Sub 6: Osteoporosis and Diabetes Flashcards
what is required to build bones?
calcium and vitamin D
what are osteoclast cells?
remove old bone material
what are osteoblast cells?
reconstruct new bone material
what hormone regulates the level of osteoclast cells?
oestrogen -it enhances the intestinal calcium absorption and limits its withdrawal from bone
how does an individual develop low bone density?
the rate of bone material replacement by osteoblast cells gradually decreases leading to a progressive loss of calcium from the bones. loss of calcium leads to bone density decreasing
what is osteoporosis?
when the loss of bone density causes the bones to become more porous and brittle and hence more susceptible to fracture
why do post-menopausal women have an increased risk of osteoporosis?
they produce lower levels of oestrogen and so reduce activity of osteoblasts, increasing the risk of loss of calcium from the bones
other symptoms of osteoporosis?
loss of weight
curvature of spine
chronic back pain
how does exercise help reduce risk of osteoporosis?
it puts bones under a degree of stress and this increases calcium deposition by osteoblasts thus increasing bone density
what is the best type of exercise for osteoporosis?
weight bearing exercises of a moderate intensity - running, walking, dancing
how can osteoporosis be reversed or stopped?
exercise
hormone treatment
calcium supplements
what are the two hormones involved in control of blood glucose levels?
insulin and glucagon
where are insulin and glucagon released?
islets of langerhans in the pancreas
what does insulin convert?
glucose into glycogen
what does glucagon convert?
glycogen to glucose
what is hyperglycaemia?
when the blood glucose levels are too high
where is glycogen stored?
liver and skeletal muscles
what is hypoglycaemia?
when blood glucose levels are too low
what are insulin and glucagon? where are their receptors found?
they are hydrophilic peptide hormones which bind to receptors that are found on the membrane of the liver cells and muscle cells
how does the body control an increase in blood glucose concentration?
the pancreas detects the increase in blood glucose levels and this causes both an increase in insulin secretion and a decrease in glucagon secretion by the islets of langerhans in the pancreas. insulin lowers the blood glucose level by binding to the receptors in the liver cells. this stimulates the uptake of glucose into the liver cells and stimulates glycogen synthesis in the liver
what are the effects of insulin on skeletal muscle and fat cells
those type of cells have low permeability to glucose in the absence of insulin. insulin stimulates uptake of glucose into muscle and fat cells
what are the effects of insulin on liver cells
liver cells have high permeability to glucose in the absence of insulin. insulin increases uptake of glucose by liver cells and increases glycogen formation
what is diabetes?
disorder resulting in the failure to control blood glucose levels and impaired ability to store glucose in the form of liver and muscle glycogen
what is type 1 diabetes?
caused by the failure of the pancreas to produce enough insulin. also called insulin dependent diabetes mellitus (IDDM)
what is type 2 diabetes?
caused by the failure of tissues to respond to insulin - insulin resistant, also called Non-insulin dependent diabetes mellitus (NIDDM)
what is the treatment for type 1 diabetes?
regular injections of insulin
what is insulin resistance?
when cells have less sensitivity to insulin, and so they have reduced uptake of glucose from blood
how is obesity linked to type 2 diabetes?
the number of insulin receptors decreases in obese people, this decreasing the glucose uptake into the cell which leads to insulin resistance
how is diabetes detected in first stages?
glucose appears in urine
what is the glucose tolerance test?
used to diagnose what type of diabetes an individual has
what is the effect of exercise on regulation of NIDDM?
regular aerobic exercise can help reduce obesity and therefore reduce the risk of NIDDM
it improves the uptake of glucose from the blood into skeletal muscle cells by increasing the number of active insulin receptors in these cells
increase in density of capillary networks in the skeletal muscles so improved blood flow better glucose availability
what are the steps in a glucose tolerance test
individuals fast
drink glucose dissolved in 1L of water
blood glucose levee;s are measured every 30mins for 2 hours
in a non-diabetic the blood glucose reaches a peak at 30mins after ingestion of glucose and falls after 2 hours indicating the pancreas has secreted adequate insulin
