Download Thyroid gland

Endocrine system
pathology
Central endocrine system
peripheral endocrine system: thyroid gland
parathyroid gland
pancreas
adrenal glands
Thyroid gland
. the weight of normal thyroid gland is about 15 grams
. under the response of TSH of the hypothalamus, the . . .
. thyroid gland secrete thyroxin (T4) and thiiodotheratine
. the thyroid gland has a vary important metabolic function
. increase in thyroid function called hyperthyroid
. decrease in thyroid function called hypothyroid
Diseases of thyroid gland
1. Inflammation
2. Tumors
thyroid gland
Hyperthyroidism
. A clinical syndrome caused by excessive circulating
thyroid gland
. Thy caused by increased tissue metabolic activity
. Thy characterized by nervousness, heat intolerance
weight loss, palpitation, and increase appetite
Graves disease
1. The most common cause of endogenous
hyperthyroidism
2. Usually characterized by diffuse enlargement of
thyroid
3. Usually present with exophlalmos
4. Usually present with myxedema (thinning and mild
hyperpegmentation of the pretibial skin)
5. The women affected seven times more than men
6. The cause is an autoimmune disease, antibodies that
cause thyroid stimulation and overfunction
7. The thyroid hormones are very high, and the TSH is
very low
hypothyroidism
A condition caused by low thyroid gland hormone
It is characterized by hoarseness, cold intolerance,
increase weight
thyroiditis
Hashemoto thyroiditis
(chronic lymphocytic thyroiditis)
The most common cause of hypothyroidism in areas
with normal iodine level
It is characterized by gradual thyroid failure because
of autoimmune destruction of thyroid gland
It is characterized by a painless symmetrical
enlargement the thyroid gland
Usually it is associated with other autoimmune
diseases such as DM type I
Usually associated with some malignancy such as nonHodgkin lymphoma
Goiter
. Can be diffuse or multinodular goiter
. Caused by dietary iodine deficiency, (endemic goiter)
which is important for the synthesis of thyroid hormones
. Low thyroid hormones leads to stimulate TSH
secretion, hypertrophy and hyperplasia of thyroid gland
. Started as diffuse simple goiter, involves the whole
gland without causing nodularity
. After a long time (if not treated ), it becomes irregular,
hard, nodular (multinodular)
•
carcinoma of
thyroid
Papillary carcinoma
Follicular carcinoma
Medullary carcinoma
Anaplastic carcinoma
Thyroid carcinoma account about 1.5% of all human cancers, the
are more common in female for unknown cause, they are usually in
adults
Papillary carcinoma of thyroid
. Is the most common type (80%)
. Can present in young before age 20
. The majority are associated with
previous irradiation
. About 9% of patients with such
irradiation developed papillary
carcinoma during there life
. They can present with hoarseness , dysphagia, cough
. Papillary carcinoma has an excellent prognosis(10 year
survival more than 95%)
Papillary carcinoma of thyroid
Parathyroid glands
. Four glands are present close to the upper and lower
poles of thyroid gland
. The gland secretes parathyroid hormone( PTH)
. The main function of PTH is calcium level controlling
(when Ca++ level is low, PTH is higher)
. PTH level is usually high in patients with chronic
renal failure( secondary hyperparathyroidism)
. Patents with high PTH has high calcium and low
phosphorus
Causes of hyperparathyroidism
primary causes
1. Adenoma 75% to 80%
2. primary hyperplasia 10% to 15%
3. parathyroid carcinoma less than 5%
Secondary causes
usually with chronic renal failure
Causes of hypoparathyroidism
The most common cause is surgically induced
during thyroid gland surgery
Adrenal gland
The adrenal gland has two parts
Cortex- outer, synthesizes three types of hormones
1. Glucocorticoids (cortisol)
2. Mineralcorticoids (aldesterone)
3. Sex steroids(estrogen and androgen)
Medulla- inner
the adrenal medulla synthesizes and secrete cathecholamines
mainly adrenaline
hypercortisolism (Cushing syndrome)
Causes
. Most cases of Cushing syndrome are the result of administration of
exogenous glucocorticoidis
to treat many diseases
Other causes are:
1.High ACTH from the hypothalamus
2.High cortisol by adrenal adenoma
3. High ectopic ACTH by different neoplasm
Clinical picture
accumulation of fat in the posterior neck
Central obesity, polydypsia, hyperglycemia, hirsutism,
moon face
Diabetes Mellitus
Type I : absolute deficiency of insulin caused by
pancreatic B cell destruction( 10% of all diabetes mellitus),
usually associated with genetic disease,
Type II: combination of peripheral resistance to insulin
action and inadequate secretory response by pancreatic Bcell relative insulin deficiency
Diabetes Mellitus
involved organs
Blood vessels
Kidney
Retinal disease
Neuropath
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