Final Exam Flashcards
(122 cards)
1
Q
Types of thyroid hormones
A
Thyroxine (T4) tetraiodothyronine
3, 5, 3 tiiodothyronine (T3)
3, 3, 5 triiodothyronine (rT3)
2
Q
Thyroid follicle
A
circle surrounded by blood capillaries. Thyroid colloid in centre that has precursor protein to form all thyroid hormones
3
Q
Thyroid hormone
A
only iodine containing hormone
4
Q
thryoglobulin
A
must be synthesized to get the tyrosine
5
Q
Thyroglobulin synthesis
A
1) tyrosines on thryoglobulin
2) iodination of tyrosine residues - thyroid peroxidase
3) conjugation of iodinated tyrosine residues to form iodinated thyronine (coupling reaction) thyroid peroxidase
4) storage of iodinated thyroglobulin in the colloid (centre part of follicle)
5) Reabsorption of colloid by phagocytotic action of thyroid epithelial cells
6) Enzymativ processing of reabsorbed thyroglobulin in thyroid epithelial cells
6
Q
DI-Tyr + DI-Tyr=
A
T4
7
Q
MI-Tyr +DI-Tyr=
A
T3 or rT3
8
Q
MI-Tyr + MI-Tyr=
A
T2 forms
9
Q
MI-Tyr +Try=
A
T1 forms
10
Q
DI-Tyr + Tyr=
A
T2 forms
11
Q
Pathways
A
Brain - hypothalamus (TRH for positive, DA for negative) - pituitary thyrotropes (TSH for positive) - thyroid - T4 and T3 - action on target cell
12
Q
TSH receptor effects
A
cAMP/PKA
cAMP to thyroglobulin
PKA to pentose pathway and ATPase pathway
13
Q
Thyroid hormone on frog metamorphosis
A
TRH affects prometamorphosis, TSH affects middle of metamorphosis, T3/T4 more for the end part. Prolactin is a precursor for this.
14
Q
why do we need more T4 than T3, when T3 seems to be used in more situations?
A
T4 binds to thyroid hormone binding globulins (TBG) albanin and pre-albanin and there is lots of TBG to be bound to
15
Q
Glucocorticoid (GRE) Hormone response element
A
16
Q
Estrogen (ERE) hormone response element
A
17
Q
Thyroid Hormone (TRE) hormone response element
A
18
Q
Vitamin D3 (DR+3, VDRE) hormone response element
A
<AGGTCA
19
Q
HRE
A
Hormone Response Elements
are often palindromic
20
Q
Steroid hormone receptor action on transcription
A
1) change in conformation and DNA independent phosphorylation
2) Receptor dimerization via Leu-rich region
3) DNA binding & DNA dependent hyperphosphorylation
4) Stabilization of receptor dimer and DNA binding
5) Recruitment tof adaptor proteins and interactions with nuclear transcription factors and transcription activators/regulators elements
6) Regulation of gene transcription
21
Q
BP
A
plasma binding protein
22
Q
TR alpha
TR beta
isoformsq
A
TR alpha in heart
TR beta in liver
23
Q
TR and RXR
A
in mitochondria - can affect maternal mitochondrial DNA
24
Q
Nuclear Receptors
A
mediate action of membrane permeant steroid and thyroid hormones (but sometimes they still bind to membrane receptors)
25
Thyroid on the PLC pathway
Only when TH bind to membranes - alphaVbeta3 - it binds TETRAC (T4)
26
Deamination of T3 and T4
T4 - TETRAC
| T3 - TRIAC
27
Insufficient Iodine
TSH induced Hypertrophy and goiter
28
Excess of Iodine
poisoning of peroxidase enzyme
29
Inhibitors of iodine uptake
cabbage, brussel sprouts, turnips, broccoli (form thiocyanates upon digestion) thioamides can also hinhibit peroxidase enzyme and deiodinase
30
MSH
Melanotropin Stimulating Hormone (action on skin color in vertebrates)
- mimic background
- skin heat absorption and relection
- visual signalling cues (behaviour)
- protection from UV radiation
31
Chromatocytes
all colored/pigmented skin cells
32
chromatophores
subgroup of cells - can rapidly redistribute pigments within them
33
Two types of color change
Morphological color change (slow, long term affects)
| Physiological color change (relatively fast, short term affects)
34
Chromatosome
organelle containing the pigments
35
POMC
Pro-opiomelanocortin
(precursor for multiple potentially active peptides)
Pars distalis
Pars intermedia
36
Pars Distalis
alpha msh and clip (corticotropin like peptide) -> ACTH
| beta msh, blank, end (endorphin) -> beta LPH
37
Pars Intermedia
alpha msh and clip
beta msh and blank -> gamma LPH
end
38
Physiological color change
melanosome aggregated in melanophore (skin light in color), then add MSH to get melanosome dispersed in melanophore and more surface area is covered by melanin-containing melanosomes, so skin darkens and is less reflective
39
Melanosomes
organelles than contain melanin
40
melanin
dark or dark brown pigments
41
melanophores
cells that contain melanosomes
42
norepinephrine causes...
aggregation of chromosomes
43
Irridophore
causes amphibians to appear irridescent - have crystals in cells
44
Releasing factor of color change
CRH (corticotropin releasing hormone)
45
Release inhibiting factor for color change is
dopamine
46
peptide hormone signal transduction
hormone - receptor - G protein - Generation and/or modulation of second messenger levels - modulation of some intracellular biochemical event - biological response
47
exopeptidase
chews N (aminopeptidase) or C (carboxypeptidase) end of peptide
48
endopeptidase
chews middle of peptide
49
Typrsin inhibitor
Part of pancreatic enzymes
50
Lumen and Brunner's glands
Lumen is centre open part of gut, surrounded by Brunner's glands
51
Peristalic action
circular muscle contraction, coordinated with longitudinal smooth muscle action
52
Segmentation
hard contraction of circular muscles to create small bolus
53
Secretin
blood borne factor released by acid on duodenum that stimulates pancreatic enzyme release
54
Carbohydrate digestion
```
complex polysaccharides (starch and glycogen) are digested by polysaccharidase (pancreatic amylase) into disaccharides.
Then maltase, sucrase, and lactase further breakdown disaccharides to monosaccharides (pentose/hexose) which can be absorbed in gut epithelium via Carrier Mediated Transport Systems
```
55
Glycogen
more extensive branching than starch. animal based carbs.
56
Acidic climates of digestion
mouth - alkaline
stomach - acidic (4-5 ph resting, 1-2 during acid secretion)
intestine - alkaline
57
GLUT2
only used in high glucose conditions - for glucose fructose and galactose (in enterocyte cells)
58
GLUT5
for fructose (in enterocyte cells)
59
Cellulose
Cellulase enzyme to break down in bacteria, snails, anthropods, other vertebrate ferment in gut with bacteria creating short chain fatty acids and methane gas.
60
Short chain fatty acids
easily absorbed since water and fat soluble.
61
Chitin
Chitinase to break down, in insect eating animals
62
Cecum
larger in animals that ferment more (cows and horses) for cellulose digestion
63
Metabolites and microflora
Microflora release microbolites which decrease inflammatory responses and cancer, probiotics help grow helpful microflora
64
Lipid Digestion
triglycerol with a glycerol backbone and 3 fatty acid side chains or a phosphosugar and 2 fatty acid side chains
65
Acidic Lipases
Lingual lipase
gastric lipase
tributyrinases
66
Alkaline lipases
pancreatic lipases
| pancreatic triacyglycerol lipase
67
lipid emulsifier
bile salts
68
micelle
single layer of fatty acids, monoglycerides, glycerol and bile salts with HYDROPHILLIC heads OUTSIDE.
can pass through plasma membrane of enterocytes at the microvillus
69
chylomicrons
lipid droplets coated in proteins formed in epithelial cells of intestine. carried via lymphatic system to venous blood and processed in liver
70
Glycerol and Fatty acids processed by
Kerb's cycle and beta oxidation pathways
71
Most lipid digestion takes place in...
the intestines - pancreatic lipase and cholesterol esterases and bile salts
72
Protein Digestion
proteases or peptidases (endopeptidases and exopeptidase) endopeptidase usually acts first (found in stomach)
73
Endopeptidase
Breaks bond in middle of peptides (eg. pepsin in stomach secretion, trypsin and chromotrypsin in pancreatic secretion)
74
pepsin
needs acidic environment
75
trypsin and chymotrypsin
needs slightly alkaline environment
76
Exopeptidase
cleaves off terminal amino acids produced by pancreas
77
Tripeptidase and dipeptidase
finish off digestion of small peptide fragments in intestine
78
amino acids and dipeptides absorbed in gut by
carrier mediated transports (amino acid-Na co-transport)
79
nucleic acid broken down by
nucleases, nucleotidases, nucleosidases
80
esters
esterase breaks down, formed from an alcohol and an acid
81
How does the stomach not eat itself?
pepsinogen (inactive) can be cleaved by acid to pepsin (active). thick layer of sugar based mucus. proenzymes and zymogen
82
proenzymes and zymogen
inactive precursor molecules
83
trysinogen and chymotrypsinogen
secreted zymogens from pancreas. high pH enterokinase can turn trypsinogen to trypsin.
which in turn, trypsin turns chymotrypsinogen to chymotrypsin.
84
Nueral vs endocrine
neural is quick
| endocrine is more long term
85
enterochromaffin like cells system
neural and endocrine control of digestive system
etero=gut
chromaffin=a cel type stainable with silver salts
86
Oral cavity digestion
amylase (in saliva, starts carb digestion)
food chewed to small bolus
mucin (in saliva, glycoprotein; poteinaceous mucopolysaccharide. acts like lubricant for swallowing)
87
Gastric secretions digestion in stomach
carbs, protein, and some fat digested.
pepsin, amylase, lipase, tributyrase present.
3 phases
88
3 phases of gastric secretions
Cephalic - initiated and controlled by neuronal input from CNS
Gastric - initiated and controlled by gastric secretions
Intestinal - initiated and controlled by intestinal secretions
89
Ach
Acetylcholine
90
SS
somatostatin
91
GRP
Gastrin releasing peptide
92
GIP
Gastric inhibitory peptide
93
VIP
Vasoactive intestinal peptide (stomach motility decrease)
94
CCK
cholecystokinin (contracts sphincter when exposed to fat)
95
Intestinal Digestion
completes protein starch and fat digestion. pancreas secretes enzymes for it.
pancreas source of alkaline fluid secretion in intestines.
bile secretion required for fat digestion
96
Ghrelin
orexigenic hormone (motilin family). secreted in stomach. absorbed in blood. fasting increases ghrelin mRNA expression. levels drop within an hour of feeding. can be trained with schedule of eating regularly. acts on brain to stimulate hunger. stimulates pituitary GH secretion ad GH in turn inhibits ghrelin release
97
Leptin
anorexigenic hormone. produced by adipocytes. indicator of fat storage. reduce hunger and increase satiation. released by stomach into blood after feeding. can act locally on stomach to decrease gastric secretion and motility. works with ghrelin as antagonistic pair.
98
Pathogen types
virus, fungus, parasite, bacterium
99
SCID
Severe combined Immunodeficiency syndrome - no T and B cells (adaptive immunity)
100
CD4 cells are
essential to having an aquired immune system response
101
Autoimmune disorder triggers
```
Stress
hormones
metals
food antigens
pesticides & poisons
```
102
Cells of innate immunity
granulocytes
monocytes
macrophages
dendritic cells
103
Cells of adaptive immunity
T cells
| B cells
104
Humoral components (innate)
complement antimicrobial proteins
enzymes
cytokines
receptors
105
humoral components (adaptive)
antibodies
| cytokines
106
1st, 2nd, and 3rd lines of defense
1st & 2nd are innate (skin, ,mucos membranes, chemicals then phagocytosis, complement, interferon, inflammation, fever)
3rd is adaptive (lymphocytes and antibodies)
107
Chemical factors as barriers to infection (innate)
fatty acids in sweat
enzymes in tears, saliva, mucos
low pH of sweat and gastric secretions
defensins (small antimicrobial proteins)
108
Biological factors as barriers to infection (innate)
normal bacterial flora of the skin and GI tract
inhibit colonization by pathogenic bacteria
Secrete toxic substances and compete for nutrients and attachment sites
109
Hematopoiesis
formation and differentiation of blood cells
110
Lymphoid progenitor creates ____ Cells
Nk cells
T cells
B cells
dendritic cells
111
Myleoid progenitor creates _____ cells
```
monocyte/macrophage
neutrophil
eosinophil
basophil
platelets
erythrocyte
dendritic cells
```
112
Myeloid lineage cells are
the first responders to infection
113
types of granulocytes (which are myeloid in lineage)
neutrophils
basophils
mast cells
eosinophils
114
myeloid antigen presenting cells
monocytes
macrophages
dendritic cells
115
Granulocyte granules..
directly damage pathogens, regulate immune cell movements, regulate the activities of other immune cells, and contribute to tissue damage and remodelling
116
chemokines
major chemoattractant
117
What is complement system
cascade of immune proteins activated by infections. different complement proteins have different functions
118
lactoferrin & transferrin
proteins that bind iron that is required for bacterial growth
119
lysozyme
enzyme that breaks down the cell well of bacteria
120
interferons (type of cytokine)
immune proteins that limit virus replication in cells
121
cytokines
hormones of the immune system, proteins that initiate and regulate immune response (kenkines are smaller cytokines) (interlucin is a cytokine)
122
monocytes vs macrophages
monocytes - more immature form of macrophage - looks like small compact cell
macrophage - involved in phagocytic processes, picking up stuff in envionrment for antigen recognition (further differentiated monocyte) - look like ball with lots of pieces coming off
