The glands of the body may be divided into those with external secretion (exocrine glands) and those with an internal secretion (endocrine glands). Examples of exocrine glands are the sweat, lacrimal and mammary glands which pass their secretion along ducts to the external surface of the body, and the glands of the mouth, stomach and intestines which pass their secretion along ducts into the alimentary tract. The endocrine or ductless glands on the other hand have no ducts or openings to the exterior. Their secretion is passed into the blood stream, and is transmitted via the circulation to modify the activity of some organ or tissue.
The endocrine glands in the body are pituitary gland (hypophysis), thyroid gland, 4 parathyroid glands, 2 adrenal glands (suprarenal glands), 2 gonads (ovaries or testes), pancreas, pineal gland, and thymus. The hypophysis is located at the base of the brain and is the chief gland of the system: it produces special substances which stimulate the activities of other endocrine glands. The thyroid gland stimulates the metabolism of all bodily parts. Parathyroid glands are located on the dorsal side of the thyroid gland. Parathyroid hormone regulates calcium level in the blood and cerebrospinal fluid.
The adrenal glands which also are called suprarenal glands are situated one on the top of each kidney. They influence the amount of mineral salts, the metabolism of sugars, fats and proteins within all body cells, intracellular metabolism, the work of the cardiovascular, digestive and respiratory systems. Sex hormones produced by these glands are necessary for development and maintaining of the reproductive system. Ovaries and testes are a part of the reproductive system and play a great role in its functioning.
The pancreas is located behind the stomach. It is the gland of the two systems: digestive and endocrine. As a part of the digestive system its function is to secrete pancreatic juice. The hormones of the pancreas are insulin and glucagon which regulate the due metabolism of sugars and starches in the body.
The pineal gland is located in the middle of the brain. The gland secretes melatonin affecting the work of other glands as a "biological clock". Its function is obscure to some extent as some scientists state it.
The thymus gland is located in the mediastinum behind the sternum and plays a certain role in the immune process in the body. The exact function of the gland is also rather uncertain.
A disturbance in the activity of the endocrine glands is accompanied by changes throughout the organism. These changes may be due to an increase (hyperfunction) in the function of a gland or decrease (hypofunction).
The endocrines coordinate the activities of all other systems. The activities of endocrine glands are regulated by the nervous system through the nerves and neurohumoral control, particularly through the hypophysis. The hormones of the endocrine glands, in their turn, affect the functions of the different parts of the nervous system.
external secretion зовнішня секреція
internal secretion внутрішня секреція
exocrine gland залоза зовнішньої секреції (екзокринна)
endocrine gland залоза внутрішньої секреції (ендокринна)
ductless який не має вивідної протоки
alimentary tract травний тракт
blood stream кровотік
to modify activity модифікувати, видозмінювати діяльність
pituitary gland (hypophysis) гіпофіз
thyroid gland щитовидна залоза
parathyroid gland паращитовидна залоза
adrenal gland (suprarenal gland) надниркова залоза
gonad гонада, статева залоза
ovary (pl. -ies) яєчник
testis (pl. -es) яєчко
pancreas підшлункова залоза
pineal gland шишкоподібна залоза, епіфіз
thymus зобна/вилочкова залоза, тимус
base of the brain основа мозку
cerebrospinal fluid спинномозкова рідина
mineral salt мінеральна сіль
intercellular metabolism міжклітинний обмін речовин
due metabolism належний обмін речовин
to maintain підтримувати, зберігати
pancreatic juice підшлунковий сік
obscure неясний, нечіткий, незрозумілий
uncertain сумнівний, неясний, точно не відомий
to be accompanied by супроводжуватись чимось
to affect впливати, шкодити, порушувати
Note: 1) it’s interesting to know the difference between “due” – належний, відповідний and “due to” – завдяки; внаслідок; в результаті;
2) mind the difference between the two troublesome words: to affect ['æfekt] – впливати, шкодити, порушувати, завдавати шкоди, погано позначатися and effect [i'fekt] – результат, наслідок, ефект, враження
I. ANSWER THE QUESTIONS
How are the glands of the body divided?
What are examples of the exocrine glands?
What endocrine glands do you know?
What is the difference between the exocrine and endocrine glands?
What is the function of the pituitary gland?
Where is the pituitary gland located?
What does the thyroid gland stimulate?
Where are the parathyroid glands located?
What do the parathyroid glands regulate?
Where are the adrenal glands located?
What do the adrenal glands influence on?
What are examples of glands belonging to the reproductive system?
What gland belongs to the digestive and endocrine systems?
What gland is called a “biological clock” and why?
What is the value of the endocrine glands in the body?
II. MATCHING (mind that five options in the right are unnecessary)
III. ARE THE FOLLOWING STATEMENTS TRUE OR FALSE?
1. The endocrine or ductless glands have no ducts or openings to the exterior.
2. The hypophysis is located at the base of the spinal cord and is the chief gland of the system.
3. Parathyroid glands are located on the dorsal side of the thyroid gland.
4. Parathyroid hormone regulates magnesium level in the blood and cerebrospinal fluid.
5. The adrenal glands which also are called suprarenal glands are situated one on the top of each lung.
6. Ovaries and testes are a part of the reproductive system and play a great role in its functioning.
7. Pancreas is located behind the liver.
8. The pineal gland secrets melatonin which affects the work of the gland as a "biological clock".
9. The exact function of the thymus is also rather uncertain.
10. A disturbance in the activity of the endocrine glands is accompanied by changes throughout the organism.
11. The pancreas is the gland of a mixed secretion.
12. Insulin and glucagon are the hormones of the thymus gland.
13. Another word for increase in the function is hypofunction.
14. The secretion of the endocrine glands is passed into the alimentary tract.
15. Adrenal glands and gonads are paired organs.
Find synonyms to the words in brackets from medical terms in the box
The endocrine system operates by a number of hormones which are (produced) _______________ into the blood stream.
Hormones either (increase) ____________ or (slow) ___________ the activity of other organs and tissues.
Many hormones (join) _____________ to carrier proteins and this has a (protective) _____________ effect against sudden changes.
Hormone levels generally (go up and down) _______________ but within limits. Thus, the production of thyroxin is (uninterrupted) _____________, while the production of other hormones is (from time to time) __________.
Any imbalance in the endocrine system can have important (results) ________________.
Problems in the functioning of the endocrine system usually involve (making too much) _____________or (making too little) _____________.
Growth hormone is valuable in children to (encourage) ________________ growth.
Calcitonin and parathormone are involved in the (utilization) ___________ of calcium.
Parathormone (keeps) _______________ calcium levels in plasma within normal limits.
Aldosterone is the most important (controller) ____________ of sodium and potassium.
Thyroxin (speeds up) _______________the release of energy in the tissues.
V. THE TEXT FOR THE CURIOUS
Scan the text in order to do the following tasks:
pick up the key words from the text and compare your list with those of your group-mates;
diseases associated with over- and underproduction of growth hormones;
causes of dwarfism and gigantism (acromegaly);
clinical manifestation of the diseases;
secular trends in human growth.
Growth hormone (GH) which is also known as somatotropin is a peptide hormone secreted by the anterior lobe of the pituitary gland. GH stimulates the growth of all the body tissues including bones. On an average the pituitary gland releases 1-2 milligrams of the hormone each day. Normal secretion of GH is especially important for proper physical development of children. Therefore, GH levels rise progressively in childhood and peak during puberty.
GH deficiency may result in dwarfism – short stature. The causes of GH deficiency may be damage to the pituitary gland of hypothalamus during fetal development or after birth, and mutations in genes. Thus, GH deficiency can be congenital or acquired.
Excessive GH production in children may lead to gigantism and acromegaly. Acromegaly is enlargement of the hands, feet, chin, and nose (distal or acral parts) due to overgrowth of the cartilages, muscles, and skin. People with acromegaly have very big internal organs as well – tongue, heart, liver, and kidneys.
Excessive GH secretion is most often caused by tumor of the pituitary gland which is also associated with severe headaches.
It’s an interesting fact that in the last hundred years the stature of people in the world has increased 10-11 cm. The top 10 tallest nations are all in Europe. The tallest people live in the Netherlands. Ukrainian women are on the tenth position in the top 10, while they were 43rd a hundred of years ago!