11.2 - Alterations of Hormone Regulation Flashcards
Mechanisms of Hormonal Alterations
1) Failure of feedback systems
- signals to increase hormone production fail
2) Dysfunction of endocrine gland
- secretory cells are unable to produce hormones or produce excessive amounts
3) Increased hormone degradation or activation
4) Ectopic hormone release
- hormones are produced by tissues other than endocrine glands
Target Cell failure
- target cells fails to respond to the hormone that is binding due to:
1) decrease in # of receptors
2) impaired receptor function
3) presence of antibodies
- interfere with hormone binding to receptor
4) antibodies can mimic hormones and activate receptor (w/out the hormone)
Diseases of Posterior Pituitary
1) SIADH
2) Diabetes Insipidus
SIADH
- hypersecretion of ADH
- causes excessive water retention
- too much water = not enough Na: hyponatremia
- symptoms of fluid overload: edema, neurological issues (confusion, seizures)
- Serum hypoosmolality: low concentration of solutes in the blood (blood is more dilute)
Diabetes Insipidus
- insufficient ADH
- kidneys do not retain enough water (= dehydration)
- Polyuria: excessive urine output (body is not retaining fluid)
- Polydipsia: extreme thirst (body is getting rid of fluid)
- hypernatremia: not enough water means too much Na
- hyper- osmolality: high concentration of solutes (blood is less dilute/more concentrated)
- bc blood is more concentrated, urine is not concentrated
3 Types of Diabetes Insipidus
1) Neurogenic
- brain does not produce enough ADH due to damage to hypothalmaus
2) Nephrogenic
- kidneys fail to respond to ADH
3) Psychogenic
- excessive water intake can suppress ADH
- causes dilute urine output = mimics DI
Diseases of Anterior Pituitary
1)Hypopituitarism
2) Panhypopituitarism
3) Hyperpituitarism
4) Hyper secretion of growth Hormone
5) Hypersecretion of Prolactin
Hypopituitarism
- anterior pituitary fails to produce ONE of its hormones
Causes
1) Pituitary Infraction - compromised blood supply (ie. hemmorhage, stroke)
2) Head trauma - can disrupt pituitary
- 1 of hormones like: TSH, FSH, ACTH, are not secreted
Panhypopituitarism
- anterior pituitary fails to produce ALL of its hormones
ACTCH deficiency
TSH deficiency - hypothyroidism (thyroid is not being stimulated)
LH and FSH deficiency - hypogonadism: not enough sex hormones being produced
GH deficiency - stunted growth, decreased muscle mass
Symptoms
- wrinkles
- puffy face
- no armpit hair
- pale/yellow skin
Hyperpituitarism
- overproduction of hormones produced by anterior pituitary
- caused by benign tumour (pituitary adenoma)
Symptoms
- hypo secretion of neighbouring hormones (suppresses production of other hormones)
- headache and fatigue - from pressure of tumour
Hyper secretion of Growth Hormone
Causes
1) Acromegaly
- hyper secretion of GH in ADULTHOOD
- since epiphseal plates of bones are closed in adulthood excessive GH does not cause increased height, it abnormal growth of tissue/bones
- symptoms: enlarged nose, lips, and protruding jaw
2) Gigantism
- hyper secretion of GH in childhood
- causes abnormal growth of long bones = increased height
Hypersecretion of Prolactin
- caused by prolactinomas (benign tumour)
Females
↑ prolactin =
- amenorrhea (no period)
- galactorrhea (produces breast milk when not pregnant
- hirsutism - excess hair growth
- osteopenia - decreased bone density
Males
- hypergonadism - decreased testosterone production
- gynecomastia - enlarged breasts
- erectile dysfunction
Alterations of Thyroid function
1) Hyperthyroidism
2) Hypothyroidism
3) Thyroid Carcinoma
Hyperthyroidism
- overactive thyroid gland
- ↑ TH levels
- ↓ TSH levels
- speeds up body’s metabolism
- causes: weight loss, tachycardia, heat intolerance (skinny)
Common Cause:
1) Graves Disease - immune system attacks thyroid
- antibodies stimulate thyroid
Symptom:
- pretibial myxedema (shin swelling)
- large and protruding eyeballs
2) Goitre - enlarged thyroid gland
- caused by nodular thyroid disease
Hypothyroidism
- thyroid does not produce enough thyroid hormone
- slows metabolism
Caused by:
Primary
1) Hashimoto - immune system attacks thyroid
- enlarged thyroid
2) Post-partum - fatigue, hair loss, depression
Congenital (in newborns)
- Results in: thick neck, stunted growth, dry skin, eyes wide apart, PROTRUDING TONGUE
Thyroid Carcinoma
- carcinoma = malignant
- caused by exposure to radiation
- present as lump or nodule
Alterations of Parathyroid Function
1) Hyperparathyroidism
2) Hypoparathyroidism
Hyperparathyroidism
Primary: excess secretion of PTH
Secondary: occurs in response to hypocalcemia
Manifestations
1) Hypercalcemia
- breaks down a lot of bone and releases a lot of Ca in blood
2) Hypercalciuria
- excessive Ca in urine = can cause kidney stones
3) Pathological fractures
- lot of PTH breaks down a lot of the bone
Hypoparathyroidism
- low parathyroid hormone
- caused by damage to parathyroid in surgery
Manifestations
1) Hypo calcemia
- bc PTH breaks down bone to increase Ca on blood
2) Chvostek
- facial twitching caused by tapping the facial nerve
3) Trousseau
- occurs when hand bends inward and hand when the BP cuff is inflated
Alterations of Pancreas
1) Type I Diabetes Mellitus
2) Type II Diabetes Mellitus
3) Other types of diabetes Mellitus
Type I Diabetes Mellitus
- immune system destroys bodys beta cells (which secrete insulin and amylin)
- causes an insulin deficiency
- glucagon levels are high = glucose levels are high (hyperglycemia)
Manifestations
- Polydipsia - extreme thirst
- Polyuria - frequent peeing
- Polyphagia - excessive hunger; cells can not take up glucose (too much glucose in blood)
Type II Diabetes Mellitus
- pancreas produces insulin, but body does not respond properly due to decreased insulin sensitivity
- overtime, beta cells lose ability to produce insulin = deficiency
Symptoms:
- overweight
- neuropathy
Other Types of Diabetes
Gestational Diabetes
- glucose intolerance developed during pregnancy (lot of glucose in blood ad not being used for energy in cells)
Maturity Onset Diabetes of Youth
- mutations affects beta cell function
Complications of Diabetes Mellitus
1) Hypoglycemia - low blood sugar
2) Diabetic Ketoacidosis
- not enough insulin, means the body can not take up glucose in cells
- body breaks down fat for energy
- causes ketone accumulations (fruity breathe)
3) Hyperglycemic Syndrome
Chronic Complications of Diabetes Mellitus
Macro
- CV
- Stroke
Micro
- Retinopathy - blindness
- Nephropathy - kidney damage
- Neuropathy - affects nerves
Infection
- due to poor circulation and
- elevated glucose also makes it difficult to heal
Symptoms of Diabetic Ketoacidosis
- nausea and vomiting
- extreme thirst
- FRUITY BREATH
- feeling weak and tired
- frequently peeing
Alterations of Adrenal Function
1) Disorders of the Adrenal Cortex
2) Hypersecretion of adrenal androgens and estrogens
3) Disorders of the Adrenal Medulla
Disorders of the Adrenal Cortex
- excessive cortisol function
1) Cushings Syndrome
- excessive production of ACTCH (anterior pituitary) = chonic excess cortisol
Symptoms
- fat pad on back
- bruising
- thin arms and legs
- large abdomen (pendulous)
- mood face: weight gain in face and neck
2) Hyperaldosteronism
- excessive production of aldosterone
1. Primary - Conns Syndrome
- ↑ aldosterone =↑ BP
2. Secondary - due to RAAS
3) Adrenocortical Hyperfunction
- not enough cortisol
- Addisons Disease
- damage to adrenal glands that causes insufficient cortisol
- addisons crisis: sudden drop in cortisol = hypotension and hypoglycemia
2. Secondary Hypercortisolism - pituitary glands fail to produce enough ACTH which stimulate adrenal gland to produce cortisol
Hypersecretion of adrenal androgens and estrogens
Feminization
- caused by excess estrogen function
- occurs in males
Symptoms
- short stature
- gynecomastia - breast tissue growth
Virilization
- caused by excess androgen function
- occurs in females
Symptoms
- enlarged clit
- male-patterned growth
- deepened of voice
Disorders of the Adrenal Medulla
- excess catecholamines
1) Adrenal Medulla Hyperfunction
- caused by tumour (pheochromocytoma)
- secretes catecholamines on a continuous basis
Symptoms:
- tachycardia
- hypertension
- anxiety
- panic attacks
