Homeostasis Flashcards
What is homeostasis?
The maintenance of a constant internal environment,
What are the three main things the body keeps constant?
- Water and ion content
- Body temperature
- Blood glucose level
Why does carbon dioxide need to be removed from the body?
It is highly toxic in large quantities.
How is carbon dioxide removed from the body?
The blood carries it to the lungs where it gets breathed out.
What is urea?
The waste products from when excess amino acids are broken down and used to make fats and carbohydrates.
Why does urea need to be removed from the body?
It’s poisonous.
How is urea removed from the body?
The liver releases it into the blood stream an then the kidneys filter it out. It’s temporarily stored in the bladder in urine and then excreted.
What are the three functions of the kidneys?
- The removal of urea
- Adjustment of ion content
- Adjustment of water content
How do ions enter the body?
In food
How does water enter the body?
Food and drink
What are the three ways water is lost from the body?
- Urine
- Sweat
- Exhaled air
What are nephrons?
Tiny structures in the kidney that filter the blood and produce urine. There are thousands in each kidney.
What is stage one of urine production?
Ultrafiltration
What happens during ultrafiltration?
Blood from the renal artery enters the kidney. High pressure builds up in the blood vessels which squeezes water, urea, ions and sugar into an area called the capsule in the nephron.
Why aren’t proteins and blood cells absorbed during ultrafiltration?
They are too large to fit through the membrane between the renal artery and the capsule.
What is stage two of urine production?
Reabsorbtion