Endocrine Intro and Appetite

Question 1

what do nociceptors detect

Answer 1

pain

Question 2

in a control system what is the afferent pathway

Answer 2

communication between the receptors and control centre through the nervous system or endocrine system

Question 3

in a control system what is the efferent pathway

Answer 3

communication between the control system and the effector to give a response

Question 4

what is a set point

Answer 4

the parameters in which a variable must lie

Question 5

what is the circadian/diurnal rhythm

Answer 5

where set points change thoughout the day during a 24 hour period

Question 6

what is melatonin and where is it produced

Answer 6

a hormone which is involved in the biological clock and is released from the pineal gland

Question 7

what is negative feedback

Answer 7

a response in a way to reverse and change in the system

Question 8

what is positive feedback

Answer 8

a response which increases the direction of the variable to give a rapid change

Question 9

where are osmoreceptors found

Answer 9

hypothalamus

Question 10

what is the difference between osmolarity and osmolality

Answer 10

osmolarity = number of osmoles per litre of solution 
osmolality = number of osmoles per Kg of solution

Question 11

what is an osmole

Answer 11

the amount of substance that dissociates in solution to form 1 mole of osmotically active particles

Question 12

what is the reference range for serum osmolality

Answer 12

275-295 mOsmol/kg

Question 13

what are the 9 endocrine organs

Answer 13

• hypothalamus
• pituitary gland
• thymus
• parathyroid
• thyroid
• gonads
• pancreas
• adrenal glands
• pineal

Question 14

what are the 4 classifications of hormones

Answer 14

• peptide
• steroid
• amino acid
• glycoproteins

Question 15

which classifications of hormones are water and lipid soluble

Answer 15

water soluble: peptide and glycoprotien hormones

lipid soluble: steroid and amino acid

Question 16

name 3 amino acid hormones deriving from tyrosine

Answer 16

adrenaline, noradrenaline, thyroid hormones

Question 17

name 3 steroid hormones

Answer 17

cortisol, aldosterone, testosterone

Question 18

where are steroid hormones derived from

Answer 18

cholesterol

Question 19

how are lipid soluble hormones transported in the blood

Answer 19

by being bound to proteins which increases their stability and solubility and allow them to be a readily available reserve

Question 20

what 3 factors determine the hormone levels in the blood

Answer 20

• rate of production
• rate of delivery
• rate of degradation

Question 21

outline how tyrosine kinase receptors work

Answer 21

following binding of a ligand dimerisation occurs which allows for autophosphorylation of the receptor. the receptor can then recruit proteins and activate them through phosphorylation to give a repsonse

Question 22

give an example of a tyrosine kinase receptor

Answer 22

insulin receptor

Question 23

where is the appetite control centre located

Answer 23

in the hypothalamus

Question 24

which part of the hypothalamus controls appetite

Answer 24

the arcute nucleus (collection of neurones)

Question 25

what types of neurones are found in the arcute nucleus

Answer 25

primary and secondary neurones which respond to signals from the body

Question 26

what are the 2 types of primary neurones in the arcute nucleus

Answer 26

type I = stimulatory neurones containing NPY and AgRP which promote hunger
type II = inhibitory neurones containing POMC, alpha-MSH and beta-endorphin

Question 27

what hormones from the gut signal to the hypothalamus about hunger

Answer 27

• Ghrelin from the stomach stimulate appetite

- PYY from the ileum supresses hunger

Question 28

name 3 hormones released from in the body (apart from the gut) which control hunger

Answer 28

• Leptin from the adipocytes stimulate inhibitory neurones and inhibits excitatory neurones in the arcute nucleus to suppress hunger
• insulin supresses hunger
• amylin from beta cells in the pancreas suppress appetite