PHTY208 Lecture 17: 17 Disorders of endocrine control
Disorders of endocrine control:!
Introduction:!
-Endocrine system affects all aspects of the body. For example:!
-Growth and development, muscle and adipose tissue distribution, sexual development, Gl
and cardiovascular function, body response to stress!
-Nutritional status describes the condition of the body related to the availability and use of
nutrients!
-Nutrients are taken into the body and used for important functions!
-The body can also store what is not needed int he form of adipose tissue!
Concept 1: Endocrine disorders:#
Categories of disturbances of endocrine function:!
-Hypofunction- underproduction of hormone!
-Causes:!
-Congenital defects, injury to glandular cells (disruption in blood flow, infection, inflammation,
autoimmune responses, neoplastic growth or invasive tumour growth), decline in function
with paging, atrophy as the result of drug therapy or unknown reasons, receptor defects!
-Hyperfunction- excessive hormone production!
-Causes:!
-Excessive stimulation and hyperplasia or hypertropy of the endocrine gland, hormone-
producing tumour of gland, ectopic hormone secretion, medication, decrease negative
feedback!
Concept 2: Hypothalamus and pituitary disorders:!
Hypothalamus and pituitary disorders:!
-Interface between nervous system and endocrine system!
-Anterior pituitary is controlled by releasing hormones secreted from the hypothalamus - travel
via a portal vein!
-Result int he release of many hormone that control- thyroid, adrenal, gonads!
Pituitary gland:!
-Anterior:!
-HGH, thyroid stimulating hormone TSH, follice stimulating hormone FSH, lutenizing hormone
LH, prolactin, adrenocortictropin ACTH, melanocyte stimulating hormone MSH!
-Posterior:!
-Oxytocin (OT), antidiuretic hormone (ADH) or vasopressin!
Causes of multi-hormone pituitary disruptions:!
-Tumours, pituitary surgery or radiation, lesions and head trauma, infection or inflammation,
autoimmune disease, malfunctioning target organ, genetic disease, hypothalamic disorder,
pituitary infarction, pituitary apoplexy, hypoxic necrosis!
Clinical manifestations of hypopituitarism:!
-Usually occur gradually!
-70-90% destroyed before clinical symptoms!
-Can present as an acute and life-threatening condition!
-Symptoms include:!
-Headache, altered mental state, postural hypotension, being chronically unfit, weakness and
fatigue, growth failure, loss of appetite, impairment of sexual function, cold intolerance,
decrease bone density, morbid obesity!
Single pituitary hormone defects:!
-Defects may only effect the release of one hormone!
-The most common are:!
-Growth hormone- excess- gigantism (children), acromegaly (adults), depletion- dwarfism
(children)!
-ADH- excess- SIAHD, depletion- Diabetes insipidus!
-ACTH- excess- Cushing’s, depletion- Addison’s!
Growth hormone:!
-Necessary for linear bone growth in children and development of musculoskeletal system!
-Stimulates cells to increase in size4 and divide more rapidly!
-Enhances amino acid transport across cell membranes!
-Increases the rate at which cells use fatty acids!
-Anti-insulin activity!
-HGH stimulates liver, muscle, cartilage, and other tissue to secrete insulin like growth factor
(IGF)!
-IGF promotes growth of body cells, protein synthesis, tissue repair, lipolysis and elevation of
blood glucose concentrations!
Growth hormone hyposecretion- children!
-Cells responsible for growth hormone secretion do not form properly or are irreversibly
damaged, interferes with linear bone growth, delayed skeletal maturation, results in short
stature or dwarfism, disrupts normal blood glucose levels, decreased muscle mass, ^
subcutaneous fat, immature facial features, delayed onset of puberty!
Growth hormone hyposecretion- adult:!
-Rare, lean body mass, reduced bone density, alterations in physical and mental well-being,
cardiac function and metabolic parameters, lower levels of energy and libido!
Growth hormone hyper secretion- children:!
-Results in ^linear bone growth- Gigantism, thickening of fingers, jaw, forehead, hands and feet,
decreased bone density, delayed puerto, double vision, weakness!
Growth hormone hyper secretion- adults:!
-Also know as acromegaly, overgrowth of the cartilaginous parts of the skeleton, enlargement of
the heart and other organs of the body, metabolic disturbances resulting in altered fat
metabolism and impaired glucose tolerance, goiter and cardiomyopathy, sleep apnoea, often
associated with deficiencies of other hormones, thickening of fingers, jaw, forehead, hands and
feet, enlarged tongue, course skin and hair, weight gain, spinal disorders, hyperphosphatemia,
tissue oedema, enlarged joints, ^ sweating, ^ risk of diabetes mellitus!
Adrenal disorders:#
Steroid hormones produced by the adrenal cortex:!
-Mineralocortocids (aldosterone):!
-Function in sodium, potassium and water balance, Glucocoryiocids (cortisol):aids in
regulating the metabolic functions of the body, and in controlling the inflammatory response ,
essential for survival in stress!
-Adrenal sex hormones (androgens):!
-Serve mainly as source of androgens for women!
Actions of cortisol:!
-Glucose metabolism, protein metabolism, fat metabolism, anti-inflammatory action, permissive
effect, important in stress response!
Manifestations of adrenal cortical insufficiency:!
-Anorexia and weight loss, fatigue and weakness, depression, inability to respond to stressful
situations, gastrointestinal symptoms, nausea, diarrhoea, myalgia, arthraligia, abdominal pain,
orthostatic hypotension, hyponatremia (low Na+), hypokalaemia, hyper pigmentation,
associated autoimmune conditions !
Adrenal Cortical hormone excess:!
-Altered fat metabolism, muscle weakness, muscle wasting, purple striae, osteoporosis,
derangements in glucose metabolism, hypokalaemia, gastric acid secretion, hirsutism, mild
acne, and menstrual irregularities, poor wound healing, extreme mood swings!
Document Summary
Endocrine system a ects all aspects of the body. Growth and development, muscle and adipose tissue distribution, sexual development, gl and cardiovascular function, body response to stress nutrients. Nutritional status describes the condition of the body related to the availability and use of. Nutrients are taken into the body and used for important functions. The body can also store what is not needed int he form of adipose tissue. Congenital defects, injury to glandular cells (disruption in blood ow, infection, in ammation, autoimmune responses, neoplastic growth or invasive tumour growth), decline in function with paging, atrophy as the result of drug therapy or unknown reasons, receptor defects. Excessive stimulation and hyperplasia or hypertropy of the endocrine gland, hormone- producing tumour of gland, ectopic hormone secretion, medication, decrease negative feedback. Interface between nervous system and endocrine system. Anterior pituitary is controlled by releasing hormones secreted from the hypothalamus - travel.
