Diana's Diahorrea Flashcards
Where does the inferior mesenteric artery arise?
At L3
What are the tributaries of the inferior vena cava?
From inferior to superior they are: median sacral vein, right and left internal and external iliac veins forming common iliac vein, iliolumbar and adcending lumbar veins, testicular/ovarian veins, right and left renal and suprarenal veins, inferior phrenic veins, right, left and middle hepatic veins
What gives the jejunum it’s distinct, floccular appearance on a contrast X-ray (barium follow through) compared to ileum?
The great numbers of plicae circulares which are few in number and smaller in the ileum
What are the attachments of psoas major?
Arises from lumbar transverse process and lumbar vertebral bodies and attaches onto lesser trochanter of femur with the iliacus muscle.
Where is the lesser omenteum?
Stretched between liver and gallbladder to stomach
Where is the appendix in relation to the caecum?
On its posterio-medial wall
Where are the Na/KATPase pumps on luminal intestinal cells?
On basal and lateral sides
Which organs lie on the posterior abdominal wall (and are therefore retroperitoneal)?
Kidneys, suprarenal glands, duodenum, pancreas, ascending and descending colon
What is the defecation reflex?
1) rectal contraction
2) contraction of external sphincter, relaxation of internal sphincter
3) reflex relaxation of external sphincter, can be inhibited by voluntary striated muscle contraction
What does the colon do?
Reabsorbs water and some electrolytes from chyme, compacts dehydrated chyme into faeces, mass peristaltic movements to move faeces to rectum
What is the lower part of the rectum called?
Rectal ampulla
What are epiploic appendages?
Fat-filled extensions of serosa in colon
Which arteries supply proctodaeum?
Inferior rectal arteries
What are crypts?
Columner absorption focused epithelial cells and mucus secreting goblet cells
What are the branches of the sigmoid arteries?
Superior sigmoid branch joins left colic and inferior sigmoid branch joins superior rectal
Where is the ligament of Treitz?
It is the suspensory ligament of the duodenum
What are the parietal branches of the abdominal aorta?
Left and right inferior phrenic arteries, four paired lumbar arteries and the median sacral artery
Which arteries supply thoracic foregut?
External carotid and oesophageal
How do osmotic laxatives like lactulose work?
Stimulate the myenteric plexuses to increase peristalsis and reduce salt and water absorption to increase faecal volume, may inhibit Na+ pump, cAMP and prostaglandins adding to this effect
What are the anatomical folds of the duodenum called?
Plicae circularis
What type of epithelium does colon have?
Simple columnar with prominent glands
Which muscle marks the beginning of the anarectal junction and what does it do?
Puborectalis (part of levator ani) forms a sling around the rectum, pulling it forward and helping control defecation
Name the parts of the stomach and where they are
Cardia: where oesophagus enters
Fundus: top part mainly air filled
Antrum: bottom of stomach
Pylorus: where stomach meets duodenum
How does the duodenum produce CCK?
Via vasoactive intestinal peptide (VIP)
What is the average epithelial cell turnover in the small intestine?
6 days
How are the inferior and superior vena cava linked?
Lumbar veins drain to the IVC, azygos veins drain to the SVC. These two are continuous with one another in the posterior mediastinum so that if the IVC or SVC is blocked, blood will be rerouted via this system
What is the cloaca?
The terminal end of the hindgut in the embryo
What kind of epithelium does the upper half of the anal canal have?
Plum-red mucosa (due to internal rectal venous plexuses)
Where is the rectouterine pouch?
Fold of peritoneum between rectum and uterus in females
How do crypts aid water reabsorption?
They suck faeces into them and dehydrate it by creating osmotic pressure across their walls which draws water into the crypt space and reabsorbs it
Where is the lumbar plexus located?
In the substance of psoas major
Where does the inferior mesenteric artery arise?
From descending abdominal aorta at the level of L3
What do lipases do?
Pancreatic enzymes that break down fats into monoglycerides and fatty acids
Where does the IVC leave the abdomen?
By piercing the central tendon of the diaphrag,m
Where is the lower end of the anal canal derived from embryologically?
Invagination of surface ectoderm
Which visceral branches of the abdominal aorta are paired?
Suprarenal, renal and testicular/ovarian
Which artery supplies hind gut?
Inferior mesenteric artery
Which artery supplies foregut?
Coeliac artery
What kind of epithelium does the lower half of the anal canal have?
Stratified, squamous, non keratinising
Describe the asymmetries of the inferior vena cava.
On the left the suprarenal vein and testicular/ovarian vein are tributaries of the renal vein, on the right they are direct tributaries of IVC. The middle hepatic vein is on the left and not the right.
Where does the coeliac artery arise?
At T12
How does paraffin oil work as a laxative?
It blocks the crypt lumens so they cannot suck fluid out of faeces
What are the branches of the inferior mesenteric artery?
Left colic artery, sigmoid arteries, superior rectal artery
Where do superior and inferior pancreaticodudodenal arteries anastomose?
At the point of entry of bile duct into duodenum, and point of foregut becoming midgut
Where is the duodenum roughly?
To the right of L1-L3 in the umbilicus region
What are teteiae coli?
Strips of longitudinal muscle which contract to produce haustra
Which branches of the superior mesenteric artery anastomose with one another?
Right colic and ileocolic anastomose. Middle colic and right colic anastomose.
What forms the roof of the abdominal cavity and the upper part of posterior abdominal wall?
The diaphragm
Where does the inferior vena cava begin?
At L5
Where does the aorta enter the abdomen?
Under the median arcuate ligament at T12
What are Peyer’s patches?
Aggregated lymph follicles in the mucus membrane of ileum
Where is the greater omenteum?
Stretched below stomach across intestines
Where does the aorta end, and how?
At L4 it splits into common iliac arteries
What are the right and left paracolic gutters?
Trench formed by peritoneum on the lateral side of the ascending colon and descending colon respectively
How are vitamins A and E transported around the body?
In chylomicrons in lymph
Describe the neural control of defecation.
Rectum senses fullness, internal anal sphincter is inhibited as is voluntary sphincter and puborectalis muscle (ano-rectal angle can become more obtuse). Pre-synaptic sacral parasympathetic outflow causes contraction hindgut. The external anal sphincter is held under voluntary tonic control until point of defecation.
What are the symptoms of malabsorption?
Steathorrea, diarrhoea, nutritional deficiency, muscle weakness,sensory loss, malaise, low bone mass
What is arterial supply of anal canal above the pectinate line?
Inferior mesenteric artery
Where is the major site of iron absorption in the small intestine?
Duodenum
What are taeniae coli?
3 longitudinal strips of muscle which maintain muscle tone of colon and produce haustra (sac like divisions)
Where do testicular/ovarian arteries arise?
At L2
Which at artery supplies mid gut?
Superior mesenteric artery
What are the names of the salivary glands?
Parotid, submandibular, sublingual
What is venous drainage of anal canal below the pectinate line?
Inferior rectal veins
Where does the superior mesenteric artery arise?
From descending abdominal aorta at the level of L1
What are the general layers of the GI tract?
1) Mucosal (epithelial) layer
2) Lamina propria (connective tissue) layer
3) Muscularis mucosa (SM)
4) Submucosa (connective tissue)
5) Muscularis externa (SM)
6) Serosa (squamous mesothelial layer)
What inhibits voluntary sphincter and puborectalis muscle?
Pudendal nerves (S2-S4)
Where do renal arteries arise?
At L1/2
Where is McBurnley’s point?
2/3 of the way down a line drawn from umbilicus to right anterior superior iliac spine