Wrap Up with Endocrine System
Notes on a few figures…
♦ Figure 16-3
♦ Fig. 16-4
♦ Fig. 16-8
♦ Fig. 16-9
♦ Fig. 16-11
♦ Figures like 16-13
♦ Iodine (as iodide) is critical for thyroid hormone production
Disorders…
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Pancreas
Diabetes
♦ Type I
• Begins in children & young adults
• Insulin production is low
• Β-cells are poorly developed/malfunction
♦ Type II
• Most common
• Hereditary disorder
• Faulty hormone receptors
• Insulin production is normal, BUT insulin sensation/reception at
the cell is faulty
In
both cases sugar levels are too HIGH
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Effect of High Sugar in the blood
Can lead to kidney disorder, altered blood composition
Sugar is not getting to cells
Therefore cells begin using other sources of energy
♦ Energy sources such as fats and amino acids
Too much storage breakdown =
♦ ketone production
♦ Acidic chemical byproducts
♦ pH of body fluids decreases
♦ Electrolytes are disrupted
♦ = Acetone breath
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Diabetes symptoms
Acetone breath
Classic symptoms of diabetes = 3 Ps
♦ Polyuria, polydipsia, polyphagia
Polyuria
♦ High urine output
♦ kidney filtrate has high sugar, so more water diffuses out
Polydipsia
♦ Water loss leads to dehydration
Polyphagia
♦ Excessive hunger because glucose does not enter cells
♦ Leads to weight gain
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No real cure, only precaution & treatment
Type I – low insulin
♦ Treatment: Insulin shots
♦ BUT shots must be monitored closely
♦ Insulin allows glucose to enter body tissues, except brain
tissues (brain has a different mechanism)
♦ High insulin – drains sugar from the brain
• This leads to HYPOGLYCEMIA, can lead to a coma
♦ Other precautions =
• Reduced sugar diet
• No food with insulin
• Balanced exercise regimen
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◦ Too much exercise increases insulin effect on cells & deprives the
brain
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No real cure, only precaution & treatment
Type II – insulin is not the problem
Need drugs to increase sensitivity of cells to insulin
♦ Sulfonylureas
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No real cure, only precaution & treatment
Gestational diabetes
♦ Develops in some pregnant women
• Temporary condition of diabetes
• Placental hormone affects insulin levels
• ↑ placental hormone, ↓ insulin = diabetes
♦ Treatment = insulin shots
• Does not affect fetus because it can’t cross the placenta
♦ If untreated
• Glucose enters fetus blood stream → fetus begins to produce
excess insulin → excess sugar becomes fat → affects
development
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Thyroid
Hyperthyroidism (Grave’s disease)
♦ Excessive thyroid hormone (thyroxine)
♦ High metabolism:
• Weight loss
• High heart rate
• High heat production
• Muscle weakness
♦ Treatment
• Inhibitory drugs
• Destroy part of thyroid gland with radioactive iodine
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Thyroid
Hypothyroidism
♦ Underproduction of thryoid hormone
♦ Low metabolism
• Lethargic
• Cold all the time
• Weight gain
♦ Cause
• Typically – emotional stress
♦ Treatment
• Hormone replacement therapy
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Thyroid
Myxedema
♦ Immune disorder
♦ Antibodies attack thyroid
♦ Inhibits T3 & T4 production
♦ Symptoms – similar to hypothyroidism
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Adrenal gland
Cushing’s syndrome
♦ Excessive glucocorticoids
• Promotes glucose storage
• Less glucose available for energy
• Muscle weakness
• Consumption and redistribution of fats (b/c they are being
expended)
♦ Cause:
• Could be too much ACTH (due to a tumor in the pituitary)
• Could be tumor in adrenal gland (increase hormone production)
♦ Treatment
• Remove pituitary (if 1st one above) – need major hormone
replacement therapy
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♦ Demo in lab – has personal story
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Adrenal gland
Conn’s syndrome
♦ Excessive aldosterone
• High Na+ retention with K+ elimination
• High BP
• Less K+ affects muscle and heme function
• Excessive urination
• Excessive aldosterone in blood (can be measured)
♦ Cause
• Tumor in adrenal glands
♦ Treatment
• Remove tumor and/or treat with drugs
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Pituitary Gland
LARGE role in homeostasis
Disturbances = disorders
Growth Hormone –
♦ Normal functions
• Bone growth epiphysis elongation until meets with diaphysis
• Muscle mass increase
• Both roles are essential in children
♦ GH levels are high during development
♦ GHRH is high
♦ As an adult – somatostatin is released – this limits growth
♦ GH helps maintain normal body in adults
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Pituitary Gland
Growth Hormone –
IF GH levels increase after bone growth is completed
♦ AGROMEGALY
• Overgrowth in middle age
• Distinct changes in:
◦ Hands & feet, lower jaw, enlarged organs, skin changes
◦ Disproportional changes – not in other areas/organs
♦ Causes
• Pituitary tumor = adenoma (term for it)
♦ Treatment
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• Removal of tumor – surgery
• Drugs to suppress GH – like somatostatin
• Example = Somavert
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Pituitary Gland
Growth Hormone –
IF GH levels surge during childhood
♦ =gigantism
♦ Most often due to pituitary turmor
♦ Not disproportional growth like agromegaly
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Pituitary Gland
Low levels of GH
♦ = Pituitary dwarfism
♦ Not disproportional like achondroplasia (genetic disorder)
♦ Sometimes caused by no response to GH
• African pygmies = genetic
♦ Rare disease – occurs in children
♦ Causes
• could be a tumor
• Emotional deprivation may stop GHRH – that can be reversed
♦ Treament
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• Hormone replacement therapy
• Tried an animal form of GH = no effect, need human – so now
they use synthetic human GH
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Pituitary Gland
Multiple pituitary hormones can be affected at once to
lead to disorders/by tumors
This leads to more serious problems
Often Reproductive problems associated with pituitary
problems
Other disorders covered in handout or on other
endocrine slide show (the one I did in lab) are also fair
game for the lecture test
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