Excretion- Chapter 13 Flashcards
What is homeostasis:
the maintenance of constant internal environment
Internal environment: conditions inside the body
Homeostasis, helps our cells to work efficiently
Keeping body temperature constant, helps enzymes work at the optimum rate.
Keeping constant water sources means that cells aren’t too damaged, due to osmosis.
And that there is also constant concentration for glucose, enough fuel for respiration.
Why is controlling blood glucose concentration so important
IF it’s low, less energy for respiration, the brain is heavily dependent on it . If it is high, then it causes water to move from cell to blood, through osmosis. This leaves cells with too little water to carry on metabolic reactions.
How is blood glucose concentration controlled and what are islets and thier function.
It is controlled by the hormone insulin which is secreted by the pancreases. It decreases blood glucose level concentration. It is also controlled by another hormone secreted by the pancreas known as glucagon. It increases blood glucose concentration. There are groups of cells called islets scattered through the pancreas. They produce hormones. Which helps the liver maintain blood- glucose levels.
What happens when we eat a meal that has a lot of glucose?
The concentration of the glucose in the blood goes up, the islets detect this and secrete insulin. When it reaches the liver, it causes the liver to absorb glucose from the blood. Some of it is used for respiration but some is converted to glycogen, which is stored in the liver.
What happens when we eat a meal that has less glucose, or our body is running low on glucose?
The secretion of the glucagon molecule causes the liver to break down its glycogen stores. The glucose molecules that are produced, more into the blood, increasing the blood-glucose concentrations.
What is Type 1 Diabetes?
In some bodies the cells that secrete insulin die. This is known as type 1 diabetes. A condition in which insufficient insulin is secreted by the pancreas, so that the blood glucose concentration isn’t controlled. It isn’t a disease that really causes this. But it’s mostly a result of the body attacking its own immune system and destroying the cells in the pancreas that secrete insulin.
How do they react to an irregulation of blood-glucose level concentration?
When a person with type 1 diabetes eats heavy glucose containing food, it makes the person feel unwell, and they have a dry mouth, blurred vision. But if they don’t eat carbohydrates their blood-glucose concentration will decrease. Because no insulin has been secreted, there are no stores of glycogen.
How do they treat and maintain their condition?
They usually check their blood-glucose level concentration with a simple sensor. They can also test for urine for glucose with a small dipstick. They also have to regulate their carbohydrates intake, and make sure it regulates with their activities. Most people will also have to inject themselves with insulin. There are several types on insulin, and the treatment plan is discussed with doctor. But if they need to take rapid-acting insulin, they take it before eating or after eating a meal. THey need to judge how much carbohydrate they are eating, and adjust the dose accordingly. They also may need to take long-acting insulin . This is taken once a time, at the same time each day, it provide a background dose of insulin.
what is urea and how is it removed
Waste products in liver to break down of excess amino acids. Too much urea in the blood is toxic.
Urea is removed by the kidneys, kidneys also release excess water and ions from the blood forming urine, when it mixes with urea. Urine flows to ureters and bladder where its stored. Once spinchter muscles near the entrance of the urethra relaxes, urine flows our through it. Ureter and urethra are tubes.
How is urea produced?
1) Protein in food is taken into alimentary canal
2) Protein molecules are broken down in amino acids during digestion
3) Amino acids are absorved into blood and take to liver in the hepatic portal vein
4) Amino acids that are needed are made into proteins in liver or reased into blood to be assimilated,
6) Amino acids that aren’t required, are deanimated into carbohydrates and a nitrogen- containing compound.
6) Carbohydrates are formed, and stored in liver
7) Nitrogen containing part is converted to urea, and flows into the blood, to be excreted.
What is the cortex and medulla?
How is urine produced
What does the hypothalamus do?
It is the center of the control mechanism that keeps internal temperature constant. Coordinates activities of other parts of body, tat helps to keep the temperature at its set point.
It acts like a thermostat. It contains temperature receptors , that sense the temperature of the blood running through it. It his is above or below set points, hypothalamus sends electrical impulses along neurons, to the parts of the body, which have functions for regulating body temperature. There are receptors on our skin, that sense the weather around, them and can plan for the future.
