EX 2; Thyroid Gland Flashcards Preview

AU14 Physiology > EX 2; Thyroid Gland > Flashcards

Flashcards in EX 2; Thyroid Gland Deck (45):
1

What is the gross anatomy of the thyroid

2 lobes
located inferior to the larynx
one of the largest endocrine glands
4 cm long/wide
20 grams

2

What is the vascularization of the thyroid gland

more capillaries per gram than the kidney

3

The internal structure of the thyroid consists of what

hollow follicles formed by spheres of epithelial cells; follicles are filled with colloid, lots of protein

4

The follicular cells of the thyroid regulate production of what

two iodine-containing hormones

5

What is thyroid hormone synthesis stimulated by

TSH, which comes from the pituitary

6

Iodide is transported into follicular cells and then does what

diffuses into the colloid

7

Follicular cells also synthesize this, which is exocytosed into colloid

thyroglobulin; lots of tyrosine

8

Iodidie oxidized by this and is linked to thryoglobulin; attaching iodide to tyrosine creating MITs and DITs

thyroid peroxidase

9

The mono-iodo-tyrosine and di-iodo-tyrosie combine to form what

MIT + DIT = T3
DIT + DIT = T4

10

The thyroid hormone stored in colloid is attached to thyroglobulin, why is this necessary

the protein backbone is not lipid soluble, so it traps the hormone

11

What three additional actions does TSH stimulate

stimulates iodide uptake
protein synthesis
mitosis in follicular cells; hypertrophy and hyperplasia

12

Thyroglobulin droplets are pinocyotsed into follicle cells and the droplets fuse with what and what occurs

lyosomes and T3 and T4 are released by lysosomal hydrolysis and diffuses into capillaries

13

10% of secreted thyroid hormone is what variety

T3

14

80% of T4 is converted to T3 in which organs

liver and kidney (and certain target cells)

15

Where are the receptors for thyroid hormone located and what are the different forms

they are in most cells of the body
α and β forms

16

Expression of receptor isoforms differs in respect to what two things

stage of development (α first)
target tissue (regulate and stimulate cell metabolism)

17

These two things combined regulate gene transcription

dimerized receptors + TH

18

Thyroid hormone is used to stimulate what

metabolism

19

thyroid hormone stimulates cellular metabolism by increasing the activity of what three things

Na/K-ATPase activity
increases substrate availability
produces heat

20

What does thyroid hormone do to the mitochondria

increases size and number

21

Insufficient TH during fetal development causes what condition

cretinism

22

True or False
diseases of the thyroid gland are the most common of endocrine diseases

True

23

How common is thyroid disease in women and in men

2-5% in women (childbearing years most common)
0.5% of men
twice as many people have thyroid disease than the number of people diagnosed

24

What is the primary cause of hypothyroidism

a primary defect in the thyroid gland
95% due to iodine deficiency

25

What are three consequences of an iodine deficiency

insufficient production of TH
lack of negative feedback
growth of goiter because hypertrophy or hyperplasia of follicular cells

26

Hypothyroid due to an iodine deficiency was primarily reversed due to what for additive

iodized salt

27

This is also known as Hashimoto's, which affects the enzymes synthesizing thyroid hormone

autoimmune thyroiditis

28

What two additional primary defects can lead to hypothyroidism

damage or destruction due to surgery/radiation, etc.
dysfunction associated with other illness

29

What is a second defect that can result in hypothyroid

problem in the pituitary; release or receptor issue

30

What are some mild symptoms of hypothyroid

cold sensitivity
low metabolism
weight gain

31

What are some moderate symptoms of hypothyroid

fatigue
poor circulation
GI/mental function is sluggish

32

What are some severs symptoms of hypothyroid

myxedema due to accumulation of glycosaminoglycans in the ECF

33

What are four primary defects that can cause hyperthyroid or thyrotoxicosis

thyroid tumor
Graves disease
thyroiditis
thyrotoxicosis facitia

34

This is when antibodies to TSH receptor stimulate the gland, the feedback mechanism is disrupted, and is more common in women

Grave's disease

35

This is when too much thyroid hormone due to ingesting of endogenous thyroid hormone

thyrotoxicosis factitia

36

What are four symptoms of hyperthroid

abnormal levels of circulating hormone
goiter
metabolic and nervous system symptoms; upregulation
ocular symptoms; fat pad behind eye is bulging

37

What are some options for treatment of hyperthyroid

surgically/radioactivity destroy the gland
anti-thyroid drugs

38

What are some dental problems associated with hypothyroid

abnormal response to drugs; increased sensitivity
myxedema; extra CSF
diminished cardiac and respiratory functions

39

What are some dental problems associated with hyperthyroid

early eruption of teeth
must avoid catecholaminergic drugs; sensitive to epinephrine, sympathetic already on "high alert"
thyroid storm
salivary gland damage due to radiation treatments

40

Thyroid hormone up regulates these receptors

beta adrenergic

41

Upregulation of beta adrenergic receptors by thyroid hormone increases sensitivity to what

catecholamines

42

When the thyroid hormone up regulates beta adrenergic receptors, what does this due to the sympathetic system

involved with the sympathetic system; NE and E
increasing HR and dilating respiration

43

The thyroid hormones also regulate production of this

GH

44

Thyroid hormone is important for this development

CNS development and function

45

Thyroid hormone regulates what in adults

normal neural responses in adults; hence why if you have limited TH in fetal development = cretinism