Thyroid disorders

Question 1

what shape is the thyroid gland

Answer 1

shield

Question 2

where is the thyroid gland

Answer 2

the neck

Question 3

What is the origin of the thyroid?

Answer 3

back of the tongue
outpouching forms a duct which elongates down - thyroglossal duct
migrates down neck and divides into 2 lobes

Question 4

What is the foramen caecum?

Answer 4

dimple at back of tongue - disappearing thyroglossal duct

Question 5

What is the adult thyroid weight?

Answer 5

20g

Question 6

How many lobes are there? Which is the largest?

Answer 6

4 lobes

right is the largest

Question 7

What glands are found embedded within the thyroid?

Answer 7

parathyroid glands

They are functionally distinct from the thyroid gland

Question 8

What important nerve runs very close to the thyroid gland and what does it supply?

Answer 8

left recurrent laryngeal nerve

supplies the vocal cord

Question 9

List the three problems that can occur with development of the thyroid.

Answer 9

Agenesis - complete absence
incomplete descent - from base of tongue to trachea
thyroglossal cyst - segment of duct persists and presents as a lump years later

Question 10

What term is used to describe an individual who has irreversible brain damage caused by lack of thyroxine in foetal and neonatal life?

Answer 10

Cretin

Question 11

Thyroid disease affects approximately 5% of the population. Is it more common in males or females?

Answer 11

females

Question 12

describe primary hypothyroidism (myxoedema)

Answer 12

Primary thyroid failure
autoimmune damage to thyroid/operation
thyroxine levels decline
TSH levels climb

Question 13

What biochemical findings occur in an individual with primary hypothyroidism?

Answer 13

Thyroxine levels decline

TSH levels climb

Question 14

List the features of primary hypothyroidism.

Answer 14

deepening voice
depression and tiredness
cold intolerance
weight gain with reduced appetite 
constipation 
bradycardia 
eventual myxoedema coma
diminished perspiration 
prolonged recovery from reflex

Question 15

Why is treatment of hypothyroidism essential?

Answer 15

patients will die otherwise
they will perform poorly
cholesterol goes up - causing death from heart attacks and strokes

Question 16

What is the treatment of hypothyroidism?

Answer 16

replace thyroxine - one tablet, 100mg on average, daily

monitor TSH and adjust dose until TSH is normal

Question 17

What biochemical findings occur in an individual with hyperthyroidism?

Answer 17

TSH levels fall to 0
raised basal metabolic rate
Raised temperature
burn up calories and lose weight
increased heart rate 
every cell in the body speeds up 
make too much thyroxine 
(immune system tell thyroid gland to make more thyroxin)

Question 18

List the features of an overactive thyroid gland.

Answer 18

myopathy
mood swings
diarrhoea
increased appetite but weight loss
tremor of hands
palpations
sore eyes
goitre

Question 19

features of hyperthyroidism

Answer 19

Tremor - over active all adrenaline affect muscles
palpatations
hot
weight loss
mood swings
sore eyes - immune problem with thyroid
goitre
myopathy
diarrhoa

Question 20

what is the blood supply to the thyroid like

Answer 20

the thyroid is very vascular

Question 21

what are the features of the thyroid gland

Answer 21

pyramidal lobe
isthamus
right and left lobe
parathyroid glands

Question 22

Is the thyroid gland essential to life

Answer 22

yes

Question 23

size of each lobe

Answer 23

4x2.5x2.5cm

Question 24

what is the origin of the pyramidal lobe

Answer 24

it is left from the descent from the tongue

Question 25

what is an aberrant parathyroid gland

Answer 25

a parathyroid gland that is in the wrong place

if it is malignant you need to find it and remove it otherwise calcium metabolism is messed up

Question 26

what is thyroid cartilage

Answer 26

it is what you can feel

Question 27

what is the problem with a lingual thyroid

Answer 27

it hasn’t grown down at all
can’t remove it because you need the thyroid to survive
without thyroxin the brain doesn’t develop properly

Question 28

features of cretinism

Answer 28

slow mentation
slow growth
small height

Question 29

how do you prevent cretinism

Answer 29

screening 
heel prick test 
measure TSH 
at the same time as Guthrie test for phenylketonuria 
given thyroxine immediately if TSH high

Question 30

what is the colloid

Answer 30

where thyroxin is stored and it contains thyroglobin

Question 31

what does thyrocine binding globulin do

Answer 31

bonds 75% of thyroxine in the circulation
only 1% of thyroxine is free
whereas thyroglobin is inside the thyroid gland only

Question 32

what is the role of the thyroid gland

Answer 32

responsible for the synthesis, storage and secretion of thyroid hormones

Question 33

what do thyroid hormones do

Answer 33

they regulate growth, development and metabolic rate

Question 34

why are females more susceptible to thyroid disease

Answer 34

the immune system attacks the thyroid

more mistakes like this occur in females because of response in pregnancy

Question 35

why does TSH increase in primary hypothyroidism

Answer 35

the production in the anterior pituitary gland is not inhibited by T3 or T4

Question 36

what is T4 also known as

Answer 36

thyroxin

Question 37

describe Grave’s disease

Answer 37

whole gland is smoothly enlarged and overactive
need to remove the thyroid gland
autoimmune
Ab bind to and stimulate TSH receptor in thyroid
cause goitre and hyperthyroidism
Ab bind to muscles behind the eyes - exophthalmos
Ab stimulate the growth of shins and cause pretibial myxoedoma (hypertrophy)

Question 38

what is pretibial myxoedema

Answer 38

the swelling (non-pitting) that occurs on the shin's of patients with Grave's disease 
growth of soft tissue