5.1.4 Flashcards
What does endocrine mean?
a tissue/organ
secretes hormones/ enzymes
directly into blood
ductless
Do endocrine organs or tissues have ducts?
no
What is an exocrine gland?
produce hormones that are transported by ducts that carry the secretion to another place
What are the 2 types of hormones?
Peptide hormones
Steroid / lipid soluble hormones
What do peptide hormones do?
not soluble so dont enter the cell
How do peptide hormones enter the cell?
1st messenger
2nd messenger
What dp steroid/ lipid soluble based hormones do?
pass through the membrane and enter the cell
acting upon DNA in nucleusu
Outline the action of adrenaline?
1) Adrenaline receptor site has shape change coplimentary to adrenaline
2) Adrenaline activates the enzyme adenyl cyclase
3) Adenyl Cyckase cinverts ATP into cAMP which activates enzmes inside the cell
What type of hormone is adrenaline an example of?
peptide hormone
What is the relationship between the adrenaline receptor site and adrenaline?
complimentary and specific in shape
What enzyme does adrenaline activate?
adenyl cyclase
What does adenyl cyclase do in the action of adrenaline?
converts ATP into cAMP
Where is the medulla?
centre of adrenal glands
Where is the cortex?
surrounding medulla ina drenal glands
What is the function of the medulla?
produced non-essential hormone
What is the function of the cortex?
produces essential hormones
What hormoned does the cortex produce?
essential hormones
cortisol
aldosterone
sex hormones
What hormones do the medulla produce?
non-essential
adrenaline
noradrenaline
What is the function of aldosterone?
N+ and k+ reabs in kidneys
What is the function of adrenaline?
inc heart rate
stimulates glycogenosis
triggers fight/flight
What is the function of noradrealine?
inc heart rate
stimulates glycogenosis
triggers fight/flight
Wht is the dunction of cortisol?
stimulates glycogenolysis
reduces inflammation
regulates B.P
what do sex hormones do?
aid development of gametes
What do exocrine glands do in pancreas?
enzymes are carried to the gall bladder in the pancreatic duct
What do endocrine glands do in pancreas?
insulin and glucagon are relased directly into the blood stream
What are the 2 cells in the islet of langerhans
alpha cells
beta cells
What do alpha cells produce?
glucagon
What do beta cells produce?
insulin
What is the normal blood glucose concentration?
4 and 6 mmol dm-3
What increases blood glucose conc?
eating a carbohydrate rich diet
glycogenolysis
gluconeogenesis
What decreases blood glucose concentration?
respiration
glycogenesis
What is insulin detected by?
beta cells
What happens when blood glucose rises too high?
Detected by beta cells
in islets of langerhans
hormone insulin secreted into blood
target cells are hepatocytes in the liver
insulin binds to receptors on plasma membrane of the hepatocytes
Adenyl cyclase activates cAMP
More glucose channels are placed in the plasma membrane of the liver/muscle cells
more glucose enters the cell
glucose is converted to glycogen for storage aka glycogenesis
More glucose is converted into fats
More glucose ised in respiration inc metabolic activity
causes blood glucose concentration to fall
What are target cells when blood glucose is too high?
hepatocytes
What does insulin do?
bind to receptors on plasma membrane of heaptocytes
What does adenyl cyclase do?
activate cAMP
What happens to glucose channels when blood glucose is too high?
more glucose channels placed in plasma membrane of the liver/muscle cells
What happens to glucose when blood glucose concentration is too high?
glycogenesis into glycogen
converted into fats
respiration
Why does glycogenesis happen?
storafe
What happens when glucose is sued in repsiration when blood glucose is too hgih?
inc in metabolic rate
What happens when blood glucose concentration is too low?
alpha cells detected in the islets of langerhans in the pancreas
glucagon secreted into blood
target cells are hepatocytes in liver
Glycogen converted into glucose by glycogenolysis
more fatty acids used n resp
amino acids and fast converted into glucose gluconeogenesis
causes blood glucose concentration to rise
What detects blood glucose falling too low?
alpha cells
What hormone is secreted into blood when blood glucose falls too low?
glucagon
What are the target cells when blood glucose falls too low?
hepatocytes
What happens to glycogen when blood glucose falls too low?
converted to glucose by glycogenolysis
What happens to fatty acids when blood glucose falls too low?
more are used in resp
What happens to amino acids and fats when blood glucose falls too low?
converted to glucose
by gluconeogenesis
What happens to blood glucose concentration?
continues to rise
How is insulin released?
Cell membrane has potassium and calcium ion channels
potassium ion channels are normally open so K+ flow out
when blood glucose concentration is too high the glucose moves into cells
glucose is metabolised to produce ATP
ATP closes potasisum ion channels
What do K+ ions do in the release of insulin?
K+ flow out
What happens to glucose when blood glucose conc is too high during release of insulin?
glucose moves into ce;;
What is metabolised to produce ATP after moving into the cell in the release of insulin?
glucose
What closes after glucose is metabolised into ATP in the release of insulin?
K+ channels
What causes the inside of the cell to become less negative?
accumulation of K+ ions altering the P.D across the cell membrane
What does the change in the potential differnce in the relase of insulin cause?
Ca2+ channels to open
What do ca2+ do in the relase of insulin?
Ca2+ cause vesicles of insulin to fuse with the cell membrane and releasing insulin by exocytosis
What causes blood glucose levels to fluctuate?
eating
exercise
What is diabetes mellitus?
disease
body can no longer control the blood glucose levels
What can diabetes mellitus cause?
hyperglycaemia
hypoglycaemia
What is hyperglycaemia>
blood sugar level too high
What is hypoglyceamia?
blood sugar level too low
What is the cause of type 1 diabetes?
autoimmune disease
genetic
triggered by env factor
What happens in type 1 diabetes?
body no longer produces any insulin
cells not functioning properly
When is type 1 diabetes?>
childhood
When is type 2 diabetes?
later in life
What factors can cause diabetes to happen earlier?
obesity
over-eating sugar
physical inactivity
high bp
asian / afro carribean descent
family history
inc with age
males
What causes type 2 diabetes?
glycoprotein for insulin doesnt work properly
What is type 2 diabetes?
body doesn’t respod properly to insulin
insulin not produced
What are lifestyle treatments for diabetes?
reducing amount of sugar in diet
more exercise
What is a type 1 diabetes treatment?
genetically engineering insulin
making beta cells
Why is genetically engineering insulin from bacteria advantgeous?
less ethical / religious issues
lots can be produced in short amount of time
