Week 1 Flashcards
(177 cards)
1
Q
What are the boundries of the anterior abdominal wall?
A
- Superior-right and left
- 7-10th ribs and xiphoid process
- inferior
- Inguil ligament and superior margins of pelvic girdle
- lateral
- lateral abdominal wall
2
Q
What are the layers of the anterior abdominal wall?
A
- Skin
- Superficial fascia
- Campers
- Scarpa’s
- Muscle with investing fascia
- external oblique
- internal oblique
- transversus abdominis
- rectus abdominis
- transversalis fascia
- parietal peritoneum
3
Q
When the external oblique contracts how does the body move?
A
- rotates truck to opposite side
- raises intra-abdominal pressure
4
Q
What is the innervation of external oblique?
A
- T7-T11
5
Q
When the internal oblique contracts, how does the body move?
A
- contraction rotates truck to same side
- compresses abdominal viscera
- supports back muscles
6
Q
When the transversus abdominis contracts, what happens to the body?
A
- compresses abdominal viscera
- supports intrinsic back muscles
7
Q
Innervation of Internal Oblique
A
- T6-T11 and L1
8
Q
Innervation of transversus abdominis?
A
- T6-T11 and L1
9
Q
What happens to the body when the rectus abdominis contracts?
A
- flexes the trunk against resistance
- compresses abdominal viscera
- stabilizes tilt of pelvis
10
Q
What are the contributions of the rectus sheath?
A
- Divided by the Arcuate line
- above the line: trasversus abdominis and internal oblique because the rest are under the rectus abdominius
- Below line: all of the aponeurotic fibers of the external, internal and transversus
11
Q
What is the blood supply to the abdominal wall?
A
- T10 and T11
- musculophrenic (arises from internal thoracic)
- Subcosta
- first lumbar
- superior epigastric (internal thoracic)
- deep inferior epigastric (external iliac)
12
Q
What nerve supplies the major labia in females and anterior wall of scrotum in males?
A
- Iliohypogastric nerve
- Iolioinguinal nerve
13
Q
Where is there an anastomomic connection in the anterior abdominal wall?
A
- between the superior epigastric artery and the inferior epigastric artery
- allows for collateral blood flow
14
Q
What sits in the inguinal canal?
A
- Males - spermatic cord
- Females - round ligament of the uterus
15
Q
What makes up the internal lining of the inguinal canal?
A
- trasversalis fascia
16
Q
What makes up the inguinal canal?
A
- Anterior wall: external oblique aponeurosis, lateral side is reinforced by internal oblique
- Posterior wall: trasnversalis fascia, medial side reinforced by interal oblique and transversus abdominis
- Roof: laterally-transversalis fascia, centerally-musculoaponeurotic, arches-internal oblique and transversus abdominis, medially-external oblique
- Floor: laterally-iliopubic tract, centrally by infloded inguinal ligament and medially by lucanar ligmanet
17
Q
What is the name of the layer of the peritoneam that is dragged by the testes?
A
processus vaginalis
when it closes it becomes the tunica vaginalis
18
Q
What folds make up the internal wall?
A
- lateral umbilical fold (2) - lateral umbilical fold formed by deep inferior epigastric vessels and cover them
- median umbilical fold - apex of bladder to umbilicus and covers median umbilical ligament
- medical umbilical fold (2) - cover medial umbilical ligaments formed by occluded parts of umbilical arteries
19
Q
What are the borders of the inguinal triangle?
A
- Medial - rectus abdominis
- Lateral - deep inferior epigastric
- Inferior - inguinal ligament
20
Q
What is the weak point in the inguinal triangle?
A
- Conjoint tendon
- made up of the transversus muscle and internal oblique
- if the two muscles make a high arch
21
Q
What is a direct hernia?
A
- passes through the Hesselbach’s triangle
- protursion medial portion of inguinal canal, medial to inferior epigastric artery
- mesh repair
22
Q
What is an indirect hernia?
A
- Through lateral portion of inguinal canal
- Usually through patent processus vaginalis and follows descent of testis
- hernia sac will be surrounded by same layers as testis
- mesh repair
23
Q
What is a femoral hernia?
A
- follows femoral vein but inferior to inguinal ligament
- lateral to lacunar ligament
- 3% of hernias, more common in older women
24
Q
What are the borders of the femoral canal?
A
- Superior - Inguinal ligament
- Medial - lucunar ligament
- Inferior - pectineal ligament
25
What is a mesentary?
pathways for vessels and nerves to reach abdominal organs but not remain where they are not needed
26
What arises from endoderm for the GI tract?
Mucosa and glands
27
What arises from splanchnic mesoderm of lateral plate?
Surrounding CT and SM
28
Where is dorsal mesentary found?
found throughout most of the entire abdominal gut tube
29
Where is the ventral mesentery?
Remains to support the developing liver and gall bladder but it disappears further down the GI tract
30
What is primarily retroperitoneal?
* Structures that never have a mesentery
* rectum
* thoracic esophagus
31
What is secondarily retroperitional?
* Structures that loose their mesentery
* pancreas
* ascending and descending colon
* duodenum
32
How is stomach formed?
* 90º rotation with anterior surface turning to right
* two landmarks develop
* greater curvature
* lesser curvature
33
What is the greater omentum?
* four-layered connecting the greater curvature of stomach and the duodenum to connect to the anterior surface of transverse colon and its mesentery
34
Where is the lesser omentum?
* very small
* connects the lesser curvature and proximal part of duodenum to liver
35
How is the midgut formed?
* midgut starts to rapidly grow and enter yolk stalk
* midgut rotation is 270º counterclockwise as it continues to grow
* midgut will then we enter the abdomen
* cecum will be in be lower right quadrant
36
What is a volvulus?
Any form of rotation of the gut tuve
* can be dangerous because it can block blood flow
37
What is gastroschisis?
* lateral walls of abdomen dont fully close so expanding GI tract goes through hole
* 1:10k births
* lateral to connecting stalk but not covered by amnion so it can be damaged by amiontic fluid
* not associated with chromosomal defect
38
What is omphalocele?
* herniation of abdominal viscera through enlarged umbilical ring
* failure of intestine to return to body but is covered of epithelium so it is protected against
* associated with high rate of infant mortality and severe defects
39
What is mechel's or ileal diverticulum?
* most common GI developemntal abnormaility
* 2-4% of population but most are asymptomatic
* results in a small portion of vitelline duct persists
* Avestigial remant of yolk salk
40
How is the hindgut developed?
* partitioning of cloaca by the urorectal septum that seperates urinary system from hindgut
* formation of anal canal
* pectinate line seperates from hindgut from proctode
* above line-endoderm
* below line-ectoderm
41
What is Hirschsprung diesease or aganglionic megacolon?
* failure of migration of neural crest cells into the developing gut tube
* usually affects rectum and sigmoid colon and results in section of gut tube that lack ganglia and unalbe to contract
42
What are the different types of surgical incisions?
* Midline
* through linea alba
* strogest area to close
* minimal nerve injury
* Transverse incision
* goes through external and internal obliques, transversus and possibly rectus
* minimize nerve injury
* weaker incision that can lead to hernias
* Laproscopic surgery
* minimalist approach
* small incisions so less chance for hernias
43
Should inguinal hernias be fixed?
* most common 3/4th of cases
* children-yes because they will get worse
* adults-can wait if asymptomatic but most will have surgery
* two types
* direct
* indirect
44
Do umbilical hernias need to be fixed?
* babies-most will close by age 2 if not or becomes symptomatic it must be repaired
* adults need to be repaired
* 6% of hernias
45
What cells line the gingiva and hard palate?
* Keratinized stratified squamous
* Parakeratinized (wet) stratified squamous
46
What cells the mucoas everywhere else except the tongue?
* Stratified squamous
* parakeratinized stratified squamous
47
What are the cells are on the tongue?
* Papillae
* taste buds on dorsal surface
48
What cells cover areas exposed to severe abrasion?
keratinized cells
49
What seperates the two sides of the lip?
orbicularis onis muscle
50
What gives the lips the red color?
* the Vermillion line (parakeratinized) lines the lip
* red color because of superficial capillary plexus reaches surface
51
What is an angular defect?
a right angle forms when a damaged lip and fixed with sutures. Instead should be superglued and butterfly bandages to get it smooth
52
Explain enamel?
* produced by ameloblasts
* only a set amount made in a lifetime
* hardest substance in body
* ectoderm
53
Explain Dentin
* sits underneath enamel
* creates dentin tubules that lead from the outer border of dentin with innervation from the pulp chamber
54
Name the regions of the tooth
* Crown
* Neck - at gingival line
* Root
55
Where is the tooth situated in?
* alveolar bone
* very trabeculated
* periodontal ligment attaches tooth to bone
* cementum - cementoblasts
56
What are the four types of lingual papillae?
* Filiform papillae
* Fungiform papillae
* Foliate papillae
* Circumvallate
57
What do filiform papillae do?
* lack taste buds
* increase friction between the tongue and food
58
What do Funigorm papillae do?
* occur on the margin on tongue. look at like mushrooms
* on the sides of the tongue
59
What are foliate papillae?
* not abundant
* mainly found in babies
60
What seperates the anterior and posterior portions of the tongue?
* Circumvallate are arranged in a v shape
* each is surrounded by large crypts to allow foods to bathe the papillae
61
what are lingual frenulum?
* the ligament that connects the tongue to the floor
* either either has deep lingual veins
* great site for drug delivery
62
What are the three types of taste bud cells?
* Neuroepithelial sensory
* Supporting cells
* Basal cells
63
What are the 5 types of tastes?
* Bitter
* Salty
* Sweet
* umami
* sour
64
What are the regions of the palate?
* hard palate anterior 2/3
* bone
* keratinized stratified squamous
* Soft palate posterior 1/3
* contracts during swallowing
65
What are the cell types of the salivary gland?
* Serous and mucous cells
* Myoepithelial cells
* myosin/actin
* Plasma cells/IgA
66
Properties of parotid salviary glands
* largest and empthing ducts open at second molar
* serous secretion
* 30% of saliva
* gets infected during mumps
67
What are the properties of submandibular?
* mixed gland
* primarily serous
* 60% of salvia
68
Describe sublingual
* mixed gland
* primarily mucous
* 10% of saliva
69
What controls salivary compostion and osmolarity?
Duct epithelium
70
What controls the volume of saliva?
* parasympathetic increase
* sympathetic decrease
71
What is GULT?
* Gut associated lymphoid tissue
* diffuse lymphatic tissue
* lympathtic nodules (submucosa/lamina propia)
* Tonisils
72
What is Waldeyer's Ring?
* Tonsillar ring - encircles the entrance of GI and respiratory tracts
* palatine
* tubual
* pharyngeal
* lingual
73
Where are submucosal glands located?
esophagus and duodenum
74
Where are Meissner's plexus?
also called the submucosal plexus in the bottom of the submucosa
75
Where is Auerbachs plexus located?
* also called the myenteric plexus
* located between the circular and longitudinal layer
76
What are the three muscularis externa regions in the esophagus?
* Upper: striated (skeletal)
* Middle: mix of striated andSM
* Lower: SM
77
What is the final layer of the esophagus?
* Adentitia - above diaphragm
* Serosa - below diaphragm
78
What is teh gastroesophageal sphincter?
* Physioligcal - lower portion
* Anatomical - proximal portion
79
What is contained in the epithelium of the stomach?
* Mucosa lining cells (very important for maintaing stomach integrety) line the gastric pit
80
What is contained in the lamina propria layer of stomach?
* SM, CT, gastric glands and lymphatic nodules
* covers entire pit and covers stretched out
81
What makes of the muscularis mucosae/muscularis externa?
* inner incomplete oblique muscle
* Middle circular muscle
* outer longtiduinal
82
What is rugae?
* longitudinal fold of gastric mucosa and submucosa
* folds allow the stomach to distend
83
Why is bicarbonate important in the stomach?
* trapped in thick viscous mucous make by mucous lining cells
* also made by parietal cell and enter fenestrated capillary in lamina propria
* increases pH to protect stomch epithelium
84
What are the regions of the stomach?
* Cardiac-cardiac glands
* short glands, longer pits
* Fundus and body- gastric glands
* working region of stomach
* short pits, long glands
* Pyloric region - pyloric glands
* really long pits, short glands and produces mucous
85
Cells of the body/fundus region
* Mucus Neck Cells
* Stem or regenerative cells
* Parietal cells
* Chief Cells
* Enteroendocrine cells
86
Describe Parietal Cells
* Secrete HCL and gastric intrinsic factor (GIF)
* pushes HCl out of intracellular canaliculi
* Tubulovesicular system-extra plasma membrane
* reservior for porton pumps
* Abudant mito
87
What does Gastric intrisic factor (GIF) do?
* binds to vit B12
* absorbtion in ileum
* important for RBC production
* lack of GIF causes pernious anemia
88
Describe Chief Cells?
* secretes pepsinogen and precursors to renin and lipase
* contained in zymogen granules
* Lots of ER
89
Describe Enteroendocrine
* Special stain to see them
* produce endocrine and paracine secretion
* full of secretory vesicles
90
How often is the surface mucous and mucous neck cells?
* Replaced every 3-6 days
91
How often are the cells of the gastric gland replaced?
* parital cells 150-200 days
* Chief and enteroendrocine cells 60-90 days
92
What are the segments of the esophagus?
* Segment 1- cervical UES
* Segment 2 - upper thoracic includes tracheal bifurcation
* Segment 3 - mid thoracic
* Segment 4 - Distal LES
93
What muscle makes up the upper esophageal sphincter?
* Cricopharyngeal muscle
94
What are the regions of the pharynx?
* Nasopharynx
* Oropharynx
* Laryngopharynx
95
What are the sequence of events for swallowing?
1. Elevation of tongue
2. Closeure of nasopharynx
3. UES relaxes
4. Closeure and protection of airway
5. pharyngeal peristalsis
96
Where is the swallowing center located
Located in the medulla
97
What is achlasia?
* also known as a bird's beak
* condition with aperistaltic contractions, increased intraesophageal and failure of LES to relax
98
Symtoms of achalasia
* Dysphagia (difficulty swallowing)
* regurgitation
* chest pain
* forceful choking
* coughing
* heartburn
* weightloss
99
Treatment of achalasia
* **Onabotulinumtoxin A** (botox, Allergan) - injections into LES, temporary but works less overtime
* **Sublingual Nifedipine** (Ca2+ channel blocker) improves outcomes in 75% of patients
* **Endoscopic Balloon Dilation** successful in 85% of patients but requires multiple interventions
* **Laparoscopic myotomy**
* **Peroral Endoscopic myotomy (POEM)** - removal of SM cells of LES
100
What is GERD?
* movement of stomach acid into esophagus that can cause problems with the lining of the stomach
101
What are the symptoms of GERD?
* heartburn
* chest pain
* sore throat
* hoarseness
* regurgitation of foods/liquids
* foods or meds can worsen GERD symptoms
102
What is the treatment of GERD?
* Intermittent/mild - LSM and non-presecription strength therpay
* Symtomatic - LSM and prescription H2RA or PPI
* Moderate/severe - LSM and prescription strenth PPI or H2RA
103
What is Barretts Esophagus?
* 5-10% of GERD patients develop Barretts
* Metaplasia of esophagus
* can lead to esophagogastric adenocarcinoma
104
How do you treat Berretts Esophagus?
* Modified PPI
* Aspirin and other NSAIDs are thought to prevent esophageal cancer
105
What is Gastroparesis?
* Delayed gastric emptying
106
What are the symptoms of gastroparesis?
* Vomiting
* postprandial nausea
* epigastric fullness after eating just a few bites
* abdominal bloating
* heartburn
* changes in blood sugar levels
* lack of appetite, weight loss malnutrituion
107
What is pyloric stenosis and what are the symptoms?
* Pyloric sphincter cant relax and unable to digest foods
Symptoms
* presents in the first weeks of life in infants
* patinet usually becomes hypokalemic, hypochloremic to cause metabolic alkalosis
* episodes of projectile, nonbilious vomiting
108
What is intestinal/colonic pseudo obstruction and what are the symptoms?
* intestinal walls are hypomotile, resembles a true obstruction but no blockage is present
* caused by problems with SM, enteric nerves or ICC
Symptoms
* abdominal pain
* vomiting
* diarrhea
* weightloss, malnutirtion
* enlargement of various parts of small intestine or bowl
109
Why do gallstones form?
* too much absorption of water from bile
* too much cholesterol
* too much absortion of bile acids from bile
110
What are gallstone symptoms?
* Stones cause sudden pain in the upper right abdomen because the block the biliary duct
111
What are the two types of gallstones?
* cholesterol stones - usually green-yellow color
* pigmetn stones - dark color made of bilirubin
112
How do you treat gallstones?
* Laparscopic cholecystectomy - but only for symptomatic gallstones
113
What is diverticular disease?
* Outpocketings of the mucosa of the (sigmoid) colon because of muscle weakness
* pressure created by trying to move stool causes weak spots and colon bulges
* low-fiber diet is the main cause
* complications can lead to death
114
What is irritable bowl syndrome?
* patient has chronic abdominal pain, discomfort, bloating
* spasms occur only after mild colonic stimulation tend to have more sensitive colons
* leads to constipation
* can get it after GI infection but cause unknown
* chocolate, milk, alcohol can make it worse
115
What is Inflammatory Bowel Disease
* Crohn's disease or ulcerative colitis
* cause unknown
* person suffers from persistent abdominal pain, bowel sores, diarrhea, fever, intestinal bleeding or weight loss
116
What is rectal prolapse?
* Rectum turns itself inside out
* straining, aging, and weakening of ligaments that support rectum can cause rectal prolapse
* may be hidden or internal
117
What is peptic ulcer disease
* chronic inflammation of stomach and duodenum
* duodenal ulcers more common than stomach ulcers
* caused by increased stomach acid
* Symptoms
* upper abdominal pain, usually an hour or two after meal
* nausea
118
What is scleroderma and its two types?
* chronic autoimmune diesase that has thickening of skin from increased deposits of collagen
* localized
* affects skin and musculoskeletal system
* systemic
* widespread skin changes and internal organ damde
* cause cause arthritis, slow contractions of GI, muscle inflmmation
119
What is sjogren's syndrome?
* autoimmune disease that has immune cells attack and destroy glands that produce teas and salivia
* associated with rheumatoid arthritis
* Symptoms
* dry mouth and eyes
* may cause skin, nose and vaginal dryness and affect many other organs
120
How is primary peristalsis initiated?
* trigged by swallowing
* takes 5-10s
* wave is intiated through the coordination of contraction (ACh) and relaxation (NO)
* latency controlled by NO
121
How is secondary peristalsis initiated?
* activation of stretch receptors
* distention activates intrinsic sensory neurons in myenteric plexus which then turns on both ascending excitatory and descending inhibitory
* swallow is not present
122
What is contained in the nucelus ambiguous?
* motor neurons to muscles of pharynx and striated muscles of esophagus
* vagal nerves onto skeletal muscle release ACh to contract
* swallow induced peristalsis is due to activation of lower motor neurons
123
What is contained in the Dorsal Motor/vagal nucleus (DMN)?
* activates inhibitory and exitatory myenteric motor neurons to SM but not the actual muscle
* rDMN release ACh to cause contraction
* cDMN release NO to cause relaxatioin
124
What is contained in the nucleus solitaries?
* integrates sensory information
* cell bodies are located here
125
What causes oropharyngeal dysphagia?
* dysphagia is difficulty swallowing
* caused by
* failure of propulsion
* obstructions to flow
* combination of both
126
What is myasthenia gravis?
* Autoimmune disease that causes circulating antibodies to block ACh receptors at postsynaptic neuromuscular juntion
* ebrophonium allows more ACh into cleft but has lots of side effects
127
What is pollo?
* Enters environment through feces and spreads through fecal-oral route
* caues failure of propulsion
128
What is Dermatomyositis
* acquired muscle diesease called inflmmatory myopathies
* problems swallowing
* characterized by inflammation and a skin rash
* cause unknown but more common in women
129
What is polymyositis?
* Similar to dermatomyositis but without skin rash
* diffculty swallowing, muscle weakness, stiffness or soreness, SOB
* inhibits transmission of signal
130
What is Nutcraker esophagus?
* causes dysphagia to both solids and liquids and chest pain
* have stronger than normal contractions in the middle of the esophagus
131
What is a histal hernia?
* When part of the stomach pushes upward through the diaphragm
* many dont show symptoms but can have GERD
132
What is GI motility?
* Muscular distortion of GI tract that puts pressure on gut contents
* reduced intraluminal pressure = storage/accommodation
* increased force = flow/propulsion
* motor patterns can also cause mixing
133
What are layers of SM in the GI and what are there effects when they contract?
* Circular
* radial contriction and dilation
* Longitudinal
* Shortening and lengthening
134
What are the motor behaviors of the stomach
* Accommodation
* Antral
* peristalsis
135
Motor behaviors of the small intestine
* peristalsis
* mixing
* segmentation
136
Motor behaviors of the colon
* Haustration
* Propulsion
137
Describe the properties of SM
* have dense bodies where actin and myosin bind instead of Z lines
* slow rate of contraction but force is comparable to skeletal muscle
* can short to half of original length when contracted
138
How does smooth muscle contract
* increased cytosolic Ca2+ due to
* voltage dependent Ca2+ channels
* release of intracellular Ca2+ stores (IP3 gated)
* other channels
* membrane exchangers/pumps
139
How doe SM relax?
* Decreased cytosolic Ca2+
* K+ (depolarization)
* Ca2+ reuptake into stores
* membrane exchangers/pumps
* mito
140
Which arrangement of SM is the fastest?
* Cells arranged in parallel move faster
141
What is the ICC?
* major control network that can organize SM contraction
* gap junctions between ICC cells and SM at the myenteric plexus
* hyperpolorizes SM to suppress spontaneous SM firing
* causing a ring ling contraction
* coordinates stimultaneous activation of LM and CM
142
Describe the Abell scoring system
* Grade 1
* mild/intermittent symtoms that are controlled with LSM (diet mods/advoidance of aggetators)
* Grade 2
* moderate serve but not weight loss and require prokinetic drugs plus antimetic agents for control
* Grade 3
* unable to maintain oral nutrition and require frequent ER visits. Require intravenous fluids, meds, enteral or pareteral nutrition
143
How can gastropariesis be diagnosed?
* Upper GI endoscopy
* Ultrasound
* Scintigraphy-gastric emptying via radioisotope
* Smart pill
* Octanoic Acid breath test
144
How is gastroparesis treated?
* 6 small meals
* chew food well, avoid high fat, fibrous foods
* Prokinetic drugs
* metoclopramid-increase GI tone but relaxes pyloric sphincter
* Erythromycin - stimulates migrating motor complex an SM contraction
* non med treatments
* Gastric electrical stimulation
* paraentral nutrition
145
What are type 1 neurons
* Rought cell body with short lamellar dendrites, single long axon
* motor neurons and interneurons have this shape
146
What are type II neurons?
* large smooth cell bodies, multipolar (lots of axons)
* filamentous dendrites
* afferent (sensory neurons) and stimulate motor neurons
* 20-30% of all enteric neurons
147
How do enteric motor neurons connect to the SM?
* Innervate ICC-IM and PDFRa-IM (inhibitory) rather than SM directory
* ICC-IM can depolarize or hyperpolarize depending on the signal from enteric neurons
* voltage changes will spread to adjacent cells
148
What is the signal setup from mucosa to sensory (afferent) neurons?
* Sensory neurons are not directly stimulated by luminal content but instead other cells release substnaces into lamina propria and are detected by neurons
* Example
* EC cells release 5-HT upon mechanical distortion of villi which binds to intrinsic afferents and extrinsic sensory neurons
149
Describe myenteric interneurons
* Most diverse class of enteric neurons
* 4 descending subtypes
* 1 ascending subtype
* Activated by sensory (intrinsic afferent) neurons or are stretch sensitive themselves
* synapse onto motor neurons or themselves (increase speed of signal)
150
What is the innervation of the GI tract?
* Vagus innervation for most of the upper GI tract
* Pelvic nerve for the descending colon
* sympathetics innervate the entire tract but only really constricts blood vessels or ongoing excitatory motor relexes
151
How do you measure contractile behavirours in whole organs?
* manometry
* strain gauges
* fluid propulsion
* extracellular electrodes
* video immagin
* Ca2+ florescence
152
What is the migrating motor complexe cycle?
* its a burst of contractions that starts in the stomach and propagates through the intestine
* triggers peristaltic waves to move things down the tract
* broken into 3 phases
* feeding interrupts the MMC cycle
153
Name the regions of the stomach and their function
* proximal stomach: fundus and corpus
* reservior function
* secretion and relaxation
* Distal stomach: antrum
* grinding of solids
154
What are the three mechanisms that regulate gastric reservior function?
* Receptive relaxation
* swallowing induces this
* Adaptive relaxation
* local reflex via enteric inhibitory motor reflex
* Feedback relaxation
* based on nutrition reaching duodenum
155
How does the vagovagal relex work?
* afferent and efferent fibers of the vagus nerve coordinate gut stimuli via dorsal vagal complex
* when food enters the stomach a "vagovagal" reflex goes from stomach to brain then back to stomach to relax SM unless it is interrupted then intra-gastric pressure increases
* duodenal nutreints, osmolarity or pH alter gastric motility via vagovagal reflex
156
What is retropulsion?
* large particles are pushed back into proximal stomach to clear the terminal antrum
* done against a closed pylorus
157
What is clustered contraction
* slow migration down gut while mixing and doing some propulsion
158
What is aboral contraction?
* gaint peristalitic wave causing the dumping of the entire colon contents
* like during diarreha
159
What is segmentation?
* Occurs in small intestine
* mixing movements that results in no net movements of contents
160
What are the motility patterns in small intestine?
* Digest macromolecular nutrients
* Absorb digestion products
* Retain nutrients in small bowl until maximal digrestiona dn absorption can be done
161
What are the colonic motility patterns?
* Conservation of water and electrolytes
* Formation, storage and periodic elimination of feces
162
What is SIP Syncitinum?
* Smooth muscle
* Intestinal cells
* PDGFR
163
What is Small Bowel syndrome?
* malabsorption syndrome from extensive intestinal resection
* Small bowel is less than 200cm after surgery
* can cause intestinal failure
* remianing intestine cant maintian nutritional balance
164
What are the etiologies of short bowel syndrome?
* IBD
* mesenteric infarction
* radiation injury
* congenital anomalies in childrens
* gastroschisis, intestinal atresia, malrotation, necrotizing, enterocolitis
165
What is citrulline?
* produced by enterocytes of small bowel
* can be a biomarker of remnant small bowel and function
* AA involved in intermediary metabolism but not incorporated in proteins
* involved in urea cycle to produce urea from ammonia
166
What occurs during the loss of absorptive surface area of small bowel?
* nutrient malabsorption
* water and electrolyte malabsorption
167
What occurs when you lose site-specific transport processes?
* nutrient absorption may take place at any level of small intestine but at different rates
* absorption of some compounds is restricted to certain areas of small intestine
* Duodenum and proximal jejunum - Ca+, Mg+, PO4, Fe, water and fat soluble vitamins
* Distal Ileum - cobalamin intrinsic factor complexes and bile acids are taken up by site specific proteins
168
What occurs with the lose of site specific endocine cells and GI hormones?
* Gi hormones
* synthesis in testinal mucosa
* distribution of site specific along GI tract
* gastrin, CCK, secretin, GIP, and motilin
* produced by endocrine cells
* proximal GI tract
* Half of patients develop hypergastrinemia
169
Where are glucagon-like pepetide 1 and 2 and peptide YY are made?
* made in ileum and proximal colon
* GLP1/2 released by intraluminal fat and carbs
* cause delay in gastric emptying and slowing of intestinal transit
170
What occurs with loss of ileocecal valve?
* Primary function to
* sperate ileal and colonic contents
* minimize bacterial colonization of small intestine
* regulate emptying of ileal contents into colon
* removed in most resections
* decreases intestinal transit time
* increases risk of small bowel bacterial overgrowth which can worsen nutrient and cobalamin malabsorption
171
How does the intestine adapt to resection?
* ileum looks more like jejunum with taller vilii and deeper crypts
* over time it will icrease in ideal diameter and length
* results of changes
* increase absorptive SA
* increase microvillous enzyme activity
* can take 1 to 2 years to develop
172
What structure is this? what vitamin does it require? What enzymes requires it?
* TPP
* Vitamin B1
* PDH
173
What structure is this and what PDH subunit needs this?
* Lipoamine not vitamin required
* E2
174
What enzymes is this? What vitamin does it require? What PDH subunt needs it?
* Coenzyme A
* Vitamin B5
* DLTA
175
What coenzyme is this? What vitamin does it require? What PDH subunit requires it?
* NAD+
* Niacin (Vitamin B3)
* DLDH
176
What structure is this? What vitamin does it require? What PDH subunit requires it?
* FAD+
* Riboflavin (Vitamin B2)
* DLDH
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