Exam 1 Flashcards
1
Q
Accessory organs of digestive system
A
Liver, gallbladder, + exocrine pancreas
2
Q
Layers of the GI tract inner to outer
A
Mucosa
Submucosa
Muscularis
Adventitious serosa
3
Q
Mucosa layer of the GI tract consists of
A
Mucosa epithelium Lamina propria (loose network of epithelium) Muscularis mucosae (allows local mvmt of mucosa; role in BD/secretion/absorption dysfxn)
4
Q
Submucosa layer of the GI tract consists of
A
Glands + assoc. ducts
5
Q
Muscularis layer of the GI tract consists of
A
Circular + longitudinal layers
6
Q
Adventitious layer of the GI tract consists of
A
connective tissue
7
Q
The enteric nervous system is considered part of the
A
ANS
8
Q
The enteric nervous system functions
A
autonomously
9
Q
The enteric nervous system is influenced extrinsically via
A
parasympathetic/sympathetic nervous systems
10
Q
Three Enteric plexus
A
Submucosal plexus
Myenteric plexus
Subserosal plexus
11
Q
The submucosal plexus is also known as
A
Meissner plexus
12
Q
The myenteric plexus is also known as
A
Auerbach plexus
13
Q
The submucosal plexus is located in
A
submucosa
SECRETION
14
Q
The myenteric plexus is located
A
Btwn circular + longitudinal layers of muscularis
MOTILITY
15
Q
Subserosal plexus is the
A
ANS innervation of BV + CT
16
Q
Three general functional components of enteric plexus
A
Sensory neurons
Motor neurons
Interneurons
17
Q
Sensory neurons monitor
A
Distention + the “chemical status” of the GI tract
Sensory afferents via SYMPATHETIC nerves
18
Q
Clinical of sensory neurons
A
GI visceral pain
19
Q
Three stimuli of GI visceral pain from sensory neurons
A
Distention-stretching/perforation
Chemical-inflammation/immune response
Ischemia-lactate, H+, K+
20
Q
Motor neurons control
A
Motility-peristalsis
Blood flow-smooth muscle of GI vasculature
Secretions-cells of the mucosa/submucosa including chief cells, parietal cells, + mucus cells
21
Q
Interneurons
A
Communication btwn sensory + motor
Mechanism for intrinsic control short loop reflexes
22
Q
Appetite
A
hunger
23
Q
Satiety
A
sensation of fullness/satisfied
24
Q
2 centers located in the hypothalamus control appetite + satiety
A
Lateral center-appetite
Medial center-satiety
25
Lateral center appetite center function
Stimulate appetite
| Excitatory to hunger contractions in stomach
26
Stimuli of lateral appetite center
Smell, visual, taste, hearing
Physiological depletion of nutrient/energy stores
Memory/fantasy-limbic/insular lobes
Gastric hormone- GHRELIN
27
Ghrelin released by
stomach
| hunger hormone
28
Medial center (satiety center) function
suppress appetite
| inhibitory to hunger contractions in the stomach
29
Medial satiety center stimuli
GI hormones
Leptin
PPY
Insulin
30
GI hormones which stimulate the medial satiety center are released during
ingestion CCK, GLP-1 short term
31
Leptin which is a stimulus for the medial satiety center is released by
fat cells + chief cells
32
PPY a stimuli of the medial satiety center is released by
Small intestine after a meal
33
Insuliin, a stimulus for the medial satiety center is released by
pancreas after increased blood glucose after meal
34
Obesity hormones
Leptin
| Ghrelin
35
Leptin a satiety hormone is _____ in obesity
Increased
| Leptin resistance causes decreased effectiveness
36
Ghrelin is _____ in obesity
Decreased
| Physiological strategy to signal feeding is adequate
37
Fast acting hunger hormone
Ghrelin
38
Levels of ghrelin ____ just before meals
rise
39
Most circulating levels of Ghrelin are produced in
the stomach
40
Other roles of ghrelin other than hunger
memory, sleep
41
Leptins long term role
Energy balance + suppressing food intake
42
Leptin is released from
fat cells
43
Fast acting counteraction hormone to ghrelin post feeding
PYY
44
PYY is released from the
small intestine
45
Other than PYY another fast acting hormone post feeding is
Insulin
46
Insulin is released from
the pancreas
47
Extrinsic regulation of the GI tract
ANS + Enteric nervous system
48
Sympathetic system pathway of extrinsic regulation
Nerves of sympathetic tract in thoracic + upper lumbar regions
49
Function of the sympathetic system
Inhibitory to GI tract-dec. peristalsis + secretions
| Inhibit blood flow
50
Parasympathetic system Pathway
Vagus nerve esophagus to transverse colon + pelvic nerves of sacral plexus
51
Function of parasympathetic system
Excitatory to GI tract
Inc. peristalsis + secretion
Relax involuntary sphincters of GI tract
Facilitate blood flow to GI tract
52
Intrinsic regulation of the enteric nervous system
2 neural networks located w/in the multiple layers of the intestinal walls
Feedback on itself + function autonomously
Brain in the gut
53
Specific functions of enteric nervous system
Controls motility
Regulation of fluid exchange + local GI blood flow
Regulation of gastric + pancreatic secretion
Regulation of gastrointestinal endocrine cells
Defense reaction
Entero-enteric reflexes
ENS + CNS interaction
54
Enteric nervous system control motility by
peristalsis, sphincter control
55
Enteric regulation of fluid exchange + local GI blood flow
Regulates permeability to ions thus influence fluid
Influences vasodilation of BV
Influences fluid secretion
56
Regulation of GI endocrine cells from the enteric nervous system
Intrinsic system can signal release of GI hormones
| Excessive serotonin released from GI walls=n/v
57
Defense reactions of the enteric nervous system
Vomit, diarrhea, + exaggerated propulsive motility reflexes
58
Entero-enteric reflexes from the enteric nervous system
Signaling system btwn regions of GI tract
Gastric activity stimulates small intestine motility + relaxation of ileocecal valve
Small intestine activity signals release of enzymes from pancr
59
There are more than ____ neurotransmitters in the intrinsic nervous system
20+
Excite smooth muscle: Ach + substance P
Inhibit smooth muscle: NO + VIP
60
Two systems that regulate the GI tract
Extrinsic para + sympathetic
| Intrinsic w/in GI wll
61
Extrinsic system directly influences the
intrinsic system
| Excitatory/inhibitory to gastric secretions
62
Three salivary glands
Submandibular
Sublingual
Parotid
63
Autonomic control of saliva
Parasympathetic + sympathetic systems stimulate salivary glands
SECRETION OF SALVA NOT CONTROLLED BY HORMONES
64
Saliva is composed of
water w/mucus, sodium, bicarbonate, chloride, + potassium
65
Bicarbonates in saliva function
Maintain pH in the mouth to neutralize bacteria (tooth decay)
66
Saliva pH
6.4-7
67
Salivary amylase
Digestion initiated in mouth
| Amylase begins first steps to breaks down carbohydrates
68
Immunoglobulin A igA in saliva
Prevents infections
69
Saliva summary
Control pH
Starch digestion
Immune defense
70
Esophagus musculature
Upper third striated voluntary muscle
Middle third mixed
Lower third involuntary muscle
71
Upper esophageal sphincter cricopharyngeus muscle location
Jct. of lower pharynx + esophagus
| Approximately @ level of cricoid cartilage
72
Function of UES
Prevent air from entering esophaguss during ventilation
73
Lower esophageal sphincter location
Narrowing of the esophagus proximal to the junction of esophagus to stomach
74
Function of lower esophageal sphincter
Barrier to the reflux regurgitation of the acidic content of the stomach
75
LES is maintained by
increased smooth muscle tone
76
Resting tone of the LES
Inc to 20mmHg
77
Belching
Air pressure in stomach exceeds LES pressure
78
GI tract consists of
Mouth, esophagus, stomach, small intestine, large intestine, rectum, + anus
79
DVT thrombus formation
Accumulation of clotting factors/platelets forms thrombus
Thrombus composed of RBC, platelets, leukocytes held together w/fibrin
Inflammation perpetuates thrombus growth
Thrombus creates "back pressure" leading to edema
80
Thrombus often form near
valves
81
Thrombus composed of
RBC, platelets, leukocytes + held together w/fibrin
82
Thrombus creates _____ leading to edema
back pressure
83
Factors in formation of DVT
Venous stasis
Endothelial damage
Hypercoaguable states
84
DVT umbrella
Insertion of umbrella serves as a catch/filter mechanism to block dislodged emboli from traveling to the heart + pulmonary circulation
85
Wells Criteria for identification of DVT
Active cancer +1
Paralysis, paresis, or recent plaster immobilization of LE +1
Bedridden >3d/major surgery w/in 4wks +1
Thigh + calf swollen +1
Calf swelling 3cm greater than asymptomatic side +1
Pitting edema +1
Dilated superficial veins in sx leg only +1
Alernative dx as or more likely then DVT -2
86
Wells criteria scores
87
To decrease risk of DVT
Ankle pumps
TEDs
Intermittent pneumatic compression (vena flow)
88
Diseases of the arteries
```
Aneurysm
Thrombi/emboli formation
PAD
Hypertension
Hypotension
Atherosclerosis
```
89
PAD two types
Atherosclerotic
| Non-atherosclerotic thomboangiitis obliterians + raynauds
90
Types of atherosclerosis
PAD
CAD
MI
Acute coronary syndromes
91
Pathogenesis of blood vessel breakdown in an abdominal aortic aneurysm
Proteolytic degradation of aortic wall connective tissue
Inflammation + immune responses
Biochemical wall stress
Molecular genetics
92
Molecular genetics as a cause of abdominal aneurysm
Family hx
93
Biochemical wall stress as a cause of abdominal aneurysm
Thoracic/abdominal aorta may be predisposed d/t collagen/elastin make-up
Calcified plaque formation in wall redistribute wall stresses
Once AAA started wall stress accelerated dilation/development
94
Inflammation + immune responses causing abdominal aortic aneurysm
Transmural infiltration of LYMPHS + MONOS
95
Proteolytic degradation of aortic wall connective tissue causing abdominal aortic aneurysm
Destruction of elastin + collagen in the media + adventitia
| Loss of medial smooth muscle cells w/thinning of the vessel wall
96
MC origin of an arterial thromboembolism is
heart valve disease
Dislodged left heart valve may obstruct
Lower, coronary, + cerebral circulation
97
Other forms of arterial emboli
Air
Fat
Amniotic fluid
Bacteria, foreign matter
98
Air causing arterial emboli
IV lines, chest trauma
99
Fat causing an arterial thromboembolism
Long bone fractures
100
Amniotic fluid causing an arterial thromboembolism
intra-abdominal pressures of child birth may introduce amniotic fluid into the mothers blood stream
101
MC form of peripheral artery diseases PAD, number one reason for amputations in US, + 16x greater risk of heart dz/stroke w/in next 10yrs
Atherosclerotic PAD
102
Chron's dz can affect
any part of the GI tract
103
Chrohns dz peak onset
15-25yo
104
In chrohns dz males/females mc?
females
105
Family history of chrohns increases the risk
2-4xs w/first degree relative
106
Etiology of Chrohns
Poorly understood genetics, autoimmune, + environmental
107
Pathophys of chrohns
Inflammation extends all layers of intestinal wall
Defective immune/inflammatory regulation
Chronic granulomatous
108
Chrohns can effect the ___ to the ___
mouth, anus
109
Which part of the GI system is most often involved in Crohns
Distal ileum + proximal colon
110
Skip lesions
In crohns two+ inflamed areas w/healthy bowel in btwn
111
Tx of crohns
Antiinflammatory: Salicylate, corticosteroids, infliximab remicade
112
Salicylate 5-ASA for crohns
anti-inflammatory typically used to tx mild-mod
113
Corticosteroids for crohns
Mod-severe dz antiinflammatory
114
Surgery for crohns is indicated when
65-75%
Multiple
Don't respond to meds
Correct complications from obstruction, perforation, + abscess
115
Types of surgery for crohns
Resection-small portion intestine removed
Adhesions/scarring creating obstructions
Stricturoplasty=chronic narrowing of intestinal lumen
116
Ulcertive colitis total colectomy + ileorectal anastamosis IRA
Colon removed except the last 5inches of the rectum
Small intestine/ileum, surgically joined to upper rectum
After pt. has normal bowel fxn
117
Colectomy with ileoanal pouch (restorative proctocolectomy) for ulcertive colitis
Colon + rectum removed leaving anal canal + sphincter muscles
New rectum made from SI +
118
IBD examples of systemic manifestations
Orthopedic sx (peripheral jt. pain + back pain)
119
Diverticulosis out pockets
In intestinal wall
| 85% asymptomatic
120
Diverticulitis
Inflammation of colonic diverticula
Impacted w/fecal material
Perforations d/t inflammation
May/may not penetrate
121
Diverticulitis most often affects
Sigmoid colon
122
Colorectal cancer is estimated _____ of all newly dx cancer in US
8.5%
123
Pathyphys of colorectal cancer
Develop from adenomatous glandular polyp
Initial mutant cancer cell develops in polyp
Slow growth on polyp as it progresses down stalk toward the deeper layers of the mucosa
If penetrates into submucosal it can reach lymphatic/bv pathway + become highly malignant
*Screening for removal of polyps critical for prevention
124
Risk factors of colorectal cancer
>50yo
125
Screening for colorectal cancer
Colonoscopy more thorough + better screening
Flexible sigmoidoscopy limited in ability to screen (45% dec. in detection rate)
Protocols: >50 every 10y + DRE + fecal occult blood yearly
126
Liver location
RUQ
127
Weight of liver
Proportion to body size
| 2-3pounds
128
Surface anatomy of the liver
R/L lobes-cantilies line
| IVC to gallbladder
129
Connective tissue of the liver
Falciform ligament
| Glissons capsule
130
Glissons capsule
Surrounds liver
| Invaginaltes @ hilum of the liver
131
Afferent pathways to the liver
Portal pathway 75% hepatic portal vein
| Arterial pathway 25% hepatic artery
132
Sinusoids of the liver
microvasculature
| Outside of the hexagon straight to the central vein
133
Efferent pathway from the liver
Central veins drain into hepatic veins
134
Hepatic portal vein recieves blood from the
GI tract, spleen, + pancreas
135
Hepatic portal anastomosis
```
Collateral venous circulation w/numberous veins of abdominopelvic region
Gastroesophageal vein
Rectal vein
Paraumbilical vein
Portorenal vein
```
136
Portal hypertension
Portal circulation congested blocked + reverses portal blood flow towards portal anastomoses
Occurs when cirrhosis develops
137
Hepatic artery
Delivers oxygenated blood to liver
Accounts for 25% blood flow to liver
Originates from celiac trunk
138
Hepatic artery + portal htn
Blood flow to liver from hepatic artery NOT impaired
| Relative high amount of 02 delivered to hepatocytes is synergistic w/regeneration
139
Stellate cells are located
in the disse space
140
Stellate cells fxn
Store vit. A
Produce/secrete hepatic growth factors
Liver regeneration
141
If stellate cells are stimulated via pahtology/disruption of enviornmental homeostasis
```
transform into fibroblastic fxn
Produce collegen
Myoblastic fxn
Contractile
Role in fibrosis
```
142
Pit cells aka
Granular lymphocytes/NK cells
143
Location of pit cells
Surface of endothelium of sinusoids
144
Function of pit cells
s
145
What produces the largest amount of lymph fluid in the body 20%
Liver
146
Hepatic lymphatics drain fluid from
Disse space, glisson's capsule,
147
Two regional zones of hepatocytes in the lobule
Periportal hepatocytes-
| Centrilobular hepatocytes
148
Third regional zone sometimes described
Mid-way btwn periportal + centrilobule zones
149
Periportal hepatocytes
First to receive 02 + nutrient rich blood
150
Centrilobular hepatocytes
Last to receive blood so less O2 + nutrient availability
Susceptible to ischemia + necrosis
Region of drug metabolism (biotransformation)
151
Liver physiological roles
Drug metabolism/biotransformation
Metabolism: carbs, fats, proteins
Storage: fat soluble + some water soluble vitamins like A, K, D, B12
Endocrine fxn
152
Vitamin K
critical for clotting cascade
153
Vitamin D
Precursor involved in conversion
154
Liver carb metabolism regulates
Blood glucose
Initial mechanismm to reduce blood glucose (insulin mediated)
Synthesis of glycogen (glycogenesis)
155
Glycogenesis
Liver stores glucose for future energy needs
Glycogen 10% total liver weight
Glycogen synthesized from glucose, amino acids + pyruvate
156
Gluconeogensis
Production of glucose from non-carb source
Glucose can be produced from fatty acids, aa, + lactate
Important to maintain blood glucose during FASTING
Stimulated by glucagon + sympathetics
157
Rate limiting step of glconeogenesis
Amount of available substrate + NOT liver enzymes
158
Liver removes ____ + ____ from plasma
FFA, lipoproteins
159
Fasting state of fat metabolism
Released into plasma from adipose tissue
FFA removed from plasma by liver
FFA in liver have 2 fates B oxidation + ketone body formation
Synthesize VLDL
160
Feeding state fat metabolism
Chylomicron remnants are removed from plasma by the liver
TG from chylomicron remnants can be used for energy (FFA formation) or to synthesize VLDL
Cholesterol from chylomicron remnants used to synthesize VLDL
161
Lipoprotein synthesis
The liver plays important role in synthesizing lipoproteins needed forr lipid transport in plasma
162
Classes of lipoproteins
Chylomicrons
VLDL
LDL
HDL
163
Chylomicrons
Largest diameter, most lipid, least conc. of proteins
| Lipids 99% TG rich
164
VLDL
Smaller diameter than chylomicron
| Lipids 90% TG rich but not as much as chylomicron
165
LDL
smaller in diameter than VLDL
| Lipids 80% cholesterol rich
166
HDL
Smallest diameter, least lipid, largest concentration of proteins
Lipids 40-60% cholesterol rich
167
Lipoprotein removal
Liver plays important role in removal catabolism of lipoproteins
LDL removal
LDL receptors on the liver bind LDL + remove from circulation
Familial hypercholesterolemia
LDL receptor deficiency
168
Hepatic cholesterol production
B oxidation of FFA in the liver creates acetyl CoA
Acetyl coA used for energy or can be used to synthesize cholesterol
Rate limiting step in cholesterol synthesis is conversion HMG CoA to mevalonate
169
Dyslipidemia
LDL have critical role in atherosclerotic plaque formation
170
Clinical of dyslipidemia
Statins
Dec. cholesterol synthesis by liver hepatocytes
Inc. production of LDL receptors on liver hepatocytes
Inc. uptake of LDL by liver hepatocytes
Dec. plasma cholesterol levels
