Tissues and Feedback Loops

If the environment gets cold, we will often shiver in order to:

• keep body temperature the same as the external temperature

• decrease body temperature

• increase body temperature

• regulate blood pressure

An example of a negative feedback loop is ...

• Blood glucose regulation

• Temperature regulation

• Heart rate regulation

• All of the above

What hormone is produced in the pancreas that lowers blood sugar?

• Insulin

• Glucagon

• Glucose

• Eating more sugar

When you get cut, your skin cells release hormones that signal platelets to come and stop the bleeding. Platelets then release more hormones that signal even more platelets to help stop bleeding. The hormone signals continue until the cut is closed. This is an example of what type of feedback?

• Negative Feedback

• Positive Feedback

Homeostasis:

• allows for a wildly fluctuating internal environment

• is the maintenance of a relatively stable internal environment and often incorporates a form of feedback regulation

• is the maintenance of a relatively stable external environment and does not incorporate a form of feedback regulation

• when you stay at home

Which of the following scenarios describes a positive feedback mechanism?

• After childbirth, high levels of prolactin induce lactation in the mother. During nursing, infant suckling triggers the release of more prolactin, which further stimulates lactation.

• After eating, blood glucose levels rise, stimulating the release of insulin from the pancreas. Insulin causes cells to uptake glucose from the blood, lowering blood glucose levels.

• several hours after a meal, blood glucose levels begin to drop, prompting the pancreas to secrete glucagon. Glucagon causes the liver to convert stored glycogen into glucose, raising blood glucose levels.

• During exercise, an increase in body temperature causes the body to produce sweat. As the sweat vaporizes, the body cools down due to evaporative cooling.

Feedback interactions in the human body are important because they

• determine the diversity necessary for evolution to occur.

• direct the synthesis of altered genes that are passed on to every cell in the body.

• regulate the shape of molecules involved in cellular communication.

• keep the internal body environment within its normal range.

Failure to maintain homeostasis could result in:

• lack of internal balance
• eventual death
• difficulty carrying on metabolism 
• all three

Which of the following is a type of muscle tissue.

• Blood
• Skin
• Cardic
• Bone

Which of the following is NOT a type of connective tissue?

• Adipose
• Blood
• Cartilage
• Skin