Week 1 Flashcards
1
Q
Conceptus
A
Product of fertilization
2
Q
Primordium
A
Organ or tissue in early stages
3
Q
Embryonic Period
A
Weeks 3-8
4
Q
Fetal period
A
Weeks 8-38
5
Q
Trimesters
A
Month 1-3, 4-6, 7-9
6
Q
Blastocyst parts (3)
A
Inner cell mass (Embryoblast)
Outer cell mass (trophoblast)
Blastocyst cavity
7
Q
Blastocyst arrival in uterus (week)
A
Week 1
8
Q
Implantation
A
Fusion of Trophoblast and endometrial epithelium
9
Q
Cytotrophoblast
A
Unfused trophoblast cells
10
Q
Syncytiotrophoblast
A
Divided trophoblast cells that are fused into endometrial epithelium
11
Q
hCG
A
Human chorionic gonadotropin
Secreted by Syncytiotophoblast –> prevents menstruation
12
Q
Gastrulation (in general)
A
Week 3
Bilaminar germ disk –> trilaminar germ disk
Endoderm
Mesoderm
Ectoderm
13
Q
Formation of endoderm
A
Epiblast cells migrate through primitive streak to replace hypoblast –> form endoderm
14
Q
Mesoderm formation
A
Epiblast cells migration through primitive streak lie between endoderm and epiblast –> mesoderm
15
Q
Ectoderm formation
A
Non migrating epiblast cells –> ectoderm
16
Q
Ectoderm develops into..
A
Epidermis
CNS
17
Q
Endoderm develops into..
A
Inner lining of digestive and respiratory tracts
18
Q
Mesoderm develops into..
A
Muscles, bones, blood, connective tissues, fat
19
Q
Sacrococcygeal teratoma
A
Occurs when primitive streak cells persist
Tumors have a lot of tissues in them, teeth/hair
20
Q
Caudal regression
A
Due to failure of mesoderm formation
Cranial structures normal, inferior structures underdeveloped
21
Q
Locations without mesoderm after gastrulation
A
Cloacal membrane
Buccopharyngeal membrane
Tightly bound ecto and endoderm
Will form oral and uro-genital-digestive openings
22
Q
3 mesoderm tissues
A
Paraxial mesoderm
Intermediate mesoderm
Lateral plate mesoderm
23
Q
Formation of intraembryonic coelom
A
Lateral plate mesoderm splits into somatic and splanchnic mesoderm
Space in between is intraembryonoic coelom
24
Q
Somatic mesoderm development –>
A
Body wall, conscious sensation and movement
25
Splanchnic mesoderm development -->
Visceral, unconscious sensation and movement
26
Intraembryonic coelom development -->
Body cavities
27
Molar pregnancy
Organism only develops placenta, no embryo
Villi swell and must be removed
28
Neurulation
Week 4 (end of week 3)
Notocord induces ectoderm to thicken = neuroectoderm
Neuroectoderm folds, creates neural groove
Neuroectoderm fuses --> neural tube formed (filled with amniotic fluid)
29
Surface ectoderm after neurulation becomes...
Epidermis
30
Direction of neural tube closure
First in middle, then cranially and caudally
31
Closing of neural tube (week)
Near week 4 end
32
Neural crest
Forms when ectoderm cells break off from neural tube and neuroectoderm
Lateral to neural tube
33
Neural crest develops..
Neural cells that are outside of CNS
Schwann cells
dorsal root ganglion
Cranial nerve ganglion
Postganglionic neurons
34
Paraxial mesoderm condensation results in
Somitomeres --> Somites
35
Somites develop into..
Bone (migrates aroung notochord), muscle, dermis
36
Somite divides into 2 parts
Sclerotome (bone)
| Dermomyotome (muscle and dermis)
37
B cell development (total)
Stem cell --> Pro B --> Pre B --> Immature B --> Mature B
38
Pro B cell development
D-J rearrangements in H chain
39
Pre B cell development and Ig expression
V-D-J rearrangement in H chain
Cytoplasmic mu and pre B cell receptors
40
Immature B cell development and Ig expression
VJ rearrangement = Single functional light chain
IgM expressed on surfaceas receptor (can't be activated by antigen)
41
Mature B cell
IgM and IgD expression
Cell exits bone marrow
42
Bruton's X linked Agammaglobulinemia
Defect in btk gene
btk gene product = pro B cell --> further development
Defect = lack of humoral immunity (no B cells)
No tonsils of papable lymph nodes
43
2 T cell types
Alpha-beta
Gamma-Delta
44
T cell marker on all T cells
CD3
45
T cell markers on alpha beta
CD4 or CD8
46
Activation of T cell (3 steps)
```
Adhesion
Signal 1 (Antigen recognition)
Signal 2 (co-stimulation, B7-CD28)
```
47
Cell adhesion
Adhesion molecules help connect Tcell and APC
LFA-1/CAM-1
Transient connection
48
Antigen recognition and adhesion
TCR recognizes MHC/peptide --> Increased affinity of LFA-1
49
Leukocyte adhesion deficiency
Affects beta2 integrin subunit of LFA-1
50
Antigen recognition
TCR binding induces CD3 signal cascade
51
Costimulatory Signal
CD28-B7 (Most studied)
B7 on APC activated by microbes or innate immune response
Connect with CD28 on Tcell
52
B-cell activation by T cell (general overview)
B cell binds antigen --> Peptide derived and presented by MHC --> T helper cell recognizes
53
Helper T cell action after connected to B cell
CD40Ligand and cytokines expressed (bind to resective receptors) --> B cell activation and proliferation
54
Hapten
Small non immunogenic molecule
Needs carrier (eg BSA)
Carrier-hapten complex is immunogenic and Ig will react to hapten alone
ONLY AFTER COMPLEX IMMUNIZATION
55
IL-2
Made by activated T-cells
Binds (autocrine) to t-cells (IL-2R) and induces clonal expansion and differentiation
56
3 CD4 subsets
Th1, Th2, Th17
57
Th1 cytokine
IFN-gamma
58
IFN-gamma
Activates macrophages
| --> increased MHC expression, cytokine secretion, reactive O-, NO, lysosomal enzymes
59
IL-12 and Th1
IL12 secreted by innate immunity --> promotes Th1 responses
60
Th2 cytokines
IL-4 --> IgE response
IL-5 --> Eosinophil activation
IL-10 --> Suppress Th1
IL-13 --> Like IL-4, hypersensitivity
61
IL-4
IgE response
62
IL-5
Eosinophil activation
63
IL-10
Suppresses Th1
64
Th17 cytokines
IL-17A
IL17-F
IL-22
65
IL-17
Inflammatory diseases
| Neutrophil action
66
CD8 activation (overview)
Adhesion
Ag recognition
Co-stimulation
IL-2 (made by CD4 or CTL)
67
CTL mechanism of action
Initiates apoptosis pathway of cell
Releases granules (perforins/granzymes) = apoptotic pathway
68
NK cells
Natural killer, kill cells without MHC-1
Inhibitory receptor binds to MHC-1/peptide --> no destruction
69
ADCC
Antibody dependent cellular cytotoxicity
NK's bind to cells coated in IgG --> Kill cell
70
3 groups of genes involved in birth defects
Growth factor receptors
Transcription Factors
Extracellular matrix proteins
71
Anencephaly
Incomplete development of cranial neural tube --> exposed brain, undifferentiated
72
Myeloschisis
Incomplete development of the caudal neural tube
Lumbar spinal cord that is undifferentiated and exposed
73
Spina bifida occulta
Asymptomatic
Unfused vertebral arch but not huge opening
74
Meningocele
Only meninges protrude through defective non fused vertebral arch
75
Meningomyelocele
Neural tube breaks from ectoderm, herniates through defect
76
Phenytoin
Anticonvulsant
Teratogen --> Fetal hydantoin syndrome
Heart malformations, facial clefts, limb defects
Metabolized by phase 1 enzyme of epoxide hydrolase
77
Mercaptopurine
Metabolized by thiopurine methyltransferase (TPMT)
78
Pili
Protein projections on surface of bacteria (made of pilin)
Major role in adherence, attach to receptors on host cell
Antigenic, anti-phagocytic, variable
79
Spores
Small metabolically quiescent forms of bacteria, produced as survival mechanism
Can withstand extreme environments
80
Exotoxin
Proteins that bind to host cell (B domain) and damage/kill host (A domain)
81
Diptheria toxin
Stops protein synthesis
A domain ADP-ribosylates elongation factor 2 --> no protein synthesis
82
Cholera toxin
A domain ADP-ribosylates GTP binding protein, constant cAMP --> diarrhea
83
Tetanus and Botulinum toxins
Cleave vesicle fusion proteins
Block neurotransmitter release
84
Bacterial endotoxins
1. Integral to bacteria structure
2. Composed of lipopolysaccharide
3. Gram negative ONLY
85
Steps for microorganism infection
1. Entry
2. Spread
3. Multiplication
4. Transmission
5. Pathology
86
TNF-alpha
Endogenous pyrogen (fever)
Made by macrophage
Increases vascular permeability --> complement and increased fluid drainage to lymph nodes
87
Type 1 Interferon response
Induce resistance to viral replication (RNA and Protein synthesis level)
Increase NK cell receptor ligands
Activate NK cells
Interferons released when cell is killed by virus, induces response in neighboring cells
88
HIV and chemokine relationship
HIV binds to chemokine receptors (CXCR4, CCR5)
89
Th1 pattern of cytokines =
Enhanced phagocytosis
90
Th2 pattern of cytokines
M2 or alternative pattern, wound healing
91
M2 macrophage
Wound repair, fibrosis
92
Superantigen
Activates T cells
Binds to MHC class 2 outside of peptide binding groove and Vbeta of TCR
93
High endothelial venules
Path of naive T cell trafficking to specific peripheral lymphoid tissue
Homing based on specific homing receptors interacting with HEV receptors
94
Difference between fungi and human cells
Plasma membrane
Cell wall
95
Fungi cell wall
90% polysaccharides
10% proteins
Mannans
Glucans
Chitin
96
Mannan
Mannose polymers
Attached to surface proteins
97
Glucans
Glucose polymers
Strength
98
Chitin
N-acetylglucosamine polymer
Strength
99
Moulds
Form hyphae
-Tube like structures
Hyphae fusion = mycelium (colony)
100
Yeast
Unicellular
Budding reproduction
101
Aflatoxin
Food contaminant
102
Fungi virulence/pathogenesis
| steps
Adherence
Invasion
Tissue damage
Host evasion
103
Fungi adherence
Fungal surface proteins/carbohydrates bind human cell receptors
104
Invasion
Hyphal pathogens
105
Tissue damage
Degradative enzymes
106
Host evasion
Avoid recognition
Escape phagocytic killing
107
Superficial fungi
Environmentally acquired
108
Opportunistic fungi
Emerge in diseased hosts only
109
Pneumocystis jirovecci
Acquired by inhalation, but held in check by immune system
Pneumocystis pneumonia in diseased patients
110
Systemic fungi
Infects healthy host
Environmental transmission
111
Histoplasmosis
Found in caves, bat is the host
112
Antifungal innate immunity
PAMP's recognized by PRR's
113
Common fungal PAMP and human PRR
PAMP: Beta Glucan
PRR: Dectin-1
114
Azoles
Block ergosterol synthesis
Fluconazole
Voriconazole
Posaconazole
115
Allylamines
Block ergosterol synthesis
Terbinafine (Lamisil)
116
Polyenes
Bind ergosterol (form pore)
Higher toxicity
Amphotericin B
Nystatin (topical)
117
Echinocandins
Block glucan synthesis
Caspofungin
Anidulofungin
Micafungin
118
Pyrimidine Analogs
Block DNA/RNA synthesis
Flucytosine
Rapid resistance, works in combo therapy
119
Fertilization (sperm)
Burrow through corona radiata and zona pellucida
Enzymes released from acrosome
120
Fertilization (oocyte)
Release cortical granules (confirmation change to prevent polyspermy)
Finish meiosis II
Begin metabolism
121
Schistosoma mansoni
Flatworm infestation
122
Tapeworm (alternate name)
Cestode
123
Fluke (alternate name)
Trematode
124
Entamoeba Histolytica
Amebic parasite found in dirty water/food
Or Butt stuff
125
Ciliated or flagellate protozoan parasites more common?
Flagellate
126
Trichomonas vaginalis
Sexually transmitted flagellate protozoan
127
T cell development stages
Double negative --> Double positive --> +/-
+/- in medulla of thymus
128
Transition from +/+
Recognition of MHC Class II = CDR-4+
Recognition of MHC class I = CD-8+
No recognition/too strong recognition = apoptosis
129
Cytokine signal transduction
JAK/STAT pathway
130
IL-2 and T cell affinity
Only activated T cells express Alpha unit of IL-2R and will respond to IL-2
131
Th2 defends host against...
Helminthic parasites
132
Th1 defends hosts against...
Foreign intracellular microbes
133
Th17 defends host against...
Extracellular bacteria/fungi
134
Pyrogens
TNF-alpha
IL-1
IL-6
135
Path of virus after entry into body
Taken up by APC (dendritic cell) --> Travel to lymphoid tissue
136
M1 phagocytosis
Microbe binds to phagocyte receptor --> Phagocyte membrane envelopes microbe --> Fuse with lysosome --> microbe killed
Th1 cytokines
137
Positive sense RNA viruses
Virion RNA = mRNA
Immediate translation
138
Negative sense RNA viruses
RNA is complementary to mRNA
Need RNA dependent RNA polymerase packaged with it to transcribe then translate
139
Double stranded RNA viruses
RNA polymerase needed to make mRNA
140
Problem of monocistronic RNAs in human?
Humans only operate with single mRNA's
Viruses translate singe mRNA and cleave product to make multiple proteins
141
Forces driving viral diversity
Mutation
Selection
Reassortment
Genetic drift/founder effect
142
Immune escape
Gradual accumulation of mutations (genetic drift)
143
Productive infection
Cell has appropriate receptors and machinery for viral replication, production, and release
144
Null
Cell does not have appropriate receptors
145
Abortive
No virion formation after entry
| Insufficient DNA/RNA production or non infectious virions produced
146
Restrictive
Cell is transiently permissive, only few viruses produced
No more production but virus genome still present
147
Gram+ bacteria
Thick peptidoglycan
| Teichoic acid
148
Gram- bacteria
Outer membrane with LPS
149
LPS
Lipopolysaccharide
Lipid A portion responsible for endotoxin activity
150
Fluconazole
Voriconazole
Posaconazole
Azole
Block ergosterol synthesis
151
Terbinafine (Lamisil)
Allylamine
Blocks ergosterol synthesis
152
Amphotericin B
Polyene
Binds ergosterol, forms pore
153
Nystatin
Polyene
Binds ergosterol, forms pore
154
Caspofungin
Anidulofungin
Micafungin
Echinocandins
Block glucan synthase
155
Flucytosine
Pyrimadine analog
Block DNA/RNA synthesis
156
Giardia lamblia
Most common intestinal protozoan in US
Diarrhea
Water borne cysts
157
Chagas disease
Parasite that causes heart disease
158
Ascariasis
Infestation of ascaris lumbridoides
Nematode
Fecal-oral transmission of eggs in contaminated food
159
Percent of babies born with birth defect
3%
120,000/year in US
160
Most common birth defect
Congenital heart defect
1% of all births
40,000 new cases per year
161
Cleft lip prevalence/incidence
P: 1/1000
I: 7000 a year
162
Down's syndrome prevalence/incidence
P: 1/1000
I: 6000 a year
163
3 major components of embryonic development
Pattern formation
Axis specification
Organogenesis
164
FGFR3 diseases
Hypochondroplasia
Thanatophoric dysplasia
Achondroplasia
165
FGFR2 disease
Apert syndrome
Digit fusion, face hypoplasia
166
Hirschsprung disease
P: 1/5000
Lack of nerve cells in enteric tract
RET oncogene mutation
167
Hox genes
Anterior/posterior axis
168
Situs inversus caused by...
Dynein
Polycystin-2
