1 - endocrine system

Question 1

what are all the endocrine glands? (10)

Answer 1

• pineal gland
• hypothalamus
• pituitary gland
• thyroid gland
• parathyriod gland
• thymus
• adrenal gland
• pancreas
• ovary (female)
• testis (male)

Question 2

what gland is considered the “master gland”?

Answer 2

pituitary gland

Question 3

what do endocrine glands do?

Answer 3

• control growth & development
• processes of reproduction
• metabolism
• maintenance of fluid & electrolyte imbalance
• stress responce

Question 4

what are the 3 different stimuli that hormones are released in response to?

Answer 4

• hormonal stimuli
• neural stimuli
• humoral stimuli

Question 5

what is the production of hormones regulated by?

Answer 5

a negative feedback system

Question 6

how does hormonal stimuli release their hormones?

Answer 6

hormones released in response to another hormone

• the stimulus is hormones from hypothalamus
• the response is AP gland secreting hormones that stimulate other endocrine glands to secrete hormones

Question 7

how does neural stimuli release their hormones?

Answer 7

nerve fibres stimulate hormone release

• stimulus is action potentials in preganglionic sympathetic fibres
• the response is adrenal medulla cells secrete epinephrine and norepinephrine

Question 8

how does humoral stimuli release their hormones?

Answer 8

changing blood levels of ions and nutrients directly simulate secretion of hormones

• the stimulus is low concentration of Ca2+ in capillary blood
• the response is parathyroid gland secreting PTH, increasing blood Ca2+

Question 9

what are some examples of protein & peptide hormones?

Answer 9

insulin and growth hormone

Question 10

what are some examples of amine & amino acids?

Answer 10

adrenaline and thyroxine

Question 11

what are some examples of steroid hormones?

Answer 11

estrogen and testosterone

Question 12

what is the process of negative feedback regulation?

Answer 12

• releasing hormones from hypothalamus
• tropic hormone from anterior pituitary
• target gland hormone from target gland

Question 13

what is a primary disorder of the endocrine system?

Answer 13

originate in target organ releasing the hormone

Question 14

what is a secondary/tertiary disorder of the endocrine system?

Answer 14

defects in hypothalamus-pituitary system

Question 15

what causes hypofunction?

Answer 15

• congenital defects
• absence of enzymes
• destruction of gland
• atrophy of gland due to medication
• autoimmune disorder - Hashimoto’s

Question 16

what causes hyperfunction?

Answer 16

• excessive hormone production
• hormone producing tumour
• autoimmune disorder - Grave’s Disease

Question 17

what are tests used to examine endocrine function?

Answer 17

• blood: provides info about hormone levels
• stimulation: hypofunction
• supression: hyperfunction
• imaging: isotopic and non-isotopic

Question 18

what is stimulation test?

Answer 18

• used for testing hypofunction
• a tropic or stimulating hormone is administered to test ability of endocrine organ to increase hormone production
• if there is an increase in hormone production then organ is working well
• if not then hypofunction of the endocrine organ

Question 19

what is suppression test?

Answer 19

• used for testing hyperfunction
• normal negative feedback mechanism of an endocrine organ is not working
• excessive amount of hormone is being produced
• external stimulus given, if it doesn’t result in reduction of hormone then there is hyperfunction of the endocrine gland.

Question 20

what is the purpose of the thyroid hormone (TH)?

Answer 20

• its the body’s major metabolic hormone, effects virtually every cell in the body
• found in 2 forms T4 and T3
• it enters target cells and binds to intracellular receptors

Question 21

what is the difference between T4 and T3?

Answer 21

• T3 is the active form, has 2 tyrosine with 3 bound iodine atoms
• T4 has 2 tyrosine molecules with 4 bound iodine atoms

Question 22

what is a thyroid function test?

Answer 22

• TSH - gives initial indication of thyroid function

Question 23

what are symptoms of hyperthyriodism?

Answer 23

elevated metabolic rate, sweating, rapid and irregular heartbeats, nervousness and weight loss

Question 24

treatment for hyperthyroidism?

Answer 24

Treatments include surgical removal of thyroid or radioactive iodine to destroy active thyroid cells

Question 25

what are the common causes of primary hypothyroidism?

Answer 25

• autoimmune disease eg: Hashimoto’s, thyroidectomy, ablation, iodine deficiency

Question 26

what are symptoms of primary hypothyroidism?

Answer 26

decreased metabolic rate, slow pulse, weight gain, cold intolerance, constipation, puffy face

Question 27

treatment for primary hypothyroidism?

Answer 27

Treatment is replacement therapy with synthetic preparations (synthetic thyroid hormone eg: levothyroxine)