second half Flashcards
(229 cards)
1
Q
adequate intake
A
level recommended for indv in particular life stage/gender group to be “adequate” when there is not enough data to set an RDA
2
Q
estimate avg req
A
value estimated to meet req in 50% of apparently healthy indv in particular life stage and gender group
3
Q
recommended daily allowance
A
estimate of avg daily nutrient level intake req to meet 97-98% US pop EAR + 2SD
4
Q
tolerated upper intake level
A
highest average of daily nutrient intake that poses no adverse risk to healthy indv in pop
5
Q
water soluble vitamins
A
ascorbic acid (vit C) B1 B2 B3 Biotin Panthothenic acid Folic acid B12 B6 =pyridoxine pyridoxal pyridoxamine
6
Q
fat solute vitamins
A
ADEK
7
Q
What reaction is biotin a cofactor in
A
acetyl co A to malonyl co A Pyruvate to OAA propionyl co A to methylmalonyl co a
8
Q
What is B12 a cofactor in
A
methylmalonyl CoA –> succinylcholine Co A homocysteine to Ile/Met/Val/Thr
9
Q
B1 name
A
Thiamine Cofactor = thiamine pyrophosphate
10
Q
B2 name
A
Riboflavin Cofactor = FMN, FAD
11
Q
B3 name
A
Niacin Cofactor = NAD+, NADP+
12
Q
B5 name
A
Panthothenic acid Cofactor = coenzyme A
13
Q
B6 name
A
Pyridoxine, pyridoxal, pyridoxine Cofactor = PLP (Pyridoxal phosphate)
14
Q
B7 name
A
Biotin
15
Q
B9 name
A
Folic acid Cofactor = tetrahydrofolate
16
Q
B12 name
A
Cobalamin Cofactor = deoxyadenosyl cobalamin, methyl cobalamin)
17
Q
B vitamins
A
water soluble; deficiencies can result from diet, defective uptake, drug interactions supplementation neither necessary nor useful for average adult
18
Q
B1
A
Thiamine
19
Q
TPP
A
what thiamine is converted to; serves as cofactor for oxidative decarboxylation reactions for ENERGY PRODUCTION
20
Q
Beriberi
A
B1 deficiency
21
Q
Wernicke-Korsakoff Syndrome
A
B1 deficiency
22
Q
which vitamins have toxicity/UL?
A
B3 (niacin), B6 (pyridoxine, pyridoxal, pyridoxine), vitamin E Folate and Vit C has UL but not toxicity
23
Q
Pellagra
A
B3 (niacin/nicotinaminde) deficiency; diarrhea, dermatitis, dementia, death
24
Q
isoniazid TB treatment
A
can cause B3 (niacin, nicotinamide) deficiency
25
avidin
protein found in egg whites that prevents the absorption of biotin and can lead to a biotin deficiency
26
genetic holocarboyxlase synthetase deficiency
ineffective use of biotin and can lead to biotin deficiency
27
megaloblastic anemia
anemia in which the RBCs don't have the ability to divide because of shortage of nucleic acids; results from folate deficiency, because folate is necessary for the generation of nucleic acids
28
spina bifida
neural tube defects resulting from folate deficiency in early pregnancy
29
a-tocopherol
vitamin E
30
hephaestin
oxidizes exported Fe+2 to Fe+3, which can then be bound to transferrin
31
transferrin
binds Fe+3 in the blood
32
Hepcidin
stimulated by IL-6; serves to decrease Fe serum levels
33
incomplete proteins
plant proteins that are deficient in an essential amino acid corn beans
34
acceptable macronutrient distribution ranges
protein 10-35% fat 20-35% carbohydrate 46-65%
35
complete proteins
includes adequate levels of all esssential amino acids
36
how to determine N excretion
24h urinary urea nitrogen + 4g (feces, sweat etc)
37
positive nitrogen balance
indicates anabolic state , overall GAIN in body protein
38
negative nitrogen balance
indicates catabolic state, loss of body protein
39
nitrogen balance in pregnancy
positive
40
low quality protein diet
negative
41
sepsis
negative hyper catabolic state!
42
total daily energy expenditure
BMR + physical activity + energy used for digestion and storage of food
43
states that increase BMR
pregnancy fever hyperthyroidism
44
states that decrease BMR
aging (lose muscle) starvation hypothyroidism
45
thermic effect of feeding
work of digestion, approx 5-10% total energy expenditure
46
BMI
weight/height^2 (kg/m^2) the ratio of weight to height weight (lbs) x 703 / height in inches ^2
47
what are the categories for BMI
underweight, normal, overweight, obese
48
What is the goal of CCK?
to promote fat digestion and absorption
49
What substances stimulate HCl secretion?
Histamine
ACh
Gastrin
50
What substances inhibit HCl secretion
somatostatin
low pH
prostaglandins
51
zymogen granules
where pancreatic enzymes are stored until a stimulus tells them to be secreted
52
what might stimulate zymogen granules to secrete their contents
CCK or parasympathetic stimulation
recall: the goal of CCK is to promote fat digestion and absorption
53
Zollinger Ellison syndrome
gastrinoma, tumor secreting excess **gastrin**
gastrin stimulates HCl secretion by **parietal** cells in the stomach
therefore in this condition - see elevated HCl and elevated parietal cell mass
Tx: cimetidine and omeprazole, surgical resection
54
cimetidine
H2 receptor inhibitor
(therefore, end result is to decrease HCl secretion)
55
omeprazole
H/K ATPase inhibitor (therefore end result is to decrease HCl secretion)
56
extrinsic autonomic NS innervation of gut
Sympathetic = celiac, superior and inferior mesenteric, hypogastric
Parasympathetic = vagus and pelvic
57
postganglionic sympathetic of gut are...
adrenergic
58
post ganglionic parasympathetic of the gut are either...
cholinergic or peptinergic
59
vasovagal reflex
reflex in which both afferent and efferent limbs are contained in vagus nerve
60
What happens in the resection of gastric antrum
removal of G cells therefore H+ secretion, gastric mucosa atrophy
61
62
what kind of cells secrete pepsinogen
gastric chief cells
63
what happens to pepsin at a pH greater than 5
it is denatured and inactivated
64
is pepsin essential for protein digestion
no
65
pancreatic enzymes
pancreatic lipase
cholesterol ester hydrolase
phospholipase A2
66
post prandial hyperemia
increased splanchnic blood flow after a meal
67
vasoactive hormones
CCK
neurotensin
bradykinin
kallidin
68
what is the overall effect of the ENS in the reseting state
Overall **inhibitory** effect
69
what does chemical denervation do to ENS
blocks most ENS Na channels
this causes an **increase** in small bowel motor activity (Recall, at rest, ENS has an overall *inhibitory* fxn)
70
what stimulates short arc reflexes in the bowel and colon?
distention
71
what are the short arc reflexes in the bowel and colon?
segmentation and peristalsis (fxn to move chyme toward colon)
## Footnote
*stimulated by distention*
72
Entero-gastric reflex
* stimulated by = acid, hypertonicity, over-distention
* decreases stomach emptying
* increases duodenal activity DISTAL to stimulus
73
gastro-colic reflex
* filling of stomach increases **distal** motor activity; esp of colon
* infant diapers must be changed soon after feeding
74
entero-enteric reflexes
* increases motor activity **distal** to a *distending or irritating stimulus* WHILE decreasing **proximal** activity!
* clears offending stimulus from bowel
75
whats another name for long arc reflexes
**vasovagal**
76
general pattern of vasovagal activity
distention and or irritation inhibits proximal motor activity and stimulate distal motor activity
77
cecal frenulae
two "lips" that flank the entrance of the ileum into the colon
78
what does the material in the terminal ileum consist of
* fluids
* electrolytes
* nutrients
* mucus
* bacteria
* poorly digested/indigestible substances
* colon recovers most fluids, nutrients and electrolytes!!!
79
colonic motor activity
1. segmentation
2. mass peristalsis
80
what is the stimulus for defecation
increased intra-rectal pressures from incr vol (\>18mmHg)
*pelvo-pelvic nerve pathway via stimulation of adenosine sitmulating nerves!*
IF intra-rectal pressure exceeds 55mmHg, defecation will occur no matter what
81
what are the two events involved in defecation
1. stimulation of defecation reflex
* contraction of distal colon and relaxation of internal anal sphincter
2. changing the ano-rectal angle
82
defecation reflex
**contraction** of distal **c**olon
relaxation of internal anal sphincter
83
is the internal anal sphincter contracted or relaxed between voidings?
between voidings the internal anal sphincter is **CONTRACTED**
colonic and rectal visceral SMC has low tonus
myogenic activity stimulates internal anal sphincter circular muscle to contract
84
what do spinal lesions have to do with pooping
if the lesion is in the upper spinal cord, patient can still defecate because the **reflex is integrated at the lower cord level**
85
pelvopelvic reflex
required for defecation
stimulus is that there are stretch receptors in the distal colon that sense the stretch
86
what is the mechanism by which the anal-rectal angle becomes more obtuse?
cessaton of efferent motor input to skeletal muscles
note: neuromuscular problems prevent inhibition and may result in constipation
87
fecal incontinence
loss of pelvic floor tone, makes nagle more obtuse, fecal incontinence
can strengthen pelvic floor muscles using kegel exercises
88
what nerve is involved in the **voluntary** modulation of defecation reflex
pudendal n.
89
constipation
inappropriate decrease from NORMAL frequency of defecation
90
what are some causes of constipation
* starvation
* dehydration
* surgery
* **antiypertensive agents \*\*\* common**
* organic obstruction
* psychogenic
* autonomic neuropathy
* laxative abuse
91
whats a common cause of constipation
antihypertensive agent
92
diarrhea
an inappropriate increase in fecal water content
93
defecation requires participation of 2 major events which are?
1) defecation reflex = contraction of distal colon and relaxation of internal anal sphincter
2) change in the analrectal angle
94
What is/ are the differences between the fed and empty small bowel motility patterns
1) Fed = incr duration of motor activity, and change in transition rate depending on food compositon (ie high fat decr transition rate)
2) Fasting = MMC = clean the debris
95
the bowel mucosa contains three types of cells - what are they?
villus
goblet
crypt cells
96
what are the three ways for amino acids to get into the hepatic portal circulation
brush boarder peptidases
separate transporters for amino acids
endocytosis of proteins and peptides (enterocytes and M cells)
97
where does nutrient absorption primarily occur
jejunum
98
what has the highest caloric density
lipids
99
starch
* chains of glucose moleucles
* digestion begins with salivary alpha amylase
* inactivation of saliary amylase is dependent on size of meal
* small bowel digestion via **pancreatic amylase**
100
What is starch hydrolyzed to
* alpha limit dextrins = 30%
* malto-oligo-saccharides = 70%
* G2 = maltose
* G3 = maltotriose
* G4-G9
101
malto-oligo saccharides
G4-G9
G2 = maltose
G3= maltotriose
made from the digestion of starch by alpha amylase (salivary and pancreatic)
102
what are the brushboarder enzymes involved in starch digestion
dextrinase and glucoamylase
103
how are glucose and glaactose absorbed by small bowel enterocytes?
luminal SGLT1-Na co-transport
basolateral GLUT2
104
how is fructose absorbed into the enterocyte?
luminal GLUT5 carriers
then basolateral GLUT2
105
trehalose
2 glucose molecules joined at the 1'-1' molecules
106
lactose
galactose and glucose
107
sucrose
fructose with glucose
108
where is vitamin C absorbed
ileum
109
what are the sources of protein
exogenous = diet
endogenous = digestive enzymes and desquamated cells
110
enterokinase
* initiates activation of pancreatic enzymes
* secreted by crypts of lieberkuhn
* binds to brushborder
* is freed via presence of bile salts
* is activated by the presence of its substrate, trypsinogen
111
3 absorptive mechanisms of luminal enterocyte
1. brush border peptidase for oligopeptides
2. aa specific transporters
3. endocytosis of proteins and peptides
112
system B0
System Bo is a **sodium dependent neutral aa transporter** that serves as a specific aa transporter on the luminal end of the enterocyte, contributing to the enterocyte absorptive mechanisms
Neutral aa = arginine, lysine, histadine
113
basolateral enterocyte membrane
3 sodium indp transporters move aa out of enterocyte
2 sodium DEPENDENT transporters move aa back into enterocyte
why? because intestinal mucosa is being replaced every 18 or so hours
114
What is net absorption of individual aa vs oligopeptides?
aa abosrption is LESS than oligopeptides
1. luminal aa absorption depends on physical proximity
2. oligopeptides have kinetic advantage over single aa
115
what are the three key pancreatic enzymes
pancreatic lipase
cholesterol ester hydrolase
phospholipase A2
116
what does bile do to pancreatic lipase
sterically hinders it; therefore pancrease must secrete pro-colipase and activate it to **colipase**
117
pancreatic lipase
forms FFA and monoglycerides
118
cholesterol ester hydrolase
paancreatic enzyme that produces cholesterol and glycerol
119
phospholipase A2
produces lysolecithin and FFA
120
what is the first enzyme that starts to break down fat
lingual lipase
121
what can lack of bile salts lead to?
steatorrhea and avitaminosis
(due to inability to absorb dietary fat)
122
Hartnup disease
inability to absorb non polar amino acids
especially, tryptophan
(CNS and skin disorders)
123
cystinuria
lack of dibasic aa transporters causes elevated excretion of cysteine
124
where is folic acid absorbed
via a speific OH exchanger in the **jejunum**
125
hemachromatosis (siderosis)
too much iron
126
two mechanisms of calcium absorption
**paracellular** = **whole small bowel**; calcium flows between cells through the tight juncitons to hepatic portal veins; *primary mechanism during high dietary ca activity*
**transcellular** = through cell, mainly in **duodenum**
*primary mechanism during moderate to low dietary ca activity*
127
Why is calcitriol necessary for proper calcium absorption
has four key fxns on duodenal and jejunal enterocytes
1. TRPV6 channels on apical mem
2. Calbindin D
3. basolateral Ca/H ATPase
4. basolateral Na/Ca exchanger
128
TRPV6
calcium channel on the apical membrane of duodenal and jejunal enterocytes
129
calbindin
binds calcium in the enterocyte
activated by calcitriol
causes incr in calcium absorption bc makes conc grad seem low
130
what does overall iron absorption depend on
fullness of iron stores
level of erythropoietic activity
amt dietary iron intake
131
where is iron primarily absorbed
duodenum
therefore damaged duodenal mucosa may cause microcytic anemia
132
what is the effect of calcium on DMT1
Calcium is a _low affinity noncompetitive inhibitor_ that **inhibits DMT-1**
therefore high dietary calcium will _impede iron absorption!!!_
DMT 1 is responsible for bringing non heme iron into cell (divalent metal ion transporter)
133
hephaestin
**oxidizes ferrous to ferric** in plasma
so tht ferric iron can be bound to **transferrin** (protein tranporter molecule)
134
hepcidin
liver hormone released during high iron plasma or inflammation
fxn: **down regulate DMT** and inhibits **ferroportin**, fe release from macrophages
135
where is the greatest fraction of HCO3 secretion located
duodenum (why- neutralize acidic chyme)
136
beneficial activities of intesetinal flora
* metabolism of indigestable carbs
* conversion of primary to secondary bile acids
* synthesis of
* vit K
* folate
* biotin
* thiamin
* prevention of overgrowht of pathogenic bacteria
* training immune system to only attack pathogens
137
primary site of water absorption
jejunum
138
where is Na/H process primarily
jejunum
therefore jejunum becomes primary site of HCO3 absorption
139
what are two ways Cl- can leave the cell?
basolateral Cl- channel
apical Cl- channel (cystic fibrosis channel)
140
engram
robust memory trace; the sensation of nausea and emesis form this as a *protective measure*
141
what do chief cells secrete
pepsinogen
142
what does delta cell secrete
somatostatin
143
somatostatin
inhibits gastric acid secreiton
* inhibits parietal cells
* inhibits gastrin secreting cells
* inhibits EC cells (histamine secretion)
144
whts the most important stimulus for D cell stimulation
pH\<2
145
what does the enterogastric reflex effect
it inhibits the parietal and G cells
146
name some things that breach the mucosal barrier of the stomach
NSAIDS (decr prostaglandin synthesis therefore decr mucosal secretion)
nicotine
ethanol
H Pylori
Bile
147
why is the duodenal mucosal barrier less effective?
the duodenum is a sensor! Therefore, dont want a super thick barrier bc then it wouldnt be able to sense things; it needs to konw what the physcial and chemical nature is of the chyme that it receives.
THEREFORE, duodenal ulceration of duodenum compared to stomach is 3:1
148
what are the two ways potassium can exit the **ileal and colonic enterocytes?**
* ****_a_**ldosterone** sensitive **_A_**pical K+ channel
* recall that aldosterone increases sodium reuptake and kicks potassium out
* basolateral K chanel
149
how does water flow
paracellularly
150
secretory diarrhea
hypercholremic, hypokalemia acidosis
H gets trapped inside cell which causes acidosis
151
how do you know its **secretory diarrhea**
loss of IONS
152
how do you know its **osmotic diarrhea**
loss of NON ELECTROLYTES
153
stool osmotic gap
SOG = [290- (stool Na+ + stool K+)
normal = 100-150 mosm/Kg
secretory \<100
osmotic\>150
154
what is the stool osmotic gap in secretory diarrhea?
SOG\<100mosm/Kg
155
what is the stool osmotic gap in osmotic diarrhea?
SOG\>150mosm/Kg
156
more sodium and potassium in the stool during ____ diarrhea
secretory
157
what can increase in cAMP synthesis within crypt cause?
cAMP synthesis incr due to toxins can cause **secretory diarrhea** which will have \<100 stool osmotic gap
158
what is the only place where bicarb is reabsorbed
Jejunum
159
what is the main site for folate Fe and Ca absorption
duodenum
160
proton pump inhibitor
selective and **IRREVERSIBLE**
block apical H/K proton pump
161
H2 receptor antagonists
competitive REVERSIBLE inhibitor
blocks H2 receptor on parietal cell, thereby preventing histamine (from ECL cell) from being able to stimulate parietal cell acid secretion
162
at what week does gut herniate into umbilical cord
week 6
90 degrees counterclockwise
163
when does intestinal folds return to abdominal cavity
week 10
180 degrees counterclockwise
164
hypospadias
due to failure of **urethral folds** to fuse; abnormal opening of penile urethra on ventral surface of penis
165
166
what does pineal gland produce?
melatonin
167
what kind of neurons respond to increased temp
sympathetic cholinerginc neurons (Acting on sweat glands and cutaneous blood vessels--\>vasodilation)
168
what kind of neurons respond to decr temp
motor neurons (shivering)
Sympathetic adrenergic neurons
169
how often does the entire epidermis renew?
every 15-30 days
170
what is the only layer of the skin with cells that undergo mitosis?
St. Basale ("germanitiro")
171
langerhans cells
immune cells responsible for trapping antigens
172
what are the four types of cells in the epidermis
Merkel
Langerhans
keratinocytes
melanocytes
173
what aa is melanin derived from?
tyrosine
174
what enzyme is involved in melanin produciton
tyrosinase
175
Lysyl oxidase
required for the crosslinking of collagen and elastin; dependent on COPPER
(Marfans symptoms are the symptoms that you would also have with significnat copper deficiency)
176
what is vitamin C's effect on vitamin E
restores vitamin E to antioxidant form
177
heme oxygenase
in the cytoplasm of the enterocyte, releases iron from heme
178
heme transporter
transports heme into enterocyte
179
hephaestin
oxidizes expored ferrous iron to ferric iron
180
describe biofilm of infection
tend to be **polymicrobial**
* neutrophils/macrophages cant engulf
* further tissue damage from innate immune cells
* resistance
* matrix can impede antibiotic penetratio
181
phosphodiesterase
inactivates cAMP
182
what are the two types of tyrosine kinases
receptor associated tyrosine kinases
receptor tyrosine kinases
183
what is anterior pituitary derived from
primitive foregut (ectoderm)
184
contraindications to breastfeeding
HIV
Human T cell lymphotropic virus
active brucellosis
active untreated tuberculosis
active herpes varicella zoster
alcohol/drug abuse
ebola
galactosemia
185
whats the bfd abt DHEA in the fetus
it is INERT! it prevents virilization of the fetus; it doesnt bind to either the androgen or the estrogen receptor
186
what cell type makes antimullerian hormone
sertoli cells of the testes; responsible for causing the mullerian duct to degenerate
187
what cell is responsible for phagocytosin germ cell cytoplasm
sertoli cell
188
protamine
sperm version of histones; compacts DNA very tightly to protect it; involved in the remodeling phase that turns early spermatid into late spermatid
189
chromaffin cell
post ganglionic sympathetic neuron; contain epinephrine or noepinephrine
190
what kind of capillary in the thyroid?
fenestrated
191
helicine arteries
dilate in erection
192
what are the acrocentric autosomes
13,14,15,21,22
193
cyp21 deficiency
hypotension
194
cyp11 deficiency
hypertension
becasue 11DOC has mineralocorticoid
195
lacunae
space where spiral arteries once were; created by proteases released by the syncytrotrophoblast
196
hyaluronidase
released from acrosome; dissolves intercellular material btwn granulosa cells of corona radiata
197
acrosin
facilitates penetration of zona by the sperm head
198
what deficiency will have elevated mma
b12 deficiency
199
what cells secrete intrinsic factor
parietal cells
| (necessary for b12 absorption)
200
what is r factor and where does it come from
comes from saliva; allows for absorption of B12
201
where does primary saliva come from
acinar secretioin
202
what is special about secondary saliva
hypotonic; derived from striated duct
203
where is saliva from in basal secretion
low flow; submaxillary gland
204
where is saliva coming from in high flow
comes from parotid gland (All serous, very watery, high pH)
205
what kind of control is salivaiton under
NEURAL
206
what phase gives most salivation
oral
207
vagotomy and swallowing
decr solid swallow
incr liquid swallow
208
what mediates mmc
motilin
209
vagotomy
reduces antral motor activity and loss of receptive relaxation
increase in tonus!
210
what kinds of cells release cck
i cells
211
chemreceptor trigger zone
CTZ acts as second level of receptors that supplement emetic center
stimulated by meningitis, spoiled food, drugs, hypoxia, etc
212
what does somatostatin bind to
recall - somatostatins goal is to decr hcl; it is released by D cells
binds to Gi receptor on parietal cell to decr cAMP
binds to receptor on EC cell to block histamine release
binds receptor on G cell to block gastrin release
213
urease
how hpylori produces ammonia
214
how does H pylori cause ulcers
cytotoxins break down mucosal barrier in stomac
inhibit SS secretion in D cells therefore incr h secretion
inhibits duodenal bicarb secretion
215
where are deoxycholic and lithocolic acid made
made in the DUODENUM because they are **secondary bile salts**
216
where are chenodeoxycholic and cholic acid made
liver because they are **primary bile salts**
217
how do you make bile salts water soluble?
you conjugate them with glycine and taurine in the liver
218
kernicterus
excess unconjugated bilirubin in infant --\> irreversible CNS damage
219
what is the most important phase of pancreas secretion
intestinal (80%) stimulated by cck and secretin
220
law of the intestine
frequency of BER greater in PROXIMAL portion of SI b/c there are less gap juncitons in distal SI
221
unstirred water layer
hypotheticallayer of water over mucosa that impedes diffusion
THICKNESS is INVERSELY PROPORTIONAL to motility of bowel
222
what prevents overflowing of the colon
ileo-cecal junction
223
what kind of metabolism is enterokinase involved in
amino acid metabolism
recall: enterokinase is produced in crypts
224
where is enterokinase produced
crypts
225
what kind of water absorption predominates in digestive period
paracellular
226
what kind of water absorption predominates in between meals
transcellularly
227
is sodium coupled nutrient transport affect by bacterial toxins?
no. in fact, this is how most na in the jejunum is absorbed and water follows paracellularly; secretory diarrhea (\<100SO, secretion of ions) can be overcome by ingestion of nutrient containing water
228
where are leaky tight junctions found
duodenum and jejunum; thats why the sodium electrogenic transport only works in ileum and colon, because those are the only places that can establish an electric potential
229
stool osmotic gap
normal = 100-150
calculated via: 290 - (Na+K in stool)
\<100 - secretory
\>150 - osmotic
