badin

1. Mardin mazhar
Shanga ismail
Hawnaz hamasalh
Hwda mhamad

2. Introduction of thyrod
gland

Second largest endocrine gland in body,Small butterfly
shaped gland located at base of neck below the
sternocleidomastoid muscles
Thyroid is controlled by the hypothalmus
and pituitary
Weighs 18-60gms in adults,Histologically it is made up
of follicular and parafollicular cells.

3. 
thyrod gland folicular cell

4. 
 Stimulates & maintains metabolic processes
 Produces thyroid hormones T3-triiodothyronine and
T4-thyroxine
 These hormones regulate metabolism & affect the
growth and function of other systems in the body
 Secretes calcitonin to lower serum calcium levels
 Parathyroid gland secretes PTH to raise serum
calcium levels
function

5. Function cont……..

 Metabolic stimulants of:
 Neural and skeletal development
 Oxygen consumption at rest
 Stimulating bone turnover by increasing
formation and resorption
 Promoting chronitropic and ionotropic effects
 Increasing number of catecholamine receptors in
heart
 Increasing production of RBC
 Altering the metabolism of carbs, fats, and protein

6. Hormones: T3 & T4

T3 (Triiodothyronine) & T4
(Tetraiodothyronine
 Stored in Follicles (round sacs) in the thyroid filled
with thyroglobulin, a thyroid protein.
 Dietary iodine enters follicles where they are stored as
T3 and T4
 T4 is converted to T3 by peripheral organs such as
kidney, liver, and spleen
 T3 is 10x more active than T 4
 Only 20% of total T3 is secreted by thyroid

7. Hormones: T4

 T4-thyroxine contains 4 iodine atoms
 It is a slow-acting pre-hormone
 T4 takes 4 days to peak in blood
 Half-life 7 days
 Overall effects take 6 weeks
 T3 is the active and faster-acting hormone
 The immediate effects of T3 last 1-2 days
 Half-life 1.5 days

8. T3 and T4 structure


9. Iodine

 Dietary Iodide is removed from the bloodstream by
means of an active pump
 The pump can concentrate iodide in the follicular
sacs at 350x greater than the blood concentration
 Oxidation of iodide by thyroid peroxidase converts
iodide iodine
 Peripheral de-iodination of T4 to T3 is regulated by
many factors including health, nutritional status, and
other hormones

10. Hormones- TSH

 TSH
 TSH is a pituitary hormone
 Controlled by TRH-thyrotropin releasing hormone
from hypothalamus
 Functions to stimulate thyroid hormone production
 May enlarge thyroid (goiter) when under producing
 Labs:
 High TSH indicates low thyroid hormone= hypo
 Low TSH indicates high thyroid hormone = hyper

11. Hormones-Calcitonin &

 Produced by thyroid to regulate serum calcium
levels
 Calcitonin stimulates movement of calcium into
bone
 Parathyroid hormone (PTH) opposite effect of
calcitonin
PTH

12. Negative Feedback
System
TRH
TSH
T3 & T4 Thyroid
The disruption
of any of these
mechanisms can
cause abnormal
levels of T3 and
T4 leading to
thyroid disease

13. Hypothyroidism

Primary Hypothyroidism
Disease of the thyroid gland
Secondary Hypothyroidism
Hypothalamic-pituitary diseases (reduced
TSH)

14. Causes of Hypothyroidism

PRIMARY
Congenital
 Agenesis
 Ectopic thyroid remnants
Defects of hormone synthesis
 Iodine deficiency
 Dyshormonogenesis
 Antithyroid drugs
 Other drugs (e.g. lithium, amiodarone, interferon)

15. Causes of Hypothyroidism

Autoimmune
 Atrophic thyroiditis
 Hashimoto's thyroiditis
 Postpartum thyroiditis
Infective
 Post-subacute thyroiditis

16. 
Iatrogenic
 Radioactive iodine therapy
 External neck irradiation
 post-surgery
Infiltration
 amyloidosis, sarcoidosis, hemochromatosis,
scleroderma
Causes of
Hypothyroidism

17. 
SECONDARY
 Hypopituitarism: tumors, pituitary surgery or
irradiation, infiltrative disorders, Sheehan's
syndrome, trauma, genetic forms of combined
pituitary hormone deficiencies
 Isolated TSH deficiency or inactivity
 Hypothalamic disease: tumors, trauma, infiltrative
disorders, idiopathic

18. 
 Although anyone can develop hypothyroidism, you're at an
increased risk if you:
 Are a woman older than age 60
 Have an autoimmune disease
 Have a close relative, such as a parent or grandparent, with an
autoimmune disease
 Have been treated with radioactive iodine or anti-thyroid
medications
 Received radiation to your neck or upper chest
 Have had thyroid surgery (partial thyroidectomy)
 Have been pregnant or delivered a baby within the past six
months
Risk factor

19. signs and symptom

 Fatigue
 Increased sensitivity to cold
 Constipation
 Dry skin
 Unexplained weight gain
 Puffy face
 Hoarseness
 Muscle weakness
 Elevated blood cholesterol level
 Muscle aches, tenderness and stiffness
 Pain, stiffness or swelling in your joints
 Heavier than normal or irregular menstrual periods
 Thinning hair
 Slowed heart rate
 Depression
 Impaired memory

20. diagnosis

 Diagnosis of hypothyroidism is based on your
symptoms and the results of blood tests that measure
the level of TSH and sometimes the level of the
thyroid hormone thyroxine. A low level of thyroxine
and high level of TSH indicate an underactive
thyroid. That's because your pituitary produces more
TSH in an effort to stimulate your thyroid gland into
producing more thyroid hormone.

21. Treatment

Replacement therapy with levothyroxine
(thyroxine, i.e. T4) is given for life.
 In the young and fit, 100 - 150 μg daily is suitable.
 thyroid function tests after at least 2 months on a
steady dose
 the aim is to restore T4 and TSH to well within the
normal range
 An annual thyroid function test is recommended .

22. 
 Excessive amounts of the hormone can cause side
effects, such as:
 Increased appetite
 Insomnia
 Heart palpitations
 Shakiness

23. Complication

 Goiter. Constant stimulation of your thyroid to release
more hormones may cause the gland to become larger —
a condition known as a goiter.
 Heart problems. Hypothyroidism may also be associated
with an increased risk of heart disease, primarily because
high levels of low-density lipoprotein (LDL) cholesterol
— the "bad" cholesterol — can occur in people with an
underactive thyroid.
 Mental health issues. Depression may occur early in
hypothyroidism and may become more severe over time.
Hypothyroidism can also cause slowed mental
functioning.

24. 
 Peripheral neuropathy. Long-term uncontrolled hypothyroidism can
cause damage to your peripheral nerves — the nerves that carry
information from your brain and spinal cord to the rest of your body,
 Myxedema. This rare, life-threatening condition is the result of long-term,
undiagnosed hypothyroidism. Its signs and symptoms include intense cold
intolerance and drowsiness followed by profound lethargy and
unconsciousness.
 Infertility. Low levels of thyroid hormone can interfere with ovulation,
which impairs fertility.
 Birth defects. Babies born to women with untreated thyroid disease may
have a higher risk of birth defects than may babies born to healthy
mothers. These children are also more prone to serious intellectual and
developmental problems. Infants with untreated hypothyroidism present
at birth are at risk of serious problems with both physical and mental
development.

25. Hyperthyrodism

 Hyperthyroidism - result of excessive thyroid
function
 major etiologies of thyrotoxicosis are
hyperthyroidism caused by Graves' disease, toxic
MNG, and toxic adenomas

26. Causes of
hyperthyroidism

Common
 Graves' disease (autoimmune)
 Toxic multinodular goitre
 Solitary toxic nodule/adenoma

27. Reasons for too much
thyroxine (T-4)

 Graves' disease. Graves' disease, an autoimmune
disorder in which antibodies produced by your immune
system stimulate your thyroid to produce too much T-4, is
the most common cause of hyperthyroidism.
 Hyperfunctioning thyroid nodules (toxic adenoma, toxic
multinodular goiter, Plummer's disease). This form of
hyperthyroidism occurs when one or more adenomas of
your thyroid produce too much T-4. An adenoma is a part
of the gland that has walled itself off from the rest of the
gland, forming noncancerous (benign) lumps that may
cause an enlargement of the thyroid. Not all adenomas
produce excess T-4, and doctors aren't sure what causes
some to begin producing too much hormone.

28. Cont……

 Thyroiditis. Sometimes your thyroid gland can
become inflamed for unknown reasons. The
inflammation can cause excess thyroid hormone
stored in the gland to leak into your bloodstream.
One rare type of thyroiditis, known as subacute
thyroiditis, causes pain in the thyroid gland. Other
types are painless and may sometimes occur after
pregnancy (postpartum thyroiditis).

29. Hyperthyrodism

 Clinical features: due to
 Hypermetabolic state
 Overactivity of sympathetic nervous system

30. Symptoms

 Weight loss
 Increased appetite
 Irritability
 Tremor
 Goiter
 Restlessness
 Stiffness
 Muscle weakness
 Breathlessness
 Palpitation
 Heat intolerance
 Excessive sweating
 Itching
 Thirst
 Vomiting
 Diarrhoea
 Oligomenorrhoea
 Loss of libido

31. Signs

 Tremor
 Irritability
 Psychosis
 Tachycardia or atrial fibrillation
 Warm peripheries
 Systolic hypertension
 Cardiac failure
 Lid lag
 Proximal myopathy
 Proximal muscle wasting
 Onycholysis
 Palmar erythema

32. diagnosis

Medical history and physical exam. During the exam
your doctor may try to detect a slight tremor in your
fingers when they're extended, overactive reflexes, eye
changes and warm, moist skin. Your doctor will also
examine your thyroid gland as you swallow.
Blood tests. A diagnosis can be confirmed with blood
tests that measure the levels of thyroxine and TSH in
your blood. High levels of thyroxine and low or
nonexistent amounts of TSH indicate an overactive
thyroid.

33. If blood tests indicate hyperthyroidism, your
doctor may recommend one of the following
tests to help determine why your thyroid is

overactive:
 Radioactive iodine uptake test. For this test, you take a
small, oral dose of radioactive iodine (radioiodine). Over
time, the iodine collects in your thyroid gland because
your thyroid uses iodine to manufacture hormones. You'll
be checked after two, six or 24 hours — and sometimes
after all three time periods — to determine how much
iodine your thyroid gland has absorbed.
A high uptake of radioiodine indicates your thyroid gland is
producing too much thyroxine. The most likely cause is
either Graves' disease or hyperfunctioning nodules.

34. 
 Thyroid scan. During this test, you'll have a
radioactive isotope injected into the vein on the
inside of your elbow or sometimes into a vein in
your hand. You then lie on a table with your head
stretched backward while a special camera produces
an image of your thyroid on a computer screen.
The time needed for the procedure may vary,
depending on how long it takes the isotope to reach
your thyroid gland. You may have some neck
discomfort with this test, and you'll be exposed to a
small amount of radiation.

35. Treatment

Antithyroid drugs:
1. Carbimazole.
2. Propylthiouracil.
 These drugs inhibit the formation of thyroid hormones
 common side effects - rash, urticaria, fever, and
arthralgia
 Rare but major side effects include hepatitis; an SLE-like
syndrome; and, most important, agranulocytosis

36. Treatment

 Radioactive iodine
 RAI accumulates in the thyroid and destroys the gland
by local radiation.
 It takes several months to be fully effective.
 Surgery:
 subtotal thyroidectomy
 Only in patient who have previously been rendered
euthyroid.

37. Goiter

 Goiter refers to an enlarged thyroid gland
 Biosynthetic defects, iodine deficiency, autoimmune
disease, and nodular diseases can each lead to goiter
 diffuse nontoxic goiter - diffuse enlargement of the
thyroid occurs in the absence of nodules and
hyperthyroidism
 Worldwide, diffuse goiter is most commonly caused
by iodine deficiency and is termed endemic goiter

38. Congenital Thyroid
Diseases

 Agenesis /Aplasia
 Hypoplasia
 Accessory or aberrant thyroid glands
 Thyroglossal duct cyst

39. Thyroglossal Duct Cyst

 A thyroglossal duct cyst is a neck mass or lump that
develops from cells and tissues remaining after the
formation of the thyroid gland during embryonic
development.
 Children
 Failure of regression
 Neck, medial
 Squamous or columnar lining
 often appears after an upper respiratory infection when it
enlarges and becomes painful.
 Complications: inflammation,
sinus tracts

40. Case with
hypothyrodism

 History: A 50 year old housewife complains of progressive
weight gain of 20 pounds in 1 year, fatigue, postural dizziness,
loss of memory, slow speech, deepening of her voice, dry skin,
constipation, and cold intolerance.
 Physical examination: Vital signs include a temperature 96.8oF,
pulse 58/minute and regular, BP 110/60. She is moderately
obese and speaks slowly and has a puffy face, with pale, cool,
dry, and thick skin. The thyroid gland is not palpable. The deep
tendon reflex time is delayed.
 Laboratory studies: CBC and differential WBC are normal. The
serum T4 concentration is 3.8 ug/dl (N=4.5-12.5), the serum
TSH is 1 uU/ml (N=0.2-3.5), and the serum cholesterol is 255
mg/dl (N<200)

41. 
 History: A 35 year old nurse complained of nervousness, mood
swings, weakness, and palpitations with exertion for the past 6
months. Recently, she noticed excessive sweating and wanted
to sleep with fewer blankets than her husband. She used oral
contraceptives and her menstrual periods were regular.
 Physical examination: Pulse was 92/minute and BP was
130/60. She appeared anxious, with a smooth, warm, and moist
skin, a fine tremor, a bounding cardiac apical impulse, and she
couldn't rise from a deep knee bend without aid. Her thyroid
was diffusely enlarged, soft, mobile, without nodularity and
there was no lymphadenopathy. Her eyes were not prominent
(proptotic) and she had no focal skin thickening.
 Laboratory studies: Serum T4=15.6 ug/dl and serum T3=210
ng/dl.
Case with
hyperthyrodism

42. 
Thank you