Hormonal coordination in humans Flashcards
(32 cards)
Give the name of the body’s coordination system which involves hormones
The endocrine system.
What is a hormone?
A hormone is a chemical messenger secreted by a gland. It travels in the blood to a target organ, where it causes a response.
What type of organ secretes hormones?
Glands.
Which gland controls many other glands in the body?
The pituitary gland.
What is the pituitary gland known as the ‘master gland’?
It secretes a wide range of hormones, some of which stimulate other endocrine glands.
What is the role of the pituitary gland in the endocrine system?
- Secretes human growth hormone: controls human growth.
- Stimulates the thyroid gland.
- Stimulates ovulation and the production of oestrogen in the ovaries.
- Stimulates the production of sperm and testosterone in the testes.
What is the role of the thyroid gland in the endocrine system?
Secretes the hormone thyroxine - controls metabolism, heart rate and body temperature.
What is the role of the pancreas in the endocrine system?
Secretes the hormone insulin - controls blood glucose levels.
What is the role of the adrenal gland in the endocrine system?
Secretes adrenaline - controls the body’s ‘fight or flight’ response.
What is the role of the testes and ovary in the endocrine system?
Testes - Secretes testosterone, which coordinates the production of sperm and the development of male secondary sexual characteristics.
Ovaries - Secretes oestrogen, which coordinates the menstrual cycle and the development of female secondary characteristics
Which organ monitors and controls blood glucose concentration?
The pancreas.
How does the pancreas respond when blood glucose levels are too high?
The pancreas secretes the hormone insulin. Insulin binds to the receptors on the liver and muscles, causing excess glucose to be converted into glycogen and stored. This brings glucose levels back to optimum.
How does the pancreas respond when blood glucose levels are too low?
The pancreas secretes the hormone glucagon. Glucagon binds to liver cells, causing glycogen to be converted into glucose and released into the blood. This brings glucose levels back to optimum.
What is type 1 diabetes?
- Type 1 diabetes is an autoimmune disorder in which the pancreas does not produce sufficient or no insulin to control the blood glucose concentration. As a result, the blood glucose levels are often very high, leading to excessive urination, tiredness and weight loss.
How can Type 1 diabetes be treated?
- Insulin injections before meals - allows glucose to be converted into glycogen.
- Limiting carbohydrate intake.
- Attempts using pancreas and pancreatic cell transplants; investigations into genetic engineering of pancreatic cells.
What is Type 2 diabetes?
Type 2 diabetes is a disorder in which the body’s cells stop responding to insulin, leading to an uncontrolled blood glucose concentration. Its onset is linked with increasing age and obesity.
How can Type 2 diabetes be treated?
- Following a carefully-controlled diet.
- Doing regular exercise.
- Losing weight.
- Use of drugs which increase insulin production and effectiveness.
What is osmosis?
Osmosis is the movement of water from a dilute solution to a concentrated solution through a partially permeable membrane.
In what ways is water lost from the body?
- During exhalation via the lungs.
- Sweating.
- Urine (some reabsorbed in the kidney).
In what ways are ions lost from the body?
- Sweating.
- Urine (some reabsorbed in the kidney).
How are excess amino acids excreted from the body?
- Excess amino acids are deaminated in the liver to form ammonia.
- Ammonia is toxic, therefore it is converted into urea in liver.
- Urea is excreted from the body via sweat and urine.
How do the kidneys maintain the balance of water and other substances in the body?
- Filter blood in order to remove waste products such as urea.
- Selectively reabsorb useful molecules such as glucose, water, ions during filtration.
What is the full name of the hormone ADH?
Anti-diuretic hormone.
Where is ADH secreted in the body?
The pituitary gland of the brain.
