Week 8 Science and Scholarship: Metabolism and Digestive system Flashcards
1
Q
what serous membrane lines the abdominopelvic cavity
A
peritoneum
2
Q
the kidneys and blood vessels are ___peritoneal
A
extraperitoneal
3
Q
the stomach and spleen are ___peritoneal
A
intraperitoneal
4
Q
name the 9 abdominal regions
A
Right hypochondriac Epigastric Left
hypochondriac
Right lumbar umbilical Left lumbar
Right iliac hypogastric Left iliac
5
Q
describe the transpyloric plane
A
-lies equidistant to the superasternal notch and pubic symphysis
6
Q
describe the embryology of the GI tract
A
*5-7 metre tube that connects the mouth to the anus
*4 layers
*3 segments
7
Q
name the 4 layers of the GI tract
A
-mucosa
-submucosa
-muscularis externa /(muscularis propria)
-serosa/(adventitia)
8
Q
name the 3 segments of the GI tract
A
foregut (superior)
midgut (middle)
hindgut (inferior)
9
Q
what artery supplies each segment of the GI tract
A
foregut = coeliac artery
midgut = superior mesenteric artery
hindgut = inferior mesenteric artery
10
Q
where is pain localised for each segment of GI tract
A
foregut = epigastric area
midgut = periumbilical area
hindgut = suprapubic area
11
Q
function of mouth in digestion
A
contains teeth for mastication (chewing), mechanical digestion
12
Q
function of oesophagus in digestion
A
conduit between mouth and stomach
13
Q
function of stomach in digestion
A
mechanical digestion and little absorption
14
Q
function of duodenum
A
digestion due to the arrival of pancreatic juice and bile allowing for significant absorption
15
Q
identify components of upper GI tract
A
oesophagus
stomach
duodenum
16
Q
structure of oesophagus
A
-25 cm peristalsis tube
-lined by squamous more proximal and columnar epithelium distally
-contains oesophageal sphincter
17
Q
function of gastro-oesophageal junction
A
prevents (acid) reflux of food and hallmarks the transition from squamous to columnar epithelium
18
Q
whats acid reflux
A
condition in which the GOJ closing is impaired, the contents of the stomach (including its acid) is regurgitated and enters oesophagus
19
Q
structure of stomach
A
-J shaped organ with 4 regions
-highly acidic (1.5-3.5)
-largely variable in size
-has two openings which are joined by two curvatures
-doesn’t absorb foods, more so fluids eg alcohol, water
20
Q
what are the two openings into the stomach
A
oesophageal + duodenum
21
Q
what are the two curvatures of the stomach
A
the greater and lesser curvature
22
Q
describe blood supply to the stomach
A
-stomach in foregut hence supplied by coeliac trunk
-coeliac trunk divides into 3 arteries : left gastric, common hepatic and gastroduodenal arteries
-the gastroduodenal artery forms the gastro-mental network that forms around the greater curvature
-the left gastric artery forms the gastric network that forms around the lesser curvature
23
Q
function of pharynx in digestion
A
upper portion of the conduit between mouth and stomach
24
Q
function of salivary glands in digestion
A
secretions help in lubrication , are antibacterial and begins digestion
25
function of small intestine in digestion
digestion and most absorption (with help of pancreatic and liver secretions)
26
function of large intestine in digestion
completion of absorption of water and electrolytes (faeces remains)
27
function of rectum in digestion
final part of large intestine where faeces are stored prior to defecation
28
function of anus in digestion
terminal part of GI tract where faeces are propelled into extracellular environment
29
function of gall bladder in digestion
Storage : store bile products between meals
Concentration: concentrates bile products by removing and clearing fluids
Regulation:regulates systemic release of bile during meals
30
function of pancreas in digestion
vital for digestion, contains enzymes for the digestion of all food categories
31
features of mucosa layer of GI wall
innermost layer
-contains epithelium, lamina propria and muscularis mucosa
32
features of submucosa layer of GI wall
layer beneath mucosa
-contains blood vessels, lymphatic tissue and nerves that provide support and nutrition to the submucosa
33
features of muscularis externa layer of GI wall
-responsible for rhythmic contractions of GI tract that are propel food through digestive system
34
features of serosa layer of GI wall
outermost layer
-secrets slippery fluid to reduce friction and facilitate movement within the abdominal cavity
35
name 4 main processes in digestion
motility
secretion
digestion
absorption
36
what is digestion stage
mechanical and biochemical breakdown of foods into smaller units
-hydrolysis of water
37
whats is absorption stage
small units (with water and electrolytes) are transferred into blood / lymph
-achieved by sodium-depended symport
38
what is secretion stage
exocrine glands secrete digestive juices and endocrine glands release hormones
39
what is motility stage
muscular contractions that propel (peristalsis) and mix (segmentation) foods, highly regulated by nerves
40
what substance(s) does mouth release
saliva (salivary amylase, mucous and lysozymes)
41
what substance(s) does pharynx/oesophagus release
mucous
42
what substance(s) does liver/gall bladder release
bile (bile salts, alkaline secretions and bilirubin)
43
what substance(s) does exocrine pancreas release
digestive enzymes (trypsin, chymotrypsin, amylase and lipase)
44
what substance(s) does stomach release
gastric juices (HCl, pepsin, mucous, intrinsic factor)
45
what substance(s) does small intestine release
succus entericus, enzymes
46
Name the factors that regulate digestive function with a focus on neural components and smooth muscle.
Autonomous smooth muscle function
Intrinsic nerve plexuses
Extrinsic nerves
Gut hormones
47
Explain how autonomous smooth muscle regulates digestive function
smooth muscle is able to contract rhythmically without neural input, which is regulated by specialised pacemaker cells (cajal cells)
48
Explain how intrinsic nerve plexuses regulates digestive function
network of nerve fibres located in the walls of digestive system that regulates functions eg motility and secretion
49
Explain how extrinsic nerves regulates digestive function
responsible for regulating functions like motility, secretion and blood flow by communicating with CNS
50
Explain how GI hormones regulates digestive function
chemical messengers produced and secreted by cells lining the digestive tract that regulate various functions eg digestion, hunger, absorption
51
Describe the components of saliva
water (99.5%), carbohydrate (0.5%) and protein (<0.01%)
-contains mucous, amylase, lingual lipase, lysozyme and bicarbonate buffer
52
function of saliva
washes particles away and acts as a solvent for taste
53
name the two reflexes for increased saliva secretion
conditioned and simple reflex
54
describe the conditioned reflex for increases saliva
Receptor: taste receptors on tongue
Afferent nerve: taste fibres of the facial and glossopharangyeal nerve
Control centre: higher centres of the brain including cerebral cortex
Efferent nerves: parasympathetic fibres of facial and glossopharangyeal nerve
Effector: salivary glands
Response: increased saliva secretion
55
describe the simple reflex for increased saliva
Receptor: chemoreceptors in the oral cavity
Afferent nerve: glossopharangyeal nerve and trigeminal nerve
Control centre: salivary centres in medulla oblongata
Efferent nerves: parasympathetic fibres of glossopharangyeal nerve
Effector: salivary glands
Response: increased salivary secretion
56
name salivary glands
parotid
sublingual
submandibular
57
Name the stages of swallowing
1. oral phase
2. pharangyeal phase
3. oesophageal phase
58
describe oral phase of swallowing
-tongue moves bolus to back of mouth triggering swallowing reflex
-causes soft palate to close off the nasal cavity
-causes epiglottis to close off the larynx
59
describe pharangyeal phase of swallowing
-bolus enters the pharynx
-triggering series of involuntary reflexes that move it into oesophagus
60
describe oesophageal phase of swallowing
-bolus is propelled down oesophagus by peristalsis until it reaches stomach
61
name the two sphincters in oesophagus
pharyngo-oesophageal sphincter
gastro-oesophageal junction/ sphincter
62
function of pharyngo-oesophageal sphincter
prevents excess air from entering GI tract
63
name 3 regions of stomach
fundus
body
antrum
64
difference between body and antrum of stomach
there is differences in glandular mucosa (secretions and cells)
65
identify the functions of the stomach
-storage of food
-secretion
-chyme
66
Describe what is meant by the stomach is involved in 'storage of food'
regulates the controlled release of food into the small intestine
67
Describe what is meant by the stomach is involved in 'secretion'
secretes enzymes and HCl to enable protein digestion
68
Describe what is meant by the stomach is involved in 'chyme'
food and secretions are mixed to create acidic chyme
69
briefly what happens in gastric filling
-eating triggers the relaxation of folds within the mucosa (gastric Rugae) in a process called receptive relaxation
-however, intragastric pressure doesn't change because of he rugae flattening
70
briefly what happens in gastric mixing
-regulated by smooth muscle in walls of stomach
-pacemaker cells generate slow wave potentials
-slow wave potentials set the basic electrical rhythm of the heart
-muscles in wall contract due to slow wave potentials
-these contractions allow for gastric mixing
71
briefly describe what happens in gastric emptying
-process in which food leaves stomach into small intestine
-regulated by rate at which pyloric sphincter opens
-gastric emptying is influenced by size of meal, presence of nutrients in small intestine, neural and hormonal signals form gut
72
whats gastroperesis + symptoms, causes
-Gastroparesis: stomach empties slowly
-Symptoms: nausea, vomiting, stomach pain, bloating, feeling full fast
-Causes: vagus nerve damage, diabetes, autoimmune diseases, certain meds
73
whats achalasia + symptoms, causes
-Muscles in the lower oesophageal sphincter (LES) don't relax properly.
-Symptoms include trouble swallowing, food coming back up, chest pain, heartburn, and weight loss.
-Nerve damage in the oesophagus often causes achalasia.
74
identify the local and distal factors that controls gastric motility and emptying
stomach: volume of chyme
stomach: fluidity
Duodenum: fat
Duodenum: acid
Duodenum: hypertonicity
Duodenum: distension
External: emotion and pain
75
describe how stomach: volume of chyme controls gastric motility and emptying
proportional to distension (stretch, intrinsic plexus, vagus nerve, gastrin)
76
describe how stomach: fluidity controls gastric motility and emptying
more easily emptied (must reach threshold fluidity to empty)
77
describe how duodenum: fat controls gastric motility and emptying
slowly digested, needs time process fat already there
78
describe how duodenum: acid controls gastric motility and emptying
chyme must be neutralised, or it inactivates enzymes and irritates duodenal mucosa
79
describe how duodenum: hypertonicity controls gastric motility and emptying
amino acids and glucose draws water from plasma to reach isotonicity
80
describe how duodenum: distension controls gastric motility and emptying
too much chyme leads to excess volume
81
describe how external: emotion and pain controls gastric motility and emptying
varies autonomic balance, activates ANS and decrease motility
82
secretin and CCK ____ _____ contractions
inhibit antral contractions
83
what regulates short and long reflexes
intrinsic nerve plexuses and autonomic nerves
84
emesis =
vomiting
85
name factors that can cause emesis
-tactile stimulation of the back of throat
-elevated intracranial pressures
-chemical factors
-irritation or distention of the stomach and duodenum
-vestibular/visual cues (motion sickness)
-psychogenic (mental/emotional factors)
86
Describe process of vomiting
1.coordinated by vomiting centres of medulla in brainstem
2.deep inspiration; glottis is closed uvula raises
3.stomach, oesophagus and gastro-oesophageal sphincter relax
4.respiratory muscles contract, stomach is squeezed between descending diaphragm and increasing intra-abdominal pressure
5.sensation of nausea , salivation , sweating, tachycardia regulated by ANS
6. Excess vomiting results in loss of fluids and acids
87
identify the exocrine secretory cells
mucous cells
chief cells
parietal cells
88
identify endocrine secretory cells
ECL cells
G cells
D cells
89
what do mucous cells secrete, the stimulus and function
secretion : alkaline mucous
stimulus: mechanical stimulation by gastric contents
function: protects mucosa against mechanical, pepsin and acidic injury
90
what do chief cells secrete, the stimulus and function
secretion: pepsinogen
stimulus: Ach
function: initiates protein digestion
91
what do parietal cells secrete, the stimulus and function
secretion: HCl, intrinsic factor
stimulus: Ach, gastrin and histamine
function : activates pepsinogen, breaks down CT, denature proteins, kill microorganisms, facilitate vitamin B12 absorption
92
what do ECL cells secrete, the stimulus and function
secretion:histamine
stimulus: Ach , gastrin
function: stimulates parietal cells
93
what do G cells secrete, the stimulus and function
secretion: gastrin
stimulus: protein products, Ach
Function: stimulates parietal, chief and ECL cells
94
what do D cells secrete, the stimulus and function
secretion: somatostatin
stimulus:acid
function: inhibits G, parietal and ECL cells
95
identify the 3 phases of gastric secretion
cephalic, gastric and intestinal
96
Describe cephalic phase of gastric secretion
-triggered by thought/thinking
-mediated by P.S NS, stimulates gastric secretion before food enters stomach
97
describe gastric phase of gastric secretion
-triggered by food entering stomach
-mediated by gastrin, which simulates secretion of gastric acid and enzymes
98
describe intestinal phase of gastric secretion
-triggered by chyme entering duodenum
-mediated by enterogastric reflexes and hormones eg gastrin, CCK, gastric inhibitory peptide
99
function of gastric mucosal barrier
helps gastric mucosa withstand strong acid and proteolytic enzymes
100
name 4 elements of gastric mucosal barrier
epithelial cells
tight junctions
mucosa
bicarbonate
101
describe elements of gastric mucosal barrier
epithelial cells: impenetrable to HCl
tight junctions:prevent acid diffusing between cells
mucosa: prevents physical penetration of HCl
bicarbonate: neutralised acid and inactivates pepsin
102
structure of small intestine
-hollow tube between 5-7 metres long
-three segments, duodenum, jejunum and ileum
103
describe functions of the small intestine
-absorption: utilises specialised epithelial cells to uptake nutrients from digested food
-secretion: release enzymes (maltase, lactase) to further beak down food molecules
-immunity: houses lymphoid tissue to to protect against foreign substances and pathogens
104
describe motility patterns in the small intestine
-segmentation (primary motility method), involves oscillating ring like contractions, this is done in an alternate manner leading to 'Mexican wave', mixing food with chyme
105
how is segmentation regulated in small intestine
-pacemaker cells (cajal) generate basic electrical rhythm
-extrinsic nerves influences by P.S NS and SNS regulate strength of contraction, while smooth muscle responsiveness is regulated by distention
106
whats another name for the gastrointestinal housekeeper
migrating motility complex (MMC)
107
What does the MMC do
moves chyme forward once most nutrients have been absorbed
108
Outline each phase of the MMC
1. (40-60 mins) relatively quiet, few contractions
2. (20-30 mins) some, inconsistent contractions
3. (5-10 mins) intense peristaltic contractions that propagate from the upper stomach to the end of small intestine (growling)
109
what hormones regulates MMC
motilin
110
what is the ileocaecal juncture
the valve between the small and large intestine (caecum)
111
name the secretions of the pancreas and what cell relates them
duct cells:
Na2CO3 solution
Acinar cells:
proteolytic enzymes
pancreatic amylase
pancreatic lipase
112
function of NA2CO3 solution secreted by pancreas
maintains alkaline environment in pancreas
113
function of proteolytic enzymes secreted by pancreas
protein digestion
114
function of pancreatic amylase secreted by pancreas
carbohydrate digestion
-polysaccharides into disaccharides
115
function of pancreatic lipase secreted by pancreas
fat digestion
-triglycerides into monoglycerides
116
name the three pancreatic proteolytic enzymes (inactive)
trypsinogen
chymotrypsinogen
procarboxypeptidase
117
trypsin = ___ + ____
enterokinase + trypsinogen
118
chymotrypsin = ___ + ____
trypsin + chymotrypsinogen
119
carboxypeptidase = ___ + ____
trypsin + procarboxypeptidase
120
Outline steps in neutralisation of duodenum
1.acid in duodenal lumen
2.secretin released from duodenal mucosa
3.secretin is carried by blood to pancreatic duct cells
4.pancreatic duct sells secrete NaHCO3- solution into duodenal lumen
121
Outline steps of digestion in duodenum
1.fat and protein products in duodenal lumen
2.CCK released from duodenal mucosa
3.CCK is carried by blood into pancreatic acinar cells
4.secretion of pancreatic digestive enzymes into duodenal lumen
122
describe structure of liver
-comprised of hexagonal lobules, each lobule has a central vein and three peripheral tubes
-contains Kupfer cells, erythrocytes, sinusoids, hepatocytes, bile canaliculis, Peripheral bile duct and common bile duct
123
what are sinusoids in liver
capillary like blood vessels found between hepatocyte plates
124
what are kupfer cells in liver
hepatic macrophages that reside in sinusoids
125
what are hepatocytes' role in liver
primary functional cells of liver, responsible for metabolism
126
what are bile canaliculi in liver
tiny ducts between hepatocytes for bile drainage
127
what are peripheral bile ducts
ducts collecting bile from bile canaliculi
128
what is the common bile duct
main duct carrying bile from liver to duodenum
129
functions of liver
-digestion
-secreting bile salts to breakdown and absorb fats in small intestine
130
outline blood flow to the liver
-two main sources arterial blood (via hepatic artery) and venous blood (through hepatic portal vein)
-venous blood supplies nutrient rich blood to sinusoids
131
structure and location of gall bladder
-small, pear shaped organ located underneath liver in URQ
132
outline flow of bile
During meals : L/R hepatic duct, common hepatic duct, bile duct, sphincter of oddi, duodenum
After meals: L/R hepatic duct, common hepatic duct, bile duct, cystic duct
133
name two processes of bile production
emulsification and micelle formation
134
what is emulsification
breakdown of fat globules into smaller droplets by bile salts
135
what is micelle formation
creation of small lipid soluble clusters for fat absorption
136
what are micelles
-have a hydrophobic core and hydrophilic shell
-if cholesterol secretion surpasses the ability of micelles this can lead to gall stones
137
how much bile is reabsorbed by active transport
95%
138
substances that increase the secretion of bile are known as ___
choleretics eg CCK
139
how is bile secretion regulated
via
Chemical factors
Hormonal factors
Neural factors
140
How do chemical factors regulate bile secretion
bile salts stimulate their own secretion when returned to the liver in digestion
141
How do hormonal factors regulate bile secretion
secretin stimulates release of NaHCO3- solution to neutralise gastric chyme
142
How do neural factors regulate bile secretion
vagal stimulation of the liver increases bile flow during the cephalic phase
143
features of bilirubin
-2nd major component of bile
-yellow t/f contributes to jaundice
-waste product of digestion
-modified bilirubin is reabsorbed, unmodified is removed via urine
144
whats hepatitis
-inflammatory disease of liver
-can lead to sorosis or failure
-
145
causes of hepatitis
virus, toxins, alcohol , autoimmune
146
symptoms of hepatitis
jaundice
fatigue
abdominal pain
loss of appetite
147
Describe how carbohydrates are converted from macronutrients into absorbable units
1. amylase breaks down polysaccharides into disaccharides and oligosaccharides
2.membrane bound enzymes (anchored to brush borders of enterocytes) break down disaccharides and glucose oligomers into monosaccharides
3. absorption of monosaccharides with two sodium ions via secondary active transport, water follows to maintain osmotic balance
148
Describe how lipids are converted from macronutrients into absorbable units
1.ingested lipids (large droplets) are emulsified by bile salts and motility
2.emulsion droplets are digested by lipase and converted to monoglycerides and FFA's
3.co-lipase binds to emulsion droplets, packaging these into micelles and moving them through the intestine to the surface of the cell
4.passive absorption of end products; micelles release their contents at cell membrane
5.end products are resynthesised into TAG, which forms a hydrophilic chylomicron that is released into the lymph via exocytosis
149
Describe how proteins are converted from macronutrients into absorbable units
1.endogenous and exogenous proteins are broken down into amino acids (one or two step process)
2.digestion of proteins occurs via tertiary active transport dependent on H+, Na+ and energy
3.amino acids exit the cell via facilitated diffusion and diffuse into capillary
150
what glucose transporter does glucose use for entry and exit
entry = SGLT-1
exit = GLUT-2
151
what glucose transporter does galactose use for entry and exit
entry = SGLT-1
exit = GLUT-2
152
what glucose transporter does fructose use for entry and exit
entry= GLUT-5
exit=GLUT-2
153
Describe how carbohydrates are transported from GI tract into liver/tissues
absorbed as monosaccharides and transported via bloodstream to tissues for energy or stored as glycogen in liver
154
Describe how amino acids are transported from GI tract into liver/tissues
broken down into amino acids and transported via bloodstream to tissues for protein synthesis or energy production
155
Describe how lipids are transported from GI tract into liver/tissues
absorbed as fatty acids and glycerol, packaged into chylomicrons, transported via lymphatic system and then delivered to tissues or stored in adipose tissue for energy or structural purposes
156
name two types of lipoproteins
HDL's and LDL's
157
role of HDL's
returns cholesterol to liver (or bile)
158
role of LDL's
delivers cholesterol to cells in body
159
name the segments of the large intestine
1.caecum
2.ascending colon
3.transverse colon
4.descending colon
5.sigmoid column
6.rectum
7.anal canal
160
structure of large intestine
-contain 'haustra', divided pouches of the column seen from caecum to rectum
-'haustral formation' (change in location) is caused by contractile activity of the circular muscle layer
-taeniae coli are also found, seperate bands of longitudinal muscles, these layers are gathered in haustral pouches
-the myenteric plexus is concentrated beneath the taeniae coli
161
brief histology of large intestine
-mucosa, submucosa and muscularis externa but no vili (t/f decreasing SA)
162
features of motility in the large intestine
-two main types of movements, haustral contractions and mass movements
-these help regulate movement and absorption of water and nutrients in large intestine (faeces form)
163
describe haustral contractions
slow, segmenting movements that occur in the haustra, pouches along colon, this aids in water and electrolyte absorption
164
describe mass movements
powerful peristalsis waves that propel faecal matter over long distances (1 to 3 times a day), facilitating defecation
165
Describe how intrinsic innervation regulates large intestine motility
regulates via the myenteric plexus concentrated beneath the taeniae coli
166
Describe how extrinsic innervation regulates large intestine motility
Parasympathetic NS: innervation via vagus nerve (proximal colon) and pelvic nerve (distal colon)
Sympathetic NS: innervation via superior mesenteric ganglion (proximal colon), inferior mesenteric ganglion (distal colon), hypogastric plexus (rectum and anal canal)
167
what regulates haustral contractions itself
mediated by reflexes (linked to slow wave AP's)
168
what controls mass movements itself
neural and hormonal stimuli predominantly after a meal
169
Outline steps in gastrocolic reflex
1.food enters stomach
2.release of gastrin and activation of extrinsic autonomic nerves
3.stimulation of colon motility (mass movement)
4.pushes content into rectum, leads to urge to defecate
170
what is defecation
-removal of dried out faeces from the body
-involves involuntary control (myenteric plexus, spinal chord and cerebrum)
-involves voluntary control (abdominal contractions, pelvic floor relaxation)
171
what is Hirschsprung's disease
absence of enteric innervation results in enlargement of colon
172
describe the absorptive mechanisms of the colonic epithelium
-absorptive enterocytes in colon enable transport of water out faeces
-these cells absorb Na+ and Cl-, water follows snd osmotic balance is retained
173
name some components of faeces
water
cellulose
bacteria
ions
bilirubin
174
describe the secretive mechanisms of the colonic epithelium
-no digestive enzymes in colon
-secretes a protective alkaline mucous, neutralises acid and lubricates): this is mediated by short reflexes and parasympathetic innervation
175
short vs long reflexes
short reflexes are local, intrinsic reflex arcs within the ENS
while
long reflexes involve more complex neural pathways that extend to the CNS and back to the GI tract.
176
name the GI microbiota in fermentation and health
colon microflora
colon fermentation
bacteria and flatulence
177
how does colon microflora play a role in gut health
-rapid increase in Bacteria in ileocecal valve, humans have a symbiotic relationship
-mostly anerobes, raise acidity
-synthesis of vitamin K and promote Ca, Mg, Zn absorption
178
how does colon fermentation play a role in gut heath
-microbiotas contribute to hosts mechanism through fermentation
-produce enzymes that breakdown nutrients that can't otherwise be hydrolysed
-excess products eg FA's, gases , glucose
179
how does bacteria and flatulence play a role in gut health
-gas passed from anus is called 'flatus
-comprised from non digestible carbs
-can be sign of functional gut health
180
what can cause food poisoning
salmonella and campylobacter
-bacteria pass epithelium and cause inflammation
181
what neurotransmitter plays a key role in salivation
Ach
182
what is xerostomia
-hyposalivation or excess salivary clearance
183
causes of xerostomia
medications
damage to salivary glands
cancer treatment
dehydration
Sjorgen's syndrome
184
how can xerostomia be treated
saliva substitutes and pilocarpine
185
whats dysphagia
reduced laryngeal closure --> aspiration (disruption in swallowing process)
186
outline control of sphincters
upper=neurally induced tonic contraction
lower=myogenic activity
187
what happens in reflux oesophagifits
(heartburn)
-LES relaxes, upon inspiration, intrapleural pressure decreases and the oesophagus expands, lower pressure in the oesophageal lumen pulls acidic content into the oesophagus
188
how do peptic ulcers occur
-H.pylori resides in mucous layer, towards the antrum and produces urase breaking down NH3 as the buffer
-H.pylori secretes toxins that cause inflammation (gastritis) and disrupting tight junctions in the epithelium and increasing (high pH gastrin) increasing the release of HCl to try decrease pH leading to peptic ulcers.
189
how does biliary obstruction occur
-most common cause is choleliths, other causes include malignancy, infection, cirrhosis
-jaundice occurs
-it is the blockage of any duct that carries bile from the liver to gall bladder to small intestine
190
how does pancreatitis occur
-inflammation of the pancreas, pancreatic enzymes irritate and damage the pancreas
-can lead to tissue loss, necrosis, pain
191
what duct blockage causes biliary obstruction
cystic duct and CBD
192
what duct blockage causes pancreatitis
CBD and pancreatic duct
193
what is celiac disease/gluten enteropathy
intolerance to gluten, caused by shortened vili and and reduced SA of small intestine
-can lead to malnutrition
194
what is diverticular disease
herniation of the sigmoid colon, causes inflammation of the diverticula
195
define metabolism
the chemical reactions in an organism that maintain life
196
define intermediary metabolism
reactions involving the degradation, synthesis, and transformation of energy rich organic molecules (carbs, fats,proteins)
197
define catabolism
degradation of larger macromolecules eg hydrolysis or oxidation
198
define anabolism
synthesis of larger macromolecules eg condensation
199
describe the fates of absorbed fuel units
metabolic pool-fuels are converted into intermediate metabolites to enter metabolic pathways for energy production or biosynthesis of biomolecules
stored-excess fuel in body is stored as glycogen in liver and muscle or triglycerides in adipose tissue
utilised-fuel is oxidised through ACR to produce ATP
200
how are different fuels metabolised
-glucose can be used for anaerobic or aerobic
-AA and FA's are only used for aerobic
201
name the three stages in ATP production (ACR)
-glycolysis
-krebs cycle
-electron transport chain
202
describe glycolysis
-glucose is split into two pyruvate
-2 ATP produced
-aerobic and anaerobic
203
describe Krebs cycle
-pyruvate converted into acetyl CoA
-citrate, ATP, NADH and FADH2 produced
-aerobic
204
describe electron transport chain
-conversion of energy from NADH and FADH2 into ATP via mitochondrial enzymes
-aerobic
205
describe insulin and glucagon in regulating fuel metabolism (fed state)
-High insulin levels
-Promotes glucose uptake and utilization
-Stimulates glycogen synthesis
-Inhibits glycogen breakdown
-Facilitates triglyceride synthesis
206
describe insulin and glucagon in regulating fuel metabolism (fasting state)
-Decreased insulin levels
-Increased glucagon levels
-Promotes glycogen breakdown and- gluconeogenesis
-Enhances lipolysis
-Increases blood glucose levels
207
role of liver in BGL control
-Storing extra glucose as glycogen when eating.
-Making new glucose from non-carb sources when fasting.
-Breaking down stored glycogen into glucose when needed.
-Releasing glucose into the blood for energy.
208
name factors effecting energy requirements
body size
activity
sex
body composition
age
hormonal status
209
define basal metabolic rate
energy expended by the body to maintain basic physiological functions at rest, such as breathing, circulation and temperature regulation
210
how to calculate BMR in men and women
M: (10 x weight) + (6.25 x height) - (5 x age) + 5
F: (10 x weight) + (6.25 x height) - (5 x age) -16
211
list the main classes of macronutrients
fats
carbs
proteins
fibres
212
function of fats
energy storage, protection of organs, insulation and absorption of fat soluble vitamins
213
function of carbs
primary source of energy for the body, fuel
214
function of proteins
building block of cells and tissues, growth, maintenance and repair
215
function of fibres
promotes health digestion and aids in bowel regularity, regulates BGL and cholesterol
216
sources of fats in food
oils and butter
217
source of protein in food
meat and poultry
218
source of carbs in food
poultry
219
source of fibres in food
wholegrain
220
is there digestive enzymes in colonic epithelium
no, digestion completed
221
pain in right scapula is indicative of
gall bladder pathology
222
pain radiating from epigastric region to back is indicative of
pancreatitis or perforated peptic ulcer
223
pain radiating from loin to groin is indicative of
ureteretic colic
224
pain radiating from periumbilical area to RIF
appendicitis
225
leukonychia is indicative of
hypoalbuminaemia due to chronic liver disease
226
Koilonychia is indicative of
chronic iron deficiency anaemia
227
clubbing is indicative of
liver cirrhosis, IBD and coeliac disease
228
pallor of palmar creases are indicative of
anaemia
229
dupuytrens contracture is indicative of
genetics, age or manual labour
230
hepatic flap (asterixis) are indicative of
hepatic encephalopathy due to chronic liver disease
231
palmar erythema is indicative of
chronic liver disease
232
ecchymoses is indicative of
clotting abnormalities due to hepatocellular damage interfering with clotting factors
233
petechiae are indicative of
thrombocytopenia due to splenomegaly
234
what is muscle wasting indicative of
late manifestation of malnutrition in alcoholic pt
235
what is spider naevi indicative of
cirrhosis due to pregnancy alcohol, virus, hepatitis
236
what is acanthosis nigricans indicative of
GI carcinoma, acromegaly, diabetes mellitus
237
what are scratch marks indicative of (chronic cholestasis)
pruritus due to obstructive/cholestatic jaundice or primary biliary cirrhosis
238
what is scleral jaundice indicative of
congestive heart failure leading to hepatic congestion
239
what is conjunctival pallor indicative of
anemia
240
what are Kayser-Fleisher rings indicative of
liver disease or Wilson's disease
241
unilateral enlargement if parotids indicates
tumour
242
bilateral enlargement of parotids indicates
alcohol use
243
gum hypertrophy and mouth ulcers indicate
numerous causes
244
tongue coatings indicative of
disease or smoking
245
leukoplakia is indicative of
maybe oral cancer
246
glossitis is indicative of
atrophy of the papillae
247
fetor hepaticus is indicative of
severe parenchymal liver disease
248
angular stomatitis is indicative of
vitamin B(6) and B(12), folate and iron deficiency
249
enlargement of the cervical or supraclavicular lymph nodes indicates
infection of mouth, pharynx,
-oropharangyeal malignancy
250
enlargement of Virchow's node (left supraclavicular node) is indicative of
metazoic spread of gastric cancer
251
gynaecamastia is indicative of
chronic liver disease
252
hair loss is indicative of
liver disease
253
caput medusae is indicative of
portal HTN
254
when is ascites present
when percussion is dull but then turns resonant (after 30s and manoeuvre)
255
whats ileus
lack of bowel movements in intestines
256
renal bruits indicate
renal artery stenosis
257
pitting oedema is indicative of
hypoalbuminaemia
258
