| Hyperthyroidism | over active thyroid |
| negative feedback | feedback is opposite to feedback |
| endocrine system main purpose | maintain home stasis by influencing cellular activity through chemical messengers-hormones, and using feedback- responding to stimulus by secreting more/less of a hormone to alter original stimulus |
| Hormone types and descriptions | protein (made of protiens) eg. insulin. -water soluble
steroid (made of lipids :. lipid soluble) eg. cortisol
amine(amino acids ) eg. adrenalin and epinephrin. -water soluble
(and paracrines (local hormones via which two adjacent organs communicate))
can effect all cells, target cells or target organs. only able to influence cells with specific receptors |
| how do hormones change cell function | via changing the type, activity or quantities of protiens/enzymes produced by:
activating genes in nucleus to protiens are produced
changing enzyme shape/ structure to turn function on/off
changing rate of production of enzyme or protein by increasing/decreasing transcription/translation |
| enzyme amplification | one hormone can activate thousands of enzymes. hormones trigger a cascade of reactions
small amount of hormone/ stimulus can produce large effect
saturation can occur so additional hormones will no longer take effect |
| paracrine action | hormone acts locally diffusing from its source to neighbouring target cell |
| Autocrine action | hormone effects the same cell that produced it |
| water soluble hormones enter the cell and take effect by: | amines and protiens are hydrophilic, cannot pass through hydrophobic tails
:. they attach to receptor protiens in target cells membrane
causes secondary messenger(g protein) to be released into cell and activate enzyme via nucleus (signal transduction)
cytoplasmic response |
| Lipid soluble hormones enter cell and take effect by: | steroids defuse through cell membrane and combine with receptor within cell
hormone receptor complex alters gene expression by activating genes controlling the formation of particular protiens |
| how are hormones controlled | secretions are regulated by negative feedback - response is opposite of feedback
-sometimes involves the nerves system stimulating the hypothalamus to secrete inhibiting or restricting factors
hormones must turn off after producing desired effect- done by breaking down hormone molecules in target cell, kidney or liver then excreted in bile, urine |
| Exocrine gland | secrete hormones into a duct , caries the secretion to surface/body cavities. eg. sweat, saliva |
| Endocrine glands | secrete hormones into extracellular fluid , passes into capillaries to circulate body |
| the bodies gland names | Hypothalamus
pituitary gland
adrenal glands
ovaries
testies
pancreas
parathyroid glands
thyroid glands
pineal gland |
| Hypothalamus | base of brain
regulates bodies basic functions, eg wate balance, heart rate
many functions varied out through the pituitary gland
produces many hormones-travel via blood and nerve fibres to pituitary where they are secreted |
| Pituitary gland | lies under hypothalamus , connected via infundibulum -vital
secretes hormones produced by hypothalamus
master gland- due to its nature to |
| element connecting hypothalamus and pituitary | infundibulum |
| segments of the pituitary gland | anterior and posterior lobes
anterior = front, connected to hypo via blood vessels
controlled by hypothalamus' restricting and inhibiting hormones
posterior =back lobe
does not secrete anything (not real gland)
joint by nerve fibres
stores oxytocin's and antidiuretic hormones produced in hypothalamus |
| hormones released by anterior pituitary | follicle stimulating hormone (fsh) -overies, testes
luteinising hormones (LH) -overies testes
growth hormone (GH) -all cells
thyroid stimulating hormone (TSH) -thyroid gland
Adrenocorticotropic hormone -adrenal cortex
Prolactin -mammary glands (initiate and maintain milk secretion)
FLAG ToP
FLaP -reproductive hormones |
| Tropic hormones | hormones that regulate other hormones
non tropic directly stimulate target cells |
| the posterior pituitary secretes? | travelled via nerves from hypo
antiduretic -causes kidney to remove water from urine + return to blood, at high conc also constricts small arteries
oxytocin -contractions during labor and milk let down |
| Peneal gland secretes?
targets?
achieves? | hormone :melatonin
target: the hypothalamus
regulates sleep patterns, released at night |
| Pancrease exo end endo functions , hormone | produces enzymes release into small intestines
hormones produced in cluster of cells called islets of langerhans
hormone: glucagon
target: liver
raises blood sugary stimulating breakdown of glycogen to glucose
hormone: insulin
target: liver, muscle cells and fat stores
lowers blood sugar by promoting glucose to glycogen conversions (liver + skeletal muscles)+ glucose to fat in fat stores. |
| Adrenal glands - adrenal cortex
is affected by?
produces?
hormones (2) , target and function. | affected by ACTH from anterior pituitary
produces corticosteroids
hormones include
cortisol: targets liver, promotes normal liver function and adaptation to stress + tissue repair
aldosterone: targets kidney , reduces sodium and increases urine potassium |
| ADRENAL GLANDS – ADRENAL MEDULLA
2 hormones and target | adrenalin (epinephrine ) -fight or flight response
Noradrenalin-similar effect
targets most cells and tissues |
| Thyroid hormone | thyroxine -controls body metabolism by regulating catabolic and anabolic reactions - release and maintain body temp
secreted in response to TSH
targets all cells |
| Parathyroids | 4 on rear surface of thyroid gland -size of peas
hormone -parathyroid hormone (PTH)
targets bones and kidneys
controls calcium and phosphate levels in blood. |
| Thymus | hormone- thymosins (hormone group)
Target : T lymphocytes. -influences their maturation |
| Gonads- Ovaries (2 hormones) | Hormone: oestrogen
effects: many tissues
regulates menstruation
Progesterone
targets uterus and mammary glands
regulates period and milk production |
| Gonads- Testes | Hormones: Androgens (e.g testosterone)
target: many tissues
stimulates sperm production
growth of skeletal muscles
development of male sex characteristics |
| feedback system steps | stimulus
receptor
message
modulator
message
effector -mucle glands
response -effector organ brings a reaction
feedback
srmmmerf
smurf |
| positive feedback | reinforces and intensifies the stimulus |
| negative feedback | feedback is opposite to feedback |
| Hyperthyroidism | over active thyroid, produces to much thyroxin -auto immune disorder |
| hypothyroidism | under active thyroid, to little thyroxin -auto immune disorder |
| carb foods | starch, sugary, milk and dairy, fruit |
| in response to injecting carbs: | carbs-> glucose in stomach
in response pancreas releases insulin
blood carries glucose+insulin to all required cells
blood glucose level decreases as glucose is stored
can be risen again through the liver releasing extra stored glucose |
| Diabetes type 1 | body makes no insulin at all due to an auto immune response all insulin producing cells are destroyed
10% of cases, occurs under 40s.
glucose in blood stream cannot enter cells so BS consistently increases
body attempts to remove excess through kidneys = frequent eurination and dehydration. glucose also leads to area for bacteria to bread=thrush and long lasting wounds
glucose also builds in eyes=blindness
tiredness, breaks down fat stores for energy= fat loss |
| Type 2 diabetes | 90% cases, over 40s
either body isn't producing enough insulin or insulin isn't working properly.
can be due to build up of fat blocking insulin receptors
regular processes occur, but insulin and glucose don't enter cells, bs levels ^
in response body makes more insulin ^
cells send signals to liver to produce more insulin from storage leading to a further increase. pancreas can't cope and tires out
similar symptoms to type 1
slow or non noticeable symptoms
can be treated by diet and lifestyle, medication |
| glucocorticoids | steriod hormones produced from adrenal glands cortex |
