Homeostatic Quiz

Quiz 1

What is the general purpose of positive feedback mechanisms?

To bring about a rapid change in the body

When body temperature rises above normal, the body responds by sweating to cool down. When body temperature drops, the body responds by shivering to generate heat. What type of feedback mechanism does this process illustrate?

negative feedback.

When a blood vessel is injured, it releases chemicals that activate platelets and cause them to stick to the injury site. The activated platelets in turn release more chemicals and attract more platelets to the injury site until the wound is fully sealed. This process of blood clotting is an example of

positive feedback.

Which of the following situations best represents a homeostatic mechanism?

After eating a large batch of salty popcorn, levels of salt in the urine increase.

The hormone insulin enhances the transport of glucose into body cells. Its secretion is controlled by a negative feedback system between the concentration of glucose in the blood and the cells that secrete insulin. Which of the following statements is most likely to be correct?

An increase in blood glucose concentration will stimulate insulin secretion, which will in turn lower the blood glucose concentration.

Which concept is the defining feature of the discipline of physiology?

Homeostasis

Physiology is the study of

how organisms function.

During childbirth, as a baby's head is pressed against the mother's cervix, signals are relayed via nerves from cervix to the mother's brain. The brain initiates the secretion of oxytocin (a hormone) from the mother's pituitary gland. Oxytocin stimulates further uterine contractions. As the uterus contracts even harder in response to oxytocin, the baby's head is pushed harder against the cervix; this stimulates yet more nerve signals to the mother's brain, resulting in yet more oxytocin secretion until finally the baby is pushed through the cervix. This process of childbirth is an example of

positive feedback.

What is a hormone?

A chemical regulator secreted from an endocrine gland that travels through the bloodstream to affect target cells

The term used for balance of the body is ____

Homeostasis