Chapter 19. Regulation of Metabolism

___ acts antagonistically to ___ after a meal to promote ___

CCK; Ghrelin; Satiety

Parathyroid hormone is released in response to a drop in blood ___ concentration

Calcium

Parathyroid hormone levels are controlled via negative feedback by blood levels of:

Calcium

Basal metabolic rate, adaptive thermogenesis, and physical activity are components of:

Caloric expenditure of the body

What is the usual cause of osteomalacia?

Lack of vitamin D

In an chronically underfed individual, ___ levels should ___ in response to decreased adiposity.

Leptin; Decrease

___ occurs in times of plenty and ___ occurs in times of fasting

Lipogenesis; Lipolysis

Adaptive Thermogenesis:

Energy expenditure in response to changes in ambient temperature and digestion/absorption of food

Basal Metabolic Rate:

Energy expenditure of relaxed, fasting person at neutral ambient temperature

Physical Activity:

Energy expenditure that varies with intensity and type of activity

Function of white adipose tissue:

Energy storage

Superoxide dismutase and catalase are examples of:

Enzymes that reduce damage due to oxidative stress

How might Metformin reduce hepatic secretion of glucose?

It may stimulate glycolysis and may increase hepatic glycogenesis

Primary determinants of basal metabolic rate:

- Age - Sex - Body surface area - Thyroid hormone level

Minerals:

- Calcium - Iron - Potassium

List the sources of calories for the body:

- Carbohydrates - Protein - Fats

Hormones secreted by the adrenal medulla:

- Epinephrine - Norepinephrine

The hormone ___ causes decreased glycogen formation, increased glycogenolysis, increased lipolysis, but has no direct effect on protein synthesis

- Glucagon - Epinephrine

The adrenal cortex secretes:

- Glucocorticoids - Mineralocorticoids

How does the graph show that the normal negative feedback control occurring in untreated Type II diabetes mellitus?

- Glucose levels increase. - Glucose levels rapidly decrease two hours after food is ingested. - Glucose levels remain constant after ingesting food.

Events occurring during the absorptive state:

- Glycogenesis; Lipogenesis - Amino acids and glucose move from blood into cells

Hormones that will stimulate the release of free fatty acids from adipose tissue during fasting, growth or stress:

- Growth hormone - Cortisol - Thyroxine - Catecholamines

Hormones that have an anabolic effect on protein metabolism:

- Growth hormone - Thyroxine - Insulin

All of the effects that the hormones released from the thyroid follicles may have on the body:

- Increase ATP reserves - Promote protein catabolism

Characteristics applying to Type 2 diabetes mellitus:

- Insulin normal or increased - Slow onset - 95% of diabetics

Circulating energy substates:

- Ketone Bodies - Glucose - Lactic acid - Amino acids

As adiposity increases, so too does the level of what two hormones?

- Leptin - Insulin

Two methods of measuring metabolic rate:

- Measuring oxygen consumption - Measuring heat generation

Functions of calcium:

- Needed for maintenance of membrane permeability - Role in muscle contraction - Acts as second messenger - Needed for blood clotting

Hormones involved in calcium regulation:

- Parathyroid hormone - Calcitonin - 1,25-dihydroxyvitamin D3

Factors an individual can use to achieve negative energy balance:

- Reduce caloric intake - Increase physical activity

Metabolic effects of growth hormone:

- Stimulates protein synthesis - Stimulates lipolysis

Mechanisms by which PTH raises blood calcium concentration:

- Stimulation of osteoclasts - Stimulation of production of vitamin D - Increased renal reabsorption of calcium

Steps in production of the active form of vitamin D:

1. 7-dehydrocholesterol 2. Vitamin D3 3. 25-hydroxyvitamin D3 4. 1,25-dihydroxyvitamin D3

As blood glucose levels increase, glucose enters beta cells of the pancreas, causing the release of insulin. List in order the steps that lead to insulin release:

1. Increased production of ATP 2. Closing of K+ channels, causing depolarization 3. Opening of voltage-gated calcium channels 4. Fusion of vesicles to plasma membrane 5. Exocytosis of insulin

According to the graph, how long does it take for blood glucose levels to return to homeostatic levels with a normal insulin response?

3.5 hours

What is the minimum amount of vitamin D for an older woman who gets little sun exposure?

800 IU per day

During the ___ state, cellular uptake of glucose and amino acids occurs, with increases in glycogenesis, protein synthesis, and lipogenesis

Absorptive

Glucagon is an antagonist of insulin. What would be glucagon's affect on blood glucose levels?

It would increase blood glucose levels

Leptin is produced and released by:

Adipocytes

Triglycerides are stored in cells called ___

Adipocytes

As part of a negative feedback loop, ___ tissue is affected by hunger and metabolism. Thus, this tissue must also influence hunger and metabolism

Adipose

The metabolic rate of an awake, rested, comfortable individual 12-14 hours after eating is called the ___ metabolic rate

Basal

The majority of caloric expenditure in adults is due to:

Basal Metabolic rate

Select the phrase that best describes why blood sugar levels after a meal remain high in type II diabetes.

Body cells are no longer sensitive to insulin, impairing their ability to utilize glucose.

The target organ of 1,25-dihydroxyvitamin D3 is:

Bone, kidneys, and intestines

What is the body's normal response when carbohydrates are ingested?

Both blood glucose levels increase and insulin release is stimulated.

Lipolysis:

Breakdown of triglycerides

Increased growth hormone:

Causes release of fatty acids from adipose tissue

Select the phrase that best describes why blood sugar levels after a meal remain high in type I diabetes.

Cellular uptake of glucose is impossible in many tissues of the body.

Which of the following is a direct result of PTH secretion?

Decreased absorption of dietary calcium

What does decreasing the size of adipocytes do?

Decreases insulin resistance

Inadequate secretion or action of insulin results in the condition called:

Diabetes Mellitus

Adipose tissue ___ influence hunger and metabolism

Does

Carbohydrates, fat, and protein provide ___ needed for body functions while vitamins and minerals do not

Energy

The production of ketone bodies is called ___

Ketogenesis

Vitamins are:

Essential nutrients

________________ is a hormone released by the stomach that stimulates hunger.

Ghrelin

The formation of glucose from noncarbohydrate molecules is called ___

Gluconeogenesis

How does elevated blood glucose contribute to polyuria?

Glucose in the kidney tubules decreases reabsorption of water in the renal tubules

How does the graph show that the normal negative feedback control is NOT occurring in untreated Type II diabetes mellitus?

Glucose levels do not decrease to normal levels because cells do not respond to insulin.

The hydrolysis of glycogen is called ___

Glycogenolysis

Insulin-like growth factors (IGFs) mediate the effects of ___ ___

Growth Hormone

Adipokines:

Hormones released by adipocytes

Chronic high blood glucose is called ___

Hyperglycemia

Individuals with _________________________________ are prone to osteoporosis.

Hyperthyroidism

Brain area involved in hunger and eating:

Hypothalamus

Growth hormone promotes a ___ in blood glucose levels

Increase

The blood level of leptin ___ as levels of stored body fat increases

Increases

Increased ACTH:

Increases cortisol levels which influence energy substrate release

How do thiazolidinediones work to decrease blood glucose levels?

Increasing target cell sensitivity

Action of calcitonin:

Inhibits resorption of bone

The parasympathetic nervous system stimulates the release of:

Insulin

The treatment for type I diabetes always includes ________.

Insulin

Which of the following hormones stimulates glycogenesis?

Insulin

What is the phrase used to describe the phenomenon where target cells do not "receive the signal"?

Insulin resistance

Most consistent with hypoglycemia:

Insulin shock

___ causes glycogenesis and ___ causes glycogenolysis

Insulin; Glucagon

Following a meal, ___ release will ___ in order to restore blood glucose to homeostatic levels. Like ___, this may act to promote ___ in the long-term

Insulin; Increase; Leptin; Satiety

The main source of glucose during the postabsorptive state is:

Liver

Vitamin D is converted to its active derivative via the action of:

Liver and kidney enzymes

Type ___ diabetes mellitus is an autoimmune disease

One

Parathyroid hormone stimulates ___ cells, causing resorption of bone and an increase in blood calcium concentration

Osteoclast

Which of the following are macrophage-like cells that resorb bone?

Osteoclasts

Bone resorption occurs by the action of cells called ___. Bone deposition occurs by the action of ___

Osteoclasts; Osteoblasts

Damage to lipids (such as those in cell membranes), proteins and DNA are examples of:

Oxidative stress

Calcitonin is released by the ____________________________________ cells of the ___________________ gland.

Parafollicular; thyroid

The number and activity of osteoclasts are stimulated by:

Parathyroid hormone (PTH)

What may cause gestational diabetes?

Placental hormones that impair the action of insulin

Blood levels of glucose and amino acids are low during the ___ state

Postabsorptive

The liver secretes glucose into the blood during the ___ state

Postabsorptive

How does metformin (glucophage) work?

Promotes liver glyocolysis and fatty acid oxidation

Decreased sex steroids:

Reduces chance of pregnancy

Decreased insulin:

Reduces energy substrate uptake

Insulin, released after a meal is eaten by a person who does not have diabetes, will cause blood sugar levels to ________.

Return to about normal

Decreased thyroxine:

Slows metabolic rate

Explain the hormonal regulation of glycogenolysis

Stimulated by glucagon; Inhibited by insulin

Energy substrates (glucose, etc.) are ___ during the absorptive state and ___ during the postabsorptive state

Stored; Released

The fat located immediately deep to the skin is called ___ fat

Subcutaneous

The fat present in the mesenteries and greater omentum of the abdomen is called ___ fat

Visceral

___-soluble vitamins acts as coenzymes in the metabolism of carbohydrates, fats and proteins

Water