glucose metabolism + homeostasis Flashcards
diff between metabolism and digestion?
digestion is like taking apart the old house to make new building blocks
metabolism = the many different systems in the house working together to keep it running smoothly
which 2 organs only use glucose for energy?
brain
retina
how do cells metabolise glucose?
using oxygen
to be able to extract energy from carbs
for body cells
through the process of respiration
what is the sole nutrient/ fuel for red blood cells?
glucose
1g of glucose provides how many
3.75 Kilocalories of energy
how is glucose metabolised?
through respiration
krebs cycle
glucose molecule is broken down into:
2 pyruvate molecules
1 ATP
importance of balancing sugars in our body?
+ sugar in body = diabetic
how are sugars balanced in our body?
insulin- beta cells
glucagon- alpha cells
from islets of langerhans
which body cells are most sensitive to insulin?
adipose tissue
skeletalmuscle cells
liver cells
have more receptors for insulin
how does insulin regulate amount of glucose in our body cells?
b cells found in islets of langerhans
secrete insulin
stimulates uptake of glucose by body cells
insulin sensitivity exists across whole body
how does glucagon regulate amount of glucose in our body cells?
found in a cells
increases glucose in blood stream
through gluconeogenesis
where glucagon stimulates liver to break down glycogen into glucose
and send out into blood stream
glucagon and insulin are?
antagonists
structure of insulin?
formed of 2 chains (carboxylic chains + b chain)
connected by disulphide bond
translated by RNA into pro pre insulin = 1 chain
which gets into cells of RER
once inside RER
packaged into PRO insulin (loses parts of peptides)= 3 chains
a chain
b chain
c chain= small peptide which joins them together
moves to be further packaged into trans golgi apparatus
LOSES C peptide
becomes 2 chains connected together with disulphide bond
Leaves cells by exocytosis
- golgi apparatus releases insulin + cleaved c peptide (has no known biological function) into blood stream
how does insulin stimulate uptake of glucose by body cells?
stimulates GLUT4
stimulates uptake of glucose
via cells which have insulin receptors
clinical application of insulin stimulating glucose uptake by body cells?
GLUT4 forms basis of hypoglycaemic drugs (used in type 2 patients)
drugs phosphorylate GLUT4
-> makes it more available
lowers insulin sensitivity of patient
normal glucose levels in body when fasting?
80-90mg/ 100ml
in random measurements (not HbA1c)
normal glucose levels in body after a meal?
120-140mg/100ml
if above this= diabetic
insulin main hormone for protection against diabetes
what is type 1 diabetes?
complete damage to pancreas
autoimmune/ genetic factors lead to:
complete absence of insulin
type 1 diabetic patients need?
need insulin replacement for life
what is type 2 diabetes?
deals with insulin sensitivity
(depends on number of receptors present on body cells’ surfaces
ability of cells to respond to insulin and uptake glucose)
initial treatment for people with insulin sensitivity?
need to improve cells’ insulin sensitivity
can take:
- oral hyp
initial treatment for people with insulin sensitivity?
drugs need to improve cells’ insulin sensitivity
can take:
- oral hypoglycaemic
- modifying edit
the effect on insulin deficiency on cells extracellularly?
insufficient insulin
too much glucose in blood
extracellular hyperglycaemia (outer environment of cells)
->above renal threshold, body tries to get rid by glucose coming out of urine (1st symptom of diabetes)
-causes polyurea (need to go to toilet more frequently, polydipsia, loss of potassium + nitrogen
leads to hyperosmosis extracellular
-> water gets drawn out of cells
= dehydration of actual cells
if gets out of hand, leads to HYPERGLYCAEMIC coma
effect of insulin = intracellular hypoglycaemia, effects of this?
causes gluconeogenesis
more glucose gets formed in cells
they are deprived of glucose + can’t take it up from outside of cell
leads to:
- LESS protein synthesis
some protein-> changes into glucose
- weakness
- general lethargy
- LESS immunoglobulins
patient = more prone to infections
+ impaired wound healing - breakdown of fats
-> leads to high levels of ketones
= diabetic ketoacidosis
= weight loss
why is diabetic ketoacidosis bad?
= buildup of ketones in the bloodstream
= toxic in high levels
can lead to coma/ death
symptoms of diabetes? (10)
frequent infections causes itching in genital organs
microvascular complications of diabetes? (6)
- xerestomia
- retinopathy (eventual blindness)
- nepropathy
- renal failure
- neuropathy
- peripheral nerve damage (feel numbness in peripheries)
-> hit their toes + don’t feel anything
macrovascular complications of diabetes? (8)
- stroke
- ischaemia
- cognitive impairment
- angina
- coronary disease
- CV ischaemia
- heart attacks
- diabetic foot/ ulcers (major causes for amuptations/ death in diabetics)
what does long term hyperglycaemia around endothelial lining of the arteries leads to?
end arthritis obliterans
= damage of blood vessels because of presence of glucose
leads to hyperglycaemia around endothelial lining of arteries/ veins/ capillaries
-> damage of wall
which helps deposition of cholesterol plaque on blood vessel walls
when happens in small vessels= microvascular
when happens in major vessels = macrovascular
dental complications of diabetes are?
MICROVASCULAR
1) tiny vessels in salivary glands are damaged
acini are damaged
= xerestomia
4) -> PD, loss of teeth, + infection rate
2) infections
3) impaired + delayed healing of wounds in mouth
our role as dentists?
- encourage to have regular hygiene visits
- need to do regular perio checks (PD is a major issue with diabetes)
people with uncontrolled diabetics can wake up and find what?
tooth on pillow!
