Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Medical Toxicology > Introduction to nanotoxicology > Flashcards

Introduction to nanotoxicology Flashcards

(75 cards)

Start Studying
1
Q

What do biotic organisms derive energy from?

A

Food

This energy sustains life and drives cellular functions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are nutrients?

A

Chemical substances necessary for proper growth, development, reproduction, cellular function, and repair following injury.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does digestion begin?

A

In the mouth via the actions of enzymes in saliva.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are gastric juices primarily composed of?

A

High amounts of hydrochloric acid and enzymes like pepsin and α-amylase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What role do bile and pancreatic enzymes play in digestion?

A

Aid in the absorption of dietary fats and further digestion of food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the primary site of nutrient absorption?

A

The jejunum and ileum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What structures increase the surface area of the intestinal mucosa?

A

Valvulae conniventes and villi.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are monosaccharides transported into enterocytes?

A

By active transport (glucose, galactose) or facilitated diffusion (fructose).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to macronutrient molecules that enter the circulation?

A

They undergo metabolism to be oxidized for energy or stored for future utilization.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the three main nutrient classes that provide energy?

A

Carbohydrates, proteins, and fats.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the principal circulating fuel in the body?

A

Glucose and free fatty acids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What hormone is primarily responsible for managing nutrient fuels?

A

Insulin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does insulin promote in peripheral tissues?

A

Glucose uptake, glycogen synthesis, lipid synthesis, and protein synthesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the set-point theory?

A

Proposes that food intake and energy expenditure are regulated to maintain a constant level of energy reserve and body weight.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which part of the brain plays a central role in energy balance?

A

The hypothalamus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is leptin?

A

A hormone secreted by adipose tissue that regulates energy balance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name two types of neurons involved in appetite control.

A

Orexigenic and anorexigenic neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the methods to assess caloric intake in studies?

A

Measuring food consumed in metabolic cages and maintaining food records.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the general calorie factors for carbohydrates, fats, and proteins?

A

4, 9, and 4 respectively.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is basal energy expenditure?

A

Energy expended at complete rest, generally after sleep.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the components of energy expenditure?

A

Basal energy expenditure, thermic effect of food, and energy expenditure associated with physical activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is body mass index (BMI)?

A

A measure of body fatness derived from weight and height.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does hydrodensitometry estimate?

A

Relative body fat using the density of the whole body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How does air displacement plethysmography work?

A

Calculates body volume by measuring the air displaced by the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does dual-energy x-ray absorptiometry measure?
Percentage of body fat, lean tissue, and bone mineral density.
26
What is the principle of nuclear magnetic resonance in body composition assessment?
Interpreting radio-frequency signals of excited nuclei in a magnetic field.
27
What does bioelectrical impedance analysis measure?
Total body composition based on electrical impedance.
28
What is the role of accelerometers in physical activity assessment?
To empirically estimate activity and convert count data into energy expenditure.
29
What is the thrifty gene hypothesis?
Suggests that genes promoting energy storage were advantageous in environments with scarce food.
30
What has changed in the environment affecting obesity risk?
Increased food availability and decreased physical activity.
31
What has led to weight gain and obesity in modern lifestyles?
A drastically altered environment with caloric abundance and less physical activity ## Footnote This change contrasts with the beneficial thrifty genes that were advantageous in environments with limited food.
32
What is the 'drifty gene' hypothesis?
It explains why not everyone becomes obese in societies with high obesity rates due to natural variation and random mutation in genes controlling energy balance ## Footnote This hypothesis suggests that genetic drift has contributed to the variability in obesity susceptibility.
33
What percentage of the interindividual difference in obesity is accounted for by genetic variability?
40% to 75% ## Footnote This statistic is based on studies comparing monozygotic and dizygotic twins.
34
What are adipokines?
Chemokines and cytokines released from adipose tissue that contribute to metabolic inflammation ## Footnote They play a role in the development of metabolic syndrome.
35
What is the relationship between maternal body composition and obesity risk in offspring?
Maternal body composition at conception and gestational weight gain influence metabolism and appetite regulation in the offspring ## Footnote This suggests that obesity susceptibility can be programmed in utero.
36
What is 'metabolic inflammation'?
A state induced by adipokines released from adipose tissue in obese individuals ## Footnote This inflammation contributes to insulin resistance and other metabolic disturbances.
37
What are triglycerides used for in the body?
To store excess caloric energy ## Footnote They are stored in adipose tissue and can accumulate in nonadipose tissues when energy storage efficiency is decreased.
38
What factors contribute to ectopic fat deposition?
Central (visceral) adiposity, waist circumference, and insulin resistance ## Footnote Ectopic fat deposition is notably correlated with metabolic dysfunction.
39
Define nonalcoholic fatty liver disease (NAFLD).
Abnormal lipid accumulation in the liver in the absence of heavy alcohol usage ## Footnote It is associated with hepatic dysfunction and can progress to more severe liver diseases.
40
What are the characteristics of metabolic syndrome?
Central obesity, insulin resistance, dyslipidemia, and hypertension ## Footnote These components collectively increase the risk for cardiovascular disease and type 2 diabetes.
41
What is the role of metformin in treating metabolic syndrome?
It reduces hepatic glucose production by activating the AMP kinase pathway ## Footnote This helps improve insulin sensitivity.
42
What progression does nonalcoholic fatty liver disease (NAFLD) undergo?
Simple steatosis to nonalcoholic steatohepatitis (NASH), then to cirrhosis, and potentially to hepatocellular carcinoma ## Footnote Each stage involves increasing severity of liver dysfunction and damage.
43
How does obesity affect drug pharmacokinetics?
It increases the volume of distribution (Vd) for lipid-soluble drugs due to larger fat compartments ## Footnote In contrast, hydrophilic drugs may not be significantly affected.
44
What is the impact of obesity on cytochrome P450 enzymes?
Obesity increases expression of CYP2E1 but suppresses CYP1A2 ## Footnote This can affect drug metabolism and therapeutic efficacy.
45
What triggers inappropriate extracellular matrix remodeling in adipose tissue?
Hypoxia and obesity ## Footnote This process can contribute to fibrosis and metabolic dysfunction.
46
What is the significance of the transcription factors SREBP-1c and ChREBP?
They are activated by excess caloric intake and drive adipose tissue hypertrophy ## Footnote Their activation promotes triglyceride synthesis in response to overnutrition.
47
Fill in the blank: The accumulation of triglycerides in the liver above 5% by weight is defined as _______.
steatosis
48
True or False: Simple steatosis is irreversible with lifestyle modifications.
False ## Footnote Simple steatosis is generally reversible with weight loss and lifestyle changes.
49
What dietary changes can improve insulin sensitivity in obese individuals?
Very low-calorie diets ## Footnote These diets can reduce intramyocellular lipid (IMCL) and enhance insulin sensitivity.
50
What enzyme's expression is increased in both animal models and human clinical studies related to metabolism?
Cytochrome P450 enzyme CYP2E1 ## Footnote Increased expression of CYP2E1 is associated with metabolic processes.
51
What happens to the hepatic expression of CYP1A2 in the context of certain conditions?
It appears to be consistently suppressed ## Footnote This suppression may affect drug metabolism.
52
What is the effect of NASH on sulfotransferase expression?
Sulfotransferase expression is reduced ## Footnote This may impact drug glucuronidation and glutathione conjugation.
53
In experimental rat models of NAFLD, what happens to hepatic uptake transporters?
Decreased expression of NTCP and OATPs ## Footnote These transporters are important for drug and nutrient uptake.
54
What type of transporters show increased expression in NAFLD models?
Efflux transporters such as Mrp2, Mrp3, and Mrp4 ## Footnote These transporters are involved in drug resistance and elimination.
55
What complications can obesity in pregnancy lead to?
Gestational diabetes, pregnancy-associated hypertension, preeclampsia, fetal abnormalities ## Footnote Abnormalities may include neural tube defects and heart defects.
56
How does obesity affect growth hormone (GH) secretion?
GH secretion is dramatically suppressed ## Footnote This involves feedback effects of insulin and reduced ghrelin secretion.
57
What hormone's levels are increased in obese prepubertal girls, affecting puberty?
Adrenal androgens ## Footnote This can lead to early pubertal development.
58
In obese boys, what hormonal changes may delay puberty?
Increased aromatization of androgens ## Footnote Negative feedback of estrogens may reduce luteinizing hormone secretion.
59
What common condition is associated with individuals having metabolic syndrome?
Hypothyroidism ## Footnote Low thyroid hormone concentrations can exacerbate liver conditions like NASH.
60
Increased BMI is associated with an increased risk of which cancers?
Endometrial, breast, prostate, GI tract cancers ## Footnote These include esophageal adenocarcinoma and colon cancer.
61
What role does leptin play in obesity-related cancer risk?
Leptin is proproliferative, antiapoptotic, proinflammatory, and angiogenic ## Footnote Increased leptin levels are associated with higher fat mass.
62
What is caloric restriction (CR) and its effect on lifespan?
CR increases lifespan and reduces age-related disease ## Footnote This has been observed in various organisms.
63
What are CR mimetics, and which compounds are examples?
Substances that mimic caloric restriction effects ## Footnote Examples include resveratrol and rapamycin.
64
What approach is usually required to achieve a healthy body composition?
Reducing caloric intake and increasing energy expenditure ## Footnote This creates a metabolic state where energy expenditure exceeds intake.
65
What is the basal metabolic rate (BMR)?
Energy expenditure of a body at rest ## Footnote BMR varies by age, gender, and body size.
66
What is a major influence of insulin on metabolism?
It causes excess sugar to be stored as fat ## Footnote Insulin also prevents fat utilization as an energy source.
67
What can happen if a diet lacks required nutrients?
Metabolism will suffer and health problems may arise ## Footnote This includes deficiencies like anemia and osteoporosis.
68
What is the main action of appetite suppressants?
They lessen psychological motivation for food ## Footnote They typically act on central nervous system appetite control centers.
69
What are some common adverse effects of long-term use of appetite suppressants?
Intracerebral hemorrhage, acute dystonia, psychosis ## Footnote Other effects include heart valve damage and pulmonary hypertension.
70
What is the purpose of bariatric surgery?
To limit food intake and promote weight loss ## Footnote This can be achieved through various surgical methods.
71
What are the potential nutritional deficiencies after bariatric surgery?
Calcium, vitamin B12, iron, fat-soluble vitamins ## Footnote Nutritional deficiencies can arise due to reduced absorptive area.
72
How does obesity affect health insurance costs?
Obesity increases risk for various diseases, affecting premiums ## Footnote Insurers may decline coverage for morbidly obese individuals.
73
What initiatives are being taken to combat obesity in communities?
Establishing community gardens, building walking trails ## Footnote Teaching cooking skills and promoting physical activity are also part of the initiatives.
74
What is the role of the FDA concerning food labeling?
To ensure foods are properly labeled and meet specific requirements ## Footnote This applies to both domestic and foreign food products.
75
What is required on food packaging by federal law?
Listing of ingredients and nutrition data ## Footnote This includes calorie counts and nutrient content.

Medical Toxicology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions