Experiment 5: Blood Glucose Levels

BMS 302

Insulin Receptors

Protein molecule for insulin binding, activates glucose transporter

Glycogen

Storage form of glucose (animal starch)

Hypoglycemia

Low blood glucose levels

Hyperglycemia

High blood glucose levels

What hormone is synthesized & secreted by the β-cells?

Secretes insulin to decrease blood glucose levels

What hormone is synthesized & secreted by the α-cells?

Secretes glucagon to increase blood glucose levels

Glycogenesis

• Synthetic or degradative?

• Molecules affected

• Fasting or after a meal?

• Effect on blood glucose levels

Synthetic

Glucose → glycogen

After a meal

↓ Blood glucose levels

Glycogenolysis

• Synthetic or degradative?

• Molecules affected

• Fasting or after a meal?

• Effect on blood glucose levels

Degradative

Glycogen → glucose

Fasting

↑ Blood glucose levels

Gluconeogenesis

• Synthetic or degradative?

• Molecules affected

• Fasting or after a meal?

• Effect on blood glucose levels

Synthetic

Amino acids → glucose

Fasting

↑ Blood glucose level

Lipogenesis

• Synthetic or degradative?

• Molecules affected

• Fasting or after a meal?

• Effect on blood glucose levels

Synthetic

Glucose → triglycerides

After a meal

↓ Blood glucose levels

Lipolysis

• Synthetic or degradative?

• Molecules affected

• Fasting or after a meal?

• Effect on blood glucose levels

Degradative

Triglycerides → free fatty acids + glycerol

Fasting

No effect on blood glucose levels

Which cells require the presence of insulin before glucose can be transported across the cell membrane?

Muscle cells

Adipose tissue

Most other cells in the tissue

What cells in the pancreas are responsible for detecting changes in blood glucose levels?

Beta cells

Role of insulin in the facilitated diffusion of glucose across cell membranes

Activates glucose transporter molecules

Role of insulin in its overall effect on blood glucose levels

Decreases blood glucose levels

Role of insulin in the stimulus for its release

Release is stimulated by increased blood glucose levels

Role of insulin with the pancreatic cells responsible for its synthesis and release

Released from beta cells in the pancreas

Metabolic processes that are stimulated by or require the presence of insulin

Glycogenesis

Lipogenesis

Role of glucagon in its overall effect on blood glucose levels

Increases blood glucose levels

Role of glucagon in the stimulus for its release

Release is stimulated by decreased blood glucose levels

Role of glucagon with the pancreatic cells responsible for its synthesis and release

Released from alpha cells in the pancreas

Metabolic processes stimulated by glucagon in the liver

Glycogenolysis

Gluconeogenesis

Both insulin and glucagon are secreted _________

Tonically

Both insulin and glucagon are released in _(larger/smaller amounts)_ when glucose levels either rise above or fall below the steady state level

larger amounts

Why are blood glucose levels about the same after an overnight fast as after a short fast?

Because the body uses stored glucose to maintain blood sugar during both periods

Role of epinephrine in its overall effect on blood glucose levels

Increases blood glucose levels

Role of epinephrine in stimulus for release

Release is stimulated by stress

Epinephrine: organ responsible for for its synthesis and release

Medullary cells of the adrenal gland

What metabolic processes are stimulated by epinephrine?

Glycogenolysis

Primary symptoms & specific causes of hyperglycemia

Glucose remains in blood because it cannot be transported into cells for use and storage

Primary symptoms & specific causes of glucosuria

Glucose levels in blood become so high that they exceed the kidney’s ability to reabsorb glucose, so glucose is found in the urine

Primary symptoms & specific causes of polyuria

Increased osmolarity of urine due to glucose in urine causes large quantities of fluid to be excreted in an attempt to dilute urine

Primary symptoms & specific causes of polydipsia

Dehydration results in an increased thirst as the body attempts to rehydrate

Primary symptoms & specific causes of acidosis (ketoacidosis)

Ketones released for energy result in a decreased blood pH

Cause of type I diabetes

Decreased insulin production

Cause of type II diabetes

Decreased receptor function

Diagnostic fasting blood glucose level

> 126mg%

Age of onset of type I diabetes

< 20 years

Age of onset of type II diabetes

> 40 years

Treatment of type I diabetes

Insulin injections

Treatment of type II diabetes

dietary control

Factors of type I diabetes

Autoimmune disease

Factors of type II diabetes

Marked family history

Associated with obesity

Cause of insulin shock

Excess insulin removes more glucose than needed

Cause of diabetic coma

Infections and noncompliance with diet and medication

Blood glucose levels of insulin shock

Very low blood glucose levels

Blood glucose levels of diabetic coma

Elevated blood glucose levels

Treatment of insulin shock

Ingestion of oral glucose or sucrose

Treatment of a diabetic coma

Insulin and IV fluids

Normal fasting blood glucose levels

< 110mg%

Diabetic fasting blood glucose levels

> 126mg%

Normal time to return to fasting levels following glucose load

e

Normal - presence or absence of glucose in urine

Absent (-)

Diabetic - presence or absence of glucose in urine

Present (+)

1 kg = __ lbs

2.2