Modules 3.1-3.3 Flashcards
What is the definition of hypo-secretion and causes?
- hormone deficient state, can occur due to glandular tissue inability to synthesize hormones or injured tissue
- tumour, infection, chronic inflammation are causes
What is the definition of hyper-secretion and examples?
- Over-excretion of hormones
Ectopic hormone production: another tissue is able to secrete hormone
Endocrine gland hypertrophy: overstimulated by pituitary gland that creates enlargement
Impaired negative feedback: impairment in feedback causing increased blood hormone levels
Medication induced
What is target tissue responsiveness?
- is the number/sensitivity of receptors, can increase or decrease depending on hormone secretion levels
What are ways to diagnose endocrine dysfunction?
- Basal hormone levels (blood or urine sample)
- Dynamic endocrine test
- CT, MRI, US
- Physical examination
What is a dynamic endocrine test?
- based on the feedback loop of hormones to monitor amount and effectiveness of hormones
- stimulatory test is when hypo. is suspected
- suppression test is when hyper. is suspected and needs to be differentiated from a tumour
What is the treatment for hyposecretion?
- hormone replacement therapy for deficient hormone (animal and human based)
- enhancing sensitivity of tissue for poor tissue responsiveness (metformin)
What is the treatment for hypersecretion?
- drug treatment to prevent hormone stimulation
- Surgical removal/chemical ablation of effected gland
What does the disruption of the hypothalamic-pituitary axis cause?
- Body growth, metabolic and mood disorders due to inc. cortisol in body
- HPA is a commuincation pathway to maintain hormone and stress levels
What is Growth hormone (GH)?
- GH promotes normal cell growth
- stimulates protein synthesis by acting as an anabolic agent
- inc. BGL through anti-insulin activity and affecting IGF-1
What are the effects of hyper/hyposecretion on GH?
Hypo: impaired GH secretion, causes pituitary dwarfism
Hyper: excessive GH secretion, causes acromegaly (adults) and gigantism (children)
What is anti-diuretic hormone (ADH)?
- facilitates water resorption from renal system into blood
- helps balance fluid levels
What are the effects of hyper/hyposecretion on ADH?
Hypo: inability to concentration urine and major water loss from body, diabetes insipidus (DI).
- caused by neurogenic (head trauma) or nephrogenic (renal tubules unresponsive)
Hyper: excessive water resorption (SIADHS)
- caused by stress or ectopic causes (tumour)
What is Goitre and the different types?
Enlargement of the thyroid gland
Non-toxic: enlarged but no CM
Toxic: CM of thyroid dysfunction present
Diffuse: whole gland is enlarged
Nodular: 1+ parts of gland are enlarged
What are examples of hypothyroidism (insufficient T3 & T4 secretion)?
Hashimoto thyroiditis: AI disorder that destroys gland overtime
Myxoedema: non-pitting oedema, can evolve into a coma
Cretinism: due to congenital hypothyroidism, gland may be non-functional or absent
What are examples of hyperthyroidism (excessive T3 & T4 secretion)?
Grave’s disease: AI disorder than cannot control secretion, causes optic nerve damage, hypermetabolic state
Thyrotoxic crisis: uncontrolled hyperthyroidism, can be fatal
WHat gland do addison’s and cushings’ disease affect?
Adrenal gland, affects the hormone cortisol
What is Addison’s disease? (CM, treatment)
- Hypocortisolism
CM: fatigue, Weight loss, hyperpigmentation salt craving
low BGL - Addison’s crisis can be fatal (tachypnoea/cardia)
- Treatment is corticosteroids and IV fluids
What is Cushing’s syndrome and the causes?
- Hypercortisolism
- Pituitary or adrenal tumour, causing inc. ACTH release, which triggers cortisol release
- Prolonged corticosteroid treatment
What are symptoms and treatment of Cushing’s syndrome?
- weight gain, muscle weakness, HTN and hyperglycaemia, thin skin
- Measuring cortisol levels in blood is diagnosis
- Surgical removal, radiation and medications to control cortisol production
What are the 3 types of diabetes?
Type 1: hormone hyposecretion due to extensive pancreatic beta islet cell damage
Type 2: hormone insensitivity, insulin that is released is dysfunctional
Gestational: elevated BGL during pregnancy
What is the pathophys. of T1DM?
- Beta cell destruction due to antibody production
- Insulin production decreases, hypergly.
- Body compensates for beta cell loss until 80-90% are destroyed, and CM appear
- genetic, 5-10% of all cases
What is the pathophys. of T2DM?
- dec. no. of of insulin receptors on beta cells or/and dysfunction in intracellular signalling
- body compensates by overproduction of insulin initially
- eventually beta cells cannot sustain hyperinsulinaemia leading to beta cell exhaustion
- BGL rises, causing hypergly.
- lifestyle, 90-95% of cases
What is the pathophys. of gestational DM?
- insulin resistance due to inc. levels of GH and placental hormones
- beta cells cannot compensate an inc. in insulin, leading to maternal hyperglycaemia
- can predispose foetus to T2DM, enhances growth factors of foetus
What are complications of hypoglycaemia?
- due to lifestyle imbalances (diet, medications)
- can lead to brain dysfunction due to glucose imbalance, which triggers SNS activation
- pale, clammy skin, seizures, headaches
What are complications of diabetic ketoacidosis (DKA)?
- due to insufficient insulin, high BGL and mobilisation of lipids, due to infection, stress or poor BGL management, T1DM
- dehydration
- ketoacidosis (kussmaul breaths)
- metabolic acidosis (decreased serum ph and H2CO3)
- electrolyte imbalances (abdo cramps, lethargy)
What is Hyperosmolar Hyperglycaemic Non-ketotic Coma?
- due to excess sugar consumption therefore excess insulin production
- hyperglycaemia and dehydration develop because of the relative insulin deficit, but there is sufficient insulin to prevent DKA
