Alimentary System Flashcards
1
Q
3 components of the small intestine
A
Duodenum
Jejunum
Ileum
2
Q
The key role of the small intestine
A
Digestion & Absorption
3
Q
The anatomical boundaries of the small intestine
A
Starts at pylorus
Ends at ileocaceal junction
4
Q
What is the Peritoneum and its function?
A
Continuous membrane lining abdominal cavity, covering abdominal viscera
Provides support for organs and blood supply route
5
Q
What are 2 continuous layers of tissue - made of simple squamous epithelial cell - known as?
A
Mesothelium
6
Q
What is the mesentery and its function?
A
Double layer of visceral peritoneum
Connects structures to posterior abdominal wall, contains blood vessels, nerves and lymphatics
7
Q
What is the Omentum?
A
Sheets of visceral peritoneum extending from the stomach and proximal duodenum to other abdominal organs
8
Q
What are Brunner’s glands?
A
Glands found within the duodenum (Above pancreatic and biliary secretion entrance)
Secrete alkaline and mucous secretions to protect duodenum from chyme acidity
Ensure optimal condition for intestinal enzymes
9
Q
What is the sphincter of Oddi?
A
Muscular valve controlling pancreatic and biliary secretions through the major papilla
Found within descending limb of duodenum
10
Q
What is the minor duodenal papilla and state its prevalence?
A
Opening of the accessory pancreatic duct, 2cm above major papilla present in 10% of people
11
Q
What are the sections/parts that make up the duodenum?
A
Superior, Descending, Inferior, Ascending
12
Q
Detail the blood supply to the duodenum?
A
Coeliac trunk → Common hepatic → Gastroduodenal artery → Superior pancreatico-duodenal artery
Superior mesenteric artery → Inferior pancreatico-duodenal artery
13
Q
What are the anatomical boundaries of the Jejunum and ileum?
A
Duodenojejunal flexure - Ileocaecal junction
14
Q
What are the main roles of each of the three components of the small intestines?
A
Duodenum - mainly digestion
Jejunum - Digestion (Brush border enzymes) & absorption
Ileum - Absorption
15
Q
Detail the two forms of innervation of the GIT
A
Submucous plexus (Meissner’s)
Myenteric plexus (Auerbach)
16
Q
What is the submucous plexus innervation path/origin and function?
A
Origin: Stemming from plexuses of parasympathetic nerves around thesuperior mesenteric artery
Function: senses the lumen environment and regulates gastrointestinal blood flow as well as controlling the epithelial cell functions and secretion
17
Q
What is the Myenteric plexus innervation path/origin and function?
A
Origin: Stemming from Vagus (Cranial nerve X), having parasympathetic and sympathetic input
Function: Lies between muscularis externa layers, controlling motility via muscle stimulation
18
Q
Name 2 adaptations of the small intestine?
A
Pilcae circulares
Permanent circular folds of mucous membrane
Numerous at final parts of duodenum - upper part of jejunum
Increase surface area 2-3x
Villi
Finger like processes - increasing surface area 10-30x
Microvilli approx 600x increase
19
Q
Detail the action of motility in the small intestine?
A
Circular - Local contraction (breakdown)
Longitudinal - Moves bolus and fragments along, also contributes to breakdown
20
Q
Mention disease that affects small intestines?
A
- Malabsorption syndromes - leading to dietary deficiences (anaemia)
- Coeliac disease
- Crohn’s disease
- Cystic fibrosis
- Meckel’s diverticulum (Rule of 2)
- Affects mostly ileal mucosa
21
Q
Large intestine parts
A
1.Caecum
a. appendix
2. Colon
a. Ascending
b. Transverse
c. Descending
d. Sigmoid
3. Rectum
22
Q
Name A & B
A
A: Hepatic flexure
B: Splenic flexure
23
Q
Name A,B&C
A
A: Taenia coli
B: Haustra(e) or haustrations
C: Appendices epiploicae
24
Q
A
Rectal valves
25
What 3 systems make up the Cervical Viscera?
R.E.A
Respiratory, Endocrine, Alimentary
26
What is the pharynx, its functions and anatomical position?
Muscular tube
Conducting air and directing bolus to oesophagus
Spans from base of skull to oesophagus (Approx C6 cervical)
27
What are the 3 parts/sections of the pharynx?
Nasopharynx - Oropharynx - Laryngopharynx
28
What are the anatomical boundaries of the Nasopharynx?
Base of skull/choana - Uvula/Soft palate
29
What is the function of the Nasopharynx?
Respiratory function
30
What tonsils are present in the Nasopharynx?
Tubal & Pharyngeal
31
What openings are present in the Nasopharynx?
Nasolacrimal duct
Eustachian tube (Auditory tube)
32
What are the anatomical boundaries of the Oropharynx?
Soft palate - Epiglottis (base of tongue)
33
What is the function of the Oropharynx?
Digestive and Respiratory
34
What tonsils are present in the Oropharynx?
Palatine & Lingual
35
Name the two arches present within the Oropharynx?
Palatoglossal arch & Palatopharyngeal arch
36
What is the name given to all pharynx based tonsils that are positioned in a ‘ring’ ?
Waylder’s Ring
37
What are the anatomical boundaries of the Laryngopharynx?
Epiglottis - Cricoid cartilage
Continuous with oesophagus
38
What is the function of the Laryngopharynx?
Digestive & Respiratory
39
Name the place that prone to food get stuck?
Piriform fossa
40
What are the two groups of pharyngeal constrictors?
Longitudinal and circular
41
Detail the nerve supply to the pharynx?
Nerve supply makes up the pharyngeal plexus
Motor - CNX (vagus)
Motor - CNIX (Stylopharyngeus only)
Sensory - CNIX
42
Name 3 clinical pathologies associated with the Pharynx?
Middle ear infection - otitis media
Tonsillitis - Inflammation of tonsils
43
What regions of the body does the oesophagus pass through?
Neck- Thorax - Abdomen
44
What is Anterior to the Oesophagus?
Trachea and heart
45
What does the Oesophagus pierce at the inferior end?
Diaphragm
46
Detail the two sphincters present in the Oesophagus?
Upper (anatomical) oesophageal sphincter - Comprised of fibres of inferior pharyngeal constrictor, influenced under swallowing reflex
Lower (physiological) oesophageal sphincter - Functional due to angle of entry into cardia of stomach
47
Dysfunction of the lower oesophageal sphincter can cause what disease?
G.O.R.D
May lead to Barrett’s oesophagus and cancer predisposition
48
Detail the Histological layers of the Oesophagus?
Mucosal membrane: Epithelium - Lamina Propria - Muscularis Mucosae (Smooth)
Submucosa
Muscularis externa - Inner circular layer - Outer longitudinal layer
49
What are the two functions of deglutition?
Swallowing: Food to stomach
Prevention of food to stomach
50
Name the 3 phases of swallowing?
Oral, pharyngeal, oesophageal
51
Describe the oral phase of swallowing?
Food moved to posterior
Liquid remains in mouth - in front of pillars
52
Describe the pharyngeal phase of swallowing?
Soft palate raises
Depression of epiglottis
Vocal cord contraction
Upper oesophageal sphincter relaxes
53
Describe the oesophageal phase of swallowing?
Upper oesophageal sphincter contracts to move bolus forward
Peristaltic action
Lower sphincter relaxes - admitting bolus into stomach
54
Name a clinical pathology associated with swallowing?
Dysphagia - difficulty swallowing
Due to neuromuscular disease
55
Name a clinical pathology associated with oesophagus formation in neonates?
Tracheooesophageal fistula
1 in 2000/4000 live births
Most common variant: A
56
What forms the lower esophageal sphincter?
Diaphragm
57
State the nerve that supplys diaphragm?
Phrenic nerve (C3,4,5)
58
List the 9 divisions of the abdomen?
59
Describe the anatomical position of the stomach?
Left hypochondrium - Epigastric region
Anterior - Superior: Liver, lower robs, Diaphragm
Posterior - Inferior: Diaphragm, spleen, kidney (L), adrenal gland, pancrease
60
What are the functions of the stomach?
Retention of food
Mixing of gastric juices
Chemical and mechanical functions
61
Name the secretory cells of the stomach and associated secretion?
Mucus secreting cells - luminal surface and gastric pits (alkaline)
Chief (zymogenic ) cells - Pepsinogen (Activated by HCL)
Parietal (Oxyntic) cells - HCL and intrinsic factor
G cells (Endocrine cells) - Gastrin
62
Detail the blood supply of the stomach? Draw this out?
Coeliac trunk → Common Hepatic → Right gastric
Coeliac trunk → Left gastric
Coeliac trunk → Common Hepatic → Gastroduodenal → Right gastroepiploic
Coeliac trunk → Splenic → Left gastroepiploic
Coeliac trunk → Splenic → Short
63
Name three surgical weight loss interventions/surgeries available
Gastric band
Gastric bypass
Sleeve gastrectomy
64
What are the folds called on stomach inner lining?
Rugae
65
What is the material called when it is churned up in stomach?
Chyme
66
Name types of stomach cells
1: Parietal cells
2: cheif cells
67
Name the anatomical regions?
1-Cardia
2-Fundus
3- Body
4-Pylorus
68
What attaches onto the greater curvature of the stomach
Greater omentum
69
What greater omentum contained?
Adipose tissue
Lymphatics
Blood vessels
Nerves
70
The role of greater omentum
Encases infection
71
What is the function of the Alimentary system?
Digestion & Absorption
72
Name the 2 groups of organs that carry out this function?
Digestive tract & accessory organs (Salivary glands, liver, pancreas, gall bladder)
73
Describe the features of the pharynx?
Muscular tube approximately 12-15cm in length
74
Describe the function of the pharynx?
Alows passage of food and air, making up alimentary & respiratory system
75
What follows from the pharynx (Alimentary)?
Oesophagus
76
What is the name for food/drink following churning by the stomach?
Chyme
77
What is the name given to the tight muscular structure mediating chyme transfer from stomach to small intestine?
Pyloric Sphincter
78
What three parts make up the small intestine? (In order)
Duodenum, jejunum, ileum
79
What five parts make up the large intestine? (In order)
Caecum, ascending/traverse/descending colon, rectum, anus
80
Name the three layers that make up the mucosa membrane of the GI system?
Epithelium, Lamina propria, Muscularis mucosae
81
What tissue type makes up the muscularis mucosae?
Smooth muscle tissue (Continuous through entire GIT)
82
What layers lie beneath the the mucosa in the GIT?
Submucosa, Muscularis propria, adventitia/serosa
83
What tissue type makes up the muscularis propria and give its function?
Smooth muscle tissue, responsible for peristalsis
84
What are the differences between adventitia and serosa?
Adventitia - outer layer of fibrous connective tissue surrounding organ
Serosa - Present in fixed parts of GIT, secretes serous fluid to reduce friction
85
What type of epithelium is present in the oral cavity, pharynx and oesophagus?
Stratified squamous epithelium (Non-keratinizing)
86
Why is St.S epithelium beneficial in various parts of alimentary system?
Can withstand repeated trauma from food/drink
87
What does GORD stand for?
Gastro-oesophageal reflux disease (Acid reflux)
88
What can continued reflux and inflammation cause?
Barrett’s oesophagus
89
What does Barrett’s oesophagus include?
Metaplasia (St.S Epithelium to Simple columnar)
Can lead to dysplasia (Abnormal growth/development)
Predispose oesophageal cancer
90
Where does epithelium type change from St.S to Si.C?
Gastro-oesophageal junction
91
What apical specialisation is present on Si.C epithelium in the small intestine?
Miro-Villi
92
What clinical condition affects villi?
Coeliac disease
93
Describe the basis of coeliac disease?
Autoimmune attack on tissues when consuming gluten, causing villous atrophy, hyperplasia of crypts and increased inflammatory response
94
What is the function of the large intestine epithelium?
Water absorption, mucous secretion
95
What is the advantage of mucous secretion in the large intestine?
Ensures indigestible material passes towards rectum/anal canal and epithelium is not damaged
96
What are the invaginations of the large intestine known as?
Colonic crypts (Intestinal glands)
97
Name two variants of inflammatory bowel disease?
Crohn’s disease, Ulcerative colitis
98
List the 5 Alimentary activities?
Secretion (Lubrication/Digestive)
Digestion (Mechanical/Chemical)
Motility (Peristalsis/smooth muscle)
Absorption (Small/large intestine)
Excretion (Faeces)
99
Where is Bile produced and stored?
Produced - Liver
Stored - Gall bladder
100
Where is Bile secreted?
Duodenum
101
State 3 areas aiding motility in the Alimentary system?
Mouth (Chewing/swallowing)
Stomach (Churning)
Intestine (Peristalsis)
102
What functional categories are present for the mouth?
Sensory, Motility, Other
103
What are the 3 general sensory functions of the mouth?
Nociception (Pain)
Mechanoreception (Movement)
Thermoreceptor (Temperature)
104
What is the special sensory function of the mouth?
Gustation (Taste)
105
What are the two motor functions of the mouth?
Feeding (Breakdown/Swallowing)
Communication
106
What are the 3 other functions of the mouth?
Salivation (Protect/Lubricate/Digestion)
Lymphoid tissue
Reflexes
107
List the anatomical boundaries of the mouth?
Anterior - lips
Lateral - Cheeks
Inferior - Mylohyoid (Forms floor of oral cavity), tongue
Superior - Palate
Posterior - Fauces (Pillars)
108
List the 3 major salivary glands and the type of secretion produced?
Parotid - Serous
Submandibular - Seromucinous (Mixed)
Sublingual (Mucinous)
109
List 3 exocrine secretions associated with the mouth?
Salt + water
Mucous
A-Amylase
110
Name 3 clinical oral pathologies associated with the salivary glands?
Mumps - paramyxovirus, enlarged parotid gland
Sialolithiasis - Salivary gland stones (Common in submandibular)
Sialoadenitis -inflammation of the salivary gland
111
What is the function of temporalis ?
Elevation and retraction of mandible
112
Site of the Major duodenal papilla
Duodenum Descending part (second part)
113
What are the two key functions of the pancreas?
Digestion (99%) -Exocrine gland
Hormonal (1%)- Endocrine portion
114
What is the name give to a functional group of pancreatic cells responsible for hormone secretion?
Islets of Langerhans
115
Detail the various types of cells comprised within the islets of Langerhans and their appropriate secretions?
Alpha cells - (15% - Glucagon)
Beta cells - (80% - Insulin)
Delta cells - Somatostatin
116
What are the functions of Insulin, glucagon and Somatostatin respectively?
Insulin - Promotes glucose absorption and storage via conversion to glycogen
Glucagon - Coverts stored glycogen into glucose - to raise blood glucose levels
Somatostatin - Reduces acid secretion & slows down digestive process
117
What is the name given to the functional unit that serves a digestive/exocrine role in the pancreas?
Acinus (Acini) - Lobulated serous glands
118
What is the function of pancreatic acini?
Secretes: digestive enzymes - from acinus, Bicarbonate - from ducts
119
Detail the enzyme secretions from pancreatic acini
Acini (digestive) Enzymes:
- Amylase - Starch → sugars
- Lipase - Fats → Monoglycerides & Fatty acids
- Trypsin, chymotrypsin - Hydrolyses proteins (-inogen Inactive form)
- nucleases - Breakdown of nucleotides
120
Detail the exocrine secretion pathway (From Acini - biliary duct) in the pancreas?
Acini → Intercalated ducts → Intralobular duct → Pancreatic duct → Biliary duct
121
What are centro-acinar cells and their function?
Spindle shaped extensions of intercalated ducts into each acinus - secrete Bicarbonate and Mucin
122
What are the 5 constituent parts of the pancreas?
123
List 5 key functions of the liver?
Metabolism
- material absorbed from G.I.T.
- storage of glycogen
- release of glucose
Protein synthesis
Inactivation of hormones, drugs
Excretion of waste
Produces bile
124
Detail the anatomical position of the liver?
Sarts at right hypochondrium and extends across the epigastrium into the left hypochondrium (1-3)
125
What are the 4 lobes of the liver?
Right, Quadrate (Inferior), Caudate (Superior), Left
126
Name the 2 ligaments of the liver?
Round ligament - Remnant of umbilical vein - sometimes continuous with ligament venosum
Falciform ligament - Embryological remnant of ventral mesentery - attaches intestines to posterior abdominal wall
127
Name A and B
A: Falciform ligament
B: Round ligament
128
Name the arteries/veins responsible for inflow of blood into the liver?
Hepatic artery (25%)
Hepatic portal vein (75%)
129
Where is Bile produced?
Liver: Hexagonal hepatic lobules → Contain Hepatocytes → produce bile
130
What does bile contain?
- Lipid emulsifiers (Bile salts) - aids cholesterol metabolism and fat soluble vitamin absorption (A,D,E,K)
- Bilirubin - Waste from RBC metabolism (Gives faeces brown colour)
- Has antioxidant effects
131
Detail the Bile workflow (Synthesis - Storage - Secretion)
- Synthesised in liver →
- Flow to gall bladder: from intrahepatic ducts → (L+R) extrahepatic ducts → common hepatic duct → Up Cystic duct →
- Stored and concentrated in gall bladder →
- High fatty content detected - Cholecystokinin (Hormone)
- Stimulating release of bile via Cystic duct → common bile duct →
- Released alongside pancreatic secretions via major duodenal papilla
132
Name the 3 constituent parts of the gall bladder?
133
Where does blood flow come from to form the Hepatic portal vein?
Venous drainage from abdominal organs (GIT, Pancreas, Spleen) to liver
HPV formed from → Superior mesenteric Vein + Splenic Vein (All tributaries)
Not a true vein - conducts blood to liver (rather than heart)
134
Detail the passage of blood out of the liver?
Sinusoids → Central vein → Hepatic Vein → Abdominal Vena cava
135
Detail the passage of Bile out of the liver?
Bile flows in opposite direction - Bile canaliculus → Bile duct → E.C.T
136
Name the constituents of the portal triad?
Hepatic artery
Hepatic portal vein
Bile duct
137
Name 4 pathologies associated with the liver?
Hepatomegaly – Enlarged liver (Signs of underlying liver complicaitons)
Cirrhosis – Scarring/fibrosis (Inflammation or chronic alcoholism)
Obstructive jaundice – cancer or gall stones
Hepatic carcinoma – primary liver caner
138
The difference between Taenia coli and Haustra?
Taenia coli - Longitudinal layer of muscularis externa\ Present on ascending, transverse and descending portions
Haustra -Circular layer of muscularis externa
139
Where does the Appendice epiploicae present ?
Mainly present on transverse & sigmoid colon (Not rectum)
140
The function of Rectal valves
Support weight of faeces; slowing movement to anus (Contain circular muscle)
141
The different between Internal and External sphincter
Internal sphincter - Involuntary control - Smooth muscle
External sphincter - Voluntary control - Skeletal muscle
142
Barium enema
Used to diagnose large intestinal disorders e.g. Colonic tumours, polyps, diverticula
143
Epithelium of Large intestine
- Simple columnar (Goblet cells)
- Lieberkühn - intestinal crypts
- Mucosal glands - Mucus
144
Key differences between L.I and S.I
- No villi
- Incomplete longitudinal muscle - Taenia coli - Mediates peristalsis
- Ring like arrangement of circular muscle - Haustrae - Mediates peristalsis
145
Function of colon
- 0.5 - 1.0 Litres of chyme enters L.I from Ileum
- Colon absorbs fluid and electrolytes from chyme
146
What is Intestinal flora and what is role?
Resident microbial populations in L.I with various roles:
- Ferment dietary fibre (cellulose) and lipid
- Vitamin synthesise - B complex & K
- Produces gases - ‘flatus’
147
The reasons and the results of Diarrhoea
Reasons:
Duo to an infection in the G.I.T which result in less mixing and less fluid absorption
Results:
Dehydration
Electrolyte imbalance
148
The reason of constipation
Associated with G.I.T. spasm and increased fluid absorption or side effect of some drugs e.g. opiate
