Digestive System

Question 1

Stages of digestion

Answer 1

Chewing Mixing with acid Digestive juices and enzymes Breaks down into constituent parts proteins, carbs, acid and fats

Question 2

The constitute parts are absorbed at what

Answer 2

Different level of digestive tract

Question 3

The digestive system is a collection of organs and tracts whose solo function is to do what

Answer 3

Break down solid and liquid food into usable basic chemicals required by the body

Question 4

What do I need to know about nutrition?

Answer 4

What do I need to know about nutrition?

The principle nutrients of the body are carbohydrates, fats and proteins. During digestion, carbohydrates are converted to glucose, fats to fatty acids and proteins to amino acids. These molecules then enter the cells and react chemically with oxygen, under the influence of enzymes , to release energy.

Question 5

Amino acids

Answer 5

Amino acids

These must be supplied in food:

Arginine

Lysine

Tryptophan

Histidine

Methionine

Leucine

Phenylalanine

Isoleucine

Question 6

Minerals

Answer 6

Minerals

A number of mineral salts play an important role in the process of metabolism. Some are present in relatively large amounts, while others are only needed in minute quantities.

All are derived from food:

Calcium

Magnesium

Fluorine

Phosphorus

Iron

Potassium

Iodine

Sodium

Question 7

Vitamins

Answer 7

Vitamins

Vitamins or accessory food factors are organic compounds that are needed in small quantities for metabolism .

These are derived from food:

Fat soluble vitamins:

1. A - liver, dairy produce, eggs and fish
2. D - fish, margarine, butter and eggs
3. E - wheatgerm, vegetable oil, dairy products
4. K - present in many foods

Water soluble vitamins:

1. B 1 - cereals, flour, peas and beans
2. B 2 - meat, milk and flour
3. B 3 - meat, liver and flour
4. B 6 - present in many foods
5. B 12 - liver meat and animal products
6. Folic acid - present in many foods
7. Pantothenic acid - liver, meat, eggs, milk
8. C - fresh fruit and vegetables

Question 8

name body’s essential nutrients

Answer 8

minerals

vitamins

Amino acids

Question 9

How is food intake regulated?

Answer 9

How is food intake regulated?

The control mechanisms to regulate food intake lie within the hypothalamus. There are two clusters of nerve cells, one in the lateral nuclei known as the feeding (hunger) centre and one in the medial nuclei, known as the satiety centre.

The feeding centre is constantly active but it is overridden when impulses are stimulated by the satiety centre.

There are five basic elements to the digestive process:

1. Ingestion - taking food into the body
2. Movement - passage of food along the digestive tract
3. Digestion - breakdown of food by chemical and mechanical processes
4. Absorption - passage of digested food from the digestive tract into the cardiovascular or lymphatic systems
5. Defecation - elimination of indigestible substances

Question 11

There are five basic elements to the digestive process name them

Answer 11

There are five basic elements to the digestive process:

1. Ingestion - taking food into the body
2. Movement - passage of food along the digestive tract
3. Digestion - breakdown of food by chemical and mechanical processes
4. Absorption - passage of digested food from the digestive tract into the cardiovascular or lymphatic systems
5. Defecation - elimination of indigestible substances

Question 12

three words describe process of eating

Answer 12

Bolus

peristalsis

chyme

Question 13

alimentary tract and function Mouth

Answer 13

Mouth

This is also known as the buccal cavity.

It is lined with a mucous membrane thinner than the skin. The boundaries of the mouth are the hard palate superior, the maxilla laterally and the soft palate or uvula inferior. The main muscles forming the walls of the mouth are the masseter, buccinator and obicularis oris muscles.

There are three pairs of salivary glands that discharge into the mouth:

Parotid glands - at the level of the cheek

Submandibular glands - at the level of the mandible

Sublingual glands - below and to the midline of the tongue

It is the parotid glands that are generally affected in the viral condition mumps.

The tongue is composed almost entirely of voluntary muscle. Its functions are those of mastication, swallowing, speech and taste. The under-surface and anterior part of the tongue are covered by a thin mucous membrane that forms a central fold, which attaches to the floor of the mouth and is called the frenulum.

Difficulty in swallowing is known as dysphagia.

Question 14

alimentary tract and function Pharynx

Answer 14

Pharynx

This is an expandable muscular tube lying posterior and inferior to the mouth and is divided into the oropharynx and laryngopharynx.

Within the oropharynx lie the palatine tonsils.

The nerve supply of the pharynx involves some of the cranial nerves

Question 15

alimentary tract and function Oesophagus

Answer 15

Oesophagus

A collapsible muscular tube extending from the pharynx to the cardiac sphincter protecting the stomach. It leaves the thorax by piercing the diaphragm to enter the abdomen.

The cardiac sphincter prevents regurgitation of stomach contents into the oesophagus

Question 16

alimentary tract and function Stomach

Answer 16

Stomach

This lies within the epigastric, umbilical and left hypochondriac regions of the abdominal cavity. To the left of the cardiac sphincter is a pouch shaped upper part of the stomach called the fundus. Below this is the body of the stomach ending at the pyloric sphincter .

The stomach is lined with a thick mucous membrane that has a smooth soft velvety surface when distended but recoils to form lots of irregular folds (rugae) when empty.

Within the lining of the pyloric vesicles are glands responsible for the secretion of the “intrinsic factor”, essential for the absorption of vitamin B12.

Question 17

alimentary tract and function Duodenum

Answer 17

Duodenum

The duodenum is approximately 25-30cm long and lies in a C shape around the head of the pancreas.

It is fixed to the abdominal wall by a loop of peritoneum.

The point of entry for the bile and pancreatic duct s is known as the ampulla of vater

Question 18

alimentary tract and function Jejunum and ileum

Answer 18

Jejunum and ileum

The jejunum forms two fifths of the small intestines and the ileum makes up the remaining three fifths.

The mucous membrane of the small intestine is arranged in permanent folds called plicae cartularies. They effectively increase the surface area for secretion and absorption. Projections of this lining extend in outward microscopic fingers called villi. Between each villus lie tubular glands (crypts of lieberkuhn). Lymphatic tissue is scattered throughout the whole of the small intestine in collected masses (peyer’s patches). Blood is suppled via the superior mesenteric artery .

Parasympathetic impulses increase peristaltic movement and secretion of intestinal glands. These impulses also cause the ileocaecal sphincter to relax.

The functions of the small intestines are to complete digestion of food (through secretion), to absorb the end products of digestion (through villi) and to move the chyme towards the ileocaecal sphincter (through peristalsis).

Question 19

Poisons fall into the 4 main groups

Answer 19

Burning or corrosive poisons

Non-burning poisons

Industrial poisons and pesticides

Irritant poisons

Question 20

alimentary tract and function Peritoneum

Answer 20

Peritoneum

The peritoneum is a serous membrane and like other important serous membranes of the body has two layers, the outer parietal layer and the inner visceral layer.

Peritoneal ligaments
The liver, uterus and other organs are partly maintained in position by means of double folds of peritoneum which form suspensory ligaments.

Omenta
These are folds of peritoneum connected to the stomach. The great omentum hangs from the lower border of the stomach like an apron in front of the small intestine.

Mesentery
This is a fold of peritoneum that encloses the small intestine and anchors it to the posterior abdominal wall. The attachment to the abdominal wall is relatively short, whereas the intestinal part is many feet long, so the mesentery can be described as a fan-shaped structure.

Functions of the peritoneum include:

Allowing movement of organs without friction

Partial/complete covering of organs

Forming ligaments and mesenteries for anchorage

Absorbing fluid in large quantities

Acting as a body store - omenta and mesentery contain fat

Slowing the spread of infection - omentum has the ability to move and will wrap around inflamed organs and tracts

Question 21

alimentary tract and function Large intestine

Answer 21

Large intestine

1. Approximately 1.5m in length the large intestine is made up of:
2. Caecum and veriform appendix
3. Ascending colon
4. Transverse colon
5. Descending colon
6. Pelvic or sigmoid colon
7. Rectum and anal canal

Blood is supplied via both the superior and inferior mesenteric arteries . The veins of the anus form dilated vessels within the anal ring called the haemorrhoidal plexus.

The functions of the large intestine are the absorption of water and electrolytes from chyme passing through it and the expulsion of waste material from the body.

The large intestine contains a multitude of bacteria. These synthesize vitamins B and K, which are then absorbed into the blood by the mucosa

Question 22

alimentary tract and function Ileum

Answer 22

Jejunum and ileum

The jejunum forms two fifths of the small intestines and the ileum makes up the remaining three fifths.

The mucous membrane of the small intestine is arranged in permanent folds called plicae cartularies. They effectively increase the surface area for secretion and absorption. Projections of this lining extend in outward microscopic fingers called villi. Between each villus lie tubular glands (crypts of lieberkuhn). Lymphatic tissue is scattered throughout the whole of the small intestine in collected masses (peyer’s patches). Blood is suppled via the superior mesenteric artery .

Parasympathetic impulses increase peristaltic movement and secretion of intestinal glands. These impulses also cause the ileocaecal sphincter to relax.

The functions of the small intestines are to complete digestion of food (through secretion), to absorb the end products of digestion (through villi) and to move the chyme towards the ileocaecal sphincter (through peristalsis).

Question 23

What is diabetes mellitus?

Answer 23

What is diabetes mellitus?

Diabetes mellitus is a chronic disorder that affects approximately 200 million people world-wide. It happens when the body is unable to metabolise carbohydrate, resulting in a raised blood sugar level.

Question 24

Hyperglycaemia signs symptoms

Answer 24

Hyperglycaemia

This is high blood sugar.

The onset of hyperglycaemia is gradual and may take several days. There are inadequate amounts of insulin for the amount of sugar, so the body’s glucose level becomes too high and body fat reserves are broken down; resulting in the production of organic acids or ketones .

The patient will show signs of restlessness but will eventually become lethargic and their level of consciousness will deteriorate into total unconsciousness and if left untreated, death. Quick medical intervention is very important.

Signs and symptoms include:

1. Gradual onset, hours or maybe days
2. Dry flushed skin
3. Deep sighing respirations
4. Pulse of 100+
5. Fruity breath smell (acetone)
6. Fever and thirst
7. Nausea
8. Lethargy
9. Drowsiness
10. Vomiting

Question 25

hypoglycaemia signs and symptoms

Answer 25

Hypoglycaemia

This is low blood sugar.

The onset of hypoglycaemia is usually quite sudden and may be as a result of too much insulin in the blood, or not enough food intake supplying carbohydrate. Alcohol prevents the liver releasing glucose into the bloodstream, which can also lead to an episode of hypoglycaemia.

With the exception of the pulse most of the signs and symptoms of hypoglycaemia are the complete opposite to those of hyperglycaemia . In spite of this fact the patient’s condition is just as serious and will also end in unconsciousness or even death.

These signs and symptoms are:

1. Rapid onset, maybe only minutes
2. Appears uncoordinated
3. Sweating pale skin
4. Normal to shallow breaths
5. Pulse of 100+ and full
6. Aggressive behaviour
7. Hunger
8. Headache
9. Dizziness
10. No breath odour
11. Fits in later stages

Question 26

General treatment of poisons

Answer 26

General treatment of poisons

Treatment of poisons, from the ambulance, include:

1. Do not induce vomiting
2. Maintain and ensure at all times an open and clear airway
3. If unconscious, place in coma position and ensure postural drainage
4. Keep a continuous watch on the airway, resuscitate if necessary
5. Ask for an accurate history
6. Look for evidence eg labels on container, hazchem code on tankers
7. If relevant, try to obtain evidence to take with you
8. Take advice on treatment or handling
9. You might find it useful to remember the following alphabetical list:
10. A: Airway - maintain it always
11. B: Breathing - can be affected, if absent restore it
12. C: Check for circulation
13. D: Depth of conscious level - coma position
14. E: Evidence - look for evidence, take it with you and alert hospital
15. F: Fresh air - carbon monoxide, sewer gas, pesticides, industrial gases, contaminated clothes
16. G: Give oxygen
17. H: Hospital - alert if necessary

Saline emetics (extract from the DHSS Circular hh/78 23)
The practice of using a saline solution in the emergency treatment of poisoning is dangerous, due to the possibility of death from hypernatraemia (abnormally high sodium level in the blood). The use of saline as an emetic is not to be practised.

Question 27

Burning or corrosive poisons

Answer 27

Burning or corrosive poisons

When swallowed these poisons will, in the first instance, burn or destroy the mucous membrane of the alimentary tract, affecting the ability to breathe.

They fall into two categories:

Corrosive acids (sulphuric, carbolic/phenol, oxalic, acetic)

Corrosive alkalines (quick lime, some bleaching fluids)

Look out for stains on lips, mouth or clothing to identify them:

Yellow (nitric acid)

Black/brown (sulphuric acid)

White (acetic acid)

Question 28

Non-burning poisons

Answer 28

Non-burning poisons

These poisons take the route of the systemic circulation and eventually are absorbed by the blood, affecting the nervous system. They include:

1. Barbiturates
2. Aspirin
3. Alcohol

Question 29

Industrial poisons and pesticides

Answer 29

Industrial poisons and pesticides

These poisons can be inhaled or absorbed by the skin

Question 30

Irritant poisons

Answer 30

Irritant poisons

These are poisons found in fungi and toadstools, rat poison and foods like shellfish.

They can produce irritation and inflammation of the digestive tract when swallowed.

Question 31

Poisons are toxic substances that in relatively small doses will have an adverse action that can destroy or seriously impair the function of organs or tissues, when it is name how posions can be taken

Answer 31