resulting in hyperglycaemia. Insufficient insulin leads to the breakdown of fat stores to be used as energy instead of glucose. However, ketones are released as a result of the fat breakdown. These ketones are acidic and hence the result is ketoacidosis
Describe the role of TSH and it is regulated
Thyroid stimulating hormone stimulates the thyroid gland to produce thyroid hormone
- low levels of thyroid hormones stimulates release of TSH from anterior pituitary
Describe the role of ACTH and it is regulated
Adrenocorticotropic hormone stimulates the adrenal cortex to produce cortisol
- ACTH is produced in the anterior pituitary gland
Production of ACTH is regulated by corticotrophin-releasing hormone (CRH) from the hypothalamus and cortisol from the adrenal gland. If ACTH levels are low, the hypothalamus releases CRH which is key to the stress hormone system and acts on many areas of the brain
Describe the role of FSH and LH and it is regulated
stimulate the gonads to produce gametes (ova and sperm) as well as the sex hormones – oestrogen (estrogen) and progesterone in the ovaries and testosterone in the testes
