AMS Exam 2 Flashcards
What is transamination
one of two main processes of Amino acid metabolism
the process of removing an amine group from one amino acid and adding it to a metabolic intermediate to create another amino acid
Important transamination examples:
pyruvate → alanine;
α-ketoglutarate → glutamate;
oxaloacetate → aspartate
With transamination, pyruvate and intermediates of the citric acid cycle provide the carbon skeletons needed for the synthesis of nonessential or dispensable amino acids.
What is the role of ZPA
The zone of polarizing activity (ZPA)
is an area of mesenchyme that contains signals which instruct the developing limb bud to form along the anterior/posterior axis.
Limb bud is undifferentiated mesenchyme enclosed by an ectoderm covering.
Eventually, the limb bud develops into bones, tendons, muscles and joints
The master gene for this regulation is the sonic hedgehog whose product is secreted by these cells
What is the Fab portion of an antibody for?
Antigen binding
What makes up antibodies?
2 heavy chains and 2 light chains
There is an Fab portion (top of “y”) and a Fc portion (bottom of “Y”)
There are constant portions and variable portions
The two sides of the Y are held together by disulfide bonds
Describe IgG antibodies.
IgG = 70-75% of antibodies
can pass throught the placenta
involved in activating the comlement system
provides long term protection because it persists for months or years after the antigen that has triggered their production - bacteria, virus, binds antigens to enhance phagocytosis by other cells
IgG is found throughout the body, mainly in most of the bodily fluids
IgG is a much more specific antibody to the antigen, therefore it binds the antigen more tightly
IgG takes the body longer to create but it stays within the body on memory cells
Describe IgA antibodies.
IgA binds antigens on microbes before they invade tissues
Causes antigen aggregation
Are teh first defense for mucosal surfaces such as intestines, lungs and nose
What percentage of T cells are TCR2 cells
90-95% of T cells
heterodimer of alpha and beta chains
MHC dependent in their recognition of antigen
subdivided into CD4 and CD 8 cells
What are the functions of the complement system
Kill pathogens
Opsonization
Complement proteins coat the outer surface of the pathogen and attract macrophages
Membrane attack complex
Enhance inflammation
Explain C5a in classical pathway
It comes from C5
When C5 is cleaved by C5 convertase (C4b2a3b)
it becomes C5a and C5b
C5a is a chemo attractatn for macrophages and neutrophils
C5a binding to these cells primes the cells for mediating their host defense functions
It increases the expression of adhesion molecules on leukocytes and the vascular endothelium so that leukocytes can squeeze out of the blood vessels and enter the tissue (diapedesis).
It also causes neutrophils to release toxic oxygen radicals for extracellular killing; and it induces fever.
Describe dendritic cells
These are antigen presenting cells (APC’s)
Process and present antigens to T cells
Express MHC II
Phagocytosis
can act as a messenger between innate and adaptive immunity
Functions of T cells
Recognition of antigens through t cell receptors
helper and regulatory finctions
activate B cells
activate other cells of the immune response through cellular interactions or production of regulatory factors
Killing of target cells (foriegn cells, infected self cells, transfromed or aged cells)
Complement proteins
Soluble Proteins in the blood, part of the innate immune system
30+ types of proteins produced by the liver
Circulate in blood in inactive form – so they don’t attack the body
Become activated when they interact with an antigen
Complementary activation cascade
Complementary proteins activate each other
What are the granulocytes
Neutrophils = Multi-lobed, granules,
phagocitize pathogens or debris (50-70%)
Eosinophils = Bi-lobed, granules, kill parasitic worms, role in allergies and asthma (2-4%)
Basophils = single nuclei, lobed, releases histamine, anitcoagulant (<1%)
Describe Unsaturated Fat
Non-Saturated Fat:
Fewer hydrogen bounds bounds to carbons
1 or more double bonds (kinks in the tails)
Liquid at room temperature
Low melting point
Most plant fats are unsaturated or polyunsaturated
Example: Oils
Describe Oligosaccharides
Condensation products of 3-10 monosaccharides
Indigestible à humans lack enzymes to break them down in the small intestine
Most are soluble fibers that help prevent constipation
Describe a Type 4 hypersensitivity reacion?
Type 4 = Regulated by T cells and are delayed reactions to antigens associated with cells
Tuberculin reactions, chronic asthma and contact dermatitis are type 4 reactions
What is deamination
one of two main processes of Amino acid metabolism
the process of removing an amine group and breaking down amino acids
With deamination, after the amino acid gets broken down, the amino nitrogen is excreted as urea
What is WNT Genes
genes that inhibited certain BMP to aid in heart development
What is Bmp (BONE MORPHOGENETIC PROTEIN)
further express dorsal and ventral regions by interacting with signals at the node
- -bmp is secreted as a growth factor in all regions and cells * *if inhibited, mesoderm layer becomes “dorsalized” forming the axial skeleton and notochord. * * if not inhibited (active), the mesoderm becomes “ventralized” to from the urogenital system, the limbs and ventral wall body
What is TBX Genes
transcription factors that specify limb direction and formation
Describe IgM antibodies.
produced during primary immune response
also enhances ingestion of cells by phagocytosis
best at activating complement system
IgM is the immediate antibody that is produced once a human body is exposed to a bacteria, virus or a toxin
IgM is larger in size compared to IgG
IgM is temporary and disappears after a few weeks. It is then replaced by IgG.
IgM is found mainly in the blood and lymphatic fluids.
Describe conjoined twins
overexpression of Goosecoid in frogs causes double-headed tadpoles:
too much goosecoid induces additional head regions
What happens when a Naive B cell is activated
After immunization or infection, Naive B cells become activated and can switch from expressing IgM or IgD on their surface to expressing IgG, IgE or IgA
What is Hox genes
play many roles in development; identity of the pharyngeal arches, limb location on the body
What is chemiosmosis in the ETC
The chemiosmotic theory explains the functioning of electron transport chains.
According to this theory, the tranfer of electrons down an electron transport system through a series of oxidation-reduction reactions releases energy.
This energy allows certain carriers in the chain to transport hydrogen ions (H+ or protons) across a membrane.
Steps in gluconeogenesis
Pyruvate → → → → → Pyruvate carboxylase Oxaloacetate → → → → → PEP carboxykinase PEP
PEP → → Fructose 1,6, bisphosphate (reverse glycolysis)
→ → → → → Fructose 1,6, bisphosphatase
Fructose 6 phosphate
Fructose 6 phosphate → → Glucose 6 phosphate
Glucose 6 phosphate
→ → → → → Glucose 6 phosphatase
Glucose
Systemic defenses of innate immune system
Systemic defenses
The elimination of foreign agents that made it through external barriers
Cellular component- Phagocytes
in acquired immunity - T cells
Soluble (humoral) Component
Antibodies
complemnt proteins
antimicrobial proteins
What results from the trilaminar disc
3 germ layers; Ectoderm, Mesoderm & Endoderm (outer/dorsal, middle, inner)
The dorsal germinal layer becomes the ectoblast/-derm.
The middle germinal layer (3rd germinal layer) becomes the mesoblast/-derm.
The ventral germinal layer receives the name endoblast/-derm.
What is the role of AER
The apical ectodermal ridge (AER)
is a structure that forms from the ectodermal cells at the distal end of each limb bud and acts as a major signaling center to ensure proper development of a limb
FGFs are secreted by the AER
What are APC cells
Antigen presenting cells
These are cells that express the MHC II
These can present antigens to T cells
Langerhans cells in skin
Dendritic cells
macrophages B cells
Describe Acquired immunity
Aquired or adaptive immunity can be active or passive
Active is exposure to deisease or vaccine and build antibodies accordingly
passive is gettting antibosie sfom another sourec ie breast milk placenta etc.
What is Fibroblast growth factor (FGF)
secreted by the node; initiates secretion of nodal from the primitive node that becomes concentrated on the left side; aids in limb growth, bone formation
Describe innate immune system
Activated cells produce their effects via the release of cytokines, complement and other systems: cytokines
What does the Embyroblast become
The embryo
Originate from Morula
inner cells from trophoblast
What are TCR 1 cells made up of
These are T cells
make up less than 10% of t cells
heterodimer of gamma and delta chains
What is the Fc portion of the antibody for?
Effector portion
Describe sacrococcygeal teratoma
tumor of the sacral area
contains every type of tissue derived from all 3 germ layers: gut from endoderm, neural tissue from ectoderm, and bones or teeth from mesoderm
This tumor may be derived from the fact that gastrulation went on too long
Is complement system innate or adaptive
Mostly Innate (both)
C1q part of the C1 complex can assist the adaptive immune response by binding to antigen antibody complexes on the surface of bacterial cells.
In most cases, this would be after the adaptive response has been initiated.
The classical pathway of complement system can also be involved in innate immunity if the complement proteins recognize and bind to the bacterial cell.
What is neurulation
Neurulation is a process in which the neural plate bends up and later fuses to form the hollow tube that will eventually differentiate into the brain and the spinal cord of the central nervous system.
Describe crouzon syndrome
Wide-set, bulging eyes and vision problems caused by shallow eye sockets
Mutation of FGFR2
beak nose, dental, jaw, hearing, cleft, eye issues
Normal intelligence
Describe diapedesis
Process of entering the tissue
attracted to endothelial cells via selectins
and bind via integrins
(this is a prcess of entering the tissue and is known as diapedesis)
Describe a Type 3 hypersensitivity reacion?
Type 3 = Results from the formation of antigens-antibody complexes that settle on tissue and organs in an attempt to remove these complexes underlying tissue is also damaged
Serum sickness and rheumatoid arthritis are type 3 reactions
What is the transverse septum
At start of 4 weeks gestation, there in only one continuous body cavity.
There is partial separation of the body cavity by a layer of mesoderm cells called the septum transversum
It will help to form the diaphragm (considered a major central tendon)
It is derived from the visceral mesoderm surrounding the heart. It is the folding of the head region that carries the septum transversum into the thoracic cavity.
creates the pericardioperitoneal cavities.
Forms the connective tissue of the liver as hepatic cells grow
What are the 2 types of light chains in antibodies?
Kappa and lamda
Describe achondroplasia
Mutation in FDFR3
Short limbed dwarf
Describe Polydactyl
Programmed celll death is interruppted
leaves too many fingers
Describe thalidomide induced limb defects
Disruption of AER
-Dactyl defects
Describe pfeiffer syndrome
Affects the shape of head and face, abnormalities in hands and feet
Mutations
Type 1 = FGFR1 or 2
Type 2 and 3 FGFR2
Most have normal intelligence and life span
What are the molecular signals of differentiation
Anterior visceral endoderm (AVE) expresses the head forming genes thus inducing the cranial region.
Goosecoid—a transcription factor which is the main head induction gene; encodes for the formation of the head
Bmp (BONE MORPHOGENETIC PROTEIN)—further express dorsal and ventral regions by interacting with signals at the node
- -bmp is secreted as a growth factor in all regions and cells * *if inhibited, mesoderm layer becomes “dorsalized” forming the axial skeleton and notochord. * * if not inhibited (active), the mesoderm becomes “ventralized” to from the urogenital system, the limbs and ventral wall body
Chordin—growth factor secreted by goosecoid
Noggin, follistatin, and nodal—growth factors secreted by the node and are proteins that inhibit BMP
Fibroblast growth factor (FGF)—secreted by the node; initiates secretion of nodal from the primitive node that becomes concentrated on the left side; aids in limb growth, bone formation
Nodal—secreted by the primitive node; its concentration on the left side of the embryo helps to establish left-sidedness by enhancing transcription factor, PItX2
PITX2—main transcription factor that induces left-sidedness
Hox genes—play many roles in development; identity of the pharyngeal arches, limb location on the body
TBX Genes- transcription factors that specify limb direction and formation
WNT–genes that inhibited certain BMP to aid in heart development
NKX2.5—the main transcription factor that encodes for heart development
What is Noggin, follistatin, and nodal
growth factors secreted by the node and are proteins that inhibit BMP
Activation of lectin pathway
Triggered by mannan-binding lectin, a normal serum constituent, that binds some encapsulated bacteria
Aka: Triggered by Lectin binding to pathogen surface
Cells: Factor D, Factor B, Prepardin, C3
What are the hypoblast cells
Hypoblast- important for early signaling to establish the cranial-caudal axis. Are eventually displaced
About 1 or 2 days after implantation, the embryo/embryoblast begin to differentiate into 2 layers
The dorsal layer, the epiblast,
and a ventral layer, the hypoblast
Explain C5a in classical pathway
It comes from C5
When C5 is cleaved by C5 convertase (C4b2a3b)
it becomes C5a and C5b
C5a is a chemo attractatn for macrophages and neutrophils
C5a binding to these cells prime sthe cells for mediating their host defense functions
What are the Agranulocytes
Lymphocytes = spherical, single nucleus, mount immune response by direct cell attack or via antibody production (20-40%)
Monocytes = U shaped nucleus, develop into macrophages in tissue and phagcitize pathogens or debris
What is a phospholipid
Glycerol molecule
two fatty acid non polar tails and a phosphate polar head
hydrophobic tails
hydrophilic heads
plasma membrane
External barriers of innate immune system
Physical barriers
skin,cilia
Chemical barriers
lysozymes in teras/saliva, mucin in mucous
Mechanical barriers
Cough, sneeze, flushing of urinary tract
microbial barriers
common flora, (gut, vagina, skin etc)
What cells are most responsible for transplant rejection
T cells
Explain C3a in classical pathway
It comes from C3
When C3 is cleaved by C3 convertase (C4b2a)
it becomes C3a and C3b
C3a is a potent chemo attractant
C3a attracts Mast cells to sites of complement activation.
Binding of C3a to mast cells and basophils induces degranulation and release of histamine.
What percentage of T cells are TCR1 cells
less than 10%
What happens when naive b cells are activated
naïve B cells become activated and can switch from
expressing IgM and IgD on their surface to expressing IgG, IgE or IgA
Describe Neutrophils
Last for 6 hours in circulation
account for 95% of circulating graulocytes and leukocytes
work through phagocytosis, can release granules causing damage to host
first cells to arrive at site of inflammation
(one way journey from bone marrow)
attracted to endothelial cells via selectins and bind via integrins
(this is a prcess of entering the tissue and is known as diapedesis)
Increased count = infection
What is the primitive streak node
The node is a shallow circular depression at the cranial end of the primitive streak. It contains transcriptional signals
the node contains the main head-inducing gene, goosecoid (a transcription factor)
What are dendritic cells
Antigen presenting cells (APC)
follicular dendritic cells present antigen to B cells
do not display MHC II
What are the differneces between CD4 and CD 8 Cells
CD4 T cells recognize MHC II complex (helper cells)
CD8 T cells regognize MHC I complex
CD8 cells cannot recognize just an antigen, their TCR2 will not bind to antigen
Cells that are expressing MHC II can present antigens to T helper cells (APC’s)
They can bind to peptides associated with MHC I molecules and kill the cells
all cells express MHC I
MHC II protein can only be found on specialized antigen presenting immune cells
Describe Monosaccharides
Sugars that cannot be hydrolysed into simpler sugars
Classified by number of carbon atoms: trioses, tetroses, pentoses, hexoses, heptoses
Classified by either aldehyde or ketone group: aldoses, ketoses
When the aldehyde or ketone group is reduced to an alcohol à polyols (polyhydric alcohols/sugar alcohols)
Xylitol, sorbitol
Transplant rejection
T cells are the population of cells responsible for most forms of graft rejection
- The T-cell antigen receptor (TCR) recognizes the complex of a small peptide located in the antigen-binding groove of an MHC molecule
- MHC molecules (also called human leukocyte antigens [HLA] in humans) are subdivided into class I molecules (found on all nucleated cells) and class II molecules, which are found on specialized antigen-presenting cells (APCs) such as dendritic cells, macrophages, B cells, and selected activated endothelial or epithelial cells
• IL2 will be used to activate TH cells in an autocrine fashion and TC cells in a
paracrine fashion
• Activated TC cells will kill using perforin and granzyme B
Name four protein complexes and two mobile transfer molecules of ETC
NADH dehydrogenase
Cytochrome BC1
Cytochrome oxidase
ATP synthase
Ubiquinone (Q) Cytocrome C (C)
What is hydrogenation
It is a reduction reaction
Adding hydrogen atoms to unsaturated fat to make it solid
Requires a catalyst (occurs spontaneously at high temps)
Describe Mast Cells
Basophils are basophils in the blood but
mast cells in the tissue
they account for 0.2% of circulating leukocytes
They are involved in hypersensitivity type 1 reactions
they have immune and inflammatory response functions
They release histamine and other inflammatory mediators
They are activated by binding specific antigens to IgE molecules
Allergens = Antigens that trigger IgE formation / basophil activation
Describe Disaccharides
Condensation products of two monosaccharide units
2 monosaccharides linked together by dehydration synthesis
Used for sugar transport or energy storage
-Effective storage reservoir à enzymes that break monosaccharides cant break these bonds
Linked together to form starch
Lactose, maltose, isomaltose, sucrose, trehalose
Describe Cellulose
Sructural component of plant and dinoflagellate cell walls
o Straight, long, unbranched chain
o Has B-glucose monomers (starch has a-glucose monomers)
§ Aka each successive glucose unit is rotated 180 degrees relative to the last repeat unit
o Forms hydrogen bonds with adjacent chains
Describe Saturated Fat
Saturated Fat Fatty acid carbons bound to as much hydrogen as possible Lack double bonds between carbon atoms Solid at room temperature Higher melting point Most animal fats are saturated Example: Butter
Describe Basophils
Basophils are basophils in the blood but mast cells in the tissue
they account for 0.2% of circulating leukocytes
They are involved in hypersensitivity type 1 reactions
they have immune and inflammatory response functions
They release histamine and other inflammatory mediators
They are activated by binding specific antigens to IgE molecules
Allergens = Antigens that trigger IgE formation / basophil activation
What patterns the embryo (caudal – cranial, dorsal ventral)
Establishment of the cranial-caudal axis requires molecular signals from two regions.
- Anterior visceral endoderm (AVE) induces the cranial region from hypoblast cells at the cranial end of the embryonic disc, expresses head forming genes.
- These signals are reinforced by the main head-inducing gene goosecoid (transcription factor), which signals from a region at the cranial end of the primitive streak called the node.
About 1 or 2 days after implantation, the embryo/embryoblast begin to differentiate into 2 layers
The dorsal layer, the epiblast,
and a ventral layer, the hypoblast
Rejection of allogeneic tissues
In the thymus, T cells are selected for maturation based on their ability to bind self‐MHC molecules.
Allo‐MHC molecules most likely resemble “altered‐self” molecules (ie, self‐MHC molecules containing a foreign peptide).
Allo‐MHC molecules, like self‐MHC molecules, can contain a wide variety of different peptides and so a large repertoire of T cells can respond
Describe IgD antibodies.
IgD is present on the surface of B cells and plays a role in the induction of antibody production
After immunization or infection, naive B cells become activated and can switch from expressing IgM and IgD on their surface to expressing IgG, IgE or IgA
How is the alternative pathway of the complement system activated? (steps)
Activates by lipopoly saccharides found on the surface of invading pathogens
The alternative pathway is always active at a very low level (due to spontaneous hydrolysis in C3)
Hydrolysed C3 is called C3H2O (C3b)
C3H2O (C3b) binds with Factor B
Factor D cleaves Factor B into Ba & Bb
Bb portion remains with C3H2O (C3b) (Ba portion leaves)
C3H2OBb (C3bBb) is the alternative pathway intiation convertase
C3bBb = C3 convertase (alternative pathway)
Describe a Type 1 hypersensitivity reacion?
Type 1 = IgE antibodies that sensitize an individual to an allergen and provoke a quick inflammatory response upon subsequent exposure.
Allergies and hay fever are both type 1
Where are IgA and IgE molecules found that do not have any antigens bound to them?
IgA are found in tears, milk and the gut
IgE are found on mast cells and in the tissue
What are the 5 types of heavy chains in antibodies
Alpha Gamma Delta Epsilon Mu
What are different types of complement systems
Classical
Alternative
Lectin
What is a steroid
Four fused carbon rings
Cholesterol and sex hormones
Bile acids, vitamin D
many stereoisomers due to asymmetry
Cholesterol is a significant part of many tissues
in all tissue except nervous tissue
Plasma membrane major part
What is a carbohydrate
all contain a C,H & O
Monosaccharides Disaccharides Oligosaccharides Polysaccharides Starch Glycogen Cellulose
Describe anencephaly
defect arises when the cranial end of the neural tube fails to close
Flat head brain may be exposed
Brain tissue forms abnormally and then degenerates due to exposure to amniotic fluid and lack of blood supply = lethal
Which layer is the epiblast
Dorsal layer
Describe Macrophages
They become Monocytes in the blood
Do not have memory
Part of Innate immune system
last 8 hours in circulation
Their functions include: phagocytosis, anti tumor, immune system regulation, inflammation, repair, APC to T helper cells
Describe caudal dysgeneisis
Mermaid syndrome
if gastrulation stops too soon
Babies die
from diabetic mothers
Whcih layer is the hypoblast
Ventral layer
What does the trophoblast become
the placenta and umbilical cord
Originate from Morula
outer cells from trophoblast
What does morula mean
Mulberry
it is a stage attained at 3 days
with 8-16 cells
Describe gastroschisis
Gastroschisis is a birth defect of the abdominal wall. The baby’s intestines are found outside of the baby’s body, exiting through a hole beside the belly button. (to the right)
90% in infants from younger mothers 18-22 years old
The incidence is increasing
What is PITX2
main transcription factor that induces left-sidedness
What are the epiblast
Epiblast cells- form all of the embryonic tissues and cells.
About 1 or 2 days after implantation, the embryo/embryoblast begin to differentiate into 2 layers
The dorsal layer, the epiblast,
and a ventral layer, the hypoblast
What are the classes of T cells
TCR 1
TCR 2
What is Nodal
secreted by the primitive node; its concentration on the left side of the embryo helps to establish left-sidedness by enhancing transcription factor, PItX2
How is a Saturated Fat different from a Non-Saturated Fat?
Saturated Fat Fatty acid carbons bound to as much hydrogen as possible Lack double bonds between carbon atoms Solid at room temperature Higher melting point Most animal fats are saturated Example: Butter
Non-Saturated Fat:
Fewer hydrogen bounds bounds to carbons
1 or more double bonds (kinks in the tails)
Liquid at room temperature
Low melting point
Most plant fats are unsaturated or polyunsaturated
Example: Oils
What is gastrulation
Gastrulation is the process of making the three germ layers from the epiblast as cell migration continues
What is Goosecoid
a transcription factor which is the main head induction gene; encodes for the formation of the head
What is the embyronic period
3 - 8 weeks
When is the highest risk for birth defects
At week 5
increases to week 5,
then decreases after that til birth
Activation of the Alternative pathway
The alternative pathway is activated when the proteins for the alternative pathway encounter LPS on the surface of an invading pathogen.
This is part of the innate response as there are no antibodies needed for the initiation of this response.
There is always a low level of activation of the alternative pathway.
Some C3(H2O) is always around but it is when the C3b binds to the invading cell and encounters activators found on the invading pathogen that it activates.
The alternative pathway will continue down the path to generating C3a, C5a, C5b, and the membrane attack complex.
Percentage of lymphoid cells that are T cells
85-95%
How are innate and adpative immunity different
Innate = fast and general
nonspecific
occurs within hours
also includes physical and chemical barriers of body
Adaptive = Slow and specific
Becomes active if innate system cannot deal with issue
only works from memory
works against specific pathogens or cells
How does neuralation occur
Neurulation in vertebrates results in the formation of the neural tube, which gives rise to both the spinal cord and the brain.
Neural crest cells are also created during neurulation.
Neural crest cells migrate away from the neural tube and give rise to a variety of cell types, including pigment cells and neurons.
Neurulation begins with the formation of a neural plate, a thickening of the ectoderm caused when cuboidal epithelial cells become columnar.
Changes in cell shape and cell adhesion cause the edges of the plate fold and rise, meeting in the midline to form a tube.
The cells at the tips of the neural folds come to lie between the neural tube and the overlying epidermis.
These cells become the neural crest cells.
Both epidermis and neural plate are capable of giving rise to neural crest cells.
Describe syndactyl
Web foot/hands
insufficient programmed cell death leaves no interdigit spaces
What is AER
Apical ectodermal ridge
Describe IgE antibodies.
Bind to mast cells and bosphils which participate in the immune response
plays a role in allergic resopnse
purpose is to stop parasites
What are the leukocytes?
WBC’s (spherical, nucleated)
Order of classical pathway complement system
Cell surface Antigen Antibody C1r + C1s = C1q C1q + C4 = *(*C4a*)* & C4b / C1q + C2 = C2a & *(*C2b*)* C4b + C2a = C4b2a C4b2a (C3 convertase) C3 + C4b2a = *(*C3a*)* & C3b C3b + C4b2a = C4b2a3b C4b2a3b (C5 convertase) C4b2a3b + C5 = *(*C5a*)* & C5b C5b + C6, C7, C8, C9 = C5b6789 MAC C5b6789 MAC
What are the types of innate immunity
Physical barriers
skin,cilia
Chemical barriers
lysozymes in teras/saliva, mucin in mucous
Mechanical barriers
Cough, sneeze, flushing of urinary tract
microbial barriers
common flora, (gut, vagina, skin etc)
Systemic defenses
The elimination of foreign agents that made it through external barriers
Cellular component- Phagocytes
in acquired immunity - T cells
Soluble (humoral) Component
Antibodies
complemnt proteins
antimicrobial proteins
Percentage of antibodies that are IgG
70-75%
How is the classical pathway of the complement system activated? (Steps)
Acitvated by antigen antibody complexes on surface of invading cell
Only IgM or IgG will activate classical pathway
One IgM or 2 IgG are required for activation
An antibody must be bound to the antigen in order to activate the classical pathway
The pathway is activated when C1 binds to the Fc portion of the antibody
C1(C1q) is made up of C1r and C1s
Describe brachydactyl
AER has stopped working properly
leaves shortened fingers
Describe eosinophils
2-5% of circulating leukocytes
if you have too many circulating you end up with allergic diseases
Response to parasitic worms
work via degranulation and toxin release, release certain proteins, cytokines and chemokines the cause inflammation
Activation is stimulated by interleukins
attracted to endothelial cells via selectins and bind via integrins
(this is a prcess of entering the tissue and is known as diapedesis)
What is the foramen ovale
The foramen ovale is the opening in
the septum
At birth, pressure rises in the left atrium due to increased blood flow from the lungs, while pressure on the right decreases with clamping of the umbilical cord and decreased blood flow from the placenta.
These changes in pressure close the
foramen ovale.
What are memory B cells
These recognize the same antigen more rapidly in a faster and higher antibody response
Transplant rejection process
APC’s from donorpresents antigen along with foreign MHC peptides on the cells surface
MHC molecules (two types)
MHC I found on nuclealted cells
MHC II found on dendritic, macrophages, b cells, endthelial and epithelial cells
CD8 T cell activation directly causes donor cell lysis
An immune synapse forms with a naive CD4 T cell which is activated to produce Interleukin 2
Cytokines: interleukin 2 activates
Helper T cells (autocrine)
Cytotoxic T cells (paracrine)
Activated Cytotoxic T cells destroy other donor cells using perforin and granzyme
Describe Polysaccharides
condensation products of more than 10 monosaccharide units
Starches and dextrins
§ May be linear or branched polymers
o Serve storage and structural functions
o Energy storage (stored as disaccharides)
§ Plants: starch
§ Animals: glycogen
o Structural support
§ Plants: cellulose
§ Arthropods/fungi: chitin
Describe apert syndrome
midface is underdeveloped as well as retruded; a subset have cleft palate
Mutation in = FGFR2
Hand always includes fusion of the middle 3 digits; thumb and 5th finger are sometimes involved
Feeding, hearing, dental issues
Heart, GI, GU,airway, nasal, tracheal issues
Normal to lower intelligence
What does C5 convertase consist of in the classical pathway
C4b2a3b
What are macrophages (APC)
Antigen presenting cells (APC)
Present antigens to T helper cells
What is NKX2.5
the main transcription factor that encodes for heart development
What are the two main processes of amino acid metabolism
Transamination
The process of removing an amine group from one amino acid and adding it to a metabolic intermediate to create another amino acid
Deamination
The process of removing an amine group and breaking down amino acids
What are antibodies
Antibodies are glycoproteins found on B cell membranes or secreted by plasma cells
What is Chordin
growth factor secreted by goosecoid
Describe split foot
Lobster claw
excessive programmed cell death
What is Anterior visceral endoderm (AVE)
expresses the head forming genes thus inducing the cranial region.
What are effector B cells
Plasma cells or antibody forming cells which secrete antibodies
Describe Starch
An insoluble polysaccharide
o Two types of starch
§ Amylose- 20%
§ Amylopectin- 80%
o Plant starch: when found in the form of amylopectin- more complicated starch (branched)
o Has a-glucose monomers
§ Aka all the repeat units are oriented in the same direction
o Starch and cellulose have same glucose-based repeat unit
What are langerhans cell in the skin
Antigen presenting cells (APC)
dendritic cells of the skin
take up microbial antigens to become fully functioning APC Cells
Trace electrons through ETC
NADH gives up 2 electrons to NADH dehydrogenase
the 2 electorns move to ubiquinone while giving up 2 H+ ions through the membrane
the 2 electrons move to the cytochrome BC1 where more H+ moves out of the membrane
1 electron at a time moves through the cytochrome C to the Cytochrome oxidase
Once htere are 4 electrons in the cytochrome oxidase, 2 waters are formed and 4 H+ are moved out of the membrane
H2O is the terminal elctron acceptor
the H+ outsode the membrane cause an ion gradient theat causes H+ to move throught the ATP synthase which forms ATP from ADP-Pi (oxidative phosphorylation)
**FADH2 can also give 2 electorns directly to the ubiquinone and start from there.
Describe a Type 2 hypersensitivity reacion?
Type 2 = involves the binding of IgG and IgM antibodies to antigens on cell surfaces. This induces a cascade of events that leads to cell death
Hemolytic transfusion reactions and hemolytic disease of newborns are type 2 reactions
Type 2 has 2 antibodies IgG & IgM
& usually involves 2 people (mother / newborn)
Roles of the neural crest cells
The fact that crest cells participate in heart septation and that they make all of the bones of the face and some of the skull explains why many children with craniofacial defects (e.g., cleft lip or palate, etc.) also have cardiac defects
Make all the bones of face
What holds the two sides of the “Y” together in an antibody?
disulfide bonds
What kind subcategories are TCR 2 cells
CD4
CD8
What are the differneces between IgG and IgM?
Differences between IgM and IgG
• While IgM antibodies are usually found in a human body after it has been exposed to a disease
• IgG is the long term response of the body to the disease
What are B cells
Antigen presenting cells (APC)
These recognize a specific antigen
they have a membrane associated antibody (immunoglobulin molecules)
prior to binding, they have IgM and IgD on the surface
After Binding it is activated, it then proliferates and differentiates
There are effector cells and memory B cells
Describe how blood circulation in the embryo changes upon birth and what effect these changes have on heart structures.
- At birth, the umbilical cord is clamped, stopping blood flow from the placenta.
- In response, the ductus venosus closes and later becomes fibrotic, forming the ligamentum venosum in the liver.
- Pressure rises in the left atrium compared to the right due to increased blood flow from the lungs and decreased blood flow to the right side from the placenta.
- The pressure change closes the flap over the foramen ovale. Later, this flap will become fibrotic and permanently seal the opening.
- Bradykinin is secreted by the lungs and causes the ductus arteriosus to close. The ductus becomes fibrotic to form the ligamentum arteriosum.
Interesting note: During the first months after birth, babies may turn blue when
they cry. This is because of pressure changes in the atria that open the foramen
ovale and create a right (venous blood) to left (arterial blood) shunt. It requires
some months for the atrial septa to fuse permanently.
What is a fat
A glycerol and 3 fatty acid tails
stores energy
Explain Membrane attack complex (MAC)
C5b combines with C6, C7, C8
Forms C5b678
The “8” portion of the complex begins to disrupt the cell membrane
C9 then binds to C8 (more C9’s then bind)
C9’s forms a pore in the cell membrane (leads to Lysis)
What are the types of antibodies? (classes)
GAMED
IgG IgA IgM IgE IgD
What do fats, steroids and phospholipids have in common
All are inslouble in water
High proportion of (hydrocarbon) nonpolar C-H bonds causing molecules to be hydrophobic
Describe amniotic band syndrome
strands of amniotic membrane can wrap around limbs or digits and cause amputations
What is the fetal period
8 - 38 weeks
Describe Glycogen
o Structurally similar to amylopectin but much more branched
o Granules occur in cytosol of cells
o Liver and muscle cells store glycogen in humans
o Once needed, glycogen is broken down into glucose by glycogen phosphorylase
Describe spina bifida
arises when neural tube closure fails in the spinal cord region
Results in a loss of function depending on the level of the lesion
Not lethal, do not affect intelligence. They can be repaired
Folic acid prevents 70% of these defects
What are the differnet hypersensitivity types
Type 1 = IgE antibodies that sensitize an individual to an allergen and provoke a quick inflammatory response upon subsequent exposure.
Type 2 = involves the binding of IgG and IgM antibodies to antigens on cell surfaces. This induces a cascade of events that leads to cell death
Type 3 = Results from the formation of antigens-antibody complexes that settle on tissue and organs in an attempt to remove these complexes underlying tissue is also damaged
Type 4 = Regulated by T cells and are delayed reactions to antigens associated with cells
What is the primitive streak
The primitive streak is a shallow groove at the caudal end of the embryo.
the primitive streak demonstrate that the head (cranial) and tail (caudal) ends of the embryo have been established.
Describe bladder extrophy
protrusion of the urinary bladder through a defect in the abdominal wall
The most important criterion for improving long-term prognosis is success of the initial closure
Common with spina bifida
Describe Innate immunity
Innate = fast and general
nonspecific
occurs within hours
also includes physical and chemical barriers of body
activated by chemical properties of the antigen
What secretes HCG?
Syncytiotrophoblast (trophoblast)
Secretes HCG
the trophoblast (that form the placenta) actually differentiates into 2 cell types; the synciotrophoblast and cytotrophoblast
Describe adaptive immunity
Adaptive = Slow and specific
Becomes active if innate system cannot deal with issue
only works from memory
works against specific pathogens or cells
Adaptive immunity refers to complex antigen specific immune response
The antigen must be recognized first
create a memory for later responses
What does the MAC coplex consist of
C5b6789
