Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HD > Thyroid > Flashcards

Thyroid Flashcards

Thyroid function control interaction with hypothalamus and pitutitary and pathologies

1
Q

describe location and shape of thyroid gland

A

Sits on trachea, two lobes joined by isthmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what do parathyroid glands do

A 
Parathyroid glands make:
Parathyroid hormone (PTH) – involved in Ca2+ metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does thyroid gland make

A

T3/T4/calcitonin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe the thyroid pituitary hypothalamus axis

A

Hypothalamus releases
THYROTROPIN RELEASING HORMONE (TRH)
3aa pyro-Glu-His-Pro-NH2
TRH stimulates thyrotrophs in anterior pituitary to
produce THYROID STIMULATING HORMONE (TSH) or
THYROTROPIN
TSH stimulates thyroid gland to synthesize and release
thyroid hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the main hormone released by thyroid

A

mainly T4 metabolised to T3 in periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

At thyroid receptors which is more potent t3 or t4

A

t3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which hormone is involved in negative feedback of thyroid

A

T3 acts on the thyrotrophs to decrease release of TSH

and to decrease release of TRH from hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

briefly describe organisation of thyroid gland

A

follicles formed by throid cells, inside each follicle is a colloid. in between follicles are c cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

outline how thyroid hormone is synthesised

A 
Active uptake of iodine
Synthesis of glycoprotein THYROGLOBULIN
contains about 115 tyrosine residues
Organification of iodine by
THYROID PEROXIDASE in the presence of
H2O2
Addition of iodine to TYROSINE
Monoiodotyrosine (MIT)
Di-iodotyrosine (DIT)
MIT + DIT ------→ tri-iodothyronine (T3
)
DIT + DIT ------→ thyroxine (T4
)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the role of TPO (thyroid peroxidase)

A

Organification of iodine by
THYROID PEROXIDASE in the presence of
H2O2
Addition of iodine to TYROSINE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does T4 travel in blood

A

majority is bound to TBG 75%,tbpa 20%, albumin 10%, small small amount is free

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does T3 travel in blood

A

TBG majority then albumin then minority 4% is free

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do thyroid hormones interact with target cells

A

Thyroid hormones interact with nuclear receptors
Thyroid hormone enters cells by diffusion or by specific
carrier
T3 enters the nucleus and binds to the thyroid receptor
Hormone-receptor complex binds to thyroid hormone
responsive element (TRE) on DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What physiological changes does T3 result in

A 
Increased mRNA production
Increased protein synthesis
Increased Na+/K+-ATPase levels
Increased ATP turnover
Increased O2 consumption
Increased number of adrenoceptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does thyroid hormone conc increase do to cardiac muscle

A

Increase cardiac muscle contractility tachycardia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does thyroid hormone conc increase do to cholesterol

A

Increase cholesterol degradation

17
Q

What does thyroid hormone conc increase do to bones

A

Increase bone turnover

18
Q

What does thyroid hormone conc increase do to gut

A

Increase gut motility

19
Q

What does thyroid hormone conc increase do to blood

A

Increase erythropoeisis

20
Q

What does thyroid hormone conc increase do to respiratory centre

A

Maintenance of hypoxic and hypercapnic drive in

respiratory centre

21
Q

What does thyroid hormone conc increase do to heat and 02 consumption

A

Increased O2 consumption and heat production

22
Q

What does thyroid hormone conc increase do to metabolism

A

Increase metabolic turnover of hormones and drugs

23
Q

what are the effects of a hypothyroid state

A

increase bodyweight, decrease oxygen consumption, heat production, bmr, cns decreased (drowsy), reflexes decreased, sns (decreased), cardiac bradycardia decreased cardiac output and bp, gut effects decreased

24
Q

Signs of hypothyroidism

A

weight gain, constipated,slow reflexes, Hypercholesterolaemia
hyperprolactinaemia

25
Q

What is Hashimoto thyroiditis

A

autoimmune disease antibodies to thryoglobulin or thyroid peroxidase

26
Q

what is cretinism

A

Failure of delivery of thyroid hormones in the foetus – cretinism

27
Q

How do you treat hypothyroidism

A 
Thyroxine (T4
)
T1/2 6 days, effects last 14 days
Liothyronine (sodium salt of T3
)
T1/2 2-4 days, effects last 8 days
28
Q

How does iodine deficiency cause hypothyroidism and how is it treated

A 
Treatment Iodine supplements
GOITROGEN - suppresses hormone secretion -
increases TSH secretion – goitre
iodine in kelp (seaweed)
brassicae (cabbage)
cassava
lithium
some local drinking water
cough mixtures
decrease intake
29
Q

Signs of hyperthyroidism

A

nervous, sweating, palpitations, fatigue,weightloss, tremor, eye signs atrial fibrillation,
pre tibial myoxedma

30
Q

what is graves disease

A

GRAVES’ DISEASE (diffuse toxic goitre)
autoimmune disease
TSAb (LATS) - produces prolonged stimulation of TSH
receptors

31
Q

What is propanolol and radioiodine

A

Treat hyperthyroidism

b-blockers
PROPRANOLOL
blocks sympathetic effects (especially on the heart)
of hormones.
RADIOIODINE (131I)
Taken up into follicular cells and irradiates them. b
and g emitter. b particles kill cells, g pass through
without causing damage
T1/2 8 days, 2 months completely decayed

32
Q

what drug inhibits TPO to treat hyperthyroidism

A

PROPYLTHIOURACIL

33
Q

what is the surgery called to treat hyperthyroidism

A

partial thyroidectomy

34
Q

Describe TSH,TRH and T4/T3 conc for someone with primary hypothyroid

A

high tsh conc, high trh conc low t3/t4

35
Q

What is Case non thyroidal ilness

A

It is when someon has had an acute illlness and thyroid hormones and tsh are abnormal. should restore after acute event has passed not directly caused by the thyroidal axis

36
Q

What is a thyroid nodule

A

can cause hyperthyroidism, can be benign low risk, (just monitor) or it can be high risk, ultrasound needed and potential surgery

37
Q

Are thyroid size and thyroid function related

A

no big thyroid can secrete small amounts of T4 t3 and vice versa

HD (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions