endocrine system and the fight or flight response

hypothalamus

connected to the pituitary gland and stimulates and controls the release of hormones from the pituitary gland.

pituitary gland

• releases hormone TSH and ACTH.

• master gland as it controls all other glands, e.g. TSH signals action in the thyroid and ACTH signals action in the adrenal glands.

pancreas

• releases hormone insulin.

• promotes absorption of glucose from the blood into fat, liver and skeletal muscle cells.

• lowers blood glucose levels.

adrenal glands

• releases hormones adrenaline and noradrenaline.

• responsible for reacting to threat during the fight or flight response.

ovaries

• releases hormones oestrogen and progesterone.

• responsible for development and regulation of the female reproductive system and secondary sex characteristics.

pineal gland

• releases hormone melatonin.

• regulates the sleep-wake cycle.

fight or flight response

• threat detected by sensors in the eye and is then passed to the hypothalamus.

• hypothalamus stimulates pituitary gland to release ACTH, which is then detected by cells in the adrenal glands.

• the adrenal glands then produce adrenaline stimulating the fight or flight response.

• this causes increased heart rate to pump blood to vital organs, stomach to divert blood to muscles to increase strength, pupils dilate for increased vision, and lungs increase breathing rate for more oxygen.

• after threat has passed, parasympathetic nervous system returns the body to normal by establishing homeostasis.

• heart rate and respiratory rates decrease, adrenaline secretion slows down, the feeling of butterflies subside and sweating stops.