UNIT 2: Foregut Flashcards
1
Q
What structures does the pharynx connect with?
A
Connects to the nasal cavity by the nasopharynx
Connects to the oral cavity through the oropharynx
Continues inferiorly as the laryngopharynx which will then split into two as the oesophagus and the trachea.
2
Q
What are the different sections of the large intestine?
A
The cecum
The ascending colon
The right colic flexure
The transverse colon
The left colic or splenic flexure
the descending colon
The sigmoid colon
3
Q
How is the excretion of food through the anus controlled?
A
Through an internal and external sphincter
4
Q
What are the accessory organs of digestion?
A
Salivary gland
Liver
Pancreas
Gall bladder
5
Q
Name the different types of slivary glands.
A
Parotid gland
Submandibular gland
Sublingual gland.
6
Q
Give an overview of bile in digestion?
A
Produced/secreted in the liver and stored in the gall bladder.
Key role in the digestion of fats
7
Q
How does accessory organs of digestion link up with the small intestine?
A
Glands from the liver, gall bladder and pancreas connect with the small intestine.
8
Q
What does the pancreas do?
A
Produces a basic mixture to neutralise acid content entering the small intestine from the stomach. Also secretes digestive enzymes.
9
Q
What is the reasoning behind where the duodenum and the pancreas connect?
A
Pancreas connects to the lower corner like appearance of the duodenum.
This acts as a pool for digesting content to sit in and be covered by secretions from the pancreas and gall bladder before entering the jejunum
10
Q
Give a basic description of the peritoneum. As if to a five year old.
A
A basic sheet like structure that covers and folds around certain abdominal structures.
11
Q
What is the difference between intraperitoneal and retroperitoneal?
A
Intraperitoneal are entirely covered on all surfaces by the peritoneum.
Retroperitoneal organs are being pushed posteriorly by the peritoneum so are only covered on their anterior side.
12
Q
What structures are intraperitoneal?
A
The stomach, the ileum and the jejunum.
13
Q
What is the difference between visceral and parietal?
A
visceral peritoneum surrounds the organs surface
Parietal is any other part of the membrane excluding the mesentry.
14
Q
What is meant as mesentry?
A
The section of the peritoneum or any pleural membrane which is being ‘pinched off’ from an organ.
15
Q
How does the peritoneal membrane affect movement?
A
Retroperitoneal structures are effectively strapped to a location such as the abdominal wall so have very little movement.
A mesentery in the peritoneal allows a greater range of movement of these structures.
16
Q
What is the greater omentum?
A
A folding of the peritoneum, it extends downwards from the greater curvate of the stomach, reaches level with the end of the descending colon (roughly), then fold back up on itself.
Foldes around the posterior section of the transverse colon then pinches off to make contact with the posterior abdominal wall.
Is a sheet like structure.
17
Q
What is the lesser omentum?
A
An extension of the peritoneum.
Extends from the lesser curvature of the stomach.
Made of the hepatogastric ligament which connects the liver to the stomach.
Also made of the hepatoduodenal ligament from the liver to the duodenum.
18
Q
What allows for extension of the stomach?
A
Rugae - folds in the lining of the stomach, they are most numerous when the stomach is at rest.
19
Q
What is the name of the collections of the longitudinally arranged smooth muscle along the wall of the large intestine?
A
Teniae coli
20
Q
What are the different sections of the aorta?
A
Asceding aorta when it first leaves the heart.
Branching aorta (vessels to supply the head and neck)
At level T4 becomes the descending aorta, divided into the thoracic and abdominal aorta by the diaphragm.
21
Q
What is the diameter of the aorta like?
A
very thick but is still highly elastic.
22
Q
What are the three unpaired vessels of the aorta?
A
The celiac trunk - supplies foregut.
The superior mesentric artery - large parts of the abdomen derived from the midgut.
The inferior mesenteric artery - inferior sections, of the gut
23
Q
What are the subdivision of the celiac trunk?
What areas of the body to they supply with blood?
A
The splenic artery - supplies the spleen and the body/tail of the pancreas
Common hepatic artery - live, gallbladder, head of pancreas, parts of duodenum and the greater curvature of the stomach
Left gastric artery - lesser curvature of the stomach
24
Q
what areas of the body does the superior meseteric artery supply with blood?
A
Supplies to parts of the duodenum and the pancreas.
2/3 of the proximal large intestine (all ascending and parts of transverse).
All of the jejunum and the ileum
The midgut.
25
What areas of the body does the inferior meseteric artery supply with blood?
Last third of the transverse colon
Descening colon
Sigmoid colon
Superior third of the rectum.
26
Where do sympathetic nerves arise from?
The central parts of the spinal cord.
27
Where do parasympathetic nerves arise from?
The inferior sections of the spinal cord.
Or within the brain stem.
28
What is the parasympathetic nerve supply for the foregut?
Originates solely from the brainstem as the vagus nerve.
Travels through the diaphragm.
Connects as a bundle of nerves called the coeliac ganglion
Travel along the branches of the abdominal aorta, end in synpases.
29
Where is the coelic ganglion located?
Near where the celiac branches originate from the abdominal aorta.
30
Explain the first part of the sympathetic nerve structure?
Branches out of vertebrae.
At each level has a sympathetic chain ganglion which are connected by the sympathetic trunk.
31
Explain how the sympathetic nerves in the foregut originate from the chain of sympathetic ganglions??
Pass through the sympathetic chain but do not synapse in the sympathetic chain ganglion.
Branch off into thoracic splanchic nerves.
Grouped as greater, lesser and least splanchnic nerves.
Greater travels towards the celiac ganglion nerves, here it synapses and the postsynaptic axon continue along the blood supply to supply organs.
32
What is contained within the foregut?
The oesophagus, the stomach, parts of the small intestine, (from which the liver and pancreas develop)
33
What is considered within the hindgut?
Distal third of the transverse colon to the pectinate line in the anal canal
34
What is contained within the midgut?
Where the major duodenal papila enters the duodenum to the second third of the transverse colon (second third included in midgut)
35
Where does the coeliac trunk orginate and what does it split into?
Orignates from the abdominal aorta at T12 levels.
Splits into:
Common hepatic artery
Splenic Artery
Left Gastric artery.
36
What direction does the common hepatic artery travel and what does it supply?
First travels in a antereolateral direction to supply the pancreas.
Then it travels to supply the first part of the duodenum and become the right gastric artery.
Travels anterosuperiorly to become the hepatic artery proper and the gastroduodenal artery supplying the liver and the pylorus of the stomach/head of duodenum/head of pancreas.
37
What direction does the left gastric artery travel in and what structures does it supply?
Travels superiorly to supply the oesophagus.
Curves backwards on itself to travel more inferiorly and anteriorly to supply the lesser curvature of the stomach.
38
What direction does the splenic artery travel and what structures does it supply?
Travels anteroinferior to the pancreas, then passes anteriorly to the left kidney and adrenal gland (does not supply these) to enter the spleen as the splenic branches and the splenic artery.
Also branches into the short gastric artery to supply the posterior and superior surface of the stomach.
And the left gastroomental artery to supply the left greater curvature if the stomach
39
Which of the branches of the celiac artery is the smallest?
Left gastric artery
40
What one of the branches of the celiac artery is described as torus and what does this mean?
The splenic artery.
Ranges in length from 8 to 32 cm.
This means the artery twists often to form donut shaped loops.
41
What two sections does the common hepatic artery split into?
A hepatic componenet made of the proper hepatic artery.
The GI tract component made of the right gastric artery and the gastroduodenal artery.
42
What is the relationship between the splenic artery and the pancreas?
The splenic artery travels anetrioinferiorly to then travel just superiorly to the body and tail of the pancreas.
43
What is the basic structure of the oesophagus?
A fibrosis cular tube, approximately 25cm in length that transports food from the pharynx to the stomach.
It originates at the cricoid artery at C6 and extends to the cardiac orifice of the stomach
44
What is the anatomical course of the oesophagus?
Begins at C6 level and is continuous with the laryngeal pharynx superiorly.
Travels down the mediastinum between the trachea and the. vertebrae.
At T10 it enters the abdomen at the oesophagus hiatus.
Then terminates by joining with the cardiac orifice at T11.
45
What is peristalsis?
Rhythmic contraction of muscle is the oesophagus to transport food.
46
Explain how the foregut develops.
It starts as a long cylindrical tube, then as it grows it rotates on its axis and lengthens along a double curve.
This continues to form a double curvature and widens to become the stomach and the proximal part of the duodenuem.
47
How does the peritoneum of the foregut differ from the rest of the digestive system in embryonic development?
Attahces to the peritoneum is two places, posteriorly and anteriorly.
These are called the dorsal and ventral mesogastrum.
Other structures of the gut only attach along the dorsal end.
48
How does the location of the dorsal and ventral mesogastrum change as the gut develops?
As the gut develops and rotates the mesogastrum also rotate from their solely anterior and posterior location.
They become more curved.
The ventral mesogastrum swings round to the right and ends up running along the lesser curvature of the stomach and the top proximal duodenum.
The dorsal mesogastrum swings round to the left and runs along the greater curvature of the stomach and the underside of the duodenum.
49
What structures develop in the mesogastrum?
The liver develops inside the ventral mesogastrum.
The spleen develops in the dorsal mesogastrum.
The liver grows rapidly in size pressing against the body walls, this creates a pocket called the lesser sack that is posterior to the stomach and
50
What are the greater and lesser omentum?
The lesser omentum attaches the stomach to the liver and the duodenum, marks the boundary of the lesser sack.
The greater omentum attaches the stomach to the transverse colon, also marks the boundary of the lesser sack.
51
How are the greater omentum and the greater sack linked?
The greater omentum grows down to become the greater sack.
The greater omentum grows inferiorly, anteriorly over the transverse colon, it fuses with the transverse mesacolon
52
What is the epiploic foramen?
The only opening to pass between the greater and the lesser sack.
Is a space rather than a hole.
53
What is the gastrocolic ligament?
Develops from the greater omentum, connects the stomach to the transverse colon.
54
What are the boundaries of the lesser sack?
The gastrocolic ligament.
The lesser omentum
The transverse colon
The fusion of the greater omentum and the transverse mesa colon.
55
What is dysphagia and what can cause it?
Dysphagia is difficulty swallowing and is caused by the hardening of muscles in the oesophagus that control peristalsis.
56
What is the deal with the upper oesophageal sphnicter?
Made of striated (skeletal) muscle.
Is located at the junction between the pharynx and the oesophagus.
Is made from the cricopharyngeus muscle.
57
What is the deal with the lower oesophageal sphincter?
Located at T11 height at the gastro-oesophageal junction.
Is classified as a physiological or a functional sphincter as it is made of no specific structures.
Aims to prevent the reflux of gastric content back into the oesophagus.
58
How is the lower oesophageal sphincter held together as it has no specific muscular structure?
The oesophagus enters the stomach at an acute angle.
The oesophagus walls are compressed when there is a positive intra-abdominal pressure.
Has prominent mucosal folds.
The right crus of the diaphragm has a pinching effect.
59
What structures cause pinch points in the oesophagus and what is the consequence of this?
The arch of the aorta.
The bronchus
The diaphragmatic hiatus.
The cricoid cartilage
(ABCD)
60
Describe the location of structures around the oesophagus?
Anterior structures : the heart, left vagus nerve.
Posterior structures: the right vagus nerve, the left crus of the diaphragm
61
Describe the location of structures around the cervical and thoracic oesophagus?
Anterior to it: the trachea
Posterior to it: the vertebrae
Posterior and to the left: the thoracic duct and the descending aorta.
Posterior and to the right is the azygous vein.
62
Explain the vasculature of the thoracic oesophagus.
Is supplied by branches of the thoracic aorta and inferior thyroid artery.
Is drained by branches of the azygous vein and inferior thyroid vein
63
Explain the vasculature of the abdominal oesophagus?
The left gastric artery
The left inferior phrenic artery.
Drained by the left gastric vein
and the azygous vein.
64
What is the portal venous system?
Carries blood from the digestive system to the liver.
65
What is the systemic venous system?
Drains blood back into the right atrium.
66
What does it mean that the oesophagus is a porto-systemic anastomosis?
Is a connection point between the hepatic and system venous system as is drained by collection of both arteries.
67
What innervates the oesophagus?
Supplied by the oesophageal plexus, which is made from branches of the vagus nerve (parasympathetic), cervical sympathetic trunk and the thoracic sympathetic trunk.
These all link to the dorsal motor nucleus and the nucleus ambiguus (in the medulla oblongata).
68
What is a nucleus in neuroanatomy?
A cluster of neurons in the central nervous system.
69
Explain the lymphatic drainage of the oesophagus.
The superior third is drained by the deep cervical lymph nodes
The middle third is drained by the superior and posterior mediastinal lymph nodes.
The inferior third is drained by the left gastric and celiac nodes.
70
Define metaplasia.
The changing from one type of differentiated cell to another type of differentiated cell that is not normally present in that area of the body.
71
What abdominal region is the stomach found in?
The epigastric (mainly)
May fall into the hypochondraic and the umbilical
72
What are the divisions of the pylorus?
The pyloric antrum
The pyloric canal
The pyloric sphincter
73
What is the deal with the greater curvature of the stomach?
Is the lateral border of the stomach.
Joins with the pyloric antrum.
Supplies by the short gastric arteris and the left/right gastro-omental arteries.
74
What is the deal with the lesser curvature of the stomach?
Forms the medial border of the stomach.
The most inferior point called the angular notch indicates when it becomes the pylorus.
Gives attachment to the hepogastric ligament.
Is supplied by the left gastric artery and the hepatic artery.
75
Give the basic position of the stomach in relation to some other anatomical structures.
The stomach is inferior to the diaphragm.
The stomach is anterior to the kidney, adrenal gland, spleen, pancreas and the lesser sac.
The stomach is posterior to the left lobe of the liver, greater omentum and the gallbladder.
76
What is chyme?
A mixture of food and gastric acid
77
What is the deal with the pylorus sphincter?
An anatomical sphincter.
Contains smooth muscle.
Limit the discharge of stomach content into the duodenum.
When intragastric pressure overcome the resistance of the pylorus it opens to allow chyme to pass through, this is aided by gastric peristalsis pulses.
78
What type of role may the greater omentum play?
Contains many lymph nodes.
May attach to inflamed areas.
Hence plays a role in immune response and stopping the spread of intraperitoneal infections.
79
What arteries supply the stomach?
Branches of the celiac artery.
The right and left gastric artery
The right and left gastro-omental artery.
80
Where do the drains that supply the stomach drain into?
The right and left gastric vein drain into the hepatic portal vein.
The short gastric vein, and the right/lest gastro-omental vein drain into the superior mesentric vein.
81
What innervates the stomach?
Paraympathetic supplies by the anterior/posterior trunks of the vagus nerve.
Sympathetic supplies from the T5-T9 spinal cord segments.
82
What is the lymphatic drainage of the stomach?
Drains into the gastromentral (greater curvature) and gastric (lesser curvature) lymph nodes.
Eventually drain into the coeliac lymph nodes.
83
Give an overview of the duodenum structure.
Splits into four parts the superior, descending, inferior and ascending.
Normally a 25cm lung c shape that ends at the duodenojejunal junction.
Wraps around the head of the pancreas.
84
What is the first section of the duodenum?
D1 is the superior section, is located at level L1.
Is connected to the liver by the hepatoduodenal ligament (which pulls it superiorly).
The first 3cm is intraperitoneal, the rest is retroperitoneal.
85
What is the second portion of the duodenum?
D2 is the descedning section between heights L1 and L3, it curves around the pancreas head.
Sits anteriorly to the right kidney and posterior to the transcending colon.
Interiorly the major duodenal papilla is where secretions enter the duodenum e.g bile from the gallbladder.
86
What is the third part of the duodenum?
The inferior section at level with L3.
Travels to the left.
Superior to the inferior vena cava and aorta.
Is inferior to the pancreas
Is posterior to the superior mesentric artery and vein.
87
What is the fourth section of the duodenum?
The ascending section at location L3 to L2.
Moves anteriorly and superiorly to join with the jejunum.
At this junction is the suspensory muscle of the duodenum that can contract to widen the angle of connection making it easier for chyme to pass.
88
Give a basic overview of the abdominal aorta.
Is an extension of the thoracic aorta, extends from T12 to L4, at the end it splits into the left and right iliac arteries.
89
What are the branches of the abdominal aorta in descending order?
The inferior phrenic arteries
The coeliac artery
Superior mesentric artery
Middle suprarenal arteries
Renal arteries
Gonadal arteries
Inferior mesentric artery
Median sacral artery
Lumbar arteries.
90
Overview of the inferior phrenic arteries.
Paired arteries at T12, supply the diaphragm.
91
Overview of the superior mesentric artery.
Unpaired artery.
Anterior.
Lower L1 level
Supplies distal duodenum, jejuno-ileum, ascending colon and part of the transverse colon.
92
Overview of the renal arteries
Paired arteries between L1 and L2, supplt the kidney.
93
Overview of the middle suprarenal arteries.
Paired.
L1 level
Supply adrenal gland.
94
Overview of the gonadal arteries?
paired L2 level
Refered to as the testicular or the ovarian artery.
95
Overview of the inferior mesenteric artery.
Large and unpaired.
Supplies the large intestine from the splenic flexure to the upper part of the rectum.
L3
96
Overview of the median sacral artery.
Unpaired
Posterior at L4.
Supplies the coccyx, lumbar vertebrae and the sacrum
97
Give an overview of the lumbar arteries
Four pairs.
Arise posterolaterally between level L1 and L4, supply the abdominal wall and spinal cord.
98
How can the splenic artery be sub-divided?
The five splenic branches which supply the spleen.
Left gastroepipolic - supplies the greater curvature of the stomach.
Short gastric - supply the fundus of the stomach
Pancreatic branches - supply the body and tail of the pancreas.
99
What is the only branch of the coeliac artery to pass to the right?
The common hepatic artery.
100
What are the branches of the proper hepatic artery?
From the common hepatic artery.
Right gastric - lesser curvature and pylorus
Right and left hepatic - appropriate sections of the liver.
Cystic - branches from the right hepatic to supply the gallbladder.
101
What are the branches from the gastroduodenal artery from the common hepatic artery?
Right gastroepipolic - greater curvature of the stomach and the greater omentum
Superior pancreaticduodenal - supplies the head of the pancreas.
102
How is blood supplied to the pancreas?
Superior pancreaticoduodenal– a branch of the gastroduodenal artery.
Inferior pancreaticoduodenal – branch of superior mesenteric artery (SMA).
103
What is the difference between a functional and an anatomical sphincter?
Anatomical contains actual smooth muscle that can contract to act as the sphincter.
Functional acts as a sphincter due to many external and internal cicrumstances.
104
What level is the lower oesophageal sphincter?
T11
105
What marks the end of the foregut?
Where the major duodenal papilla drains substances from the pancreas and gallbladder into the duodenum. .
106
Where does the peritoneum start?
Just after the bare area on the liver. First section of peritoneum makes up the coronary ligament, where the liver attaches to the diaphragm.
107
What is meant by the periotneal cavity being a potential space?
The lavery between the pariteal peritoneum and the visceral peritoneum is the peritoneal cavity.
This is a potential space because you can in theory put something between these layers and it is often filled with peritoneal fluid.
However, abdominal viscera push against this space making it almost non-existent.
108
What is the clinical significant of the peritoneal cavity?
During illness fluid can accumulate in the cavity causing swelling.
109
Define omenta.
A double layer of visceral peritoneum. Connects abdominal viscera to other viscera
110
Define mesentry.
A double layer of visceral peritoneum that surrounds an organ linking it to the pariteal peritoneum whilst allowing a great degrees of movement.
111
What are visceral ligaments?
Short doubles layers of serous membranes that connect organs to other organs or the abdominal wall.
Allow for very little movement.
112
What organs are retorperitoneal?
How do you remember this?
SADPUCKER
Suprarenal glands
Aorta
Duodenum
Pancreas (except the tail)
Ureter
Colon
Kidneys
Esophagus
Rectum
113
What is the function of the peritoneum?
Acts as a conduit for lymphatics and neurovasculature.
Suspension
Connection
Restriction.
Negative: allow infection to travel within the peritoneum
114
What organ surrounds the head of the pancreas?
Duodenum
115
What organ surrounds the tail of the pancreas?
The spleen.
116
How many layers is the greater omentum made up of?
Four
117
What is the hepatogastric ligament?
Made from the lesser omentum, connects the liver to the stomach.
118
What is the hepatoduodenal ligament?
Made from the lesser omentum, links the duodenum to the liver.
119
What is the portal triad?
Found within the hepatoduodenal ligament.
Contains three main structures:
The common bile duct
The Proper hepatic artery
Hepatic portal vein.
120
What does epiploic mean?
to the omentum.
121
How is the peritoneal cavity different in men and women?
The peritoneal cavity is open in women. - open at the end of the fallopian tubes
The peritoneal cavity is fully closed in men.
122
What is a perionteal reflection?
When the peritoneum changes direction and flows over itself
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c
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123
What are the gastrophrenic and gastrosplenic ligaments made of?
The greater omentum
124
What type of folding is in the oesophagus?
transverse
125
What is the blood supply to the oesophagus?
Thoracic aorta
Inferior thyroid artery (supply superior section)
126
What is the function of the upper duodenum?
Neutralise acidic gastric juice, mechanical digestion of chyme, mixes bile and pancreatic juice onto content, absorption of bile electrolytes and nutrients.
127
Why is the splenic artery tortuous?
Relatively straight in paediatrics.
As age, the vessel grows considerably more in length than the gap between the origin and destination, so must curve in order to accommodation extra length.
128
Describe the location of different parts of the duodenum.
Superior - L1 level, travels laterally towards the gallbladder
Descening - to L3 level, posterior to the transverse colon and lateral to the head of the pancreas.
Inferior - crosses the mdiline over the vena cava, aorta and vertebrae.
Ascending - Travels superior to L2 level for duodenojejunal flexure
