Digestion, Nutrition & Obesity

Question 1

What is a nutrient?

Answer 1

substance in food that are used to promote normal, growth, maintenance and repair (metabolised for building blocks or energy)

Question 2

What are the uses of carbohydrates in the body?

Answer 2

Glucose (monosaccharide) = fuel

Question 3

What can happen if you have excess carbohydrates in the body?

Answer 3

• depressed brain function and neurone death
• obesity
• diabetes mellitus
• dental cares
• gastrointestinal irritation
• excess glucose converted to fat and glycogen

Question 4

What can happen if you have deficient carbohydrates in the body?

Answer 4

• tissue wasting
• metabolic acidosis

Question 5

What are the uses of lipids in the body?

Answer 5

• provides protection for organs
• integral part of myelin sheaths
• cholesterol used in plasma membranes
• major energy fuel of skeletal muscle

Question 6

What can happen if you have deficient lipids in the body?

Answer 6

• weight loss
• problems controlling heat
• poor growth, skin lesions

Question 7

What can happen if you have excess lipids in the body?

Answer 7

• obesity
• increased risk of cardiovascular disease
• atherosclerosis

Question 8

What are the uses of proteins in the body?

Answer 8

• tissue maintenance and growth
• rate protein synthesis = breakdown
• positive nitrogen balance needed needed for pregnant women or growing children
• negative nitrogen balance (seen in physical and emotional stress)

Question 9

What can happen if you have deficient proteins in the body?

Answer 9

• profound weight loss
• tissue wasting
• anaemia
• oedema

Question 10

What can happen if you have excess proteins in the body?

Answer 10

• obesity
• enhanced calcium excretion
• bone loss

Question 11

What are vitamins?

Answer 11

organic compounds needed for growth and good health

Question 12

What are electrolytes?

Answer 12

chemicals that regulate nerve and muscle function, hydrate the body, balance blood acidity and pressure, and help rebuild damaged tissue

Question 13

What are some examples of electrolytes?

Answer 13

• Sodium
• Potassium
• Calcium
• Bicarbonate
• Magnesium
• Chlorine
• Phosphate

Question 14

What is anabolism?

Answer 14

reactions that build larger molecules and structures

Question 15

What is catabolism?

Answer 15

process of breaking down, complex structures into simpler ones

Question 16

What is oxidation?

Answer 16

food molecules react with oxygen present in our body causing formation of water and carbon dioxide and release of energy

Question 17

What are the short term controls of food intake?

Answer 17

• Vagus nerve
• nutrient signals
• gut hormones

Question 18

What are the long-term controls of food intake?

Answer 18

• insulin
• leptin

Question 19

What is basal metabolic rate (BMR)?

Answer 19

Energy of cost of living
- reflects the need to maintain essential activities like breathing and maintaining organ function
- controlled by thyroxine hormone

Question 20

What is metabolic rate?

Answer 20

kilocalorie consumption required to fuel all ongoing activities

Question 21

What does the digestive system consist of?

Answer 21

• Mouth
• Oesophagus
• Stomach
• Liver
• Gall bladder
• Pancreas
• Small intestine – duodenum, jejunum and ileum
• Large intestine
• Anus

Question 22

What are the major processes occurring in the digestive system?

Answer 22

• Ingestion
• Secretion
• Mixing and Propulsion
• Digestion
• Absorption
• Defecation

Question 23

What are the (3) mouth functions?

Answer 23

• ingest food
• masticate (chewing)
• mix food with saliva

Question 24

What are the (3) functions of the salivary glands?

Answer 24

• cleanses mouth
• dissolves food chemicals to facilitate taste
• moistens food to enable bolus formation

Question 25

What are the 2 phases of deglutition (swallowing)?

Answer 25

- Buccal phase – bolus formation - Pharyngeal-oesophageal phase – tongue blocks mouth, epiglottis closes and upper oesophageal sphincter relaxes to allow food into oesophagus

Question 26

What (2) muscles help push food into the oesophagus?

Answer 26

- oropharynx - laryngopharynx

Question 27

What does the epiglottis do?

Answer 27

closes to prevent food going into the trachea and direct it to the oesophagus

Question 28

How does the oesophagus connect to the stomach?

Answer 28

via the oesophageal hiatus and the cardiac sphincter

Question 29

What is propulsion?

Answer 29

peristalsis pushes food to fundus

Question 30

What is grinding?

Answer 30

vigorous mixing motion close to pylorus

Question 31

What is retropulsion?

Answer 31

pylorus forced back to the stomach

Question 32

What are the (6) functions of the liver?

Answer 32

1. Metabolism of carbohydrate, lipid and protein (maintains normal blood glucose level) 2. Detoxification (removes and excretes alcohol and some drugs; chemically alters some hormones) 3. Storage for nutrients (stores glycogen, vitamins A, B12, D, E + K; minerals like Fe and copper) 4. Phagocytosis (breaks down worn out red blood cells, white blood cells and some bacteria) 5. Activation of vitamin D 6. Production of bile

Question 33

What is the purpose of bile?

Answer 33

helps with digestion by breaking fats into fatty acids

Question 34

What is the purpose of the pancreas?

Answer 34

- Supplies most of the enzymes that digest chyme - Exocrine part produces pancreatic juice of enzymes - Supplies bicarbonates that neutralise stomach acids

Question 35

What is the purpose of the small intestine?

Answer 35

major site for digestion and absorption due to its invaginated structure (folds of mucosa are lines with villi)

Question 36

Between the villi of the small intestine are intestinal crypts containing what (2) things?

Answer 36

- Enterocytes = absorb nutrients and electrolytes - Goblet cells = secrete mucous

Question 37

What is the purpose of the large intestine?

Answer 37

mainly to absorb water

Question 38

What is an appendix?

Answer 38

- contains lymph tissue - involved in immunity and as a storehouse of bacteria for the gut

Question 39

What initiates the defecation reflex of the rectum?

Answer 39

stretching

Question 40

How does defecation take place?

Answer 40

- faeces forced into rectum, distends the rectal wall - this stretches it and initiates the defecation reflex - the sphincter relaxes and rectal walls contract to expel faeces aided by glottis closing and contraction of diaphragm

Question 41

What BMI is considered overweight?

Answer 41

greater than or equal to 25

Question 42

What BMI is considered obesity?

Answer 42

greater than or equal to 30

Question 43

How do you calculate BMI?

Answer 43

Person's weight in kilograms divided by the square of his height in meters (kg/m2).

Question 44

What are (5) ways to measure body fat?

Answer 44

- BMI - DEXA (dual-energy X-ray absorptiometry) scan - Bathroom scales - Waist measurement

Question 45

What is the fundamental cause of obesity and being overweight?

Answer 45

an energy imbalance between calories consumed and calories expended

Question 46

What causes obesity and being overweight?

Answer 46

- Increased intake of energy-dense foods that are high in fat and sugars - Increase in physical inactivity due to the increasingly sedentary nature of work, changing modes of transportation, and increasing urbanisation

Question 47

What factors can cause someone to be overweight?

Answer 47

- genetic - socioeconomic - ethnicity - lack of exercise - sedentary lifestyle - diet - medications - stress + mental illness - poor sleep

Question 48

How does a patient manage their obesity?

Answer 48

- lifestyle interventions - diet - exercise - behavioural therapy - medical managements (appetite suppressant) - bariatric surgery - patient education