homeostasis - blood glucose conc. Flashcards
(18 cards)
What is homeostasis?
Homeostasis is the maintenance of a constant internal environment.
How is our kidneys an example of homeostasis?
When there are toxic molecules such as urea, excess water, and excess ions in our blood, our kidneys filter them out so we have the correct levels of everything in our blood, keeping our cells working efficiently.
What are three things we need to keep constant (or almost constant) in our body, and why?
Temperature (37C) - so our enzymes can work properly (optimum temp)
Quantity of water (so cells are not damaged by losing/gaining water)
Concentration of glucose in blood. (for respiration, so we can have enough energy)
Equation for respiration?
Glucose + oxygen -> water + CO₂
What 2 systems does homeostasis involve?
The nervous system and the endocrine system (hormones).
What are the 2 hormones secreted by ____ to control blood glucose concentration?
Insulin and Glucagon, secreted by islets (small groups of cells) in the pancreas.
What is a set point?
A range of values for a particular parameter- the concentration of glucose in our blood does not stay absolutely constant, at one value. It should be in between 0.8-1.1 mg/cm³.
What can lower our blood glucose conc. below the set point?
Forgetting to eat and exercising/overly exerting yourself.
What are the 3 components of negative feedback?
- A set point the system tries to maintain
- a measuring point to keep track of the level (ex: the pancreas keeping track of blood glucose levels)
What are the features of a hormone?
Made by an endocrine gland, transported in the blood, and used to alter the activity of a certain target organ.
What is type 1 diabetes?
A condition in which insufficient (not enough) insulin is secreted by the pancreas. So blood glucose conc. is not controlled.
What is thought to have caused type 1?
The body’s immune system attacking itself.
What happens if you have type 1 diabetes and your blood glucose conc. increases?
Because no insulin is being secreted (causes liver to absorb glucose) to combat this, blood glucose levels remain high, above the set point.
What are the symptoms one might feel if their blood glucose conc. was too high?
They would feel unwell, having a dry mouth and blurred vision, as well as feeling thirsty, and might even have a high heart and breathing rate.
What happens if you have type 1 diabetes and your blood glucose conc. decreases?
Because no insulin has been secreted, glycogen stores have not built up, and they cannot be broken down to release glucose. Blood glucose levels remain low, below the set point.
What are the symptoms one might feel if their blood glucose conc. was too low?
As there is not enough glucose, respiration cannot happen, and cannot release energy, making the person feel very tired, with low energy. This can cause confusion and irrational behavior, eventually, leading to them becoming unconcious.
How can we treat Type 1?
Usually, people with type 1 usually check their blood sugar with a simple sensor. They also check their urine for glucose with a dipstick. If blood glucose is very high, not all of it can be reabsorbed back into the blood, so some remains in the blood when excreted. To stop it from fluctuating too much, we can eat little, and often, avoiding large amounts of carbs and sugars, and eating regularly and especially after exercising.
What are the 2 types of insulin injections we can use to treat type 1?
Rapid-acting: Taken before/after meals, and depends on how much carbs (sugars) have been eaten.
Long-acting: taken once a day, usually at the same time, kind of acts like a “Backup dosage” of insulin.
