Unit 2 Lesson 1 Quiz Review

Hormone

A product of living cells that circulates in blood and produces a specific, often stimulatory, effect on the activity of cells that are often far from the source of the hormone.

Glucagon

A protein hormone secreted by pancreatic endocrine cells that raises blood glucose levels; an antagonistic hormone to insulin.

Insulin

A protein hormone secreted by the pancreas that is essential for the metabolism of carbohydrates and the regulation of glucose levels in the blood.

Glucose Tolerance Test

A test of the body's ability to metabolize glucose that involves the administration of a measured dose of glucose to the fasting stomach and the determination of blood glucose levels in the blood or urine at intervals thereafter and that is used especially to detect diabetes.

Positive Feedback

Feedback that tends to magnify a process or increase its output.

What do you think it means if doctors say that a person is "pre-diabetic"?

The term "pre-diabetic" is used to describe an individual whose cells are starting to become resistant to insulin. The cells aren't completely resistant, but will become more resistant if the patient does not make some serious lifestyle changes.

Explain the basic relationship between insulin and glucose

When glucose levels increase, the body releases insulin. In a healthy individual, this will cause blood glucose levels to decrease due to the body cells being signaled to take in the excess glucose. This is a relatively inverse relationship, although there is some time delay.

What is homeostasis?

Homeostasis is the maintenance of relatively stable internal physiological conditions (as body temperature or the pH of blood) in higher animals under fluctuating environmental conditions. The human body maintains homeostasis, a steady state, by monitoring changes in the internal and external environment and feeding this information back to the body so that it can make necessary change.

How does the body regulate the level of blood glucose?

If blood glucose is too high, the pancreas releases insulin which lowers blood sugar back to homeostasis. If blood glucose is too low, the pancreas releases glucagon, which increases blood sugar back to homeostasis. It does this by triggering the liver to break down glycogen (a complex sugar) into the simple sugar glucose.

Explain how a problem with insulin receptors would affect the ability to achieve homeostasis.

If there is something wrong with the insulin receptors, the cells will never be able to take in extra glucose. This means glucose levels in the blood may remain high and homeostasis will not be able to be achieved.

Type 2 Diabetes

that develops especially in adults and most often obese individuals and that is characterized by high blood glucose resulting from impaired insulin utilization coupled with the body's inability to compensate with increased insulin production.

Negative feedback

A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

Is blood sugar regulated by negative or positive feedback?

Blood sugar is regulated by a negative feedback loop. When sugar levels rise, the body reacts to try to reduce them, when sugar levels decrease; the body reacts to raise them. The body does this in order to maintain relatively consistent blood glucose levels.

What is diabetes?

Diabetes is a set of diseases characterized by high blood glucose. Diabetes is one of the top health issues facing Americans in the twenty-first century.

Type 1 Diabetes

Diabetes of a form that usually develops during childhood or adolescence and is characterized by a severe deficiency of insulin, leading to high blood glucose levels.

How does insulin assist with the movement of glucose into body cells?

Insulin binds to insulin receptors on the surface of body cells. It triggers glucose transport proteins (contained in vesicles inside the cells) to merge with the cell membrane. Glucose then enters the body cells via these glucose transport proteins and the result is lowered blood glucose.

Explain why insulin injections are not the course of treatment for all diabetics.

Insulin injections are only effective for patients with type I diabetes. Patients with type II diabetes will not benefit from these injections because their cells have become resistant to the effects of the insulin.

What is the relationship between insulin and glucose?

Insulin is a hormone released by the pancreas in response to increased blood glucose. It lowers blood glucose levels.

Explain how it is possible that a problem with hormones and feedback led to Anna Garcia's untimely death.

It is possible that high glucose levels in Anna's blood due to a problem with hormones led to diabetic neuropathy, meaning that nerves in her body have been damaged. This could have lead to an infection that she did not realize she had, eventually leading to fever, organ damage, her passing out and hitting her head, and her death.

What does feedback refer to in the human body?

The control of body temperature, heart rate, and the concentration of sugar in the blood are all regulated by these feedback mechanisms or feedback loops. There are actually two types of feedback mechanisms: negative feedback and positive feedback. In this instance, the terms positive and negative do not infer good or bad. Instead, the terms refer to the effect the input of information (feedback) has on the output (action) of the system. Positive feedback causes a reinforcement of the original action, so the input causes the reaction to increase. Negative feedback causes the system to stop doing the original action and to either take no action or to perform an opposite action.

Homeostasis

The maintenance of relatively stable internal physiological conditions(as body temperature or the pH of blood) in higher animals under fluctuating environment conditions

How does the development of Type 1 and Type 2 diabetes relate to how the body produces and uses insulin?

There are two major type of diabetes - type 1 and type 2. Each type causes high blood sugar levels; however, the reason for this increase is different for each type. The hormone insulin is produced by the body to help cells take in the glucose found in the blood. The glucose is then used as an energy supply for the cell. Without enough insulin, our cells are not able to take in the necessary glucose. The level of insulin in the blood helps doctors further define a diagnosis of diabetes. Type 1 diabetics do not produce insulin. Type 2 diabetics produce insulin, but the body does not permit this hormone to effectively do its job.

How is glucose tolerance testing used to diagnose diabetes?

Your blood always contains trace amounts of glucose, as this simple sugar found in food is used by the body as fuel for everyday activities. Normally the amount of sugar in urine is too low to be detected. If routine testing reveals significant levels of sugar in the urine or a patient complains of excessive thirst or urination, a patient is sent for additional tests to rule out diabetes. An examination of levels of glucose in the blood can provide definitive proof of disease. Glucose Tolerance Testing (GTT) monitors the amount of sugar in the liquid portion of blood called plasma, over a set time period and gives doctors information as to how the body utilizes sugar. Prior to testing, patients are asked not to eat or drink anything for 12 hours. At the beginning of the appointment, each patient has his/her blood drawn to establish a baseline blood glucose level. Each patient is then asked to drink a concentrated sugar solution. More blood was drawn and the level of glucose in the blood was monitored at varying time intervals to show how glucose was broken down by the body. Normally, blood glucose does not rise very much from baseline and returns to normal within 2 to 3 hours.