Flashcards in Hormones and Homeostasis Deck (43):
What is the endocrine system made up of?
Glands that secrete hormones directly into the bloodstream
What are hormones?
Chemical messengers that are carried in blood to target organs
What are the 2 differences between endocrine and nervous system?
1) Slower than effects of nervous system
2) Act for longer
Where is the pituitary gland and what is it classed as?
In the brain, the 'master gland'
What doe some of the hormones it releases do?
Stimulate the release of other hormones
Where is adrenaline produced?
When is adrenaline produced?
In times or fear or stress
What is the effect of adrenaline?
Increases the heart rate, boosting the delivery of oxygen and glucose
Why is adrenaline produced?
To prepare the body for fight or flight
Where is thyroxine produced?
What does thyroxine do?
Increases the metabolic rate
What does thyroxine control?
Growth and development in young animals
How is thyroxine controlled?
By negative feedback
Where do enzymes come from and go to?
From glands and pass into tubes called ducts
What are endocrine glands?
Ductless glands, because hormones pass into blood
What does the pancreas control?
Blood glucose concentration
If the blood glucose level is too high...
1) Pancreas releases more insulin
2) Insulin causes glucose to move from blood into cells
3) In liver and muscle cells, excess glucose converted into glycogen for storage
If blood glucose level is too low...
1) Pancreas releases glucagon
2) Glucagon stimulates glycogen to be converted back into glucose and released into blood
What is the control of blood glucose an example of?
What is type one diabetes caused by?
Pancreas failing to produce enough insulin
What does type one diabetes cause?
Uncontrolled high blood glucose levels
How is type one diabetes treated?
What is type two diabetes caused by?
Body cells no longer responding to insulin
What is one risk factor of type two diabetes?
How is type two diabetes treated?
Controlled diet and regular exercise
When does water leave the body?
From the lungs during breathing
How does water leave the body?
Through skin in sweat and in urine
If the concentration of the blood changes...
Body cells will gain too much water by osmosis
What does the kidney regulate?
Balance of water and ions
What do the kidneys excrete?
What is urea?
A waste product that is produced by the liver from the breakdown of protiens
What does the digestion of proteins from food result in?
Excess amino acids
What happens to the excess amino acids?
Converted into ammonia by demination by the liver
Why is ammonia converted to urea and sent to kidneys?
It is toxic
How do kidneys produce urine?
1) Filtering the blood
2) Selective re absorption of useful substances e.g. glucose, ions and water
3) Leaves urea and excess water and ions to form urine
Where does the production of urine take place?
In tiny tubes in the kidneys called tubules
What controls water level
The hormone ADH
When is ADH released?
When blood is too concentrated
What releases ADH?
The pituitary gland
What does ADH cause?
More water to be reabsorbed into the blood
Where does ADH pass in?
The blood to the kidney tubules
What 2 ways can kidney failure be treated?
1) Organ transplant
2) Kidney dialysis