Endocrine system

endocrine system

the endocrine system is a set of hormone secreting glands within the body of an animal.

function of endocrine system

homeostasis, communication and response to stimuli

sensitivity

ability to detect change and to respond

differences between the exocrine and endocrine system

endocrine = ductless+ secreted through blood, exocrine = has ducts, secreted through glands

hormones

chemical messengers produced in one part of the body which causes a response in another part of the body

hormones vs nervous system

hormones - chemical messenger, wide ranging effect, slow and long lasting, carries in the blood,
Nervous- nerves, electrical message, specific and localised, quick and short term, carried in the nerves

Hypothalamus

secretes hormones that control the pituitary gland in response to messages from the brain and other hormones
produces ADH and growth hormone releasing factor

Pituitary gland

stores ADH, produces TSH. FSH, LH, Oxytocin, prolactin and growth hormone

Pineal gland

produces melatonin

Thyroid gland

produces thyroxin which controls metabolism

Hypothyroidism ( under production)

Cretinism ( retarded physical/ mental development)
myxoedema ( weight gain, lack of energy slow response)
Goitre ( swelling of thyroid due to excess of TSH due to lack of iodine in diet)

Hyperthyroidism (overproduction)

graves disease ( exathalmos, increased rate of metabolism, nervousness, weight loss)

parathyroid glands( 4 in thyroid )

produce parathormone - stimulates release of calcium from bones

Pancreas (exocrine)

digestive organ - secretes pancreatic juice containing digestive enzymes

pancreas (endocrine)

produces insulin, glucagon and somatostalin

insulin

produces in islets of Langerhans- stimulates blood glucose levels by stimulating cells to absorb glucose from the blood.

Diabetes

lack on insulin = high blood glucose levels. production of large amounts of urine, severe thirst, tiredness

type 1

pancreas no longer makes insulin.

type 2

either the pancreas doesnt make enough insulin or the body is unable to use insulin correctly

thymus gland

produces thymosin that causes lymphocytes to mature and active. eliminates T cells that attack the body’s own proteins.

adrenal gland

produces adrenaline - fight or flight hormone

testes

produces testosterone (steroid)- triggers sperm production and growth in males

ovaries

produces oestrogen and progesterone to control menstruation.

negative feedback mechanism

low conc thyroxin - stimulates pituitary to produce TSH - more thyroxin. normal thyroxin levels - pituitary gland is prohibited from releasing TSH