Chemistry Exam 2 Flashcards
Half-life of Steroids
Hours
Half-life of Protein Hormones
Minutes
Steroid hormones are made from
cholesterol
Master Gland of the Endocrine System
Hypothalamus
The Pineal Gland produces
melatonin from serotonin
1° Disorder
Organ doesn’t respond
2° Disorder
Pituitary doesn’t make stimulating hormone
3° Disorder
Hypothalmus doesn’t produce releasing hormone
Anterior Pituitary produces
- TSH
- ACTH
- Prolactin (PL)
- FSH/LH
- Growth Hormone (GH)
GH production is triggered by
Growth Hormone Releasing Hormone
Negative Feedback of GH is mediated by
Somatostatin
Effects of GH
- Fat cell breakdown
- Protein anabolism
- Inc. blood glucose
- Liver makes IGF-1
Effects of overproduction of GH
Before Puberty: giantism
After Puberty: acromegaly
Effects of underproduction of GH
Pituitary Dwarfism
Prolactin
- associated with milk production
- tumors that make prolactin can cause men to produce milk
Posterior Pituitary produces
- Oxytocin
- ADH
Parts of the Adrenal Gland
Cortex, subdivided into:
- Zona glommerulosa
- Zona fasciculata
- Zona reticularis
Medula
Zona glomerulosa produces
Aldosterone and other mineral corticoids
Zona fasciculata produces
Cortisol and other glucocorticoids
Zona reticularis produces
Sex hormones
Adrenal Medulla produces
Catecholamines:
- “Fight or Flight” hormones - epinephrine and norepinephrine
- Dopamine
Hirsutism
excess facial hair (especially notable in women)
Cushing’s Syndrome etiology
Excess adrenal hormones from adrenal tumor or exogenous cortisol
Cushing’s Disease etiology
- more severe than syndrome
- excess adrenal hormones from pituitary tumor
Adrenal diabetes
- Cushing’s syndrome causes high blood glucose, causes long-term burn out of insulin-producing cells
- Diabetes insipidus progresses to diabetes mellitus
Symptoms of Cushing’s
- inc cortisol with no diurnal variation
- inc blood gluc
- inc aldosterone
- inc Na+, dec K+
- acidosis
- physical symptoms (moon face, striae, buffalo hump)
Addison’s Disease etiology
Low adrenal hormones
Symptoms of Addison’s
- dec blood gluc
- dec Na+, inc K+
- acidosis
- physical symptoms (very thin, darkening of skin an mucus membranes)
Dopamine is made from/in
Tyrosine, Adrenal Medulla
Adrenal Liver Metabolites
- Metanephrine (from epinephrine)
- Normetanephrine (from norepinephrine)
Adrenal Urinary Metabolites
- HVA (from dopamine)
- VMA (from metanephrine)
Neuroblastoma
- undifferentiated tumor
- all catecholamines increased
Pheochromocytoma
- differentiated tumor of the adrenal medulla
- increased norepinephrine and epinephrine
- increased liver metabolites and VMA
- NORMAL HVA and dopamine
CaPO4
Hydroxyapatite
Physiologically active Calcium
Ca2+
Elevated Mg
- Mg intoxication
- Renal failure
Low Mg
- Low intake or absorption
- Excess renal loss
Parathyroids produce
Parathyroid Hormone (PTH)
PTH stimulates
Calcium and Phosphorus from bones to blood
Calcitonin stimulates
Calcium and Phosphorus from blood to bones
Calcitonin is produced by
C-cells of the thyroid
Normal ratio of calcium to phosphorus
2:1
Osteoclasts
involved in bone resorption
Osteoblasts
involved in bone formation
Vitamin D
- steroid made from cholestrol
- inc. absorption of calcium and phosphate in GI
- inc calcium reabsorption and phosphate excretion in kidneys
Active form of Vitamin D
1,25 Hydroxy Vitamin D
Paget’s Disease
- excess activity of osteoclasts and osteoblasts degrades bones in some areas and deposits them irregularly in others
- Inc. Alkaline Phosphatase
EGTA
Chelates calcium
Total Calcium Assay methodology
- Calcium complexes with o-CPC dye
- interference removed with 8-hydroxy quinoline
Ionized Calcium Assay methodology
Ion-selective electrode
Ionized Calcium calculation
Ca++ = (6x total Ca - 1/3 total protein) / total protein + 6
Phosphorus Assay methodology
ion complex with molybdate, then reduced with cupric acid to make Molybdenum Blue
Magnesium Assay methodology
- Magnesium binds dye (blue -> red)
- interference removed with cyanide
Thyroid hormones are built from
Mono- and di-iodated tyrosine (MIT and DIT)
T3 is made from
MIT + DIT (3 iodines)
T4 is made from
DIT + DIT (4 iodines)
T3 vs T4
- 10x as much T4 made
- T3 is 5x as biologically active
Reverse t3 (rT3)
- liver deactivates T4 (remove an iodine)
- not biologically active
- related to energy conservation (inc in severe illness)
How do thyroid hormones circulate in the body?
Bound to proteins, especially Thyroid Binding Globulin (TBG). Inactive in this state.
Normal % free T4 (fT4)
0.03%
Normal % free T3 (fT3)
0.3%
Most common Thyroid Antibodies
- Thyroid Peroxidase (TPO) Antibodies
- Anti-thyroglobulin
- Anti-TSH Receptor
Hashimoto’s Thyroiditis almost always has what antibody?
TPOa
Grave’s Disease almost always has what antibody?
Anti-TSH Receptor
Papillary carcinoma
Hypothyroid neoplasm - firm, solitary nodule
Follicular carcinoma
Hypothyroid neoplasm - can metastasize
Primary Congenital Hypothyroidism
- Creatinism
- Deficiency of thyroid tissue in newborns
- Treat with T3 and T4
Thyrotoxicosis
- Inc in free and total thyroid hormones
Hypothyroidism
- slow metabolism
- cold intolerance
- goiter (inflammation)
- tissue thickening (skin, tongue, vocal cords)
Hyperthyroidism
- metabolism in overdrive
- heat intolerance
- goiter (excess thyroid tissue)
- Exophthalmos (eyelid retraction)
Latrogenic hyperthyroidism
- Lab numbers look bad, but no symptoms
Thyroid Storm
- acute hyperthyroidism
- tachycardia, heart failure, fever, vomiting
- 70-80% fatal if untreated
Hashimoto’s: hypo or hyper?
Hypothyroidism
Grave’s: hypo or hyper?
Hyperthyroidism
Euthyroid Syndromes
Thyroid function tests are abnormal in seriously ill patients, but there is no thyroid condition (the body is coping with their illness)
Estrogen effect on TBG
Inc TBG, T4 inc, normal fT3 and fT4
Aldose
carbohydrate with 1 aldehyde
Ketose
carbohydrate with 1 ketone
Monosaccharide
Sugar with 1 ring
Disaccharide
Sugar with 2 rings
Oligosaccharide
Sugar with several rings
Polysaccharides
Long chain branched carbohydrates (25-2500 rings)
Primary polysaccharide of plants
Starch
Primary polysaccharide of animals
Glycogen
Glycogenesis
Synthesis of glycogen in the liver
Glycogenolysis
Breakdown of glycogen
Gluconeogenesis
Glucose formation from non-carbohydrate sources (fats, etc)
Hormones that store glucose
- insulin
Hormones that pull glucose out of storage
- Glucagon
- Growth Hormone
- Cortisol
- Adrenal/Epinephrine
- T4
Insulin is produced by
beta cells of the islets of Langerhans in the pancreas
Glucagon is produced by
alpha cells of the islets of Langerhans in the pancreas
Which hormones trigger gluconeogenesis?
Glucagon and Cortisol
Pre-diabetic Fasting Glucose
105-125 mg/dL
Diabetic Fasting Glucose
> = 126 mg/dL
Pre-diabetic 2 hr Glucose Tolerance/Postprandial
140-199 mg/dL
Diabetic 2 hr Glucose Tolerance/Postprandial
> =200 mg/dL
How fast is glucose lost on unspun tubes?
7% per hour
CSF glucose level
2/3 of serum glucose. If lower in a septic patient, suggests organism is in the CSF
Ketone Bodies
- form when fat is used as the sole energy source
- indicate the degree of ketosis
- associated with Type 1 diabetics
Ketone Body methodology
Sodium nitroprusside - purple when +
HBA1C is also called
glycated hemoglobins
HBA1C methodology
Immunoassay (structural difference)
Urine Microalbumin
- sensitive test for albumin
- monitor diabetes associated renal disease
- 30-300 mg/day = reversible
- > 550 mg/day = not reversible
Type 1 Diabetes
- “absolute”
- juvenile onset
- high fasting glucose
- autoimmune
Type 2 Diabetes
- “relative”
- adult onset
- can have normal fasting glucose
- familial association
Insulinoma
Insulin-producing tumor, causes fasting hypoglycemia
Reactive hypoglycemia
pancreas over-produces insulin at mealtimes, crashing the blood glucose level