M7: Endo, obesity, nutrition Flashcards
Graves Disease
1 cause of hypothryorid (1.5-2%of females)
autoimmune disease-dev. antibodies
stimulation of the thyroid by autoantibodies directed against the tsh receptor. autoantibodies (thyroid-stimulating immunoglobulins or thyroid stimulating antibodies override the normal regulatory mechanisms.
7x more common in females
DX: radioactive reuptake test
Diffuse reuptake=graves
focal point area-not graves
CM: Exophthalmos: (incr secretion of hyalurinoic acid, orbital fat accum, inflamm, and edema of orbital contents
Pretibial myxedema: dermopathy: thickness/pigment changes, LE edema
TX: antithyroid meds, radioactive iodine, surg. tx: does not reverse infiltrative opthalmopathy or pretibial myxedema
Graves DS (2)
-TSI stimulation of tsh receptors in the gland results in hyperplasia of the gland (goiter) and increased synthesis of TH especially of T3. increased levels of TH result in classic signs and symptoms of hyperthyroidism.
TSH production in pitutiary inhibited through norm neg. feedback loop
Diabetes Insipidus-
ds of posterior pituitary
-Insufficient ADH activity leads to polyuria and polydipsia.
3 forms: neurogenic or central di, nephrogenic di, primary polydipsia or excessive thirst appreciation.
neurogenic or central DI- insufficient secretion of ADH.
-Occurs when any organic lesion of the hypothalamus, pituitary stalk, or posterior pituitary interferes with ADH synthesis, transport, or release.
-Causative lesions include primary brain tumors, TBI, hypophysectomy, aneurysms, thrombosis, infections, and immunological disorders. Genetics.
nephrogenic DI- inadequate response of the renal tubules to ADH.
-caused by disorders and drugs that damage the renal tubules.
-Can include pyelonephritis, amyloidosis, destructive uropathies, and polycystic kidney disease. -Drugs can affect include lithium, colchicine, amphotericin B, loop diuretics, and general anesthesia. Genetics.
Diabetes Insipidus-Primary Polydipsia
ds of posterior pituitary
Primary Polydipsia- rare form of DI-
level of vasopressin-degrading enzyme vasopressinase is increased, resulting in ADH deficiency.
-have a partial to total inability to concentrate urine.
causes large volumes of dilute urine excretion, leading to increased plasma osmolality.
In conscious individuals, the thirst mechanism is stimulated and induces polydipsia; dehydration develops rapidly without ongoing fluid replacement.
-if the individual with di cannot conserve as much water as is lost in the urine, serum hypernatremia and hyperosmolality occur.
Concentrations of other serum electrolytes are generally not affected. Urine output can increase from a normal of 1-2 l/day to 8-12 l a day.
DX; includes polyuria, polydipsia, low urine specific gravity under 1.010, low urine osmolality, hypernatremia, high serum osmolality, and continued diuresis despite a serum sodium level of 145 or greater.
TX: based on the extent of adh deficiency. fluid replacement using oral, or iv routes is adequate. some people require adh replacement with the synthetic vasopressin analog desmopressin (DDVAP)
Cortisol
Stim-ACTH in the adrenal cortex; synthesized from cholesterol, lipid-soluble
Secretion is regulated primarily by the hypothalamus and anterior pituitary gland.
Most POTENT naturally occurring glucocorticoid
needed to maintain life and protect body from stress
-3 factors appear to be primarily involved in regulating the secretion of ACTH: negative feedback effects of high circulating levels of cortisol, diurnal rhythms with peak levels during sleep, and psychological and physiologic stress increase ACTH secretion, leading to increased cortisol levels.
- Functions: Regulates blood sugar, reduces inflammation, controls blood pressure.
- Dysfunction:
Excess cortisol can lead to Cushing’s syndrome; deficiency may result in Addison’s disease.
Chronic steriod use-they have NO Cortisol, be very careful w/ tapering
Aging: clearance of cortisol is decr
Action of Catecholamines (epinepherine and norepinepherine)
Chromaffin cells AKA: pheochromocytes of the adrenal medula secrete epi/norepi; synth from the amino acid PHENYLALANINE
releasing into
FIGHT or FLIGHT mode/Sympathetic
(htn, tachy/arrhymias, vasoconstriction)
EX: adrenal medulla hyperfxn–
PHEOCHROOCYTOMAS
Promote hyperglycemia through interference with the usual glucose regulatory feedback mechanisms.
Clinical Significance: Imbalances can affect stress response, metabolic processes, and cardiovascular health.
Present in BAT (Brown Adipose Tissue) when exposed to cold-activates sympathetic rxn
T3 stim BAT to rapidly generate heat through activation of uncoupling protein 1 (UCP1)=
NON-SHIVERING THERMOGENESIS
Glands - Thyroid verus Parathyroid
- Thyroid Gland: Produces thyroid hormones (T3 and T4) which regulate metabolism. (90/10 ratio)
- parafollicular cells (C cells) secrete calcitonin, which decr CA++ levels
- Parathyroid Gland: Produces parathyroid hormone (PTH) which regulates calcium levels in the blood.
- Dysfunction:
Hyper-/hypothyroidism affects metabolism, while hyper-/hypoparathyroidism impacts calcium balance.
Pancrease gland
Endocrine: produces hormones
Exocrine: digestive enzymes
Houses the Islets of Langerhans
Alpha=glucagon
B=insulin and amylin
D=somatostatin and gastrin
Acromegaly vs Giantism
- Acromegaly: Caused by excess growth hormone (GH) in adulthood, leading to bone thickening and tissue growth.
- Giantism: Occurs in children due to excess GH, resulting in abnormal height and growth.
- Diagnostics: GH and IGF-1 levels, oral glucose tolerance test.
Hormone release
- Mechanism: Typically regulated by the hypothalamic-pituitary axis via releasing and inhibiting hormones.
- Significance: Ensures precise control of hormone levels, affecting growth, metabolism, and homeostasis.
Prolactin vs LH vs FSH
- Prolactin: Stimulates milk production postpartum.
- LH (Luteinizing Hormone): Triggers ovulation and testosterone synthesis.
- FSH (Follicle-Stimulating Hormone): Stimulates ovarian follicle growth in females and spermatogenesis in males.
- Regulation: Controlled by gonadotropin-releasing hormone (GnRH) from the hypothalamus.
Leptin, Adipocytes
- Leptin: A hormone produced by adipocytes (fat cells) that helps to regulate energy balance by inhibiting hunger.
- Significance: Leptin resistance can contribute to obesity and metabolic disorders.
Obesity including complications and risk assessment
- Complications: Increased risk of type 2 diabetes, cardiovascular disease, certain cancers, and musculoskeletal disorders.
- Risk Assessment: BMI measurement, waist circumference, family history, and lifestyle factors.
- Management: Lifestyle modification, medication, possibly surgery.
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Anorexia of aging
- Description: Decreased appetite and food intake in older adults, leading to weight loss and nutritional deficiencies.
- Etiology: Could be related to reduced sense of smell and taste, dental issues, medications, or social factors.
- Clinical Significance: Increases risk of frailty, immune dysfunction, and poor quality of life.
GH and Insulin structures (are they steroids, amines, peptides? etc.)
- Growth Hormone (GH): A peptide hormone that stimulates growth, cell reproduction, and regeneration.
- Insulin: Also a peptide hormone; regulates metabolism by promoting the absorption of glucose from the blood.
- Classification: Neither are steroids or amines; both are peptide hormones with complex protein structures.