B3 Anatomy & Histology of GI Tract Flashcards Preview

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Flashcards in B3 Anatomy & Histology of GI Tract Deck (140)
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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
Q

Where does the oesophageus run down?

A

C6- T10

26
Q

What are the two sphincters associated with the oesophageus?

A

Upper

Lower

27
Q

When does the upper oesophageal sphincter relax?

A

During swallowing

28
Q

True or false? The upper oesophageal sphincter is voluntary

A

True - Think Harry Houdini

29
Q

What is the lower oesophageal sphincter also known as?

A

Cardiac sphincter

30
Q

What is the strength of the lower oesophageal sphincter?

A

Weak - needs the diaphragm to hold and support it.

31
Q

Why is the oesophageal sphincter necessary?

A

Prevents gastro- oesophageal reflux

32
Q

What type of epithelium is in the stomach?

A

Non-keratinised simple squamous epithelium

33
Q

When would you get keratinised epithelium in the stomach?

A

Long standing mutation

34
Q

What type of epithelium is at the top of the oesophageus?

A

Stratified squamous

35
Q

What is the change in colouration histologically?

A

Histological junction- Pale pink (stacked epithelium) to briliant red (simple squamous)

36
Q

What is the histological junction of the GI tract referring to?

A
Oesophageus - stomach
Pale pink (stacked epithelium) to briliant red (simple squamous)
37
Q

What is the stomach?

A

A proximally fixed muscular bag in the left upper quadrants

38
Q

What is the lining of the stomach?

A

Peritoneal

39
Q

What is the arterial supply of the stomach?

A

Coeliac trunk

40
Q

What are the lymphatics of the stomach bed?

A

Coeliac nodes

41
Q

What is the sympathetic nervous system’s association with the stomach?

A

Visceral pain and vasculature

42
Q

What is the capacity of the stomach dependent on?

A

How much you eat

43
Q

Where is the fundus of the stomach?

A

At the top, near the cardiac sphincter

44
Q

Where is the antrum of the stomach?

A

At the bottom, near the pyloric sphincter

45
Q

What is the cardiac region of the stomach?

A

The bit that’s closest to the heart

46
Q

Where does the stomach end?

A

Pylorus

47
Q

What are rugae?

A

Longitudinal folds of mucosa running all the way down the stomach

48
Q

Why are rugae necessary in the stomach?

A

Epithelia don’t have the capacity to stretch/ expand

49
Q

What happens to the rugae when food fills the stomach?

A

They flatten out

50
Q

What are the qualities of the pyloric sphincter?

A

Big, strong and palpable

51
Q

Where is the pyloric sphincter?

A

Trans-pyloric plane

52
Q

Where is the trans-pyloric plane?

A

Horizontal line half way between suprasternal notch and pubic symphisis

53
Q

How many structures lie on the trans-pyloric plane?

A

12

54
Q

What structures lie approximately on the trans-pyloric plane?

A
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
Q

Where is the duodenum?

A

Retropertioneal

Where pylorus ends

56
Q

How long is the duodenum?

A

25cm

57
Q

What are the different parts of the duodenum?

A

Superior
Descending
Horizontal
Ascending

58
Q

What part of the duodenum recieves the common bowel duct and pancreatic duct?

A

Descending

59
Q

What part of the duodenum has the duodenojejunal flexure?

A

Ascending

60
Q

Where is the pancreas?

A

Retroperitoneal

Situated in the duodenum’s curvature forming C shape

61
Q

What does uncinate mean?

A

Hook like

62
Q

What are the different parts of the pancreas called?

A
Uncinate process
Head
Neck
Body
Tail
63
Q

What organ does the spleen point towards?

A

Spleen

64
Q

What lies over the abdominal wall?

A

Skin and two layers of fascia

65
Q

What muscles make up the anterolateral abdominal wall?

A

External oblique
Internal oblique
Transversus Abdominis

66
Q

What direction do the external oblique muscles run in?

A

Inferiorly and medially

Same direction as external intercostals in thorax

67
Q

What is the linea alba?

A

A white line on the front midline

68
Q

Where does the inguinal ligament run?

A

Anterior superior iliac spine - Pubic tubercle

69
Q

When does the external oblique become a tendon?

A

At the 9th costal cartilage

70
Q

Where do the internal oblique fibres run?

A

Superiorly and medially

71
Q

What is the transversus abdominis adbdominis fibre orientation?

A

Transverse

72
Q

What is the most posterior of the anterior wall muscles?

A

Rectus abdominis

73
Q

Where does the rectus abdominis run?

A

Pubic crest - Costal cartilages

74
Q

What does the rectus abdominis look like from the front?

A

3 tendinous insertions ; the reason for six packs

75
Q

What does the rectus abdominis look like from the back?

A

One muscle

76
Q

What is a pyramidalis?

A

A little pyramid between the umbilicus and pubic symphysis on the midline

77
Q

What is the importance of the pyramidalis?

A

It does absolutely nothing

78
Q

What happens to the 3 muscle layers between rib 9 and the anterior superior iliac spine?

A

They become aponeurotic (tendinous)

79
Q

What happens to the muscles below the anterior superior iliac spine?

A

Posterior and rectus sheath (made from the internal oblique and transversus abdominis) run to the front

80
Q

What is the name given to the region including and below the anterior superior iliac spine?

A

Arcuate line

81
Q

Where does the parietal peritoneum attach onto the muscle wall?

A

Behind all of the muscle (posteriorly)

82
Q

Why do we need abdominal muscle?

A

To support the intestines

83
Q

What is the shape of muscle determined by?

A

Muscle tone

84
Q

What is the Quadratus lumborum?

A

A back abdominal muscle

85
Q

What does omentum mean?

A

Apron

86
Q

What is mesentary?

A

Double layer of peritoneum which links visceral to parietal peritoneum

87
Q

What is the name for parietal peritoneum which folds in on itself to become visceral?

A

Peritoneal fold/ reflection

88
Q

Where is the ileum?

A

Distal 3/5 of the small intestine; Hypogastric and right inguinal region

89
Q

What are the physical properties of the ileum?

A
In comparison to jejunum:
Thinner wall
Smaller calibre 
More Peyer's patches
Short vasa recta
More arterial arcades
90
Q

What are the physical properties of the jejunum?

A

In comparison to ileum:
Thicker wall
Bigger blood vessels- more vascular
Long vasa recta

91
Q

Where is the jejunum?

A

Umbilical towards the left iliac fossa

92
Q

What is absorbed in the ileum?

A

B12, H2O and electrolytes

93
Q

What is Merkel’s diverticulum?

A

An outpouching

94
Q

What is absorbed in the large intestine?

A

H2O, electrolytes and drugs

95
Q

How can the large intestine be distinguished from the small intestine?

A
Has fat hanging off it
Has Teniae Coli
Has Haustra
Is mobile
Has distinct flexures
96
Q

What is the right flexure of the large intestine known as?

A

Right colic flexure

Hepatic flexure

97
Q

What is the left flexure of the large intestine known as?

A

Left colic flexure

Splenic flexure

98
Q

What is the structure described as ‘a tube within a funnel’ called?

A

Anal canal

99
Q

What are the properties of the anal canal?

A

Circular layer outside

External sphincter and internal sphincter

100
Q

What is the visceral surface of the liver?

A

The contact that the liver has with organs inferior to it

101
Q

What is the coronary ligament?

A

A fold/ reflection of peritoneum directly beneath the visceral surface of the liver

102
Q

What is the hepatorenal recess?

A

The deepest part of the peritoneal cavity when a person is lying down

103
Q

What is the falciform ligament?

A

A double layer of peritoneum which closes off to form the ligament of Teres

104
Q

What is another name for the hepatorenal recess?

A

Pouch of Morrison

105
Q

What is the bare area of the liver?

A

The surface of the liver which is not covered in any peritoneum and is directly in contact with the diaphragm

106
Q

How can you identify the bare area of the liver?

A

It will be dull in comparison to the rest of the liver which will look shiny because of the peritoneum

107
Q

What is the significance of the foramen of Winslow?

A

It is the passage between the greater and lesser sacs of the peritoneal cavities

108
Q

What is the foramen of Winslow also known as?

A

The epiploic foramen

109
Q

What lies anterior to the foramen of Winslow?

A

Free border of the hepatoduodenal ligament

110
Q

How much BLOOD does the hepatic portal vein supply to the liver?

A

80%

111
Q

How much OXYGEN does the hepatic portal vein supply to the liver?

A

20%

112
Q

How much BLOOD does the hepatic artery supply to the liver?

A

20%

113
Q

How much OXYGEN does the hepatic artery supply to the liver?

A

80%

114
Q

Where do the hepatic veins drain to?

A

Inferior vena cava

115
Q

What is the difference between the anatomical and physiological left lobes?

A

Anatomical: Left excludes the quadrate and caudate lobes

Physiological: Left includes the quadrate and caudate lobes

116
Q

Why can you remove segments of liver without complications?

A

Liver segments are functionally independent

Liver can regrow and retain function

117
Q

Where is the gallbladder?

A

Tucks into the right lobe of the liver

118
Q

What is the relationship between the 9th costal cartilage and the gallbladder?

A

This means that the gallbladder lies on the trans-pyloric plane

119
Q

Where is the body of the gallbladder?

A

On the inferior surface of the liver

120
Q

Where is the neck of the gallbladder?

A

Connecting to the cystic duct

121
Q

Where does the gallbladder receive its blood supply?

A

The right hepatic artery via the cystic artery

122
Q

True or false? The spleen is part of the GI tract

A

False- Not really…

123
Q

How big is the spleen?

A

1 X 3 X 5 inches

124
Q

How heavy is the spleen?

A

7 ounces

125
Q

Where is the spleen?

A

Left hypochondrium
Reticuloendothelial
Posterior to ribs 9-11

126
Q

What is the arterial supply of the spleen?

A

Coeliac artery

127
Q

What does reticuloendothelial mean?

A

Mononuclear Phagocytic System (MPS) - part of the immune system that consists of the phagocytic cells

128
Q

What is the embryological origin of the spleen?

A

Mesoderm

129
Q

How can you tell the difference between the spleen and liver when both are enlarged?

A

The spleen is notched

130
Q

What is the visceral surface of the spleen related to?

A

Surface of stomach, left colic flexure and kidney

131
Q

What is the common hepatic artery made from?

A

Left hepatic + Right hepatic arteries

132
Q

What is the common bile duct made from?

A

Common hepatic artery and cystic duct

133
Q

Where does the common bile duct run?

A

Posteriorly to the first part of the duodenum

134
Q

What is the sphincter of Oddi also known as?

A

Hepatopancreatic sphincter

135
Q

What generally happens to lymphatics when you block them?

A

They go backwards

136
Q

What are clusters of glandular epithelial cells called?

A

Acini

137
Q

What constitutes the endocrine portion of the pancreas?

A

Islets of Langerhans

138
Q

What is the difference between Langerhan cells and Islets of Langerhans?

A

Langerhans cells found in skin + mucosa

Islets of Langerhans found in pancreas

139
Q

What constitutes the exocrine portion of the pancreas?

A

Acini

140
Q

What consititutes the reticuloendothelial system?

A

Spleen, liver, renal tubular cells and macrophages