Download Lab Blood Glucose & Diabetes

Blood Glucose Lab
Review of Biochemistry
• Glucose is a monosaccharide (simple
sugar).
• Respiration – a process in cells where
glucose is broken down for energy
• Polysaccharide - many sugars joined
together
• Glycogen – a polysaccharide
– Many glucose molecules joined
together
– When you have extra glucose, your
liver joins glucose molecules
together and makes glycogen
– Acts like a temporary glucose
storage
Review of Digestion and Circulation
• When you eat carbohydrates your
digestive system breaks the complex
carbohydrates (polysaccharides and
disaccharides) into monosaccharides
(like glucose).
• The monosaccharides (like glucose)
are absorbed into the blood from the
small intestine.
• The blood carries glucose to all cells
of the body so they can make energy.
ENDOCRINE SYSTEM
• Endocrine system – chemical signaling by
hormones
• Endocrine glands – hormone secreting
organs
• Hormones – chemical signals that are
secreted into body fluids (usually blood)
and communicate regulatory messages
throughout body
– Regulate growth, development,
reproduction, metabolism, and
behavior
HUMAN ENDOCRINE GLANDS
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Hypothalamus
Pineal gland
Pituitary gland
Thyroid gland
Parathyroid glands
Thymus
Adrenal glands
Pancreas
Ovary or testis (gonads)
Human endocrine glands surveyed in this chapter
PANCREAS
• Islets of Langerhans - endocrine
cells scattered throughout the
pancreas
• In the Islets of Langerhans:
– Alpha cells make glucagon
– Beta cells make insulin
– Insulin and glucagon are
antagonistic hormones.
– Both hormones are secreted
into the blood from the
Pancreas
• Metabolic balance requires a minimum
of 90 mg glucose/100 ml blood.
• When blood glucose rises over
90mg/100ml:
– Insulin lowers blood glucose by
stimulating body cells to take in
glucose (take it out of blood).
– Insulin also slows glycogen
breakdown in liver so less glucose.
• Before blood glucose reaches
90mg/100ml:
– Glucagon signals liver cells to
break down glycogen into
glucose and release glucose into
blood
– Signals liver cells to convert
amino acids and glycerol into
glucose and release glucose into
blood
Glucose homeostasis maintained by insulin and glucagon
Diabetes Mellitus
• Caused by a deficiency of insulin or loss
of response in target tissues (body cells)
• Result is high blood glucose levels – so
high that a diabetic’s urine contains
glucose
• More glucose in urine means more water
needed in urine = thirst
• When cells don’t get the glucose they
need they break down fat instead, which
forms harmful, acidic metabolites.
• Type I diabetes mellitus
– Insulin dependent
– Autoimmune disease where immune
system attacks pancreas ( cells)
and cannot make insulin
– “Juvenile” (adults too)
– Inheritance may play a minor role
– Potentially caused by infections
• Type II diabetes mellitus
– Non-insulin dependent
– Often inherited (although related to
poor diets and lack of exercise)
– Either insulin deficient or lack of
response in target cells
– Accounts for 90% of all diabetics
– 7th most common cause of death in the
USA
– Gastric by-pass surgery (duodenum and
jejunum removal) ends diabetes in most
obese patients
• Gestational diabetes – happens to
pregnant women (may be from
hormones from placenta causing
insulin resistance in mom)