Week 2 Flashcards
Cholesterol esters and Triglycerides are located in the hydrophobic core of the macromolecule, surrounded by phospholipids and apoproteins
Lipoproteins
Chylomicrons
VLDL
LDL
HDL
Four types of lipoprotein
Relationship of proteins to density
The more protein, the more dense, as protein is more dense than lipids
first step of chyloformation
diary fat eaten, salivary lipase secreted, presence of free fatty acids, monoglycerides, cholesterol.
Presence of fat globules, hard to break up, what is secreted?
bile salts
what do bile salts do?
make surface-optimized fat droplets
what breaks up surface-optimized fat droplets into micelles?
pancreatic lipase
what breaks up micelles into chylomicrons?
enterocytes
name three apoproteins that bind to chylomicrons in the lymphatic system
ApoB48, ApoC2, ApoE
what does ApoB48 do?
Micelles secretion of chylomicrons from GI to lymph
what does ApoC2 do?
Hydrolyzes conversion of TG to Fatty Acids for absorption (LPL)
What does ApoE do?
Mediates reuptake of multiple remnants
what organ secretes VLDL?
Liver
what does VLDL carry?
Triglycerides and cholesterol
ApoC2 activates LPL which then does what?
cut and cleave TG and FA, converts VLDL into IDL that carries TG and cholesterol in it with ApoB100 and ApoE bonded on its surface
low density lipoprotein
chylomicrons
medium low density lipoprotein
VLDL
medium high density lipoprotein
LDL
high density lipoprotein
HDL
How does lipoprotein change in the small intestine?
from low density to high density
which is “bad” type of lipoprotein that forms plaques and causes arteriosclerosis?
LDL
what is main component in low density lipoproteins?
triglycerides
Main component in “bad” lipoprotein?
cholesterol (50%)
Main component in “good” lipoprotein?
Protein (50%)
HDL comes from where?
“nascent HDL” comes from LV and SI
ApoA1 in bloodstream activates Lecithin-Cholesterol Acyltranserase (LCAT) does what?
converts NaSCENT HDL into Mature HDL that carries ApoE and ApoC2 on its surface
how long do glycogen stores last?
1 day
how long do fat stores last?
3 days
how long do protein stores last?
1+ week
after 1-3 days, what is the fuel source?
Hepatic gluconeogenesis, driven by Alanine and Lactate fort the brain
since RBCs have no mitochondria, the cannot use what
keynotes
insulin drives what state?
“Fed” state (storage of protein, carbohydrates, fat)
priority targets for fuel sources
Brain and RBCs
what is most common Gi diagnosis in primary care visits?
GERD
Definition of GERD
a condition which develops when the reflux of stomach contents causes troublesome symptoms and/or complications
Reflux that is not troublesome is not GERD
“Troublesome”: mild symptoms 2 or more times/week or severe symptoms 1 or more times/week
Sx of GERD
- Chest pain
- Chronic cough
- Chronic laryngitis
- Asthma
- GERD often not the sole cause of
atypical symptoms - Atypical symptoms without
concomitant heartburn/reflux
unlikely to be due to GERD
Defensive factors in GERD
Lower Esophageal Sphincter
Upper Esophageal Sphincter
Peristalsis
Saliva
Bicarbonate
Aggressive factors in GERD
Hiatus Hernia
Acid
Pepsin
Bile acids
Trypsin
Alcohol
Acidic foods
Nervous activity in GERD
Hallmark Sx of GERD is
Heartburn
in GERD, LES is
Transiently relaxed, has decreased resting tone
Two typical complications of GERD
Erosive Esophagitis
Barrett’s Esophagus
Erosive Esophagus
Barrett’s Esophagus, replacement of squamous cells to columnar cells, beginning of potential malignancy
Problem with sympathetic stimulation from GERD?
Sympathetic stops digestion, stomach stagnates, acidity goes up, reflux happens, gastric emptying is delayed.
Esophageal Adenocarcinoma
Alarm Sx of GERD
- Weight loss
- Bleeding
- Dysphagia
- Family history of esophageal or gastric cancer
EGD (upper endoscopy) prompted by?
- Refractory to treatment
- Long duration of symptoms
- Atypical symptoms, dysphagia
EGD (upper endoscopy) sees normal esophagus in how many patients with heartburn and regurgitation?
2/3
Presence of erosive esophagus confirms GERD?
Yes
Relationship b/t GERD and BMI
Positive correlation
Surgical solutions to GERD
Bariatric Surgery
Sleeve Gastrectomy
Bariatric surgery
Roux-en-Y Gastric Bypass. Make stomach pouch, connect to duodenum. Connect duodenum to middle LI.
Reduces Reflux
Clinical trial shows big success
Sleep Gastrectomy
Increases Reflux, LES is modified, provoking a decrease in LES resting pressure
Major Histamine Producing Cells, Study This!
Histamine 1
Histamine 2
Two types of medications
H2 Receptor Antagonists
PPI (Proton Pump Inhibitors)
What do H2R receptor antagonists and PPIs do?
