B3 Anatomy & Histology of GI Tract Flashcards
1
Q
What forms the roof of the mouth?
A
Hard and soft palates
2
Q
What forms the floor of the mouth?
A
Mylohyoid muscle
3
Q
True or false? The tongue is the floor of the mouth
A
False - it’s superior to the hammock-shaped mylohyoid floor
4
Q
What form the lateral walls of the mouth?
A
Cheeks
5
Q
What forms the anterior of the mouth?
A
Lips
6
Q
What is the posterior part of the mouth?
A
Palatoglossal floor
7
Q
What structures are responsible for the mouth having two distinct spaces?
A
Teeth
8
Q
What does the oral cavity refer to?
A
The whole mouth
9
Q
What is the vestibule of the mouth?
A
Space between lips and teeth (run tongue along front of teeth)
10
Q
What does the oral cavity proper refer to?
A
The region of the mouth enclosed by the teeth
11
Q
What are the teeth and gums collectively known as?
A
Gingivae
12
Q
What is the parotid gland?
A
The biggest salivary gland
13
Q
What does the parotid gland secrete?
A
Serous secretions
14
Q
Where is the parotid gland?
A
Posterior to the ramus of the mandible
15
Q
Where is the submandibular gland?
A
Inferior to the angle of the mandible
16
Q
Where is the sublingual gland?
A
Between the mylohyoid muscle and tongue
17
Q
How long are the parotid and submandibular ducts?
A
5cm
18
Q
Where does the submandibular gland lie?
A
Outside the mouth
19
Q
Why are the openings of glands important?
A
You can occlude their secretions
20
Q
What is the most anterior fold at the back of the mouth?
A
Palatoglossal fold
21
Q
What is the most posterior fold of the mouth?
A
Palatolaryngeal fold
22
Q
What structure is found between the folds of the mouth?
A
Tonsila fossa
23
Q
What structures exist in the tonsila fossa?
A
Palatine tonsils
24
Q
How long is the oesophageus?
A
25 cm
25
Where does the oesophageus run down?
C6- T10
26
What are the two sphincters associated with the oesophageus?
Upper
| Lower
27
When does the upper oesophageal sphincter relax?
During swallowing
28
True or false? The upper oesophageal sphincter is voluntary
True - Think Harry Houdini
29
What is the lower oesophageal sphincter also known as?
Cardiac sphincter
30
What is the strength of the lower oesophageal sphincter?
Weak - needs the diaphragm to hold and support it.
31
Why is the oesophageal sphincter necessary?
Prevents gastro- oesophageal reflux
32
What type of epithelium is in the stomach?
Non-keratinised simple squamous epithelium
33
When would you get keratinised epithelium in the stomach?
Long standing mutation
34
What type of epithelium is at the top of the oesophageus?
Stratified squamous
35
What is the change in colouration histologically?
Histological junction- Pale pink (stacked epithelium) to briliant red (simple squamous)
36
What is the histological junction of the GI tract referring to?
```
Oesophageus - stomach
Pale pink (stacked epithelium) to briliant red (simple squamous)
```
37
What is the stomach?
A proximally fixed muscular bag in the left upper quadrants
38
What is the lining of the stomach?
Peritoneal
39
What is the arterial supply of the stomach?
Coeliac trunk
40
What are the lymphatics of the stomach bed?
Coeliac nodes
41
What is the sympathetic nervous system's association with the stomach?
Visceral pain and vasculature
42
What is the capacity of the stomach dependent on?
How much you eat
43
Where is the fundus of the stomach?
At the top, near the cardiac sphincter
44
Where is the antrum of the stomach?
At the bottom, near the pyloric sphincter
45
What is the cardiac region of the stomach?
The bit that's closest to the heart
46
Where does the stomach end?
Pylorus
47
What are rugae?
Longitudinal folds of mucosa running all the way down the stomach
48
Why are rugae necessary in the stomach?
Epithelia don't have the capacity to stretch/ expand
49
What happens to the rugae when food fills the stomach?
They flatten out
50
What are the qualities of the pyloric sphincter?
Big, strong and palpable
51
Where is the pyloric sphincter?
Trans-pyloric plane
52
Where is the trans-pyloric plane?
Horizontal line half way between suprasternal notch and pubic symphisis
53
How many structures lie on the trans-pyloric plane?
12
54
What structures lie approximately on the trans-pyloric plane?
```
End of spinal cord
L1 of vertebral body
Origin of superior mesenteric artery
Origin of portal vein
Neck of pancreas
Pylorus of stomach
Second part of duodenum
Sphincter of Oddi
Hilum of kidneys
Duodenojejunal flexure
Fundus of gallbladder
Tips of 9th costal cartilages
```
55
Where is the duodenum?
Retropertioneal
| Where pylorus ends
56
How long is the duodenum?
25cm
57
What are the different parts of the duodenum?
Superior
Descending
Horizontal
Ascending
58
What part of the duodenum recieves the common bowel duct and pancreatic duct?
Descending
59
What part of the duodenum has the duodenojejunal flexure?
Ascending
60
Where is the pancreas?
Retroperitoneal
| Situated in the duodenum's curvature forming C shape
61
What does uncinate mean?
Hook like
62
What are the different parts of the pancreas called?
```
Uncinate process
Head
Neck
Body
Tail
```
63
What organ does the spleen point towards?
Spleen
64
What lies over the abdominal wall?
Skin and two layers of fascia
65
What muscles make up the anterolateral abdominal wall?
External oblique
Internal oblique
Transversus Abdominis
66
What direction do the external oblique muscles run in?
Inferiorly and medially
| Same direction as external intercostals in thorax
67
What is the linea alba?
A white line on the front midline
68
Where does the inguinal ligament run?
Anterior superior iliac spine - Pubic tubercle
69
When does the external oblique become a tendon?
At the 9th costal cartilage
70
Where do the internal oblique fibres run?
Superiorly and medially
71
What is the transversus abdominis adbdominis fibre orientation?
Transverse
72
What is the most posterior of the anterior wall muscles?
Rectus abdominis
73
Where does the rectus abdominis run?
Pubic crest - Costal cartilages
74
What does the rectus abdominis look like from the front?
3 tendinous insertions ; the reason for six packs
75
What does the rectus abdominis look like from the back?
One muscle
76
What is a pyramidalis?
A little pyramid between the umbilicus and pubic symphysis on the midline
77
What is the importance of the pyramidalis?
It does absolutely nothing
78
What happens to the 3 muscle layers between rib 9 and the anterior superior iliac spine?
They become aponeurotic (tendinous)
79
What happens to the muscles below the anterior superior iliac spine?
Posterior and rectus sheath (made from the internal oblique and transversus abdominis) run to the front
80
What is the name given to the region including and below the anterior superior iliac spine?
Arcuate line
81
Where does the parietal peritoneum attach onto the muscle wall?
Behind all of the muscle (posteriorly)
82
Why do we need abdominal muscle?
To support the intestines
83
What is the shape of muscle determined by?
Muscle tone
84
What is the Quadratus lumborum?
A back abdominal muscle
85
What does omentum mean?
Apron
86
What is mesentary?
Double layer of peritoneum which links visceral to parietal peritoneum
87
What is the name for parietal peritoneum which folds in on itself to become visceral?
Peritoneal fold/ reflection
88
Where is the ileum?
Distal 3/5 of the small intestine; Hypogastric and right inguinal region
89
What are the physical properties of the ileum?
```
In comparison to jejunum:
Thinner wall
Smaller calibre
More Peyer's patches
Short vasa recta
More arterial arcades
```
90
What are the physical properties of the jejunum?
In comparison to ileum:
Thicker wall
Bigger blood vessels- more vascular
Long vasa recta
91
Where is the jejunum?
Umbilical towards the left iliac fossa
92
What is absorbed in the ileum?
B12, H2O and electrolytes
93
What is Merkel's diverticulum?
An outpouching
94
What is absorbed in the large intestine?
H2O, electrolytes and drugs
95
How can the large intestine be distinguished from the small intestine?
```
Has fat hanging off it
Has Teniae Coli
Has Haustra
Is mobile
Has distinct flexures
```
96
What is the right flexure of the large intestine known as?
Right colic flexure
| Hepatic flexure
97
What is the left flexure of the large intestine known as?
Left colic flexure
| Splenic flexure
98
What is the structure described as 'a tube within a funnel' called?
Anal canal
99
What are the properties of the anal canal?
Circular layer outside
| External sphincter and internal sphincter
100
What is the visceral surface of the liver?
The contact that the liver has with organs inferior to it
101
What is the coronary ligament?
A fold/ reflection of peritoneum directly beneath the visceral surface of the liver
102
What is the hepatorenal recess?
The deepest part of the peritoneal cavity when a person is lying down
103
What is the falciform ligament?
A double layer of peritoneum which closes off to form the ligament of Teres
104
What is another name for the hepatorenal recess?
Pouch of Morrison
105
What is the bare area of the liver?
The surface of the liver which is not covered in any peritoneum and is directly in contact with the diaphragm
106
How can you identify the bare area of the liver?
It will be dull in comparison to the rest of the liver which will look shiny because of the peritoneum
107
What is the significance of the foramen of Winslow?
It is the passage between the greater and lesser sacs of the peritoneal cavities
108
What is the foramen of Winslow also known as?
The epiploic foramen
109
What lies anterior to the foramen of Winslow?
Free border of the hepatoduodenal ligament
110
How much BLOOD does the hepatic portal vein supply to the liver?
80%
111
How much OXYGEN does the hepatic portal vein supply to the liver?
20%
112
How much BLOOD does the hepatic artery supply to the liver?
20%
113
How much OXYGEN does the hepatic artery supply to the liver?
80%
114
Where do the hepatic veins drain to?
Inferior vena cava
115
What is the difference between the anatomical and physiological left lobes?
Anatomical: Left excludes the quadrate and caudate lobes
Physiological: Left includes the quadrate and caudate lobes
116
Why can you remove segments of liver without complications?
Liver segments are functionally independent
| Liver can regrow and retain function
117
Where is the gallbladder?
Tucks into the right lobe of the liver
118
What is the relationship between the 9th costal cartilage and the gallbladder?
This means that the gallbladder lies on the trans-pyloric plane
119
Where is the body of the gallbladder?
On the inferior surface of the liver
120
Where is the neck of the gallbladder?
Connecting to the cystic duct
121
Where does the gallbladder receive its blood supply?
The right hepatic artery via the cystic artery
122
True or false? The spleen is part of the GI tract
False- Not really...
123
How big is the spleen?
1 X 3 X 5 inches
124
How heavy is the spleen?
7 ounces
125
Where is the spleen?
Left hypochondrium
Reticuloendothelial
Posterior to ribs 9-11
126
What is the arterial supply of the spleen?
Coeliac artery
127
What does reticuloendothelial mean?
Mononuclear Phagocytic System (MPS) - part of the immune system that consists of the phagocytic cells
128
What is the embryological origin of the spleen?
Mesoderm
129
How can you tell the difference between the spleen and liver when both are enlarged?
The spleen is notched
130
What is the visceral surface of the spleen related to?
Surface of stomach, left colic flexure and kidney
131
What is the common hepatic artery made from?
Left hepatic + Right hepatic arteries
132
What is the common bile duct made from?
Common hepatic artery and cystic duct
133
Where does the common bile duct run?
Posteriorly to the first part of the duodenum
134
What is the sphincter of Oddi also known as?
Hepatopancreatic sphincter
135
What generally happens to lymphatics when you block them?
They go backwards
136
What are clusters of glandular epithelial cells called?
Acini
137
What constitutes the endocrine portion of the pancreas?
Islets of Langerhans
138
What is the difference between Langerhan cells and Islets of Langerhans?
Langerhans cells found in skin + mucosa
| Islets of Langerhans found in pancreas
139
What constitutes the exocrine portion of the pancreas?
Acini
140
What consititutes the reticuloendothelial system?
Spleen, liver, renal tubular cells and macrophages
