Endocrine or Hormonal System Year 9 Science Add slide about difference between endocrine and nervous system

Endocrine system Many endocrine glands form part of the endocrine system Controls many body activities such as the body temperature, water balance, and growth and our sexual characteristics

Endocrine Glands Located in various areas around the body The pituitary gland plays a major role in regulating and homeostasis and is found below the hypothalamus of the brain Other endocrine glands include the thyroid gland, pancreas, adrenal glands and sex organs Many are controlled by the pituitary gland

Hormones Hormones are chemical substances produced by the endocrine glands and act as messengers in the body Are produced in very small amounts but can have a long-lasting effect Hormones are released directly into the bloodstream so endocrine glands are referred to as ‘ductless’ glands Effect of hormones is slower than nerves

Hormones They are transported by the blood and have the potential to reach and affect every cell of the body Most hormones act or have an effect on only particular parts of the body which are called the target tissue or organ.

What makes hormones? Hormones can either be made mostly from proteins of mostly from fats (steroid hormones) This has important implications for the mechanism of delivery when a person’s endocrine system requires supplementation

Pituitary Gland Is about 1 cm in diameter - the size of a pea Located at the base of the brain It is connected to and controlled by the hypothalamus in the brain Provides a link between the nervous and endocrine systems

Pituitary Gland… Considered one of the most important glands in the body Releases its own hormones and also controls the activities of other endocrine glands such as the ovaries, testes and the thyroid gland It directly controls many body activities such as the body temperature, water balance, and growth

Example of a negative feedback loop

Example of a positive feedback loop – oxytocin