Hyperthyroidism and hypothyroidism Flashcards

1
Q

name some secondary endocrine organs

A

Heart
Liver
Kidneys
Skin
Small intestines
Stomach

Secondary endocrine organs are organs that have primary functions that are not endocrine, but also have endocrine functions.

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2
Q

hormonal signalling is usually fast, true or false

A

false, it is slow

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3
Q

pituitary gland aka?

A

the hypophysis

anterior pituitary= adenohypophysis
posterior= neurohypophysis

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4
Q

when synthesised , where are peptide hormones stored?

A

in the terminals, which are found in the posterior pituitary gland

note that the hormones are synthesised in the cell bodies which lie in the hypothalamus

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5
Q

what are releasing hormones? where are they produced?

A

peptide hormones that control the release of other hormones

they are produced in the hypothalamus

GnRH, CRH, GHRH, PRH , TRH are all releasing hormones

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6
Q

neurophysis= posterior pituitary

the two hormones found in the neurophysis and their target organs

A

oxytocin (targets mammary glands)

ADH(KIDNEYS)

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7
Q

the target organs for each of these hormones;
FSH/LH
ACTH
PROLACTIN
TSH
GH

A

gonads
adrenal cortex
mammary glands
thyroids
all the body

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8
Q

these releasing hormones control the release of which hormones?
GnRH
CRH
PRH
TRH
GHRH

A

FSH/LH
ACTH
PROLACTIN
TSH
GH

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9
Q

it is converted to TH

which mineral is utilised in the production of the thyroid hormone

A

IODINE

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10
Q

how many lobes does the thyroid gland have and what are they connected by

A

2(right and left)

connected by the isthmus

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11
Q

follicle cells of the thyroid gland are found in the?

A

lobules

T glang has numerous lobules, each with 20-30 follicle cells

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12
Q

colloid

A

A concentrated solution of thyroglobulin that fills the lumen of the thyroid gland’s follicles. The colloid is the center of thyroid hormone production

(Thyroglobulin)Tg is a precursor to thyroid hormones, triiodothyronine (T3) and thyroxine (T4). Tyrosine residues in Tg are iodinated to form monoiodo- and diiodotyrosine, which then lead to the formation of T3 and T4

Tg stores iodide as well

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13
Q

describe the synthesis of the thyroid hormones

A
  1. Thyroglobulin is synthesised and
    stored in the colloid
  2. Iodide (I-) enters the follicle cell
    and then the colloid
  3. Iodide becomes oxidised to iodine
    I2
  4. I2 binds to thyroglobin
  5. One or two I2 bind to each
    tyrosine ring
    * Monoiodotyrosine (MIT)
    * Diiodotyrosine (DIT)
  6. MIT and DIT couple with each
    other to form T3 and T4
  7. The iodinated thyroglobulin, now containing T3 and T4, is stored in the colloid of the thyroid follicle. These hormones can be stored for weeks to months, meaning that even if iodine deficiency occurs, the physiological effects (like hypothyroidism) may not appear immediately due to the body’s thyroid hormone reserves.
  8. Thyroglobulin is removed and T3
    and T4 are release in free form
  9. T3 and T4 enter the blood
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14
Q

thyroglobulin

A

a protein rich in tyrosine, that helps with iodination and storage of THs

synthesized by follicle cells (thyrocytes) and secreted into the follicular lumen

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15
Q

what mode of transport is used to transport TH and why

A

they are carried in the blood via the thyroid protein, because they are lipid hormones, and the blood is hydrophillic

TBG(Thyroxine-binding globulin ) is the primary protein used

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16
Q

T3 is released directly from the pituitary gland mostly true or false

A

false
only 3% is released directly from the pituitary gland

17
Q

the most active or more potent thyroid hormone

18
Q

T4 converted to T3 by?

A

deiodinase enzymes

19
Q

how many thyroid hormone receptors are there, name them

A

2
THRA: Expressed in the brain, heart, intestine, and bone
THRB: Expressed in the pituitary and liver

IMPORTANT THRs normally binds to other receptors like Rentinoid X receptor to enhance their action

20
Q

roles of the TH

A

regulate metabolism
regulate growth and tissue differentiation

21
Q

the two autoimmune diseases linked to;
low TH levels
high TH levels

A

Hashimoto’s disease
Graves disease

22
Q

classifications of thyroid disorders , explain them

A

primary(at the level of the thyroid gland)

secondary (at the level of the pituitary gland)

tertiary (at the level of the hypothalamus)

23
Q

hypothyroidism affects more men than women, true or false

A

false, affects more women

24
Q

clinical features of hypothyroidism

A

Feeling tired
Weight gain
* Feeling cold/cold intolerance
* Depression
* Puffy face
* Hair loss
* Hoarse/deeper voice
* Heart problems
* Bowel problems

25
goiter
an enlargement of the thyroid gland, often resulting from insufficient iodine intake, which leads to low thyroid hormone production (hypothyroidism). The lack of iodine prompts the pituitary gland to release more thyroid-stimulating hormone (TSH), stimulating the thyroid to grow in an attempt to produce more hormones.
26
myxoedema
Term used to describe sever hypothyroidism AND also used to describe skin changes in someone with severely advanced hypothyroidism ## Footnote features include Deposition of **mucopolysaccharides** in the dermis, which results in swelling of the affected area swelling and thickening of skin anywhere on your body, especially in your lower legs
27
the most common cause of hypothyroidism
Hashimoto's ## Footnote more prevalent in men than in women
28
what happens in Hashimoto's disease
autoantibodies are raised against thyroglobulin and thyroid peroxidase damage caused to the thyroid gland Apoptosis and necrosis of thyroid cells, ability to produce TH impaired ## Footnote TPO uses hydrogen peroxide to oxidize iodide (I-) to iodine (I2) during TH synthesis
29
treatments for Hashimoto's disease
T4 replacement therapy(levothyroxine) T3 repalcement therapy( Liothyronine) T3 replacement therapy more potent but less used ## Footnote note that levothyroxine needs about 6-8 wks to reach a steady
30
causes of hyperthyroidism
graves disease thyroiditis overstimulation of TSH
31
some signs and symptoms of hyperthyroidism
weight loss fine straight hair enlarged thyroid tachycardia muscle wasting...etc
32