Topic 5 Biochemical activity of Thyroid and Parathyroid hormones

what effect on the kidney can you have if you have hyperparathyroidism?

kidneys would retain calcium and return it in your blood instead of flushing it out through urine. too much calcium in your kidneys can cause kidney stones

are thyroid hormones lipophilic or hydrophilic?

lipophilic. they are hydrophobic

What does Calcitonin do to bone?

(check this) stops osteoclasts from killing bone cells

what is the active form of Vitamin D (3)

1,25(OH)2-D3, Cholecalciferoal or calcitriol

what are the ways to inactivate thyroid hormones

1. T4 to rT3 2. Deiodination (removing the iodine) 3. Decarboxylation (removing the carboxyl group) 4. Deamination (amino group is removed) 5. Glucuronidation (make the hormone soluble in the blood stream so its excreted in the urine.

what are the 5 signs and symptoms of hypothyroidism

1. fatigue 2. weight gain 3. dry skin 4. hair loss 5. constipation

PTH acts on which body parts? (3)

1.osteoclasts 2. kidney tubules 3. intestine

what is the major form of Vitamin D found in the blood?

25(OH)-D3

what does 1-alpha hydroxylase do?

25(OH)D3 is converted to 1,25(OH)2-D3 in the renal tubule

which hormone increases calcium excretion in the urine

Calcitonin

what receptor system does PTH use?

JAK/STAT

what is rT3 and what is the structure?

Reverse T3. Two iodine on the bottom cyclic structure and one on the top. T3 is the opposite

Triiodothyronine

T3

Which thyroid hormone is more active?

T3

Combining MIT and DIT residues on thyroglobulin will form ______

T3 and T4

Is more T4 or T3 produced?

T4

thyroxine aka

T4

What is thyroxin binding globulin and thyroxin binding prealbumin

a carrier protein for T3 and T4

what is subacute thyroiditis

a painful enlarged thyroid from virus or bacteria causes hyperthyroidism

what is calcitriol

active biological form of vitamin D

overactive thyroid nodules can cause _____

amp up thyroid hormone production aka hyperthyroidism

What is graves disease

autoimmune disorder that results in body creating too much thyroid hormone.

which hormone lowers the circulating Calcium and phosphate levels?

calcitonin

function of thyroperoxidase

converts iodide to I+ (iodine)

how does calcitonin act on the kidney tubules?

decreases calcium reabsorption

increased iodine consumption can cause ______ how do you get increased iodine consumption?

eating too much food and medication that contain iodine. causes overstimulation of thyroid aka hyperthyroidism

Are free or bound thyroid hormones more active?

free thyroid hormones are more active

What is the most common cause of hyperthyroidism

graves disease

goiter is a sign of

hyper and hypothyroidism

Weight loss is a sign of

hyperthyroidism

diarrhea is a sign of

hyperthyroidism

hair loss is a sign of

hyperthyroidism

heat intolerance is a sign of

hyperthyroidism

rapid heartbeat is a sign of

hyperthyroidism

cold intolerance is a sign of

hypothyroidism

dry hair is a symptom of

hypothyroidism

puffy face is a sign of

hypothyroidism

slow heartbeat is a sign of

hypothyroidism

where are T3 receptors located?

in the cell in the nucleus.

what does PTH do to the kidneys?

increases calcium reabsorption causes phosphate secretion

what is thyroiditis and what is the effect of it

inflammation of thyroid. causes hyperthyroidism. arrives in 3 ways: 1. subacute 2. postpartum 3. silent

where is Thyroperoxidase found

only in thyroid tissue *

where is calcitonin produced ( gland and cell names)

parafollicular C cells of the thyroid

PTH is first synthesized as ______

prepro-PTH

calcitonin is synthesized as ____

preprocalcitonin

when synthesizing thyroid hormones what does the addition of I+ to thyroglobulin create?

production of thyroglobulin containing Monoiodotyrosyl and Diiodotyrosyl residues

Calcitonin structure

protein of 32 amino acids

what kind of hormone is PTH

protein of 84 amino acids

How do thyroid proteins travel through the blood?

since they're lipophilic they need a carrier protein to get through.

function of PTH

stimulates bone resorption to increase Ca2+ levels and depressing plasma phosphate levels

what does PTH do to phosphate levels?

stimulates phosphate secretion by kidneys

what does Deiodinase do?

target tissues contain this and it will convert T4 to T3

thyroid hormones are produced and secreted by which gland

thyroid gland

Thyroid hormones are synthesized from ___ residues in ____

tyrosyl residues in throglobulin