Lesson 7
Date: 2015-10-07; view: 395.
Goiter
The term non-toxic goiter refers to enlargement of the thyroid that is not associated with overproduction of thyroid hormone or malignancy. The thyroid can become very large so that it can easily be seen as a mass in the neck. There are a number of factors that may cause the thyroid gland to become enlarged. A diet deficient in iodine can cause a goiter. A more common cause of goiter is an increase in thyroid stimulating hormone (TSH) in response to a defect in normal hormone synthesis within the thyroid gland. The thyroid stimulating hormone comes from the pituitary and causes the thyroid to enlarge.
· Try to guess what disease of endocrine system is spoken about?
1. It is a disorder of the adrenal cortex caused by a malignant or benign adrenal cortex tumor that results in excess production of cortisol. Some symptoms of this disease may include kidney stones, central body obesity, glucose intolerance and emotional liability.
2. This is a bone disease caused due to lack of minerals (especially calcium) and a significant loss of bone mass or density, when parathyroid gland does not function well.
3. This is a growth disorder caused by too much growth hormone being released by the pituitary gland, leading to excessive growth.
4. An enlargement because of swelling caused by disease of the thyroid gland, often visible in the lower part of the neck.
5. A chronic disease involving an insulin deficiency because of hypofunction of the pancreas that can be characterizes by the excess of sugar in the urine, hunger, thirst and gradual increase in weight.
6. This is primary adrenal insufficiency that develops when the adrenal glands do not produce enough of the hormone cortisol.
7. The disease of the endocrine system caused by the excessive secretion of somatotropin by adenohypophysis of the pituitary gland that results in short stature and undersize.
· What do you know about hormones as biological substances? Share your ideas with your partner.
· Try to continue the puzzle with your own word concerning the topic HORMONES:
H – hunger craving, _______________________________
O – oxytocin, ____________________________________
R – regulation of metabolism, ________________________
M – melatonin,___________________________________
O – osteocalcin, ___________________________________
N – norepinephrine, ________________________________
E – estrogen,_____________________________________
S – somatostatin, __________________________________
· Read the text HUMAN HORMONES, make up a plan to it and try to retell using active vocabulary to the topic:
to alter cell metabolism – çì³íþâàòè êë³òèííèé ìåòàáîë³çì
to be inhibited by – áóòè ïðèãí³÷åíèì, çíèæåíèì
mental activity – ðîçóìîâà ä³ÿëüí³ñòü
inhibition of growth – ïðèãí³÷åííÿ ðîñòó
mood swings – ð³çê³ çì³íè íàñòðîþ
induction/suppression of apoptosis – çáóäæåííÿ/ïðèãí³÷åííÿ àïîïòîçó
derivatives of the amino acid – ïîõ³äí³ àì³íîêèñëîò
therapeutic administration – òåðàïåâòè÷íå, ë³êóâàëüíå ââåäåííÿ
to suppress inflammation – ïîñëàáèòè, çóïèíèòè, ïîäîëàòè çàïàëåííÿ
to measure the hormone level – âèì³ðþâàòè ð³âåíü ãîðìîí³â
HUMAN HORMONES
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a little amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one cell to another. Hormones in humans are often transported in the blood. Cells respond to a hormone when they express a specific receptor for that hormone.
Hormone secretion can be stimulated and inhibited by:
ü Other hormones (stimulating- or releasing -hormones)
ü Plasma concentrations of ions or nutrients, as well as binding globulins
ü Neurons and mental activity
ü Environmental changes, e.g. of light or temperature
One special group of hormones is the tropic hormones that stimulate the hormone production of other endocrine glands. For example, thyroid-stimulating hormone (TSH) causes growth and increased activity of another endocrine gland, the thyroid, which increases output of thyroid hormones.
Hormones have the following effects on the body:
ü stimulation or inhibition of growth
ü mood swings
ü induction or suppression of apoptosis (programmed cell death)
ü activation or inhibition of the immune system
ü regulation of metabolism
ü preparation of the body for a new phase of life, such as puberty, parenting, and menopause
ü control of the reproductive cycle
ü hunger cravings
ü sexual arousal
A hormone may also regulate the production and release of other hormones. Hormone signals control the internal environment of the body through homeostasis.
Chemically, most hormones belong to one of three major groups: proteins and peptides, steroids (fat-soluble molecules whose basic structure is a skeleton of four carbon rings), or derivatives of the amino acid tyrosine. There are some hormones, such as melatonin from the pineal gland and the locally acting prostaglandins, which cannot be included in any of these groups, but may share a number of their characteristics. The glands which produce protein and peptide hormones are the pituitary, certain cells of the thyroid, the parathyroids, and the pancreas. Steroids are produced by the cortex or outer layer of the adrenal gland and by the ovaries and testes. The tyrosine derivatives are the thyroid hormones, and the catecholamines (adrenaline and noradrenaline) which are produced in the medulla of the adrenal glands.
Knowledge of the chemical nature of a hormone is important as it enables one to predict how the hormone is produced, how rapidly it can be released in response to a stimulus, in what form it circulates in the blood, how it acts, the time course of its effect, and the route of administration therapeutically.
Many hormones and their analogues are used as medication. The most commonly prescribed hormones are estrogens and progestagens (as methods of hormonal contraception), thyroxine (for hypothyroidism) and steroids (for autoimmune diseases and several respiratory disorders). Insulin is used by many diabetics. Local preparations for use in otolaryngology often contain pharmacologic equivalents of adrenaline, while steroid and vitamin D creams are used extensively in dermatological practice.
A "pharmacologic dose" of a hormone is a medical usage referring to an amount of a hormone far greater than naturally occurs in a healthy body. The effects of pharmacologic doses of hormones may be different from responses to naturally occurring amounts and may be therapeutically useful. An example is the ability of pharmacologic doses of glucocorticoid to suppress inflammation.
Hormones are powerful. It takes only a tiny amount to cause big changes in cells or even your whole body. That is why too much or too little of a certain hormone can be serious. Laboratory tests can measure the hormone levels in your blood, urine or saliva. Your doctor may perform these tests if you have symptoms of a hormone disorder.
· Decide if the statements are true or false:
1. Endocrine hormone molecules are secreted directly into the bloodstream.
2. The classical hormones produced by cells in the endocrine glands are cellular products, specialized to serve as regulators at the overall organism level.
3. Human hormones fall into four chemical classes.
4. Peptide hormones consist of chains of amino acids.
5. Hormones are produced not only by major endocrine glands but also by organs or tissues whose function is not primarily an endocrine one.
6. Hormones act as chemical messengers helping to regulate specific body functions.
7. Hormone secretion can be stimulated by nervous and respiratory systems, mental activity, other hormones and environmental changes.
8. Activation or inhibition of the immune system is the function that can never be regulated by endocrine hormones.
9. Metabolism regulation is the main function of hormones.
10. Many hormones and their analogues are used as medication in dermatological practice, otolaryngology and for autoimmune diseases treatment.
11. Only a huge amount of hormones can cause big changes in cells or even your whole body.
12. A "pharmacologic dose" of a hormone is a medical usage referring to an amount of a hormone equal to naturally occurring in a healthy body.
13. Simple laboratory tests of your sweat, urine or saliva can measure the hormone levels in body.
14. If prescribed correctly hormones can be used to treat hypothyroidism, autoimmune diseases, respiratory disorders and diabetes.
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