alimentary Flashcards
(159 cards)
1
Q
What does the oral cavity consist of?
A
Vestibule & oral cavity proper
2
Q
What is the oral cavity proper?
A
Alveolar arches to palatoglossal folds
3
Q
What is the vestibule?
A
space between lips/cheeks & teeth
4
Q
Extent of nsaopharynx?
A
Choana to soft plate
5
Q
Extent of oropharynx?
A
Soft plate to epiglottis
6
Q
Extent of laryngopharynx?
A
post to larynx - epiglottis to top of trachea
7
Q
Walls of pharynx?
A
mucosa + 3 verically overlapping constrictor muscles.
8
Q
What is in the foregut?
A
Oesophagus, stomach, duodenum (to just below greater duodenal papilla), organs formed in the mesentaries of foregut (pancreas, spleen, liver, gall bladder & ducts)
9
Q
What is the midgut?
A
Duodenum (from just below greater duodenal papilla), jejunum, ilieum, caecum, appendix, ascending colon, right 2/3 transverse colon
10
Q
What is the hindgut?
A
Left 1/3 (approx) transverse colon, descending colon, sigmoid colon, rectum & most of anal canal
11
Q
What is the microstructure of the alimentary canal?
A
Mucosa:
- epithelium, glands, lamina propria, muscularis mucosa
- submucosa: connective tissue
- external muscle: usually inner circular and outer longitudinal
- either adventitia: connecting ti surrounding fascia or
- serosa - peritoneum
12
Q
Extend of oesophagus?
A
C6-T11
13
Q
What is posterior to the oesophagus?
A
Vertebral column,
14
Q
What is anterior to the oesophagus?
A
Trachea, bronchi, pericardium & left atrium
15
Q
What gives the oesphagus the characteristic appearance of longitudinal streaks?
A
Outer longitudinal layer of external muscle
16
Q
Nerves to oesophagus?
A
Vagus and sympathetic trunk ? form oesophageal plexus.
17
Q
How long is abdominal part of oesophagus?
A
1cm
18
Q
Where does abdominal oesophagus lie?
A
Groove on posterior surface of liver.
19
Q
How does the abdominal oesophagus attach to the diaphragm?
A
The gastrophrenic ligament. Attaches to posterior diaphragm.
20
Q
What does the gastrophrenic ligament attach to?
A
- Abdominal oesophagus
- Fundus of stomach
- Diaphragm
21
Q
What does the gastrocolic ligament attach to?
A
- Greater curvature of the stomach
- Anterior part of transverse colon
- First part duodenum
22
Q
What does the gastrosplenic ligament attach to?
A
- Greater curvature of the stomach
- Spleen
23
Q
What are the constrictions in the oesphags?
A
- Upper sphincter - cricopharyngeus
- At level of arch of aorta
- At left of left primary bronchus
- At level of oesophageal hiatus - lower sphincter.
24
Q
What does the lower oesophagel sphincter consist of?
A
- specialised circular muscle in wall if oesophagus - maintained by tone of myentric plexus
- muscle of right crus forms external sphincter - tightens during inspiration or when intraabdominal pressure is increased.
25
In the development of the gut, the ___ is attached to the posterior body wall by a_____. The stomach and first (foregut) part of the duodenum are attached to the ____ by a _____
entire abdominal part of the gut tube, dorsal mesentary, anterior body wall, ventral mesentary
26
What forms in the ventral mesentery?
The liver, the biliary system & ventral pancreas.
27
The part of the ventral mesentery ___ to the liver forms the ____
anterior, falciform ligament
28
The part of the ventral mesentery which is between the ____ ____ and _____ ______ will form the ____ ___
liver anteriorly, stomach posteriorly, less omentum
29
Dorsal mesentery forms?
Mesentery, mesoappendix, transverse mesocolon, sigmoid mesocolon
30
What forms in the dorsal mesentery?
Dorsal pancreas, spleen
31
What happens to the mesentery around retroperitoneal organs?
dorsal mesentery fuses with posterior body wall and is obliterated (fixation of the intestines)
32
MIdpart of duodenum (in development) is attached to what?
Dorsal mesentery to posterior abdominal wall.
33
What is the greater omentum?
Double fold of peritoneum, attached tp greater curvature of stomach and first part of the duodenum and transverse mesocolon.
34
Appearance of greater omentum.
Hangs down to cover anterior surface of abdominal organs. Grainy appearance - fatty regions separated by translucent fat free regions. Accumulations of macrophages, may be recognised with eye in unembalmed tissue as whitish, opaque, 'milk spots'
35
Development of greater omentum
Initially a double layer but layers fuse. Transverse mesocolon becomes attached to posterior surface.
36
Function of greater omentum
Thought to be protective (macrophages & other immune cells) and also because it adhere to areas of peritoneal damage and inflammation.
37
Lesser omentum
fold of peritoneum that extends from lesser curvature of stomach to posterior surface of liver. also has grainy fat.
38
What run in the lesser omentum just to the left of the free edge?
Hepatic artery, portal vein and bile duct (with lymph vessels and nerves)
39
Where is the lesser sac? function?
Space posterior to stomach and lesser omentum. Allows for movement & expansion of the stomach.
40
Greater sac?
rest of peritoneal cavity, (besides the lesser sac)
41
What connects the greater and lesser sacs?
The epiploic foramen
42
What is the stomach bed?
Posterior wall of lesser sac. includes retroperitoneal structures such as upper pole of left kidney & left suprarenal , diaphragm, part of spleen, pancreas, part of transverse mesocolon (which attaches to pancreas as well as greater omentum)
43
What is the function of the stomach?
Food storage and predigestion
44
Features of stomach.
HIghly distensible. cardia, fundus (fairly fixed). body, pyloric part (antrum, canal, sphincter). Rugae - temporary longitudinal folds. Mucosa has glands that produce mucus in cardia, pyloric part. Different glands in fundus and body which produce digestive enzymes and HCl.
45
Relationships of stomach?
Anterior - liver diaphragm
| Posterior - omental bursa & structures of stomach bed
46
What controls gastric emptying of stomach?
Stretch, endocrine
47
Where is cardiac orifice (stomach)?
Level of 7th costal cartilage (attaches at ziphosteral joint and is about 3cm from midline)
48
Ligament that attaches Greater curvature of stomach to spleen?
Gastrosplenic
49
LIgament that attaches greater curvature of stomach to diaphragm?
Gastrophrenic
50
Small intestine.
Pyloris to ileocaecal valve. Duodenum, jejunum,ileum.
51
Small intestine function?
Digestion and absorption of nutrients
52
First part of duodenum. Relations.
superior part - attached to greater and lesser omentum. Portal vein and bile duct are posterior. Quadrate lobe of liver and gall bladder are anterior.
53
Second part of duodenum. Relations.
Descending part - head of pancreas is medial. Hilum of right kidney is posterior.
54
Third part of duodenum. Relations.
Horizontal part. Upper RIGHT psoas is posterior. Superior mesenteric vessels are anterior.
55
Fourth part of duodenum. Relations.
Ascending part. Upper LEFt posas is posterior.
56
At what level is the duodenojejunal junction?
Level of L2 just medial to Left kidney. Easy to recognise by appearance of mesentary to support jejunum.
57
At what level is the duodenojejunal junction?
Level of L2 just medial to Left kidney. Easy to recognise by appearance of mesentery to support jejunum.
58
Flexures in the duodenum?
Superior duodenal, inferior duodenal, duodenaljejunal
59
Jejunum
2/5 of length (of j+i) Largely in umbilical region.
60
Ilium
3/5 of length, mainly in lower abdomen and pubic regions.
61
Where does the root of mesentary run from?
Upper left to lower right. Fan shaped so intestinal edge is long.
62
What is the attachement of the mesentary for the jejunum and ilium to the posterior abdominal wall called?
Root of mesentary
63
Internal features of of jejunum & ilium.
Internal transverse folds - permanent. Mucosa with villi, THIN muscularis mucosae, submucosa and THICK external muscle.
64
What is the mesentary?
2 layers of peritoneum containing variably fatty CT & carrying vessels & nerves in & out of gut. also lymph nodes
65
Jejunum.
mesentary: long vasa recta, relatively few side to side anastomoses (arcades) joining vasa recta. Less fatty mesentary. Thicker walled, more vascular. Folds larger and longer. Villi longer. Aggregated lymph follicles (payers patches) FEW & aggregations small.
66
Ilium.
Shorter vasa recta, more arcades, more fat in mesentary. Folds decrease and almost disappear in distal part. Thinner wall. More peyers patches.
67
Large intestine parts. Function?
Caecum and appendix, ascending, transverse, descending colon, sigmoid colon, rectum, anus. Absorption of water and ions.
68
Features of large intestine.
Sacculations/haustra (regular expanded areas of colon interspersed with constrictions. Taenia coli (3 thickenings on longitudinal part of external muscle - not present in appendix and rectum junction). Epiploic/emntal appendices (not on caucum, present TV and sigmoid). No villi in large int.
69
The Caecum is found in the __ ___ ___. It is a _____ intestinal _____(_ ____). Suspended from ascending colon.
Right iliac fossa, blind, pouch, no mesentary.
70
Where is junction of caecum and ascending colon?
level of ileocaecal valve.
71
Edges of ileoceacal valves?
Frenulae. (tightens)
72
What is the gastroileal reflex?
food in stomach initiates contration of small intestine and thus expulsion of ileal contents into caecum.
73
Where is the appendix found?
Often in the retrocaecal recess (behind caecum) or hanging down over pelvic brim, close to opening of uterine tube in females.
74
Opening of appendix is where?
McBurneys point - junctino of lateral and middler thirds of line from umbilicus with ASIS.
75
Is the appendix suspended?
Yes. on mesoappendix which is attached to ileal mesentary.
76
Is the caecum suspended?
Yes. but no mesentary.
77
What are features of the appendix?
Ring of lymphatic nodules in mucosa & submucosa. No taenia coli, no epiploic appendices.
78
Extent if the ascending colon?
From ileocaecal valve to right colic flexure.
79
Relations of ascending colon?
Anterior to right kidney & descending duodenum. Posterior to fundus of gall bladder.
80
Is the transverse colon retroperiotoneal?
Usually described as retropreitoneal but up to 50% of individuals have a very SHORT mesentery (no mobility)
81
Where does transverse mesocolon attach?
Greater omentum, pancreas, transverse colon.
82
The _____ attaches the ___ colic flexure to ______.
Phrenicocolic ligament, left, diaphragm.
83
Where is the left colic flexure located?
In front of left kidney and below Spleen and Pancreas.
84
Which ligaments provide support for the spleen?
Splenocolic & phrenicocolic
85
Extent of descending colon?
Left colic flexure to pelvic inlet.
86
What structures do the descending colon cross?
Gonadal (testicular/ovarian) vessels and external iliac vessels.
87
Sigmoid colon extent.
Pelvic brim to S3. (approx middle of sacrum)
88
Is the sigmoid suspended?
Yes. Sigmoid mesocolon forms and inverted V. There is a intersigmoidal recess behind sigmoid mesocolon.
89
What lies behind sigmoid mesocolon?
intersigmoidal recess
90
What are the relations of the sigmoid mesocolon?
Overlies left ureter & external iliac vessels.
91
Rectum features.
Retroperitoneal, no sacculations, no epiploic appendices, no taenia.
92
Extent of the rectum
S3 to pelvic diaphragm
93
Relations of the rectum
Post: Sacrum, coccyx, pelvic diaphragm
Lat: Pelvic diaphragm, sigmoid colon, ilium
Ant: male: rectovesicular pouch then base of bladder, seminal vesicles, ductus deferens, prostate. female: rectouterine pouch then uterus, vagina
94
Anal canal features
Upper part- 6-10 vertical folds or columns. Lower ends columns joined by transverse folds - valves. Spaces between columns are sinuses.
95
What is the extent of the anal canal?
From top of columns to anus.
96
What are the relations of the anal canal?
Posterior: Annococcygeal ligament (dense Ct from coccyx to anal margin)
Anterior: perineal body + membranous urethra/bulb of penis OR vagina.
Lateral: ischiorectal fossa
97
What are the regions of the pancreas?
Head and uncinate process (within curve of duodenum), Body (triangular in profile with transverse mesocolon attached to ANTERIOR angle), Tail.
98
What is the peritoneal realtions of the rectum?
Upper 1/3 - on anterior and sides
Middle 1/3 - on anterior only
Lower 1/3 - no peritoneum
99
What are the features of the pancreas? where is it>
12-15cm long. duodenum to spleen behind stomach. retroperitoneal apart from tail in splenorenal ligament.
100
What marks the junction of the anal canal and the rectum?
Rectoanal junction: Sling of skeletal muscle (puborectalis), at level of the top of the columns, narrower than ampulla.
101
What is the mucosa of the anal canal?
Transition from simple columnar epithelium (as rectum), to transitional zone of non-keratinised stratified squamous to skin (keratinised). Transition zone begins below pectinate line.
102
Where does the transition zone begin?
Below pectinate line/Mucocutaneous junction.
103
What are the sphincters in the anal canal?
Internal - upper 2/3 - thickened circular layer of external smooth muscle (stops at junction with skin).
External - lower 2/3 - skeletal muscle. 3 parts. Partly reflex, partly voluntary.
104
What is the movement of BOLUS?
slow rhythmic movements. 1-3 hours in stomach, 1-6 hours in small intestine - segmenting contractions & peristalsis from one end to the other (motilin). Gastrocolic reflex: ileum --> Large intestine
105
what controls Continence (bowels)?
- muscle tone in Sphincters & puborectalis. (stimulated by SYMPATHETIC nerves) keep anus closed. Tone noramlly increases when intraabdominal pressure rises
- Puborectalis - tone pulls upper part of anal canal forward and presses on upper part of external sphincter.
- reverse peristalsis
- relaxation of muscle wall of rectum & sigmoid
106
What is the control of the gastrocolic reflex?
Parasymp nervous system , gut homones e.g. motilin
107
What triggers defecation? What happens during defecation?
Rectal stretching. Prior to defecation feces pases into ampulla and held until voided. Defecation reflex from MEDULLA oblongata. Relaxation of sphincters & puborectalis. Peristalsis in descending and sigmoid colon increases. Contration of abdominal muscles and diaphragm --> increases abdominal pressure.
108
What triggers defecation? What happens during defecation?
Rectal stretching. Prior to defecation feces pases into ampulla and held until voided. Defecation reflex from MEDULLA oblongata. Relaxation of sphincters & puborectalis. Peristalsis in descending and sigmoid colon increases. Contration of abdominal muscles and diaphragm --> increases abdominal pressure. Feces from splenic flexure down is voided
109
From where in the alimentary canal is feces voided?
From splenic flexure (descending colon) down.
110
What is the function of the pancreas?
Exocrine - digestive enzymes
| Endocrine - islets of Langerhans
111
What do the pancreatic buds look like intitally?
Series of branching epithelial lined tubules arising from distal foregut.
112
What will the tubules in the pancreatic buds form?
Pancreatic ducts, acini develop by further growth later. Iselts arise from tubule cells - lie in CT between tubules.
113
Which way does the ventral pancreas rotate?
Posteriorly.
114
Which duct remains as the main pancreatic duct?
Ventral duct. Most of dorsal duct rearanges to drain into this
115
What is the minor pancreatic duct from?
Part of dorsal duct nearest to duodenum.
116
What does the ventral pancreatic bud become?
Inferior head and uncinate process
117
Relations of head and uncinante process (pancreas)
IVC and Aorta are posterior.
118
Relations of body of pancreas.
Anterosuperior surface faces lesser sac & the anteroinferior surface the greater sac
119
Which surface of the pancreas faces the lesser sac?
Anterosuperior
120
What attaches to the anterior angle of the pancreas?
Transverse mesocolon
121
What might the main pancreatic duct and bile duct join to form?
hepatopancreatic ampulla
122
Describe the distribution of ducts within the pancreas.
"herringbone" pattern of LOBAR ducts draining into the main pancreatic duct.
123
How can you tell the difference between a spleen and kidney?
Kidney - visceral/hilar surface is pointed. Spleen is flattened. Spleen also has notched anterior border.
124
Function of the spleen?
Red pulp - Haemolytic (breaks down RBC)
| White pulp - lymphoid tissue (production of lymphocytes and immunosurveilance)
125
Where does the spleen develop? (LAYER)
In the mesenchyme (connective tissue) of the dorsal mesentery as MULTIPLE primordia with own blood supply. Then fuse to form lobulated structure - seen as notching on ext surface especially the superior border.
126
Why are accessory spleens common?
Start of as multiple primordia in fetus which then fuse to form single spleen. Could be result of unsuccessful fusing.
127
The spleen is initially a ____ organ but is later colonised by ___ cells.
Haemopoitic, lymphoid
128
True or False: The anterior border is often notched in the spleen.
FALSE: the superior border (sometimes inferior)
129
Where is the spleen located?
Related to Left ribs 9-11. Long axis parallel to rib 10. Upper left posterior region of stomach between fundus of stomach and diaphragm
130
Is the spleen suspended?
Yes. But splenorenal and gastrosplenic ligaments.
131
What are the surfaces of the spleen?
Diaphragmatic, visceral (with impressions).
132
What are the borders of the spleen?
Superior (most common site of notching), inferior, anterior (often SHARP), posterior (often ROUNDED)
133
What are the impressions on the spleen?
Gastric (broad, concave impression ABOVE hilus), Pancreatic (small, may not be visible) & colic (anteriorly, BELOW hilus), Renal (posterior, Below hilus)
134
What forms the colic impression on the spleen?
The left (splenic flexure)
135
What impression on the spleen is posterior and below the hilus?
Renal impression
136
TRUE or FALSE: Different cells in the liver are needed to carry out the many functions.
FALSE: one cell type - hepatocyte
137
What is the cell of the liver?
Hepatocyte.
138
What are the functions of the liver?
Complex exocrine (bile) and endocrine gland and metabolic organ. Also detoxification.
139
What is the exocrine function of the liver?
Produces bile which is involved in digestion of fats. Contains bile pigments from breakdown of RBC in spleen.
140
What is metabolic function of liver?
Especially protein and carbs.
141
What is endocrine function of liver?
Release of glucose, plasma proteins etc into blood.
142
Where is the Liver located?
Under the lower right ribs and diaphragm. Extends from level of 5th rib to costal margin. Gall bladder protrudes from below its lower surface at about level of 9th costal cart and linea semilunaris.
143
What are the features of the liver?
Largest organ (1.5 kg approx) - approx 2% body weight in adults, 5% in kids. HIGHLY vascular
144
What are the surfaces of the liver?
Diaphragmatic and visceral. Covered with peritoneum except sites of attachments of ligaments.
145
What are the anatomical lobes of the liver?
Left, right, caudate (superior), quadrate (inferior)
146
How is right liver separated from left?
Line drawn up through fossa for gall bladder.
147
What are the functional lobes of the liver?
Left (with caudate and quadrate). Right. On the basis of supply by right or left hepatic arteries.
148
What are the ligaments of the liver?
Coronary ligament, Left and right triangular ligaments on either side, falciform ligament, lesser omentum.
149
What is the place on the liver called that lacks peritoneum?
Bare area.
150
The ___ ligament derived from ____ mesentery, extends from ____ surface of liver to ____ abdominal wall
Falciform, ventral, anterior, anterior
151
Where do they coronary and triangular ligaments attach?
Attaches superior liver to right dome and central tendon diaphragm. BARE AREA (lacks peritoneum)
152
Where does the lesser omentum attach?
From lesser curvature of stomach & first part of duodenum to surround porta hepatis & then superiorly into fissure for ligamentum VENOSUM. Finally attached to diaphragm and surrounds osephagus.
153
What are the fissures in the liver?
Fissure for ligamentum venosum (between L and caudate), fissure for ligamentum teres.(between l and quadrate)
154
What is the hilum of the liver known as?
Porta hepatis, marks lower edge pf lesser omentum.
155
What are the remnants of the left feotal umbilical vein?
Ligamentum venosum and teres.
156
Function of the left umbilical vein
- brought OXYGEN RICH blood from the placenta to fetal IVC - mostly bypassed the liver apart from a connection to the left branch of the portal vein which collected oxygen rich blood to nourish the liver.
157
Function of the gall bladder?
Sore, concentrate and transport bile.
158
Gall bladder location.
In fossa on post. surface of right hepatic lobe.
159
Ducts - biliary system
Left and right hepatic ducts join to form common hepatic duct. That joins cystic duct to form bile duct.
