Homeostastis

Question 1

Define Homeostasis

Answer 1

The maintenance within narrow limits of a stable internal environment despite a changing external environment.

Question 2

Explain the negative feedback model

Answer 2

Negative feedback are mechanisms that counteract the stimulus e.g. high blood glucose is counteracted by the storage of glucose as glucogen in tissue.

Question 3

Explain how body temperature is kept constant using stimulus response model

Answer 3

Temperature receptors in skins detect a change in temperature. A signal is sent to the brain and the pituitary gland. The brain uses effector nerves to stimulate effectors. The body temperature is kept stable

Question 4

Explain the function of 4 effectors in thermotregulation, two physical and two metabolic.

Answer 4

Arrector pilli muscles raise or flatten hairs to insulate body. Sweat gland secrete water to cool down the body. The thyroid secretes thyroxine to speed up metabolism. The adrenal medulla gland produces adrenaline