Week 18 Flashcards
What is epidemiology?
the branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health.
How common is abdominal pain?
Common - 25% of the adult population has some form of abdominal pain at any one time.
What are the common causes of upper abdominal pain?
- Gas
- Indigestion
- Gastritis
- Stomach virus
- Muscle pain
- Appendicitis
- Gallstones
- Liver issue
- pancreatic issues
Etc
What is functional abdominal pain?
Ongoing abdominal pain for which there is no known medical explanation .
What is gastritis vs gastropathy?
- Gastritis refers to inflammation of the gastric mucosa, whereas
- Gastropathy is a nonspecific microscopic injury pattern with little or no inflammatory cell infiltration.
Risk factors for peptic ulcers?
- Chronic use of NSAID
- Helicobacter pylori
- Smoking
- Alcohol
- Stress
- Spicy food
What is the typical pathophysiology of gastritis and how does it present in the clinic?
- Gastritis- inflammation of the stomach lining. Commonly by infection
- Presents as Nausea or recurrent upset stomach. Abdominal bloating. Abdominal pain. Vomiting. Indigestion.
What is the typical pathophysiology of Reflux oesophagitis and how does it present in the clinic?
- When acid reflux from the stomach is frequent and persistent, the result is damage to the lining of the oesophagus.
- Can present as eroded teeth, vomiting etc (white gastric acid)
What is the typical pathophysiology of duodenal ulcer and how does it present in the clinic?
- Ulcer in duodenum
2. Can present as pain a few hours after eating
Most common causes of GI haemorrhage?
Upper: 1. Peptic ulcer 2. Mallory-Weiss tears (oesophageal tears) 3. Esophageal varices (enlarged veins) 4. Esophagitis Lower: 1. Diverticulosis (small budging pouches in the GI tract) 2. IBD 3. Tumours 4. Colon polyps 5. Hemorrhoids (swollen veins in anus) 6. Anal fissures (anal tears) Proctitis (rectum inflammation)
What are some symptoms for GI haemorrhage?
- Hypovolemic shock (low bp)
- Vomiting blood
- Bloody stool
- Abdominal pain
- Chest pain
- Difficulty breathing
- Lightheaded
- Fainting
- Tachycardia
- Oliguria (decreased urine output)
What are types of vomitus and their clinical implications (7 colours)
- Clear- Gastroenteritis, gastric outlet obstruction.
- White or foamy- acid reflux, gastritis,
- Green or yellow- Bile reflux, Gastroenteritis
- Orange- Gastroenteritis
- Pink or red- Peptic ulcer, cancer
- Brown- stomach cancer, peptic ulcer, injury, severe constipation.
- Black- injury, peptic ulcer, infection (fungal), cancer, severe constipation
What is the scale for stool classification known as?
Bristol stool scale
What are the different types in the bristol stool scale. (7 types)
Type 1- separate hard lumps, like nuts (hard to pass)
Type 2- sausage shaped but lumpy
Type 3- Sausage but with cracks on the surface
Type 4- sausage but smooth and soft
Type 5- soft blobs with clear cut edges
Type 6- fluffy pieces- a mushy stool
Type 7- entirely liquid
What do some of the types of stool indicate?
- Type 1-2 indicate constipation
What do colours of stool indicate? (6 different colours but 2 are black)
- Black stools not sticky- can be medication or GI bleeding
- Black stool and sticky- usually GI bleeding
- Red stools- haemmorhoids, anal fissure
- Gray stool- lack of bile in the stool (liver disease)
- Yellow stool- malabsorption, lipids, pancreatic issues
Green stool- fast tract through GI, Diarrhoea
What is the purpose of an endoscope?
Visualize and biopsy.
Effect of acid suppression on nutrition?
- Food breakdown reduced
- Protein breakdown reduced
Hence malabsorption.
- Protein breakdown reduced
What is the difference between norovirus and rotavirus?
Noravirus can affect anyone, hard to get immunity, no vaccine
Rotavirus affects people under 5, easy to get immune, vaccine available.
What are brush border enzymes?
Enzymes of the microvilli, allow for nutrient absorption
What is ghrelin?
Ghrelin is a hormone that is produced and released mainly by the stomach with small amounts also released by the small intestine, pancreas and brain. Ghrelin has numerous functions. It is termed the ‘hunger hormone’ because it stimulates appetite, increases food intake and promotes fat storage.
What are the major structures of the oral cavity?
- Teeth
- Tongue
- Lips
- Salivary glands
What is the digestive purposes the oral cavity serves?
- Receives food
- Mechanical digestion (mastication with teeth and tongue)
- Mixing food with saliva (enzymes in saliva, lubricates and helps form bolus to allow transfer to the oesophagus)
- Gustation (tongue has taste receptors)
What cranial nerves do taste buds use to send signals to the gustatory centers of the brain?
- Cranial nerves (7) VII
- (9) IX
- (10) X.
What are the three major salivary glands in the oral cavity?
- Parotid (upper molars) (20% of saliva)
- Sublingual (under the tongue) (70% of saliva)
- Submandibular gland (10% of saliva)
What are the main components of saliva?
- Water (99.5%)
- Enzymes
- Amylase- starch to sugars (glucose and maltose)
- Lipase- lipid digestion (triglycerides to diglycerides and free fatty acids) - Mucous
- Lubricates food
- Protects mouth lining (like from acid when vomiting)
- Antimicrobial activity (Leukocytes, lysozyme, IgA)
- Enzymes
What is the impact of sympathetic and parasympathetic input on salivary glands?
- Sympathetic- more viscous saliva to facilitate respiration- sticks to surfaces and prevents desiccation.
- Parasympathetic- input creates watery saliva (to facilitate digestion)
What is the three main phases of the swallowing reflex?
Oral phase (voluntary) Pharyngeal phase (involuntary) Oesophageal phase (involuntary)
What are the two steps in the oral phase of swallowing?
- Moistening of the food with saliva/mastication
- Lubricates
- mechanical mastication
- lingual nerve senses the state of the bolus (if too dry swallowing will not continue)
2. Trough formation and posterior bolus movement. - Trough in back of tongue
- Bolus forced back
- Lips contract to seal the oral cavity
- Bolus moved to palatoglossal arch
What are the four main steps in the pharyngeal phase of swallowing?
- Soft palate is elevated- prevent bolus from entering nasal cavity.
- Initiation of pharyngeal peristalsis- bolus moved to the oesophageal sphincter
- Elevation and closure of the larynx- by the epiglottis
- Relaxation of upper oesophageal sphincter.
What are the 5 main steps in the oesophageal phase in swallowing?
- Bolus enters oesophagus- peristaltic wave pushes towards stomach
- Peristaltic wave from alternating relaxation (ahead of bolus) and contraction (behind)
- Lower oesophageal sphincter relaxes and allows bolus to enter stomach
What is the relative speed of the bolus in the pharyngeal phase vs the oesophageal phase?
Pharyngeal- fast (40cm/sec)
Oesophageal- slow (5cm/sec)
What mechanisms allow food to propel down the oesophagus?
A peristaltic wave- contracting of circular muscle behind and relaxation in front of.
What is the normal function of the upper and lower oesophageal sphincters?
- Upper
- prevent oesophageal air during inspiration
- prevent esophagopharyngeal/laryngeal reflux during oesophageal peristalsis.
2. Lower - Prevent retrograde movement of stomach acid.
- ??????
What are the four main parts of the stomach?
- Cardia
- Fundus
- Body
- Pylorus
How many muscle layers does the stomach have and what are their names?
There are 3 - Longitudinal, Circular, Oblique
How does the stomach mainly achieve its role of food storage?
The interior mucosal layer folds (Rugae) allow for expansion of the stomach with assistance from smooth muscle.
What is the volume of an empty stomach vs a full stomach?
Empty 75ml
Full 1-5L-4L
How long does a typical meal take to empty from the stomach?
1 hour
What 3 things does the stomach secrete to aid digestion?
- HCL- denatures proteins and activates pepsinogen –> pepsin
- Pepsin- digests proteins
- Gastric lipase- hydrolyses lipids
How does the stomach achieve motility and what is the effect of this?
- When full peristaltic waves begin - contraction in all three muscle layers.
- Waves happen 3 times per minute
- Waves cause churning (mechanical digestion)
- Contractions move contents from pylorus –> antrum and back again.
- Contents become a watery acidic mixture (chyme)
- Pyloric sphincter opens with each wave.
What is the mucosal surface of the stomach covered with?
Gastric pits
What are the four cell types to gastric glands contain?
- Parietal cells
- Chief cells
- Goblet cells
- Enteroendocrine
Where are parietal cells found and what do they do?
- They are found in the fundus, corpus and antrum
2. Secrete HCL by secreting H+ and Cl separately.
Where are chief cells found and what do they do?
- Found predominately in the corpus
- Secrete pepsin precursor (pepsinogen)
- When pepsinogen is exposed to acid it is activated
- Pepsin then hydrolyses protein residues in the chyme
Where are Goblet cells found and what do they do?
- Found in the gastric pits
- Secrete alkaline mucous
- Mucous protects the epithelium