Unit 10 The Endocrine System

pituitary [pıˊtjuıtərı] - гипофиз

goiter [ˊɡͻıtə] -зоб

nodule [ˊnͻdju:l] - узелок

bruit – шум

EXCESS AND DEFICIENCY

An excess - too much , or a deficiency - too litle, of circulating hormones causes a wide range of medical conditions, for example hyperthyroidism and hypothyroidism. Where there is an excess of hormone , one form of treatment consists of giving the patient something which inhibits the production of that hormone, as in the use of carbimazole to treat hyperthyroism. When a hormone is deficient, treatment may be by replacement therapy, for example injections of insulin in the treatment of Type 1 diabetes.

Doctors say: suffers of type 1 diabetes are deficient in insulin

NEGATIVE FEEDBACK SYSTEMS

1. TRH (thyrotrophin-releasing hormone) is secreted in the hypothalamus and triggers the production of TSH (thyroid-stimulating hormone) in the pituitary.

2. TSH stimulates the TSH receptor in the thyroid to increase synthesis of both T4 (thyroxine) and T3 (triiodothyronine) and also to release stored hormone, producing increased plasma levels of T4 and T3.

3. T3 feeds back on the pituitary and perhaps the hypothalamus to inhibit TRH and TSH secretion.

GOITRE

An enlarged thyroid gland is called a goitre. The enlargement may be diffuse - involving most of the gland, or localized - limited to a particular area, as in a solitary (single) nodule. The increased blood flow in diffuse enlargement , for example in Graves' disease, may give rise to a palpable thrill - vibration felt with the hand , and an audible bruit - noise heard through a stethoscope, over the gland.

A LETTER OF REFERRAL

Dear Doctor, I would be grateful if you would see this 50-year-old woman who has lost 20 kilos in weight in spite of eating more than usual. She describes herself as overactive and at first she thought the weight loss was due to this. But more recently she has developed palpitations and heat intolerance. She has noticed that her hands have a tendency to shake. Her symptoms suggested hyperthyroidism and was confirmed by my examination which revealed an enlarged thyroid, sweaty palms and fine tremor of the hands.

Heat intolerance:

inability to cope

with high

temperatures

Overactive: more active than is usual

Palpitations: awareness of rapid or irregular heartbeat

Fine tremor: very slight involuntary movements

Exercises:

1.Complete the table with words from A,B,C and related forms. Put a stress mark in front of the stressed syllable in each word.

Verb	Noun
in'hibit
produce
release
replace
	secretion
	stimulation

2.Complete the sentences . Look at A and C to help you.

1 A …………. change affects many parts of an organ or gland.

2. A …………. change affects only one part.

3. His diet is ………… in iron: he doesn't get enough iron.

4. ………… T3 and T4 increase the metabolic rate.

3.Match Mrs Davis's symptoms (1-6 ) with the questions her doctor asked (a-f ).

1. eating more

2. heat intolerance

3. overactivity

4. palpitations

5. weight loss

6. tremor

1. Do you prefer hot weather or cold?

2. Is your weight steady?

3. What is your appetite like?

4. Are you able to sit and relax?

5. Do your hands shake ?

6. Have you ever felt your heart beating rapidly or irregularly ?