Block 5 Flashcards
What is the embryological origin of the GI tract?
Endoderm
What is the embryological origin of kidneys, gonads, connective tissue, and muscle
Mesoderm
What does the ectoderm of the embryo form?
Epidermal layer of the skin
What parts of GI are derived from the foregut?
Esophagus, stomach, proximal duodenum, liver, pancreas, lungs
What is dissolved to form the mouth?
Oropharyngeal Membrane
What parts of the GI are derived from the midgut?
Remaining small intestine, cecum, proximal colon
What parts of the GI system are derived from the hind gut?
Distal colon, rectum
What does the cloacal membrane dissolve into?
Anal orifice and urogenital opening
What is a very potent cell type in the colon?
Goblet cells for “poop lube”
In the upper GI, what are the regions that are covered with stratified epithelial cells?
Tongue, esophagus, oral cavity (gingiva)
In the upper GI, what type of regions contain actin in and ducts (simple cuboidal epithelium)
Salivary glands (parotid salivary gland, sublingual, zygomatic, mandibular)
What are the differentiating characteristics of the different regions of the small intestine?
Duodenum: Brunner’s Glands, potentially pancreas
Jejunum: Really long villi
Ileum: Peyer’s patches, small villi
What is the most common cell type of the intestine?
Enterocytes
What cells overly the Peyer’s Patches of the ileum?
M-cells aka GALT cells
Is the gingiva’s stratified squamous epithelium keratinized?
Sometimes
What type of cells line the tongue and what physical characteristics does it have?
Stratified squamous epithelium (may be keratinized) and the dorsal surface have papillae
The internal core of the tongue has skeletal muscle
What are acini and what are ducts?
Acini are cells that make and secrete saliva
Ducts are cells that convey saliva to the mouth
What are the two types of epithelial cells in acini?
Mucous: pale, basophilic (blue) to clear cytoplasm for lubrication
Serous: pale, eosinophilic (pink), granular cytoplasm for proteins that are digestive enzymes (amylase)
What are the 4 layers of the tubular GI?
Mucosa
Submucosa
Muscularis
Serosa
What 3 components make up the mucosa of the GI?
Epithelium
Lamina propria
Muscularis mucosae
Which type of feeder does not have any keratinization in their esophagus and which feeders have a lot of keratinization?
No keratinization in carnivores
Lots of keratinization in roughage eaters (ruminants)
What do the muscular layers of the pig and human’s esophagus look like?
Middle 1/3 = smooth + striated. Distal 1/3
What do the muscular layers of the esophagus for the cat and horse look like?
Proximal 2/3 skeletal muscle, distal 1/3 smooth muscle
What does the muscular layers of the dog and ruminants esophagus look like?
100% skeletal: Ruminants need to be able to chew their cud and dogs need to be able to voluntarily vomit
What is the only species where the squamous region of the stomach plays a large role?
Ruminants!
Which chambers of the ruminant stomach are stratified squamous epithelium and which are glandular (simple columnar epithelium)?
The rumen and reticulum are stratified squamous
The abomasum and omasum are both simple cuboidal
Which regions of the ruminants stomach is keratinized?
Rumen and reticulum
What is the composition of the rumenal lamina propria
NO SMOOTH MUSCLE
What is the composition of the reticulum’s lamina propria?
Isolated smooth muscle in the lamina propria
What is the composition of the omasum’s lamina propria?
3 different smooth muscle layers
What are the 4 main secretory products of the glandular stomach?
Hydrochloric acid
Mucous
Gastrin
Pepsin
What cell secrete pepsinogen?
Chief cells
What cells secrete hydrochloric acid?
Parietal cells
How do parietal cells show up in histology (eosinophilic (pink) or basophilic (blue))
Eosinophilic
How do chief cells show up in histology (eosinophilic (pink) or basophilic (blue))
Basophilic
Where are mucous cells in the stomach?
Present throughout
Where are chief cells and parietal cells?
More prevalent in fundus / body of stomach
Where are gastrin - producing cells present in the stomach?
More prevalent in the pylorus (can’t histologically distinguish)
What is the function of gastrin?
Gastrin secreted in the fundic region fo
What are the pouches of the colon called?
Haustra
What are the bands of the colon called?
Teniae coli
What are the glands in the duodenum?
Brunner’s Glands
What is the junction between glandular and non glandular regions of the equine stomach
Margo plicatus
Does the ventral or dorsal colon of the horse have haustra and teniae?
Ventral
Where are the two levels of ascending colon joined?
On the left side
At what anatomical point does the descending (small colon) turn into the rectum?
At the pelvic inlet
Talk through the horse GI from Ilium on
Ilium>RVC>sternal flexure>LVC>Pelvic flexure (on left)>LDC>diaphragmatic flexure>RDC>transverse colon>descending colon>rectum> anus
What rib does the diaphragm bulge toward to in the horse
6
on the left, Where is the liver in the horse
7-9 high
On the left, Where is the stomach of the horse
9-15 high
On the left, Where is the spleen of the horse
base: 15-18 high
Apex: 9-12 low
Does the small colon have teniae coli?
Yes
Does the small intestine have teniae coli?
NO
Does the ventral or dorsal large colon have teniae coli and haustra
VENTRAL
On the right side of the horse, where is the liver
7-16 high
On the right side of the horse, where is the liver
7-16 high
Where is the base, body, and apex of the cecum?
BAse: Right paralumbar fossa
Body: Against flank
Apex: located close to xyphoid process
Where is the root of the mesentery in the horse?
L1
Where is the right kidney of the horse?
T16,17,18. L1
Where is the left kidney of the horse?
T18. L1, L2, L3`
Where are the ovaries of the horse?
Half way between the tuber coxae and the last rib
What are the 2 surfaces of the liver and what way do they face?
Diaphragmatic surface: faces diaphragm
Visceral surface: Faces intestines
What are the 4 lobes of the liver?
Left lateral, left medial, quadrate, right
Is the caudate a lobe or a process of the liver in horses?
Process!
Where does the falciform ligament (round ligament) pass through on the liver?
The left medial and the quadrate lobes
What is the round ligament of the liver a remnant from?
Umbilical vein
What is the tendon on the liver that is from the central tendon of the diaphragm?
The coronary ligament
What are the 3 things in the porta of the liver?
Portal vein, hepatic artery, hepatic duct (bile)
What is the ligament between the stomach and spleen?
Gastrosplenic ligament
What is another name for the fundus of the stomach?
The blind sac
What are the 3 reasons that a horse rarely vomits?
Cardiac sphincter is very strong
Very acute angle of the esophagus
Folds of mucosa blocks opening
What is the region that allows the portal vein to pass through the pancreas in the horse?
The pancreatic ring
What are the 6 parts to the equine duodenum?
Cranial part of duodenum
Cranial duodenal flexure
Descending duodenum
Caudal duodenal flexure
Ascending duodenum
Duodenal jujunal flexure
What are the 2 openings on the major duodenal papillae
Pancreatic duct
Hepatic duct
What are the opening(s) on the minor duodenal papillae?
Accessory pancreatic duct
What is the landmark of mesenteric tissue that marks the end of the small intesting?
The ileocecal fold
What is the protuberance of ileum into the cecum called?
Ileal papilla
Where does the cecocolic ligament attach to?
Right ventral colon
How many bands does the cecum, RVC, LVC have?
4
How many bands does the LDC have?
1
How many bands the RDC have?
3
How many bands does the small colon have?
2
What is the telescoping of the intestine called?
Intussusception (commonly occurs at the ileocecal junction)
What are their 3 arteries that supply blood to the whole abdominal cavity in the horse?
Celiac
Cranial Mesenteric
Caudal Mesenteric
What 3 arteries branch off of the celiac artery in the horse?
Splenic
Left gastric (lesser curvature)
Hepatic
What artery supplies the spleen in the horse?
Splenic
What artery supplies the liver in the horse?
Hepatic
What artery supplies the lesser curvature of the stomach in the horse
Left gastric
What are the arteries of the cranial mesenteric in the horse to the small intestine?
Caudal pancreaticoduodenal artery
Jejunal artery
Ileal artery ->iliocolic artery
What artery supplies the duodenum in the horse?
Caudal pancreaticoduodenal artery
What artery supplies the jejunum of the horse?
Jejunal arteries
What arteries supply the ilium of the horse?
Ileal and ileocolic arteries
What arteries supply the colon of the horse?
Middle colic
Right colic
Ileocolic
Colic branch of ileocolic artery
What artery supples the transverse colon? in the horse
Middle colic artery
What artery supplies the left and right dorsal colon?
Right colic artery
What artery supplies the ventral colon?
Colic branch of the ileocolic
What artery supplies the cecum in a horse?
The cecal arteries (medial and lateral)
What artery supplies the small colon on the horse?
Caudal mesenteric artery
What are the branches of the caudal mesenteric artery?
Cranial rectal
Left colic
What artery supplies the proximal small colon in the horse?
Left colic (then anastomoses with middle colic)
What artery supplies blood to distal small colon and rectum?
Cranial rectum
How many ribs does a ruminant have?
13 (just like dog)
How many ribs does a horse have?
18
What are the borders of the paralumbar fossa of the cow?
Cranially: 13th rib
Caudal: tuber coxae
Dorsally: Transverse processes of lumbar vertebrae
Ventrally: Line of tension of internal abdominal oblique
Where is the site of incision for the paralumbar fossa?
Halfway between the ribs and tuber coxae
What do the grooves on the outside of the rumen contain?
Arteries and nerves
What do the longitudinal grooves of the rumen separate?
The ventral and dorsal sacs
What is the only “pillar” on the inside of the rumen that isn’t called a pillar?
Rumenoreticular fold
What is the groove within the rumen?
Gastric groove helps to shunt blood from esophagus to the abomasum
What are the 3 parts of the gastric groove?
Reticular groove
Omasal groove
Abomasal groove
What are the 3 arteries coming from the celiac artery in the cow?
Splenic
Left gastric
Hepatic
What are the 3 arteries that come from the splenic artery in the cow?
Reticular
Left ruminal
Right ruminal
What artery is the principal supply of blood to the rumen?
Right rumenal artery from splenic artery from celiac artery
What is the parasympathetic innervation of the rumen?
The dorsal and ventral ventral trunks
Where does the ilium empty in the cow?
Ileocecocolic orifice
What are the 3 parts to the ascending bovine colon?
Proximal loop
Spiral loop
Distal loop
What are the 3 parts of the spiral loop?
Centripetal gyri
Central flexure
Centrifugal gyri
What are the gyri going into the spiral loop?
Centripetal gyri
What are the gyri coming out the spiral loop?
Centrifugal gyri
What is the difference in the pancreas between small ruminants and bovine?
Small ruminants have a pancreatic duct emptying into the major papilla while bovine only have an accessory pancreatic duct emptying into minor papilla
Why are ruminant livers more vertical?
The rumen pushes everything right
Where is the gall bladder in teh cow located?
10th-11th intercostal space between right lobe and quad rate lobe
Where does the superficial leaf of the greater omentum attach in the cow?
The left longitudinal groove
Where does the deep leaf of the greater omentum attach in the cow?
Right longitudinal groove
What is the space between the superficial and deep leaf of the omentum called?
OMental bursa
What is the topographic region of flank?
Abdominal wall from ribs to thigh
What is the skin and cutaneous trunci bridging to thigh?
Fold of the flank
What is the innervation of the flank?
Costoabdominal nerve: Thoracic nerve #18 (T18)
Iliohypogastric nerve: L1
Ilioinguinal nerve: L2
Genitofemoral nerve: L3
Lateral cutaneous femoral nerve: L4
What muscle would you be cutting if you cut paramedical to the linea alba?
The rectus abdominus muscle
What is the cutaneous muscle over the shoulder region of the horse?
Cutaneous omobrachialis
Which direction does the external abdominal oblique muscles run?
Caudoventral (Jacket pockets)
Which direction do the internal abdominal oblique muscles run?
Cranioventral (up into jacket)
What muscle does the cremaster muscle originate from?
Internal abdominal oblique
What direction does the trans versus abdominis run?
Vertical
Which direction does rectus abdominus run?
Straight cranially
What are the internal boundaries of the abdomen?
Cranial: Diaphragm
Caudal: Pelvic Inlet
Dorsal: Paired hypaxial muscles and lumbar and sacral vertebrae
Where are the hypaxial muscles?
On the inside of the abdominal cavity, paired on each side of the lumbar vertebrae
What are the 3 paired abdominal hypaxial muscles?
Psoas major
Psoas minor
Quadratus lumborum
What are the hypaxial mm innervated by?
The ventral branches of lumbar nerves
What vital functions do the lateral abdominal muscles help with?
Expiration, urination, defecation, and parturition
What is the muscle that extended from prepublication tendon to sternum?
Rectus abdominis
What is the collagenous mass cranial to the pubic bone called?
Prepubic tendon
What is the fibrous connective tissue associated with the rectus abdominis?
Aponeurosis (rectus sheath)
What are the abdominal muscles from superficial to deep?
External abdominal oblique
Internal abdominal oblique
Transversus abdominis
What muscle is associated with cremaster m?
Internal abdominal oblique
What muscle is associated with teh inguinal ligament?
External abdominal oblique
What is the thin connective tissue attaching abdominal wall to peritoneum?
Transversalis fascia
What is the mideventral strip of collagenous tissue on the abdomen?
Where does it extend from and enter?
Linea alba
Xiphoid process to pelvic symphysis
Where are epaxial muscles?
Where are Hypaxial muscles?
Dorsal to vertebrae
Ventral to vertebrae
What are the 3 epaxial muscle systems (from lateral to medial)
(ILT)
Iliocostalis system
Longissimus system
Transversospinalis system
What is the layer that lines the abdominal cavity called?
Peritoneum (encloses peritoneal cavity)
Do any organs lie within the peritoneal cavity?
No! Only fluid
What is the parietal peritoneum?
Lines the body wall
What is the visceral peritoneum?
Lines the organs
What is teh connecting peritoneum?
Connects organs to body walls. Connects parietal and visceral peritoneum or between visceral peritoneum
What are examples of connecting peritoneum?
Mesentery
Ligaments
Omentum
Folds
Where is the root of mesentery in the dog?
L2
Where is the greater omentum and where is the lesser omentum?
Greater omentum to greater curvature of stomach
Lesser omentum to lesser curvature of stomach
What is the omental bursa?
Space between superficial and deep leaves of omentum
What is the lesser omentum between the stomach and liver called?
Hepatogastric ligament
What is the lesser omentum between the liver and the duodenum?
Hepatoduodenal
What is the small hole between stomach and liver in the lesser omentum? And where does it lie compared to the median plane?
Epiploic foramen right of median plane
What are the boundaries of the epiploic foramen?
Dorsally: Caudal vena cava
Ventrally: Portal vein
Cranially: Caudate lobe of liver
Which side of the body is the epiploic foramen on?
THE RIGHT!
Which side of the body is the spleen on?
Left
What does the spleen do in the fetus?
Produces red blood cells
What does the spleen do in the adult?
Stores red blood cells, stores iron, destroys worn out red blood cells, and produces lymphocytes
What is the ligament that connects spleen and stomach?
Gastrosplenic ligament
What are the 6 lobes of the dog liver?
Left lateral lobe
Left medial lobe
Quadrate lobe
Right medial lobe
Right lateral lobe
Caudate lobe
In the dog, where is the gallbladder located between?
The right medial lobe and the quadrate lobe
What are the two processes on the caudate lobe of the dog liver?
The caudate process and the papillary process
What are the 8 ligaments of the liver?
Falciform ligament
Round ligament of the liver
Right triangular ligament
Left triangular ligament
Coronary ligament
Hepatorenal ligament
Hepatogastric ligament
Hepatoduodenal ligament
What are the ducts that flow bile from liver to gall bladder?
Hepatic duct
What are ducts that flow bile from gallbladder to and from the liver?
Cystic duct
What are ducts that flow bile from cystic duct to major papilla?
Common bile duct
What is the sphincter that controls the flow of bile?What chemical signals for relaxation?
Sphincter of Oddi
CCK
What opens at the minor duodenal papilla?
Accessory pancreatic duct
What are the 3(ish) paired visceral veins in the abdomen
Renal, adrenal, and either testicular or ovarian
What are the paired parietal veins in the abdomen
Caudal phrenic, cranial abdominal, lumbar, deep circumflex iliac
What lobe of the liver does the caudal vena cava run in the dog?
Caudate lobe
Where does the caudal vena cava run through in the dog?
Caval foramen
Where does the left testicular/ovarian vein drain into?
Left renal vein
Where does the portal vein form in teh dog?
At the root of the mesentery (L2)
Does the portal vein contain valves?
Yes
Where is the epiploic foramen?
On the right side
What are the boundaries of the epiploic foramen in the dog?
Dorsally: Caudal vena cava
Ventrally: Portal vein
Cranially: Caudate lobe of live
What 4 veins does the portal vein receive blood from?
Splenic vein
Gastroduodenal vein
Cranial mesenteric veins
Caudal mesenteric vein
Where do hepatic veins receive blood from and empty into?
The liver and drain into the caudal vena cava
Where is the thoracic duct located in relation to azygos and caudal vena cava?
Thoracic duct
What is the cisterna chyli?
Dilated structure that receives lymph drainage
***What are the parietal lymph node groups?
Lumbar lymph nodes
Aortic lymph nodes
Renal lymph nodes
Medial iliac lymph nodes
What are te visceral lymph nodes?
Celiac
Cranial mesenteric
Caudal mesenteric
What are the folds of the stomach wall called?
Rugae
What does the cardiac part of stomach mostly produce?
Mucous
What does the fundus of the stomach mostly produce?
Gastric juice
What does the body of the stomach mostly produce?
Gastric juice
What does the pyloric part of the stomach mostly produce?
Mucus
What are the two parts to the pylorus?
First: Pyloric antrum
Second: Pyloric canal -> pyloric sphincter
Where is the cardia (fixed part of stomach) located in the dog?
Left 9th intercostal space
What is the most fixed part of the small intestine?
Duodenum
Where is the caudal duodenal flexure located?
L6 vertebra
What is the artery that lies opposite of mesentary on ileum
Antimesenteric ileal artery
What is the connection between the ileum and the cecum called
Ileocecal fold
What is the purpose of the appendix?
Serves as a safe haven for good bacteria to be recruited from when needed
What suspends the colon?
Mesocolon
Where are the anal sacs located between?
Internal and external anal sphincters
What is the sympathetic innervation from the foregut and midgut?
Celiacomesenteric ganglion
What is the sympathetic innervation from the hindgut?
Caudal mesenteric ganglion via hypogastric
What is the parasympathetic innervation of the foregut and midgut
Vagus n
What is the parasympathetic innervation of the hindgut
pelvic n
What is the neurotransmitter for rest and digest (parasympathetic)
acetylcholine
What is a general term for a network of lymphatics, nerves, or veins, both in the sympathetic and parasympathetic?
Plexus
What is a general term for a group of cell bodies located outside the central nervous system, only in the sympathetic system?
Ganglion
What are the sympathetic nerves that run between the sympathetic trunk and autonomic ganglion?
Splanchnic nerves
What are the 3 splanchnic nerves?
Major splanchnic
Minor splanchnic
Lumbar splanchnic
Where does major splanchnic nerve go?
Adrenal and celicomesenteric ganglion and plexus
Where does minor splanchnic nerve go?
Adrenal and celiacomesenteric ganglia and plexus
Where does lumbar splanchnic nerve go?
Cranial mesenteric and caudal mesenteric ganglia nad plexus
What controls the sympathetic innervation of the pelvic organs?
Pelvic organs
What does the ventral and dorsal vagal trunk innervate respectively?
Ventral: Parietal
Dorsal: Visceral
What does retroperitoneum mean?
Behind abdominal cavity
Where does the descending aorta terminate?
At L7
How is the aorta situated relative to the caudal vena cava?
To the left
What artery supplies the foregut?
Celiac artery
What artery supplies the midgut?
Cranial mesenteric
What artery supplies the hindgut?
Caudal mesenteric
What are the 3 branches of the hepatic artery?
Hepatic branch
Right gastric branch
Gastroduodenal branch
What are the 2 branchs of the gastroduodenal branch fo teh hepatic artery?
Right gastroepiploic
Cranial pancreaticoduodenal
What are the 2 branches of the splenic artery in the dog?
Left gastroepiploic
Short gastric branches
What artery supplies the pancreas with blood?
Caudal pancreaticoduodenal
What are the two arteries of the ventral abdominal wall?
Cranial epigastric
Caudal epigastric
What two arteries supply the dorsal abdominal wall?
Cranial abdominal
Deep circumflex iliac
What is the primary purpose of the large intestine in horses?
Microbial fermentation and absorption
What are the 4 cell types of the intestinal mucosa?
Paneth cells
Goblet cells
Enterocytes
M cells
What are the 3 layers of the mucosa?
Epithelium
Laminae Propria
Musclaris mucosa
Where are pits located?
Stomach
Where are villi and crypts located?
Intestine
What are the histological characteristics of the colon?
NO VILLI, JUST CRYPTS
Increased goblet cells
frequent peyer’s patches
Are the cecum, colon, and rectum distinguishable
Nope
What are the 4 possible places for GALT to be seen?
Tonsils
Colon / cecum
Major papilla of duodenum
Ileum
What are the 5 functions of the liver?
Bile production
Production and breakdown of lipids, protein, and carbs
Storage of carbs and lipids
Xenobiotic metabolism and biotransformation
Immune function (blood filtration)
How are livers microscopically organized?
Lobule
What type of endothelium does the liver have?
Fenestrated endothelium with incomplete basal lamina
what are the blood vessels through the liver called?
Sinusoids
What are the cells in the liver that we should know?
Stellate
Kupffer
Hepatocyte
Endothelial
What do stellate cells do?
Store fat, vitamin A, contribute to fibrosis and regeneration
What do Kupffer cells do?
Resident liver macrophages
What do stellate cells look like histologically?
Look like adipose cells a little
What do Kupffer cells look like histologically?
Like stellate but with basophilicish pigment
What are the 4 things within the portal triad?
Artery, bile duct, portal vein, lymphatics
Where do the portal veins and hepatic arteries drain in the sinusoids?
Toward the central vein of the lobule
Which way does the bile flow in the liver?
Opposite direction of blood, toward bile duct
What is the most deoxygenated zone of the liver?
3 least oxygenated and 1 is most
What is the acinus of rappaport
Ovals radiating from adjacent portal triads and bordered by central veins
What is zone 1 of acinus of rappaport called?
Portal
What is zone 2 of acinus of rappaport called?
Midzonal
What is zone 3 of acinus of rappaport called?
Centrilobular
Which acinus of rappaport is most susceptible to hypoxia
Centrilobular
Which acinus of rappaport is most susceptible to injury from toxins?
Portal
What are the lining cells of the liver?
Endothelium and biliary epithelium
Whats another name for the stellate cells?
Ito cells
What cell makes bile?
Hepatocytes
What are islets of langerhans?
Islands of endocrine producing cells of the pancreas
What color are acinir cells of the pancreas?
Pink zymogen granules
What does the exocrine pancreas produce?
Proenzyme for digestion
Active enzymes
Factors for cobalamine (B12) absorption
Zinc homeostasis
What is something you should consider when presented with a low muscle dog?
GI issues
What is nutrient assimilation
Breakdown of larger molecules into basic units (polysaccharides into monosacchrides)
What is the frist enzyme that begins to breakdown protein?
Pepsin
What are the 4 purposes of the GI?
Digestion
Secretion
Absorption
Motility
What animals dont have salivary amylase?
Cattle, dogs, and cats
Is UES skeletal or smooth muscle?
Skeletal muscle
What esophagus composition are cow and dog (maybe pig)
All skeletal muscle
What esophagus composition are humans, cats, and horses?
Skeletal>smooth/skeletal>smooth
What is goal of LES?
To reduce acid reflux
Is the LES physiological or anatomic?
Physiological, not really a muscle in itself but many things contribute to it
What stomach cells produce gastrin?
G-cells
What stomach cells produce somatostatin
D cells
What are the most common cells in the crypts of the GI?
Stem cells
What are the 4 functions of small intestines?
Digestions
Nutrient absorption
Extract water
motility
what are the 3 biggest locations that digestive enzymes come from in teh small instestine?
Bile (liver/gall bladder), villi themselves, and pancreas
What are the 3 largest areas from which digestive enzymes come from in the small intestine?
Pancreas, liver (bile), and the villi themselves
Where are bile salts and B12 reabsorbed?
Ileum
What are the 3 functions of teh colon?
Recovery of water and electrolytes
Storage of feces
Microbial fermentation
What is teh largest endocrine organ in the body?`
GI tract
What is the target of gastrin?
Parietal cells to increase gastric acid secretion
What is a trigger for gastrin secretion?
high pH, gastric distension, and increased vagal stimulation
What is the negative feedback for G-cells?
D-cells secrete somatostatin when pH is too low (negative feedback)
***What nerve plexus is responsible for moving stuff along intestine?
Myenteric plexus
***What nerve plexus is responsible for intestinal secretion?
Submucosal plexus
Are splanchnic nerves sympathetic or parasympathetic?
Sympathetic
What is a neurotransmitter that will promote GI function?
Acetylcholine
What is dysphagia?
Difficulty chewing and swallowing
What are stimuli for salivation?
Resting
Food in mouth
Irritating substance
Thought
Is salivation parasympathetic or sympathetic?
parasympathetic
What is in mucus?
Bicarbonate
What activates pepsinogen?
HCl
What are 3 epithelial defenses for gastric mucosa from acid?
Tight junctions
Ion pumps (remove H+)
Epithelial restitution
What are the 3 chemical triggers to acid secretion?
Gastrin
Histamine
Acetylcholine
What are the 3 steps to gastric acid secretion?
cephalic phase: Vagus tone from scent, sight, etc.
Gastric phase: Stretch receptors and chemoreceptors
Intestinal phase: Food in duodenum turns off acid secretion
What are the 3 phases of swallowing?
Oropharyngeal phase
Esophageal phase
Gastroesophageal phase
What is the most, middle, and least likely foods to stimulate swallowing?
Most: Food
Middle: Liquid
Lowest: Oil
What is primary vs secondary peristalsis
Primary: First wave with ingesta
Secondary: Cleanup wave
What is the movement in the intestine during a fasted state?
Migrating Motor Complex (erythromycin does not work in cats!!!)
What is the difference between peristaliss and segmentations?
Peristalsis is the controlled ovement of bolus through the GI while segmentation is the breakdown and mechanical digestion of foods while moving down the GI
What is the reflex that causes you to have to poop after eating a meal?
Gastrocolic reflex
What are the 3 phases to vomiting
1) Closed glottis increases pressure
2) Diaphragm tenses and involuntary contractions
3) More pressure in stomach and proximal duodenum
What are the 4 inputs for vomiting?
Abdominal viscera
Chemoreceptor trigger zone
Vestibular apparatus
Cerebral cortex
What are the receptors for vestibular apparatus in dogs?
M1
What are the receptors for abdominal viscera in dogs?
NK1 and 5-HT3
What are the receptors for chemoreceptor trigger zone in dogs?
D2, alpha2, NK1, H1, 5-HT3
Where does vestibular apparatus go through in dogs?
Goes through chemoreceptor trigger zone
What are the receptors in the vomiting center of the dog brain?
alpha2 and NK1
What are the main differences in the cat vomiting receptors than dog?
Cats dont have a D2 or H1 trigger in their chemoreceptor trigger zone
What causes metabolic alkalosis?
Gastric vomiting because acid leaves body leaving a lot of base
What causes metabolic acidosis?
Duodenal vomiting because a lot of base leaves the body leaving acid in the system
Where is folate found and what would cause low folate?
Proximal small intestine “folate first” and a disease blocking access to small intestine or a proximal disease
Where is B12 (cobalamin) absorbed?
Ileum
Does motaline work in cats?
NO!
Why do certain microbiota cause some people to be obese?
The microbiota have unique transporters that allow more carbs to be digested
Where in the GI are the most bacteria found?
Colon (anaerobic bacteria)
What is dysbiosis?
Disruption in a community
What are the unique organs of bird GI?
Crop
Proventriculus (true stomach)
Ventriculus (gizzard)
Cloaca
Vent
What are the microbes in the rumen (fermentation vat) that break down the complex carbs?
Protozoa
Bacteria
Fungi
What are normal rumination times of a cow?
2-3/2 min
What are some ways to determine rumen function?
of ruminations
New methylene blue reduction test
Chloride
PH
Smell
Visualization of Protozoa
Where is reticulum located anatomically?
Cranioventrally (across diaphragm from heart)
What is the function of the omasum?
Absorbs water, electrolytes, and VFAs
What is the largest compartment in the calf?
Abomasum
Where does the dorsal and vagal trunks go to in the bovine stomach
Dorsal: Rumen
Ventral trunk: Reticulum, omasum, abomasum
What stimulates the closer of the esophageal groove (gastric groove?)
Suckling
What are the 5 functions of the liver?
Storage of blood
Metabolism of fats, carbs, proteins, hormones, and foreign chemicals
Formation and excretion of bile
Storage of vitamins and iron
Formation of coagulation factors
What are the 2 interhepatic parts of the biliary tract?
Interlobular ducts
Bile canaliculi
How many openings does the cat have in its duodenum?
Just one with common bile duct and pancreatic duct together!`
What is the space of Disse
Fenestrated endothelium of the endothelium allowing for mixing of blood with cells
What are the cells in the liver responsible for cleaning the blood?
Kupffer cells
What cells of the liver are responsible for the metabolic function?
Hepatocytes
What are the 3 functions of bile?
Emulsification of fat
Aid in absorption of digested fats
Secretion of substances through biliary tract (like bilirubin)
What percent of bile acids are reabsorbed and where are they reabsorbed?
95% in the ileum
What is a bile marker of a sick liver?
Sick hepatocytes will have a decreased ability to extract bile acids from portal blood.
Assay of systemic levels of bile acid is used clinically as a sensitive indicator of hepatic disease
What is the hormone that causes an increase in bile secretion?
Secretin
What causes the yellowing of skin during liver disease?
Inability to remove bilirubin from blood (jaundice or icterus)
What is bilirubin?
A useless and toxic breakdown of hemoglobin
What is conserved during RBC digestion?
Iron
What are the steps to eliminating heme?
1) Heme is converted into free bilirubin inside phagocytes cell
2) Free bilirubin is stripped off albumin and absorbed by hepatocytes
3) Conjugated bilirubin is secreted into the bile canaliculus as part of bile and this delivered to the small intestine
What does high bilirubin indicate?
Liver dysfunction
Where does portal blood flow from?
Intestines
Pancreas
Spleen
Stomach
What are 2 mechanisms in liver disease?
Decreased synthesis of clotting factors
Vitamin K deficiency
What are fat soluble vitamins?
A, D, E, K
What are water soluble vitamins?
B
What are the 2 phases to liver metabolism?
Primary oxidation (convert active > active, inactive> active, bio activate > toxic compound)
Primary Conjugation
What are targets of hepatoencephalopathy?
Astrocytes
What is the acronym for complications with liver disease?
CANINE
What are markers of increased hepatic activity (hepatic necrosis)
ALT (high in injury), AST (not liver specific and short half-life), SDH
What are markers of cholestasis?
ALP, GGT
What are the 2 primary liver function tests?
Serum bile acids
Blood ammonia levels
What is the primary indicator for portosystemic shunt?
Blood Ammonia
What does the pancreas secrete?
Bicarbonate
Digestive enzymes
What are 3 functions of the pancreas?
Secretion (bicarbonate, digestive enzymes)
Intrinsic factors for B12 absorption (in ileum)
Trypsin inhibitor (to not auto digest)
How are pancreatic cells not autodigested?
Digestive enzymes are secreted in inactive form
Duodenal wall secretes enterokinase to activate inactive enzymes
What inhibits insulin secretion?
Amylin
What inhibits both insulin and glucagon?
Somatostatin
What is first phase of insulin secretion
3-5 minutes after increase of blood glucose, beta cells secrete first wave of insulin
Wha this phase 2 of insulin secretion
If high blood glucose is maintained, more insulin is produced and a sustained level of blood glucose occurs at about 2-3 hours
What 2 hormones are needed for growth?
Insulin and growth hormone
What duct goes to the gallbladder?
Cystic duct
What is the chemical that causes the contraction of the gallbladder?
CCK
What are the biochemical markers in the liver that allude to disease caused from hepatocellular origins
ALT, AST, LDH, SDA, Argininase
What are enzymes responsible for cholestasis?
ALP and GGT
Are ALP and ALT markers of liver functions?
NO!
Is elevated ALP in cats or dogs more concerning?
Cats!
Does the cat have an accessory pancreatic duct?
NO
What do the duct cells do for the pancreas
Secrete bicarbonate, water, cations, and anions
What is the pancreas’ role in absorbing B12 (cobalamin)
Release of intrinsic factors for B12 to be absorbed in the ileum
What is the gallbladder lined with?
Simple columnar
Where is the gall bladder located?
Between quadrate and right medial lobe
Are bands found on the rumen digestive system?
NOPE!
Can hypomotility be treated with drugs in cats? Dogs?
Cats: yes
Dogs: no
What is the most common emetic used in dogs?
Apomorphine
What is the most common emetic in cats?
Xylazine
