The diagram shows the loop that follows a rise in body temperature. Stage 3 is missing. Which structure belongs there, the one that receives the signals and orders the correction?

When core body temperature falls, the hypothalamus sends signals that make skeletal muscles contract rapidly in shivering. In this feedback loop, the skeletal muscles act as the:

Several hours after a meal, blood glucose drops below its normal level, and cells in the pancreas detect the drop. What part does the drop in blood glucose itself play in this loop?

The diagram shows how the body corrects a rise in blood pressure, but stage 2 is missing. Which event belongs there?

Core body temperature is held near 37 degrees Celsius, and every correction the body makes pushes it back towards that value. What is this value called?

Blood carbon dioxide rises during hard exercise, chemoreceptors detect it, and the brain stem then makes breathing faster and deeper. In this loop, the faster, deeper breathing is the:

When a blood vessel wall is torn, platelets stick to the damaged area and release chemicals that attract still more platelets, until a clot seals the vessel. What kind of loop is this?

Follow the loop in the diagram from the rise in blood glucose through to the last stage. How is this loop best classified?

Blood calcium rises above normal. The thyroid releases calcitonin, calcium moves from the blood into bone, and blood calcium falls back. Which statement about this loop is correct?

Two hours into a long run, an athlete's blood glucose has fallen below the normal range. Which response brings it back up towards normal?

A student exercising in a warm gym has a core temperature 0.6 degrees Celsius above normal. Which pair of responses returns the temperature towards the set point?

A person who has been lying down stands up quickly, and blood pressure in the arteries of the neck falls for a moment. Which correction restores it?

The diagram shows the loop that follows heavy sweating, but stage 4 is missing. Which event belongs there?

The diagram shows what should happen when the air turns cold, but one stage is wrong. Which replacement makes it a working loop that returns body temperature to normal?

A climber spends three weeks at high altitude, where the air holds less oxygen and the oxygen carried in the blood drops. Which long-term correction does the body make?

A person drinks 1 liter of water quickly, and the water content of the blood rises above normal. Which correction returns it towards the set point?

During a marathon in hot weather a runner becomes badly dehydrated and stops sweating, but keeps running. What is the direct result?

In type 2 diabetes, body cells respond poorly to insulin even though the pancreas is still releasing it. What is the direct result after a meal?

The diagram shows the loop that controls thyroid hormone. In one disorder, antibodies stimulate the thyroid directly, so it ignores the pituitary. Which stage fails, and what follows?

A kidney disorder leaves a patient's kidneys unable to change how much water they return to the blood. Which variable is no longer held near its set point?