Understanding the absorptive and post absorptive states during meals

Lecturer 1 Download Physiology MCQ Android and Desktop App for Nigerian Medical School Two functional metabolic states — the absorptive state and the postabsorptive state — relate to eating and fasting cycles respectively. This state is also called fed state.

Understanding the absorptive and post absorptive states during meals

Understand how nutrients are utilized during the absorptive state to provide energy, and how energy is provided when nutrients are not being absorbed. Consider how the absorptive and post-absorptive patterns of metabolism are controlled by hormones, and how this control is impaired in diabetes mellitus.

Introduction The nutrient state of the blood depends on whether or not a meal is being processed in the gastrointestinal tract. When nutrients such as glucose and lipid are being absorbed, and their concentrations in the blood are high, the pattern of energy metabolism is known as the absorptive state.

In this state, a fraction of the blood glucose is used by various tissues to meet their immediate energy needs. The excess glucose and the absorbed lipid are stored as glycogen and lipid that can be used to provide energy between meals or during fasting: The change from the absorptive state pattern to the post-absorptive state pattern is brought about by changes in the blood concentrations of insulin and other hormones.

The importance of maintaining the appropriate patterns of metabolism can be illustrated by considering the metabolic defects present in insulin-dependent diabetes mellitus IDDM, or type I diabetesin which the secretion of insulin is severely impaired.

In this chapter we shall consider the metabolic abnormalities present in this condition, and the consequences of these defects Case 9. Her parents were worried because she seemed listless and was losing weight.

They said she also seemed to be drinking a lot and was frequently having to pass urine. The doctor noticed that her breathing was rapid and shallow Kussmaul breathingand that it smelled of acetone.

The patient provided a sample of urine. Clinistix tests on the urine sample indicated the presence of glucose and ketones. An appointment was made for her to attend a diabetes clinic.

She was told to fast from the evening before the appointment. A blood sample was taken and the blood glucose concentration was found to be This is above the normal range 3.

Hypoinsulinaemia low plasma insulin and ketoacidosis high levels of ketone bodies in the blood were also noted. The results confirmed that the patient was diabetic. She was later taught how to inject herself with insulin, which had to be done three times a day, before meals. After considering the details of this case we can address the following questions: What are the basic defects in each condition?

Would the concentration of plasma insulin be low in both conditions? What is the explanation for the listlessness in this patient? Why was her acid—base status changed? Why was her breathing abnormal rapid and shallow? How would the body normally compensate for the acidosis? This condition affects mostly young people, the commonest age of onset being between 10 and 14 years, whereas NIDDM usually affects people in middle or later life.

Hyperglycaemia is a characteristic of both conditions. In the patient described above, the insulin concentration was low. The presence of ketones on the breath would therefore also support a diagnosis of IDDM. IDDM affects both sexes equally, but there is a slightly earlier peak in age of onset in girls than boys.

It is more prevalent in Caucasians than non-Caucasians, and more prevalent in people living in the Northern hemisphere than the Southern hemisphere.

There is a higher incidence of first diagnoses in winter than summer. The frequency of the disease has been increasing during the last 60 years. This is probably in part due to dietary factors and increased obesity. There is evidence for a genetic predisposition, particularly to IDDM.

The HLA genes on chromosome 6 are associated with the condition, and a number of rare predisposing genetic mutations have recently been identified. However, other factors are important see below.

IDDM is an immune-mediated disease. Evidence for a more direct involvement of antigens that react with intracellular enzyme proteins, such as glutamic acid decarboxylase and tyrosine phosphatase is emerging.

Absorptive state - an overview | ScienceDirect Topics

There is also strong evidence for defects in cell-mediated immunity in IDDM.The absorptive state represents the time immediately after a meal when ingested nutrient molecules are being absorbed into the blood.

This state is also called fed state. During this time, glucose is abundant and serves as the main energy source. Understanding the Absorptive and Post absorptive States During Meals PAGES 1.

WORDS View Full Essay. More essays like this: absorptive, postabsorptive states, meal. Not sure what I'd do without @Kibin - Alfredo Alvarez, student @ Miami University. Exactly what I needed. - Jenna Kraig, student @ UCLA. Consider how the absorptive and post-absorptive patterns of metabolism are controlled by hormones, and how this control is impaired in diabetes mellitus.

Introduction The nutrient state of the blood depends on whether or not a meal is being processed in the gastrointestinal tract. Chapter 21 Endocrine System. STUDY. adipose tissue in absorptive and post-absorptive states?

Metabolism During the Postabsorptive State - Within a few hours after a typical meal - Primarily a catabolic state • Secretion increases during absorptive state • Increase glucose in plasma • Increase [amino acids] in plasma. During the absorptive state nutrients may be used immediately to meet energy demands.

Blood glucose drops dramatically during the absorptive state. Gluconeogenesis most likely occurs at least 4 hours after the last meal.

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You commonly fast overnight, but skipping meals during the day puts your body in the postabsorptive state as well. During this state, the body must rely initially on stored glycogen.

Glucose levels in the blood begin to drop as it is absorbed and used by the cells.

Understanding the absorptive and post absorptive states during meals

There are three main metabolic states of the body: absorptive (fed.

THE ABSORPTIVE AND POST-ABSORPTIVE STATES | Abdominal Key