The endocrine system Hormones

LO:

• Define the term hormone • Identify specific endocrine glands and their

secretions (adrenal glands and adrenaline, pancreas and insulin, testes and testosterone and ovaries and oestrogen)

• Describe adrenaline as the hormone secreted in ‘fight or flight’ situations and its effects

LO:

• Discuss the role of the hormone adrenaline in the chemical control of metabolic activity, including increasing the blood glucose concentration and pulse rate

• Give examples of situations in which adrenaline secretion increases

• Compare nervous and hormonal control systems in terms of speed and longevity of action;

• State the functions of insulin, oestrogen and testosterone

THE ENDOCRINE SYSTEM

• Carries out long term coordination of the organism

• Consists of organs – glands which secrete chemicals called hormones

• The glands are ductless – secrete their hormones directly to the blood stream

LO: Define the term hormone

HORMONE

• a chemical substance• produced by a gland, carried by the blood, • alters the activity of one or more specific

target organs • is then destroyed by the liver

LO: Identify specific endocrine glands and their secretions

ADRENAL GLANDS - ADRENALINE

LO: Describe adrenaline as the hormone secreted in ‘fight or flight’ situations and its effects

Adrenaline

• It is chemical messenger and is released directly into the bloodstream

• Its actions are often very rapid and may last for a very short time

• It is released when the body is given a shock

Bridges the gap between nervous and endocrine system

LO: Describe adrenaline as the hormone secreted in ‘fight or flight’ situations and its effectsEffects of adrenaline• Skin becomes pale as blood is diverted away• Deeper, more rapid breathing and airways become wider• Heart beats more rapidly• Blood is diverted away from digestive system to muscles

by using sphincters• Adrenal glands release the hormone adrenaline• Glycogen in muscles is converted to glucose, and released

into the blood• Widened pupils• Adrenaline

LO: Identify specific endocrine glands and their secretions

PANCREAS - INSULIN

LO: Identify specific endocrine glands and their secretions

PANCREAS - INSULIN • Produces: insulin and glucagon control blood

sugar concentration• Insulin is produced in the β cells of pancreas• It allows cells to use glucose for respiration

LO: Identify specific endocrine glands and their secretions

TESTIS - TESTOSTERONE• Responsible for many of the

physical characteristics specific to adult males

• It plays a key role in reproduction and the maintenance of bone and muscle strength

• In women, testosterone is produced by the ovaries and adrenal glands.

• The majority of testosterone produced in the ovary is converted to the principle female sex hormone, oestradiol

LO: Identify specific endocrine glands and their secretions

OVARIES - OESTROGEN• Is the primary female sex

hormone and is responsible for development and regulation of the female reproductive system and secondary sex characteristics

• This includes the fat distribution on our hips, breasts, abdomen, thighs, buttocks

• It also maintains the health of our inner reproductive organs especially the endometrial lining of the uterus

LO: Compare nervous and hormonal control systems in terms of speed and longevity of action

Nervous system vs. endocrine system