Homeostasis Flashcards
All 14 cards in this deck
What is homeostasis?
The maintenance of a constant internal environment (constant internal body conditions) in response to internal and external change.
Why must the body keep its internal environment constant?
So that cells and enzymes work properly, at their optimum conditions, so the body functions normally.
True or false? Blood glucose concentration is one of the internal conditions controlled by homeostasis.
True. Homeostasis keeps blood glucose concentration within narrow limits.
Which endocrine gland and which hormone control blood glucose concentration?
The pancreas — insulin.
What are the steps by which insulin lowers blood glucose concentration?
e.g. after eating a meal containing carbohydrate
- Blood glucose rises, so the pancreas releases (more) insulin.
- Insulin makes the liver and muscle cells absorb glucose.
- Glucose is converted to / stored as glycogen, or used in respiration — so blood glucose falls.
True or false? Insulin raises blood glucose concentration.
False. Insulin lowers blood glucose concentration.
In a healthy person, what trend is seen in blood glucose concentration in the hour after a meal?
It increases first, then decreases back towards the pre-meal level as insulin is released.
How is type 1 diabetes controlled?
By insulin injections, together with controlling carbohydrate/sugar in the diet and exercise.
State the cause of type 2 diabetes.
The body's cells have stopped responding to insulin (insulin resistance).
State two ways a person with type 2 diabetes can control their blood glucose concentration.
Reduce carbohydrate / sugar in their diet, lose weight, exercise more, or take medication (e.g. metformin or insulin).
What is the equation for BMI?
BMI = mass (kg) ÷ (height (m))²
How is a waist : hip ratio calculated, and what does a high value mean?
Waist measurement ÷ hip measurement. A high ratio means more fat is stored around the waist, which is linked to a higher risk of type 2 diabetes.
What correlation do data show between body mass and type 2 diabetes?
A positive correlation — as body mass (or BMI) increases, the risk of developing type 2 diabetes increases.
What is the cause of type 1 diabetes?
The pancreas produces little or no insulin, so blood glucose concentration can rise too high.