Chapter 11 - Homeostasis

Vasodilation

the relaxation of smooth muscles in the arteriole walls.

hypothalamus

The organ which is stimulated to send out nerve impulses to arterioles in the skin, stimulating vasoconstriction.

Thermoregulation

the maintenance of body temperature within a range that will allow cells to function effectively.

epidermis

the outermost layer which forms a waterproof and protective covering in the skin

Negative feedback

a corrective mechanism in which the bodys response is to restore the normal conditions of the internal environment.

sweat

The fluid which evaporates so that heat can be removed through evaporation

thermoreceptors

Structures in the skin send signals to the hypothalamus.

Homeostasis

the maintenance of a constant internal environment.

Stimulus

a change in internal environment

adipose tissue

the always-present layer beneath the skin which acts as insulation.

Osmoregulation

the maintenance of a constant water potential and pH

Dermis

layer containing hair follicles, sweat glands, sebaceous glands, blood vessels and thermoreceptors.

sweat glands

coiled tubes that secrete sweat through a sweat duct.

Hair erector muscles

muscles which relax so that hair follicles lie flat.