Homestasis Positive Feedback Loop

Blood Clotting – Stimulus

Blood vessel injury

Blood Clotting – Receptor

Platelets detect injury

Blood Clotting – Control Center

Platelets release chemicals

Blood Clotting – Effector

More platelets & clotting factors activated

Blood Clotting – Response

Clot forms

Childbirth Contractions – Stimulus

Baby pushes on cervix

Childbirth Contractions – Receptor

Cervical stretch receptors

Childbirth Contractions – Control Center

Hypothalamus → pituitary (oxytocin)

Childbirth Contractions – Effector

Uterine muscles contract

Childbirth Contractions – Response

Baby pushed further → stronger contractions

Fever – Stimulus

Infection → pyrogens released

Fever – Receptor

Hypothalamus detects pyrogens

Fever – Control Center

Hypothalamus resets temperature set-point

Fever – Effector

Muscles shiver; blood vessels vasoconstrict

Fever – Response

Body temperature increases

Lactation – Stimulus

Baby suckling

Lactation – Receptor

Nipple mechanoreceptors

Lactation – Control Center

Hypothalamus → pituitary (oxytocin)

Lactation – Effector

Mammary glands release milk

Lactation – Response

Milk ejection continues as long as baby nurses

Ovulation – Stimulus

Rising estrogen from follicle

Ovulation – Receptor

Hypothalamus detects estrogen

Ovulation – Control Center

Hypothalamus → anterior pituitary (LH surge)

Ovulation – Effector

Ovary releases egg

Ovulation – Response

Ovulation occurs