Endocrine system

Endocrine system

A regulation system comprised of glands

Glands

Organs that release or secrete a substance

Exocrine glands

Secrete their product through a duct

Endocrine glands

Are ductless glands that secrete their products straight into the bloodstream

Difference in message and type of message

electrical or chemical nerve impulse, chemical hormone

Difference in how it is transmitted

Neurones, bloodstream or pore

Difference in response

Short lived, longer lasting

Difference in area of effect

Localised, widespread

Difference in cells it acts on

Neurones muscles and glands, target cells with protein receptors on membrane

Difference in speed of reaction

Fast with instant effect, slower taking longer to act

Endocrine glands in the body

Pituitary, thyroid, pancreas, adrenals, testes, ovaries

Pituitary

Located in the brain

What hormones does the pituitary produce

Follicle stimulating hormone, luteinsing hormon, antidiuretic hormone

Follicle stimulating hormone (FSH)

Stimulates egg development and oestrogen secretion in females, sperm production in males

Luteinising hormone (LH)

Stimulates egg release in females and testosterone production in males

Antidiuretic hormone (ADH)

Controls water content of the blood by stimulating reabsorption of water in the kidneys

Thyroid

Produces the hormones Thyroxime T4,T3 which controls the body metabolic rate

Pancreas

Produces insulin and glucagon which raises blood levels by stimulating the breakdown of glycogen to glucose in the liver

Insulin

Lowers blood glucose levels by increase glucose uptake, is responsible for the conversion of glucose to glycogen in the liver

Diabetes

When a person body can’t make enough insulin to keep blood glucose level constant making the person thirsty

Adrenals

Produces adrenaline when frightened which prepares the body for physical activity and initiates the fight or flight response

Fight or flight response

Breathing rate increase to increase aerobic respiration, heart beats faster, blood is diverted away from the intestine, glycogen is converted to glucose, pupils dilate, body hair stands up

Testicles

Produces testosterone which controls the development of male secondary sexual characteristics

Ovaries

Produces oestrogen which controls the development of female secondary sexual characteristics, progesterone which regulates the menstrual cycle