coordination in humans Flashcards
give the name of the body’s coordination system which involves hormones
the endocrine system
what is a hormone?
a chemical messenger secreted by a gland. It travels in the blood to a target organ where it produces a response
what type of organ secretes hormones?
glands
what are the differences between the endocrine and nervous systems?
- in the NS, electrical impulses travel down neurones but the endocrine system uses hormones which are chemicals that travel via bloodstream
- signalling in the NS is extremely fast but the endocrine system produces a slower effect that is longer lasting
which gland controls many other glands in the body ?
the pituitary gland
why is the pituitary gland considered the ‘master gland’?
secretes several hormones into the blood in response to body conditions. These hormones in turn act on other glands to stimulate other hormones to be
released to bring about effects.
what is the role of the pituitary gland in the endocrine system?
- secretes growth hormone, controls human growth
- stimulates the thyroid gland
- stimulates ovulation and 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
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 receptors on the liver and muscles, excess glucose converted into glycogen and stored.
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
how is blood glucose concentration controlled using a negative feedback loop?
- when the blood glucose concentration rises or falls below the optimum, a hormone is secreted by the pancreas
- the action of either hormone (insulin or glucagon) bring back the concentration to the correct level
what is type 1 diabetes?
- an autoimmune disorder in which the pancreas does not produce sufficient insulin to control the blood glucose concentration
- as a result, 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 - allow glucose to be converted into glycogen
- limiting carbohydrate intake
- regular exercise
what is type 2 diabetes?
a disorder in which the body’s cells stop responding to insulin, leading to an uncontrolled blood glucose concentration. Obesity and increasing age are risk factors
how can type 2 diabetes be treated?
- following a carefully controlled diet ( low carb diet )
- doing regular exercise
- losing weight
- use of drugs which increase insulin production and effectiveness
in what ways are ions lost from the body?
- sweating
- urine ( some reabsorbed in the kidney)
in what ways is water lost from the body?
- during exhalation via the lungs
- 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 converted into urea
- 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 e.g. urea
- selectively reabsorbed useful molecules e.g. glucose, water, ions
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