physiology 1 Flashcards
1
Q
satiation
A
the feeling of fullness generated during a meal
2
Q
satiety
A
period of time between termination of one meal and the initiation of the next
3
Q
adiposity
A
the state of being obese
4
Q
what do satiation signals do during meal
A
inc to limit meal size
5
Q
satiation signals - 3
A
CCK peptide YY GLP-1 oxyntomodulin obesatin
6
Q
what is ghrelin
A
hunger signal
7
Q
what do monoamines do
A
suppress food intake
8
Q
what does glutamate, gaba and opioids do
A
inc food intake when injected into hypothalamic centres
9
Q
which hormones report fat status to brain
A
leptin and insulin
10
Q
where is leptin made
A
made and released from fat cells
11
Q
what is use of leptin therapy limited by
A
leptin resistance
12
Q
what is the present drug for the treatment of obesity
A
orlistat
13
Q
what does orlistat do
A
inhibits pancreatic lipase dec triglyceride absorption
14
Q
what effect does gastric by pass surgery have on those with type2 diabetes
A
complete resolution sometimes
15
Q
what does uncoupling of electron transport do
A
non shivering thermogenesis - maintains body temp
16
Q
what does brown adipose tissue contain
A
UCP
17
Q
what is 24 DNP
A
an artificial uncoupler, anti obesity drug
18
Q
what does overdose of DNP cause
A
death by overheating
19
Q
where is UCP 3 found
A
skeletal muscle - involved in thermogenesis here
20
Q
how does MDMA cause death
A
targets UCP 3 - death through sustained hyperthermia followed by skeletal muscle breakdown
21
Q
what is the overall process of digestion and absorption called
A
assimilation
22
Q
what is sucrose made of
A
glucose and fructose
23
Q
what is lactose made of
A
glucose and galactose
24
Q
what is amylose like
A
straight chain
25
what is amylopectin like
branched chain
26
compare the branching of glycogen to amylopectin
glycogen is more branched than amylopectin
27
what breaks eg starch down to oligosaccharides
alpha amylase
28
name some oligosaccharides
lactose and sucrose
29
what breaks oligosaccharides down to monosaccharides
oligosaccharidases
30
what does alpha amylase do
break down internal a1-4 linkages
31
what do oligosaccharidases do
cleave the terminal a1-4 linkages
32
because oligosaccharidases can cleave terminal linkages wht can they produce
glucose
33
what can maltase do
degrade the a1-4 linkages in straight chain oligomers up to 9 monomers in length
34
isomaltase
can split the branching a1-6 linkages of a limit dextrins
35
what is primary lactase deficiency due to
lack of LP allele
36
what is secondary lactase deficiency due to
damage to or infection of proximal small intestine
37
what is congenital lactase deficiency
rare Au R - no ability to digest lactose from birth
38
what happens if lactose intolerant and eat lactose
bloating abdominal pain and flatulence, loose stools and diarrhoea
39
what does a lactose challenge detect
hydrogen on the breath of individuals that has been produced from lactose
40
what does SGLT1 transport
gluucose or galactose
41
what does GLUT5 transport
fructose
42
what does GLUT2 transport
glucose and fructose as they exit from enterocytes
43
where is GLUT3 found
in neuronal cells
44
how much of our daily intake does protein assimilation account for
10-15%
45
what is the optimum pH of pepsin
1.8-3.5
46
what do endopeptidases produce
oligopeptides
47
name some endopeptidases
trypsin, chemotrypsin and elastase
48
what do exopeptidases produce
single amino acids
49
name some exopeptidases
Procarboxypeptidase A and B
50
disfunction of what results in Hartnup disease
system B AT1
| Na dependent
51
disfunction of what results in cystinuria
system b AT1
| Na independent
52
1. what happens to protein in the lumen
digested to amino acids or oligopeptides by pepsin and pancreatic protesases
53
2. what happens to oligopeptids at brush border
further hydrolysed to amino acids by peptidases
| the amino acids are transported across the membrane via Na in/dependent transporters
54
3. how are oligopeptides transported across the brush border
by PepT1
55
4. what happens to oligopeptides in the cytoplasm
hydrolysed to AA by peptidases in the enterocyte
56
what environment do lipids require
ampipathic
57
how is an emulsion formed
churning and mixing and the alkaline pH
58
what forms mixed micelles with emulsified dietary lipids
bile acids, phospholipids and cholesterol esters
59
what are bile salts secreted in response to
CCK
60
what do bile salts do to lipid
emulsify large droplets to small droplets
| - inc surface area for the action of lipase
61
what does failure to secrete bile salts result in
steatorrhoea
62
function of colipase
allows lipase to access the lipid
63
how are short chain fatty acids absorbed
diffuse through the enterocyte
64
how are long chain fatty acids absrobed
resynthesized to triglycerides and incorporated into chylomicrons with apolipoproteins
65
how do chylomicrons exit the enterocyte
exocytosis
66
where are chylomicrons taken after the exit the enterocyte
in lymph vessels to systemic circulation via the thoracic duct
67
what protein helps with the absorptionof choelsterol
NPC1L1
68
what does ezetimbe blocks
NPC1L1 protein
69
which form of iron can be absorbed
Fe 2+
70
how does iron enter the enterocyte
via DMT1
71
what is the storage form of iron
ferratin
72
how does iron exit the enterocyte
via ferroportin
73
how is vitamin B12 absorbed
ingested in food, salivary glands secrete haptocorin which binds to vitamin B12 in the stomach.
stomach parietal cells release IF - vitamin B12 is released from haptocorin and binds to IF in small intestine - this complex is absorbed in the terminal ileum by enterocytes
74
what duct drains from the parotid gland
duct of stensen
75
what duct drains from the submandibular gland
duct of wharton
76
what duct drains from the sublingual gland
duct of Rinivus and common Bartholin
77
what is the functional unit of the gland
salivon
78
what do striated ducts unite to form
interlobular and excretory ducts
79
what does a salivon consist of
acinus, serous demilunes, contractile myoepithelial cells surrounding the acinus and striated and intercalated ducts
80
what can the acini be
mucus cells or serous cells
81
what do serous cells produce
watery solution rich in a amylase
82
what do the mucous cells produce
mucus rich secretion
83
what are the functions of saliva
lubrication
protection
digestion
facilitate sucking by infant
84
how does saliva provide protection
high Ca salt content to prevent deminerlisation of tooth enamel
lysosome attacks bacterial cell walls
lactoferrin chelates iron - limits its availability for bacteria requiring it
IgA
protein coats the teeth reducing bacterial adherence
85
what are found in high conc in saliva
K and HCO3
86
what is the secretion like from parotid glands
watery a amylase rich
87
what is the secretion like from sublingual glands
mainly mucous cells
88
how does HCO3 and K conc vary with flow rate
with inc flow rate
| - HCO3 conc inc and K conc dec
89
where is saliva secreted and modified
secreted from the acinar cells
modified by the duct cells
90
what does modification of saliva do
remove Na and Cl and add K and HCO3
91
what is the overall effect of modification of saliva
diluting
92
what does simple stimulus of food activate
nucleus tractus solitarius
93
what does acquired stimulus of food activate
cerebral cortex
94
what does parasympathetic stimulation of the salivary glands occur via
CNIX (parotid) and CNVII
95
what is the parasympathetic stimulation of the salivary glands mediated by
M3/M1 receptors
96
what does sympathetic stimulation of the salivary glands occur via
Postganglionic fibres from superior cervical ganglia and adrenaline from adrenal medulla
97
what is the sympathetic stimulation of the salivary glands mediated by
a and B1 receptors
small volume of thick mucous rich saliva
98
what does the stomach mix food with gastric secretions to form
chyme
99
how can the duondenum delay gastric emptying
neuronal response (enterogastric reflex)decreases antral peristalic activity
Hormonal response – release of enterogastrones [e.g. secretin and cholecystokinin CCK)] from duodenum inhibits stomach contraction
100
why does fat delay gastric emptying
required for digestion and absorption in the small intestine
101
why does Hypertonicity delay gastric emptying
products of carbohydrate and protein digestion are osmotically active and draw water into the small intestine – danger of reduced plasma volume and circulatory disturbances
102
what do parietal cells secrete
HCl and IF
103
what do enterochromaffin cells secrete
histamine
104
what do D cells secrete
somatostatin
105
what does somatostatin do
inhibit Hcl secretion
106
what does histamine do
inc HCl secretion
