Pathophysiology Final Exam Review

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PathophysiologyFinalExam b b




Review b




Hypopituitarism
Etiology o Congenital, geneticdisease
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o Destruction of the gland (surgery/ radiation) b b b b b



o Tumor/ mass lesions o Pituitary infection b b b b b



o Deficiency of hypothalamic hormones b b b




Disorders of the posterior pituitary
b b b b



ADH
• ADH: peptide synthesized by cells in the hypothalamus -> transported along a neural
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pathway -> store in pituitary
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• Nerve impulses causes stored ADH to be released into circulation based on serum
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osmolality (so based on what your body needs) o Too much concentration – you
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hold pee to balance
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▪ Very sweet juice, you dilute it with water so you hold it in o Too little
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concentration- you let it out
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▪ Unsweetened juice, you pee it out to make it sweet b b b b b b b b b




Exerts effects on tubular cells of the kidney to cause reabsorption of water
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bOsmolality is how concentrated or diluted the serum is
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Sensitive changes in blood pressure and can lead to the release of ADH
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Abnormal synthesis of ADH because of trauma, stress, severe pain, nausea and certain
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medications
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You can check for osmolality on a blood test
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b Usually 280-310 osm/L b b




Isotonic – 300 b b



Lactate ringers, normal saline 0.9%
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bHypertonic – above 300 b b b




Hypotonic- less than 300 b b b




Trigger is higher the osmolality the higher the concentration
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Secretes ADH and ADH vasoconstricts and keeps fluid on board
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b Comes from posterior pituitary b b b




SIADH vs DI b b




Diabetes insipidus b SIADH
(syndrome b of b inappropriate b ADH)
b Insipidus –no b
Super b increased b ADH


b flavor

ADH (regulates H2O) and
b b b Deficiency Excessive secretion b

vasoconstriction
b




Serum osmolalityb ↑blood very concentrated b b ↓blood very diluted
b b




Urine osmolality
b ↓ ↑

Urine outputb High urine output b b Low urine output
b b


(diluted) b5-24 bL bper bday




Fluid volume status
b b Deficit Overload

Sodium level b Hypernatremia Hyponatremia


• Diabetes insipidus is a disorder of the posterior lobe of the pituitary
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• Vasodepressor
• Diabetes insipidus are unable to concentrate their urine and excretes large volumes of
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burine o CNS component to it because of something in the ADH ex: head trauma,
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bsurgery
• When kidneys don’t respond to ADH
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• Drugs that cause DI- electrolyte disorders…
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• We can evaluate antidiuretic hormone levels along with osmolality of the urine
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• If you can’t excrete urine it stays in the tissue o Polyuria: lots of urine o Sodium is low
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bbecause there is a lot of fluid o Syndrome of ADH is a result of brain tumors
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• Brain tumors can start secreting hormones
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o -surgery o b b



-temperature changes b




Disorders of the thyroid b b b



• Thyroid releases T3 and T4 b b b b

, 3




•• Both are carried by binding proteins
T3 stimulates metabolism
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• T4 is inactive until converted into T3 in the tissues o Needs iodine to activate
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• Both exert negative feedback on the hypothalamus
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• Located in the larynx b b b


• TSH is very important in hypo and hyperthyroidism and how we measure thyroid
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function
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Actions of the thyroid hormone
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• Most major organs are affected by altered levels of thyroid hormone
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o Metabolic rate b



▪ Glucose, fat, and protein usage b b b b



▪ Lipids mobilized from adipose tissue
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▪ Catabolism of cholesterol by the liver b b b b b



▪ Muscle protein is broken down and used as fuel o Cardiovascular function
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▪ Increase in oxygen consumption b b b



▪ Increase in vasodilation b b



▪ Increase in heart rate and contractility, BP
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▪ Tachycardia o GI function b b b



▪ Absorption is increased b b



▪ GI secretions
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▪ Hungry
▪ Hyperactive bowel sounds o Neuromuscular effects b b b b b



▪ React more vigorouslyb b


• Hypereflexsive

Clinical manifestations
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• Metabolic rate o Basal metabolic rate can increase by 60-100% above normal
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with the large amounts of T4 are present o Increase use of protein, glucose and
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fat
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, 4
lOMoAR b cPSD|



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Muscle proteins broken down and used as fuel b b b b b b b



o Changes in cholesterol b b



• Cardiovascular function o With increase metabolism= rise in oxygen
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consumption, production of end products
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o Vasodilation
o Increase blood volume, cardiac output, HR and contractilityb b b b b b b



• GI Function
b



o Increase in motility and production of GI secretions (diarrhea) o Increase in
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appetite o Weight loss
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• Neuromuscular effects o Changes in skeletal muscle reaction b b b b b b b



▪ Hyperthyroid: fine muscle tremor, extreme nervousness, anxiety b b b b b b



▪ Increased HR, palpitations b b




Diagnostics
• T3
o Low in primary hypothyroidism b b b



• T4
o Measures unbound portion (produces effects) o Free T4 decreased in primary
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hyperthyroidism
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• TSH
o Differentiates between primary and secondary thyroid disorders b b b b b b



• Radioiodine uptake test b b



• Ultrasound o Cysts or lesions b b b b



• CT/MRI
• Needle biopsy o Done with guided ultrasound
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□ Will tell if benign or malignantb b b b b b




We really look at TSH and is important in the negative feedback loop
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Hypothyroidism is elevated TSH because it keeps sending the signal to increase T3 and T4
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We monitor medication therapy through this
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TSH increased, T3 and T4 decreased
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Hyperthyroidism
• Excessively high levels of circulating thyroid hormone
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• Common causes o Graves disease
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▪ Enlarged thyroid b