wk 9- endocrine Flashcards
Compare & contrast type I & II diabetes inc causes, pathogenesis, typical initial clinical presentation (prior to diagnosis/treatment)
type I:
-5-10% cases
-autoimmune disease, genetic predisposition, environmental factors
-develops in early childhood and presents in early teenage years
-can be normal or under weight
-lack of insulin despite high serum glucose so cells are starving
-energy deposits broken down (fat and muscle)
-renal effects including appearance of glucose in urine
-hyperglycemia, low blood volume, ketoacidosis might mean they present an acute medical emergency in a hyperglycemia coma
type II:
-lifestyle and environment, genetic factors
-insulin resistance (insensitive), b cell dysfunction (inappropriate response)
-they still make insulin but the respondence isn’t occurring as well.
-sensitize tissues to insulin by losing weight to reverse the disease
-has enough insulin to prevent ketoacidosis (prevents breakdown of fat stores)
-symptoms are non-specific, chronic
long term complications of diabetes mellitus
- Hyperglycaemic
- hyperosmolar state
- Diabetic neuropathies
- Microvascular disease
– Diabetic retinopathy
– Diabetic nephropathy - Macrovascular disease
– Coronary artery disease
– Cerebrovascular accidents
– Peripheral vascular disease - Infection
-atherosclerosis (can lead to peripheral, cardio and cerebral vascular disease)
Understand what is meant by ‘functional’ tumour & the possible implications for hormone levels
tumour cells are able to still make that hormone, an excess of the hormone
What is the most common cause of hyperthyroidism & the symptoms associated with the condition?
grave’s disease-immune system that makes an antibody that has a similar structure to TSH so it binds to the TSH receptor to stimulate the gland to make T3 and T4 which leads to increased levels of circulating T3/4
symptoms:
increased metabolic rate
weight loss
anxiety and irritability
fine tremor
proptosis (bulging eyes)
How does GH excess differ in pre/post puberty?
- If adenoma presents in childhood before epiphyses close -gigantism
– If adenoma presents after closure of epiphyses- acromegaly causes enlargement of body features
What is the result of GH deficiency in embryogenesis?
dwarfism
What is Cushing’s syndrome & how may it be caused?
condition caused by exposure to high levels of cortisol, what occurs in the body is; hyperglyceamia, immune suppression, loss of muscle/ fat / bone in periphery and redistribution of fat in the trunk and thinning of hair and skin
caused by excessive cortisol
how does MELANOMA differ from the common carcinomas of the skin?
-fewer mutations to get aggressive melanoma
-increased risk is associated with severe suburn at young age not a dose dependent exposure to UV
-people are genetically predisposed and some with increased risk bc of fari skin/blue or green eyes
-grow vertically rather than radially
-metastasized at time of diagnosis
how does basal cell carcinoma differ to the other skin carcinomas
-most common
-increases in incidence with age and UV exposure radiation
-grows slowly due to high rate of apoptosis and radially as a papule
-rarely metastasizes
how do squamous cell carcinomas differ to the other skin cancers
-common
-increases in incidence with age and UV exposure and radiation
-grows slower than melanoma but faster than BCC and radially
-usually diagnosed before it metastasizes
what is graves disease and what causes the condition?
Hyperthyroidism caused by an immune disorder in which B cells produce antibodies that mimic TSH.
Ordinarily TSH is released from the anterior pituitary in response to TRH from the hyperthalamus. TSH
induces growth of the thyroid gland and the synthesis and release of T3 and T4 which negatively
feedback to decrease the signals of TRH and TSH. The TSH mimicking antibodies are continually
produced but not subject to negative feedback regulation so TRH and TSH are low but T3/T4 and the antibody levels are high.
symptoms present with someone with graves disease
Increased metabolic rate, heat intolerance, weight loss, anxiety and agitation, fine tremor, proptosis
difference between well differentiated tumour versus a poorly-
differentiated tumour?
A well-differentiated tumour = functional tumour derived from endocrine cells cause hormone excess
non functional tumours cause a decrease in hormone production
how does GH excess differ in children v adults
children- growth plates have yet to fuse so we see gigantism
adult- acromegaly by growth of bones in skull, hands, feet and thickening of connective tissue leading to a coarsening of appearance
What is Cushing’s syndrome and how is it caused
caused by excess cortisol or prolonged use of corticosteroids, it includes increased fat
deposition in the trunk & face (moon face); the development of a buffalo hump, muscle atrophy & weakness,osteoporosis, thinning skin & the formation of striae (stretch marks); poor wound healing & increased risk of infections; hyperglycaemia & hypertension; mood changes & depression
caused by
-cortisol
-ACTH secreting tumour
-chronic stress
-inappropriate or excessive use of corticosteroids/glucocorticoids
