Chapter 19 - Alterations in Hormonal Regulation Flashcards
Abnormal secretion of ADH is a disorder of the ___________ gland
posterior pituitary
ADH is aka ___________
vasopressin, hormone that signals water reabsorption
Reduced ADH secretion leads to water __________ and ECF ____________
secretion; hyperosmolarity
Excess ADH secretion leads to water ________ and ECF _____________
reabsorption; hypo-osmolarity
Disease of the posterior pituitary can also lead to insufficient hormonal _______ proteins in plasma
carrier
What does SIADH stand for?
syndrome of inappropriate (EXCESSIVE) antidiuretic hormone
When does SIADH occur?
when high ADH levels are present in the absence of normal stimuli for its release
SIADH can be caused by: (3)
-ectopic ADH secretion via tumour
-surgery
-medications
Cancers of the _______, duodenum, and ______ as well as lymphomas and sarcomas can lead to SIADH
stomach; pancreas
SIADH can be caused by CNS disorders such as: (2)
encephalitis and meningitis
Surgery can result in increased ADH for __-__ days
5-7
Why does surgery lead to SIADH?
fluid and volume changes occur after surgery
How is ADH released following pituitary surgery?
unregulated
____________ medications for diabetes mellitus, along with opioids, antidepressants, and anti___________ may lead to SIADH
Hypo-glycemic; inflammatories
SIADH’s key feature is increased water ________ by the kidneys to the peritubular capillaries
reabsorption
Increased ADH secretion leads to an increase in which protein being inserted into the luminal membrane?
water channel proteins
Na+ = H20 is _______ osmolarity
normal
more Na+ than H20 = _____osmolarity
hyper
less Na+ than H2- = ______-osmolarity
hypo
Hyponatremia causes the symptoms of _______-
SIADH
Hyponatremia occurs when _____ in the blood is low
Na+
The effects of SIADH depend on how fast and ________ onset is
severe
What is a normal serum sodium level?
140-130 mmol/L
What serum sodium level signifies vomiting, abdominal cramps, and weight gain?
130-120 mmol/L
What serum sodium level involves confusion, lethargy, muscle twitches, and convulsions?
below 110 mmol/L
Correction of hyponatremia…
resolves symptoms
Diabetes insipidus is an ______ insufficiency
ADH
DI leads to polyuria and poly______
polydipsia
Polyuria
frequent urination
Polydipsia
frequent drinking
DI can be _______ (central) or nephrogenic
neurogenic
Neurogenic DI is caused by: insufficient ____ secretion, lesions on the ________, interference with ADH transport/________, brain tumours, aneurysms, TBI
ADH; hypothalamus; release
Nephrogenic DI can be ________ or genetic
acquired
Acquired DI is related to medication disorders that damage ______ ______
renal tubules
What are the two disorders that cause acquired DI?
-pyelonephritis
-polycystic kidney disease
Pyelonephritis
urinary tract infection
Polycystic Kidney Disease
genetic disorder that causes many fluid-filled cysts to grow in your kidneys
Genetic DI occurs from a mutation of the gene coding for _________-__
aquaporon-2 (water channel)
DI associated with pregnancy is ______
rare
Gestational DI involves an increase in ____________
vasopressinase (vasopressin-degrading enzyme)
Gestational DI is usually ______ and doesn’t require treatment
mild
DI leads to a large volume of ________ urine
dilute
DI _________ plasma osmolarity
increases
What are the clinical signs of DI?
-polyuria
-nocturia (waking at night to pee)
-polydipsia
What is a normal urinary output?
1-2 L/day
DI can cause urine output to be as high as __-___ L/day (may be higher than daily fluid intake!)
8-12
Longstanding DI leads to an enlarged _______ _______ and hydronephrosis
bladder capacity
Hydronephrosis
swelling of one or both kidneys
Neurogenic DI has a _______ onset
sudden
Nephrogenic DI has a ________ onset
gradual
How is DI diagnosed?
-dilute urine
-hyperosmolarity
-hypernatremia
Continued diuresis despite high serum osmolarity is abnormal because normally there is only extra urine when….
the body needs to get rid of something
How is DI treated?
-ADH replacement
-oral/intravenous fluid replacement
-reversing aquaporing-2 dysfunction (new!)
-medications that increase ADH (carbamazepine/Tegretol)
Primary thyroid disorder is due to dysfunction of the…
thyroid gland
Secondary thyroid disorder is due to dysfunction of the…
pituitary gland or hypothalamus
What is subclinical thyroid disease?
thyroid disease with no symptoms but abnormal lab values
Thyrotoxicosis
a condition resulting from any cause of increased thyroid levels
Hyperthyroidism
excess secretion of thyroid hormone from the thyroid gland
Graves disease and toxica mutinodular goiter are _____thyroid diseases
hyper
Thyrotoxicosis symptoms are caused by the metabolic effects of increased serum _______ _______
thyroid hormones
Increased metabolic rate leads to _______ heat INtolerance and increased tissue sensitivity to __________ stimulation
increased; sympathetic
Periorbital edema, smaller thyroid, bradycardia, constipation, and edema of the extremeties are symptoms of…
hypothyroidism
Periorbital edema
swelling around the eyes
Exophthalmos, elarged thyroid, tachycardia, diarrhea, and pretibial edema are symptoms of…
hyperthyroidism
Exophthalmos
bulging, protruding eyeballs
Pretibial Edema
anterior skin lesions of tibial region
___________ is the underlying cause of up to 80% of hyperthyroidism
Graves’ disease
Graves’ disease is more common in ________
women
Graves’ disease is an ____________ disorder with an unknown (but likely genetic) cause
autoimmune
With Graves’ disease, autoantibodies called ________________ (TSIs) override normal mechanisms
thyroid-stimulating immunogolbulins
TSI leads to _________ of the thyroid gland and increased secretion of TH (especially ____!)
hyperplasia; T3
TSI accounts for abnormalities of the __________ NS and ________ muscles
sympathetic; orbital
Diplopia (_______ vision) and decreased acuity also results from Graves’
double
Pretibial Myxedema: subcutaneous swelling of anterior portion of the legs from recruited __ cells which stimulate _____ acid production
T; hyaluronic
Where is hyaluronic acid naturally found?
eyes and joints
Normally after enlarging to respond to TH demand, the thyroid…
returns to normal size
Nodular thyroid disease causes irreversible changes in _______ cells causing them to produce excess TH
follicular
Thyroid multinodular goitre results from…
enlarged cells from an increased TH output
Thyrotoxic crisis is aka…
the thyroid storm
Death can occur within ___ hours without treatment with a thyrotoxic crisis
24
Thyrotoxic Crisis may result from:
-Graves’ disease (esp. those subject to infection, pulmonary, or CV) disorder
-Thyroid surgery
Which type (primary or central) accounts for most cases of hypothyroidism?
primary
Which type (primary or central) is related to pituitary or hypothalamic failure?
central aka secondary
What are 2 alternative names for autoimmune thyroiditis?
-Hashimoto’s disease
-Chronic Lymphocytic Thyroiditis
What is the most common cause of primary hypothyroidism in Canada?
autoimmune thyroiditis
What causes autoimmune thyroiditis?
auto-reactive T cells, NK cells and induction of apoptosis
Congenital hypothyroidism occurs when a) thyroid tissue is _____ or with b) ___ synthesis defects
absent; TH
How long is the fetus dependent on maternal T4?
first 20 weeks of gestation
Insufficient T4 from mom to baby may lead to _______ defects
cognitive
Symptoms of Congenital Hypothyroidism:
-high birth weight
-hypothermia
-neonatal jaundice
-difficulty eating
-horse cry
-protruding tongue
-excessive sleeping
An examination of ______________ tells about T4 and TSH levels
umbilical cord
___________ treatment will lead to normal growth and intellectual function if administered before 4 months of age
levothyroxine
Without screening, congenital hypothyroidism may be difficult to determine before ___ months
4
What is the most common pediatric chronic disease?
Type I Diabetes Mellitus
___% of Canadians have type I diabetes mellitus
10
Type I DM has a strong ______ link
genetic (can also be due to medications or virus)
Is T1D fast or slow progressing?
slow
T1D is an _________ __-cell-mediated disease
autoimmune T-cell
What cells do the T1D T cells destroy?
pancreatic
Where do T1D autoantigens express?
pancreatic beta cells
Autoantigens detach and circulate to activate __-________ cells and macrophages to produce ________
T-cytotoxic; autoantibodies
Autoantibodie production destroys beta cells and reduces ________ secretions
insulin
Hyperglycemia results from insulin declining from __-__% of beta cells are destroyed
80-90%
Why does T1D have glucose in urine?
glucose builds up in the blood and must be eliminated
Diuresis is a T1D symptoms because…
there is a dramatic increase in thirst
Diuresis
excessive urination
Diabetic Ketoacidosis (life-threatening)
when proteins and fat are utilized due to insulin deficiency and cause high levels of circulating ketones
Type II Diabetes Mellitus accounts for ___% of all diabetes in Canada
90
What are the risk factors for T2D?
-age
-obesity
-hypertension
-physical activity
-family history
T2D is linked to more than ___ genes that code for beta cell mass and functionality
60
T2D results from insulin resistance and…
decreased insulin secretion by beta cells
T2D is a _____-_______ response of insulin sensitive tissue
sub-optimal
What are some examples of insulin sensitive tissue?
liver, muscle, adipose tissue
The sub-optimal response of these tissues leads to insulin ____________
resistance
Insulin Resistance
cell dysfunction of insulin receptors
With T2D, ________ results in increased serum levels of ________ and decreased levels of _________
obesity; leptin; adiponectin
With T2D, elevated levels of serum ____-____-acids lead to intracellular deposits of _____________ which decrease tissue response to insulin and lead to insulin resistance
free-fatty; triglycerides
T2D - obesity is linked to ______insulinemia and decreased insulin receptor ________
hyper; density
What is the effect of T2D?
beta-cell exhaustion - a decrease in beta cell mass and dysfunction
Cushing’s syndrome occurs from chronic exposure to excess ________
cortisol
Cushing’s disease results from excess ______ secretion or an ectopic-secreting ______________ tumour
ACTH; nonpituitary
With hypercortisolism, normal dinural secretion patterns of ______ and _______ are lost and there is no increased ACTH or cortisol secretion in response to stress
ACTCH and cortisol
Hypercortisolism results in _______ ACTH secretion with no _________________ control
excess; negative-feedback
Cushing’s Disease Manifestations
-weight gain
-cravings
-increased glucose release
-osteoporosis
-muscle wasting
-vertebral compression fractures
-kyphosis
-reduced height
-stretched skin
-immunosuppression
With Cushing’s disease, where does the weight gain occur?
-face
-trunk
-buffalo hump (upper back/neck area)
Why do cravings happen with Cushing’s?
to increase fats and carbs available for fuel
Why does Cushing’s involve glucose intolerance?
because of cortisol-induced insulin resistance
What leads to osteoporosis?
reabsorption of bone components
What leads to muscle wasting?
cortisol promotes protein breakdown for amino acid release
Kyphosis
outward curvature of the spine “humpback”
What leads to stretched skin?
weakened integumentary tissue
