Endocrine system Lecture Flashcards
Endocrine regulation
An endocrine gland can be regulated via direct regulation, neuronal control or feedback regulation (slide 3)
What are the anterior pituitary hormones and what are their target organs and actions?
- GH- liver- stimulates IGF-1 production which promotes tissue growth and differention
- inhibits action of insulin on carbs and lipids
- stimulates lipolysis
2. LH and FSH- Repro organs M: -LH- causes leydig cells to make testosterone -FSH- spermatogenesis F: -LH- ovulation -FSH- follicle development
3. ACTH MSH (melanocyte stimulating hormone) Adrenal cortex and melanocytes -stimulates synthesis of glucocorticoids and androgens by adrenal cortex -MSH-melanin synthesis
- Prolactin- mammary glands and repro organs
- promotes secretion of milk
- initiates lactation - TSH
- thyroid gland
- stimulates production of thyroid hormones
- maintains size of follicular cells.
What is the posterior pituitary hormones
target organ
effect
- ADH or vasopressin
- kidney
- promotes insertion of aquaporins into DCT + CD
- decreases H20 excretion
- vasoconstriction
2. Oxytocin Uterus and mammary glands -smooth muscle ocntractions -uterus - labour -lactation- milk ejection.
What are the different types of endocrine disease you can get?
- Hormone excess
- Hormone deficiency
- Hormone hypersensitivity
- failure of inactivation of hormone
- target organ over-active/ hypersensitive - Hormone resistance
- failure of activation hormone
- target organ resistance - Non-functioning tumors
What are the pertinent investigations?
- Adrenal tests
- plasma cortisol
- ACTH stimulation - Thyroid tests:
- TSH
- T3/T4 - Parathyroid tests;
- PTH
- serum calcium
- serum phosphate - Pancreatic tests
- glucose tolerance
- fasting
- postpranial
- HbA1C - Other:
- serum electrolytes
- urinary ketons
- urinary creatinine
List some of the common condition:
- Pituitary
- diabetes Inspidus - Pancreatic dysfunction
- Diabetes Mellitus (t1 and t2) - Adrenal
- cushings syndrome
- hyperaldosteronism (conn’s syndome)
- Addisons
- pheochromocytoma - Thyroid disease
- hypothyroidism (hashimotos)
- hyperthyroidism (graves diseas)
- Thyroid neoplasia - Parathyroid dysfunction
- hyperparathyroidism
- hypoparathyroidism
What are non specific presentations of endocrine disease?
lethargy and depression
- weight gain
- weight loss
- polyuria
- polydipsia (excessive thirst)
- heat intolerance
- palpitations
- headache
- muscle weakness (usually proximally)
- coarsening of features
Diabetes Inspidus (DI definition causes aetiology risk factors Hx/ Ex Investigations managament complications prognosis
Def: inability to concentrate urine so produce large amounts of dilute urine.
causes: Cranial (central)- ADH deficiency
- nephrogenic: unresponsive renal tubules
Atiology:
cranial: headtrauma, surgery, autoimmune, CNS infection, CVA
nephrogenic- medications, genetic defects, chronic kidney disease
risk factors:
Pituitary surgery, tumors in area, lesions of pituitary, trauma to brain, medication, autoimmune disease,
Hx/Ex: polyuria, nocturia, polydipsia (thirst), hypernatraemia (elevated sodium levels in blood), muscle twtiching, visual defects
Investigations:
- increase serum sodium
- decrease urine osmolarity while normal or increase serum osmolarity
- 24hr urine collection (<2lt rules out DI)
- water deprivation test
management:
-must be differentiated from primary poldipsia
-fluid administration
-central (desmopressin)- an analogue of AVP with longer half-life
nephrogenic- fluid intake and treat underlying cause
-low sodium diets.
Complications:
- hypernatraemia
- iatrogenic hypoatraemia
prognosis:
DI is usually a lifelong condition
Diabetes Mellitus What are the abnormalities you see in hands and feet? clinical presentation symptoms management Complications
Chronic hyperglycaemia- can affect every system in the body Type1- insulin deficiency Type 2- insulin deficiency -insulin resistance -both
In a diabetic patient, at every consultation check:
- BP
- eyes
- insulin injection sites
- hands
- feet
Common abnormalities in hand:
- limited joint mobility which is painless, stiffness
- Dupuytrens contracture
- carpal tunnel syndrome
- trigger finger
- muscle wasting/ sensory changes
Common abnormalities in feet:
- discolouration of skin, localised infection, ulcers
- charcot neuroarthropathy
- fungal infection may affect skin between toes, and nails
- arterial insufficiency (diminished pulses)
- stocking and gloves ditribution peripheral polyneuropathy
Clinical presentation: -acute (within weeks) -subacute (months to years) -asymptomatic Symptoms of hyperglycaemia: -polyuria, polydipsiam polyphagia, weight loss, fatigue, lethargy, blurred vision, tingling and numbess in feet, erectile dysfunction, arterial disease, nausea and vomiting, abdominal pain, tachypnoea, skin infections, mood changes
management:
- patient education
- multidisiplinary apprach needed
- In type 1 DM urgent treatment with insulin required
- oral anti-diabtetic drugs
- insulin
complications of DM:
- macrovascular:
- CVD
- CVA
- PVD
- microvascular:
- retinopathy
- neuropathy (peripheral, autonomic)
- nephropathy
- diabetic foot
- infections
- cancers
Difference between type 1 and 2 DM
slide 19
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What is teh criteria for the Dx of DM
- fasting plasma glucose >7mmol/L
- random plasma glucose >11.1mmol
- glucose tolerance test is only required for boarderline cases and diagnosis of gestational diabetes
- HbA1C >6.5
- urine glucose (glycosuria) -not reliable in early stages
- urine ketons (ketonuria)-
Look at the acute effects of Insulin deficiency
22
what are the targets for glucose control?
25
What are the effects of cortisol?
- maintains BP (Na retention and K+ loss)
- decrease bone formation
- anti-inflammatory
- decrease immune function
- inc. gluconeogenesis, lipolysis and proteolysis
Cushings syndrmome Cushings disease vs cushings syndrome? Causes: ACTH dpendant and ACTH dependant Clinical signs and symptoms:
symptoms are a aresult of chronic exposure to excess glucocorticoid. There is large spectrum of symptoms depending on duration and intensity of excess steroid production.
Cushings disease: pituitary dependant cause of Cushings syndorme. A adenoma in the pituitary gland produces ACTH, causing elevated levels of cortisol
Cushing syndrome: ACTH decrease= Cushings syndrome: due to increased -ve feedback of cortisol
Causes:
m. c iatrogenic administration of glucocorticoids
- seconly: adenoma produces ACTH. or ACTH tumor and tumors from other areas.
ACTH depenent (ianotropic)
- normal or elevated levels of ACTH
- bilateral adrenocortucal hyperplasia
- increased cortisol
- inhibited hypothalmic (corticotropic releasing hormone)
ACTH dependant tumor
- increased cortisol secretion (due to adenoma, carcinoma or any primary issues inside the adrenal gland.
- suppressed CRH and ACTH.
clinical signs and symptoms: Progressive centripetal obesity (moon face, neck, trunk and abdomen), buffalo hump. -waisted extremities Dermatologic manifestations: -skin atrophy -easily bruised -fragile skin stretch (purple) -fungal infections -hyperpigmentation
Menstural irregularities Signs of adrenal androgen excess -hirsutism --oily facial skin (Acne) -increased libido -virilisation (balding, deep voice etc)
Bone changes:
- bone loss
- vertebral compression
- rib and long bone fractures
- LBP
Other:
- glucose intolerance(gluconeogenesis)
- HTN, CV and thromboembolic events
