Year 1; Phase 1; Pbl 9

Front 1

Describe the healthy eating plate

Back 1

- plenty of fruit andvegetables – approximately 1/3

- plenty of starchy food(wholegrain when possible) – approximately 1/3

- small amount of milkand dairy – approximately 1/9

- small amount ofnon-dairy protein (meat, fish , eggs, beans etc) – approximately1/9

- small amount of food ordrinks high in fat and/or sugar – approximately 1/10

Front 2

Give 4 examples of starch foods

Back 2

wholegrainbread, whole wheat pasta, brown rice and wholegrain breakfast cereals

Front 3

What are the organs of the digestive tract?

Back 3

mouth,most of the pharynx, oesophagus, stomach, small intestine and largeintestine

Front 4

List 6 accessory organs for digestion

Back 4

teeth,the tongue, salivary glands, the liver, gallbladder and pancreas

Front 5

Describe the 5 functions of the digestive tract

Back 5

(1)ingestion: eating

(2)secretion: i.e. GI tract secretes water, acid, buffers and enzymes

(3)mixing and propulsion: contraction and relaxation of smooth musclemixes food and secretions toward the anus. This is called motility

(4)digestion: chemical (e.g. hydrolysis of macromolecules by enzymesfrom the salivary glands, tongue, stomach, pancreas, and smallintestine) and mechanical (e.g. chewing and peristalsis)

(5)defecation: release of wastes, indigestible substances, bacteria,cells and undigested substances through the anus

Front 6

What are the three stages of swallowing?

Back 6

(1) voluntary stage(bolus passed into the oropharynx),

(2) pharyngeal stage (boluspassed involuntarily through the pharynx into the oesophagus, and

(3)oesophageal stage (bolus passed from the oesophagus into the stomach

Front 7

Describe the stomach's role in digestion

Back 7

- acts as a mixingchamber and holding resevoir- at regular intervals,the stomach releases small amounts of material into the duedenum

- digestion of starchesand triglycerides continues in the stomach, while the digestion ofproteins begins

- stomach is composed offour regions: cardia, fundus, body and pyloric part

- the fundus is in thesuperior region of the stomach and is involve in storing gasesproduced through digestion

- the body is the centralregion

- the pylorus has threeregions: the pyloric antrum (connects to the body), the pyloric canal(the middle region) and the pylorus (connects to the duodenum)

- the stomach containscolumns of secretory cells called gastric glands, which empty intogastric pits. The gastic glands are composed of thee types ofexocrine gland cell: mucous neck cells, chief cells and parietalcells.

- mucous neck cells (andsurface mucuous cells) secrete mucous.

- parietal cells produceintrinsic factor – needed for absorption of vitamin B12 andhydrochloric acid

- chief cells secretepepsinogen - which, when activated to pepsin, catabolises proteins -and gastric lipase, which catabolises triglycerides into fatty acidsand monoglycerides

- the collectivesubstance produced from these gastric glands is called gastric juice

- the gastric glands alsosecrete an enteroendocrine cell, called the G-cell, which secretesthe hormone gastrin into the bloodstream. Gastrin has many functions:stimulates parietal cells and chief cells, contracts the loweroesophageal sphincter, increases motility in the stomach, and relaxesthe pyloric sphincter

Front 8

Draw and label the stomach

Back 8

Front 9

Describe the role of the pancreas in digestion

Back 9

- pancreas connects tothe duodenum by two ducts

- it delivers pancreaticjuice to assist with absorption

- some of the enzymes inpancreatic juice include; pancreatic amylase (digests starch);trypsin, chymotrypsin, carboxypeptidase and elastase (digest proteinsinto peptides); pancreatic lipase (triglyceride catabolisation); andribonuclease and deoxyribonuclease (nucleic acids)

- protein-digestingenzymes are kept in a deactivated form to prevent digestion of thepancreas. Trypsinogen is activated at the brush border of the smallintestine by enterokinase

Front 10

What does bile consist of?

What is its function?

Back 10

- water, bile salts,cholesterol, a phospholipid called lecithin, bile pigments, and ions

- bile salts are composedof mainly sodium salts and potassium salts, and have a role inemulsification – breaking down large lipid globules into smalllipid globules. Breaking lipid globules down increases surface areafor pancreatic lipase to act on triglycerides

Front 11

what are the components of the small intestine?

Back 11

- divided into duodenum(starts at pyloric sphincter), jejunum (longest region of the smallintestine) and ileum (joins large intestine at the ileocecalsphincter

Front 12

How is mechanical digestion achieved in the small intestine?

Back 12

- there are two types ofmechanical movement in the small intestine: segmentations, and typeof peristalsis called migrating motility complexes

- segmentation is enabledby smooth muscle fibres. It involves localised contractions which mixthe chyme with the digestive juices, and allow it to come intocontact with the mucosa. Segmentation does not propel the chymethrough the small intestine.

- the Migrating MotilityComplex (MMC) is a type of peristalsis which moves the chyme from thestomach, through the small intestine.

Front 13

How are the following chemically digested in the small intestine;

carbohydrates

proteins

lipids

nucleic acids

Back 13

carbohydrates:m pancreatic amylase, alpha-dextrinase, sucrase, lactase and maltase

proteins: trypsin, chymotrypsin,carboxypeptidase and elastase

lipids: pancreatic lipase

nucleic acid: ribonucleases anddeoxyribonucleases

Front 14

What are the different phases of digestion?

Back 14

- cephalic: anticipatory response todigestion

- gastric: occurs in the stomach

- intestinal: begins when chyme enters the small intestine

Front 15

Define eating disorder

Back 15

persistentdisturbance of eating or eating-related behaviour resulting inaltered consumption or absorption of food, that significantly impairsphysical health or psychosocial function.

Front 16

List the 5 eating disorders

Back 16

AnorexiaNervosa (AN)

Bulimia Nervosa (BN)

EatingDisorder Not Otherwise Specified (EDNOS)

Pica ( appetitefor non-nutritive substances e.g. paper, clay, metal and chalk)

Ruminationdisorder (regurgitating and re-chewing food)

Front 17

Summarise anorexia nervosa

Back 17

-marked by weight loss due to food avoidance

-often associated with binging, purging (vomiting, laxatives, enemasetc) or excessive exercise

-distorted body image – despite often profound emaciation (extremeweight loss) – while still feeling overweight and fearful of weightgain

Front 18

List presentations and sequelae of anorexia nervosa

Back 18

-often accompanied by anxiety and depression

-may present with lanugo (fine, downy hair) on back, forearms andcheeks

-has a range of sequelae – both psychological (e.g. anxiety anddepression) and physical e.g.cardiac (ECG abnormalities and arrhythmias),haematological (anaemia (reduced RBCs), thrombocytopaenia (reducedplatelets) and leukopaenia (reduced WBCs)),endocrine (delay or arrest of puberty, reduced growth, amenorrhea(absence of menstruation) and sick euthyroid state (low serum thyroidhormones)),metabolic (uraemia (blood in urine), renal calculi (kidney stones),osteoporosis (brittle, fragile bones)) andgastrointestinal (constipation, abnormal liver function).

Front 19

Discuss the aetiology of AN

Back 19

- unknown though likelyinvolves environmental, psychological and genetic factors

- rarely occurs beforepuberty or after 40

- more common in woman:10:1

- more common inaffluent, westernised societies

- often associated with astressful life event e.g. leaving home, parental divorce etc

- those with anxiety orcompulsive disorders are at greater risk

- there is associationswith cultural stresses of being thin, and in some casessports-related stresses

- concordance rates ofmonzygotic twins are higher than that of dizygotic twins, suggestingpartially genetic aetiological basis

- most will achieveremission within 5 years. Death rate is ~5% per decade

Front 20

How is AN diagnosed?

Back 20

(A) dietary intake belowthat of requirements, resulting in significantly low body weight forage sex, expected development and physical health.

(B) intense fear ofweight gain and becoming “fat”, or behaviour which preventsweight, despite significantly low weight

(C) disturbed body imageor shape and persistent lack of recognition of the seriousness of thecurrent low weight

Front 21

What are the 2 subtypes of AN?

Back 21

Restrictingtype: when weight loss isaccomplished by dieting, fasting and/or excessive exercise, withoutbinging or purging (over period of three months).

Bingeeating/purging type: whenindividuals had engaged in recurrent purging or binge eating (overperiod of three months)

Front 22

Summarise bulimia nervosa

Back 22

- usually at or nearnormal weight

- can occur but is lesscommon in obese individuals

- display disorderedeating and have a morbid fear of fatness

- associated withrecurrent eating binges, often followed by purging behaviour

-occurs in similar proportions toAN, though patients are less likely to seek help

Front 23

Give 9 presentations of BN

Back 23

- recurrent self-inducedvomiting is associated with pitted teeth (erosion and decay)

– dueto gastric acid- Russell's signs on knuckles

- callouses due to mechanical sheer when inducing vomiting

-parotid gland enlargement –enlargement of salivary glands

- dental and oesophagealcomplications

- electrolyteabnormalities

- arrhythmias

- renal problems

- amenorrhea is common infemales. Causes are unclear as it can be associated with weight,nutrition of emotional stress

- disturbed fluid andelectrolyte balance

Front 24

Discuss the aetiology of BN

Back 24

- unknown though likelyinvolves environmental, psychological and genetic factors

- more common in woman:10:1

- rarely occurs beforepuberty or after 40

- possible familialassociation – 4 times more likely if a close family member has/hadBN

- more common inaffluent, westernised societies

- often associated with astressful life event e.g. difficult upbringing, sexual abuse

- low self-esteem,depression and stress are factors which can lead to BN

- those with anxiety orcompulsive disorders are at greater risk

- there is associationswith cultural/social stresses of being thin, and in some casessports-related stresses

Front 25

How is BN diagnosed

Back 25

(A) Recurrent episodes ofbinge eating

- eating, within adiscrete amount of time (e.g. 2 hours), an amount much larger thanwould be considered normal.

- sense of lack ofcontrol during binge eating periods

(B) Recurrentinappropriate behavioural to counter weight gain – e.g. vomiting,laxatives, diuretics etc

(C) Binge eating andcompensatory behaviour occur ~ once a week for three months

(D) Opinions of one'sself is disproportionately related to body shape and weight

(E) Disturbances do notoccur during episodes of AN