homeostasis

2 mechanisms your body uses to heat itself

-blood vessels in skin constrict, reducing heat loss -muscles being to shiver generating heat

positive feedback examples

-enhancement of labor contractions by oxytocin -platelet plug formation and blood clotting

positive feedback

A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.

Which of the following is true of positive feedback?

Change in amplified

When blood sugar levels increase after a meal, insulin is released. This lowers sugar levels back toward normal. This is an example of

Negative feedback

When there is a change in the internal body environment, how will the body react to maintain homeostasis by negative feedback?

Oppose the change

During childbirth, the baby pushes on the wall of the uterus. This is detected by pressure receptors that signal the brain to release oxytocin. If this is a positive feedback process, select the likely next step.

Oxytocin causes the uterus to contract, further stimulating the receptors and releasing more oxytocin from the brain

When a blood vessel is damaged, platelets attach and recruit more platelets to the area. These new platelets recruit even more, quickly increasing the number of platelets until the damage is sealed with a blood clot. This amplification is an example of

Positive feedback

Thermoreceptors detect body temperature and send impulses to the brain for analysis. If body temperature is low, the brain will signal skeletal muscles to perform brief, repeated contractions to help generate heat. In this example, what is the effector?

Skeletal muscles

When a variable is regulated by negative feedback, its value fluctuates above and below the set point rather than being a constant.

True

positive feedback

When a stimulus is reinforced to continue in the same direction until a climactic event occurs, it is best as described as which of the following?

negative feedback

a mechanism of response in which a stimulus initiates reactions that reduce the stimulus

thermoregulation

a process that allows your body to maintain its core internal temperature

mechanism that the body uses to cool itself 1

blood vessels in skin dilate to radiate heat

what portion of the brain contains sensors that monitor body temperature

hypothalamus

stimulus for childbirth

hypothalamus releases oxytocin

hormone released from brain that increases intensity of contractions

oxytocin

mechanism that the body uses to cool itself 2

sweat glands increase sweat production

Homeostasis is best described as

the maintenance of a stable internal environment despite a changing external environment.

Response for childbirth

uterine walls contract and baby pushes against the cervix