Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
129 Cards in this Set
- Front
- Back
|
What is a stem cell?
|
Cells that can self-renew in the proper conditions (e.g., when a correct “niche” of surrounding cells is provided) and can also give rise to differentiated cells via asymmetric divisions.
|
|
|
What is the ectoderm?
|
External germ layer that gives rise to skin and its derivatives (hair, nails, mammary gland), the central nervous system (CNS), and the neural crest (sympathetic ganglia, sensory ganglia of cranial and spinal nerves, adrenal medulla, pharyngeal arches, and bones of the cranium).
Remember the ectoderm is everything you can see plus the nervous system. The ectoderm is like a condom....it protects your head (bones for the cranium), its everything you see and you can feel it (CNS). |
|
|
What is the mesoderm?
|
The middle germ layer that gives rise to notochord, muscles, skeleton, dermis, kidneys, connective tissue and blood.
Remember the mesoderm is the middle layer. Any place that something you inhale or swallow end up. ...AKA if you didn't use your ectoderm. |
|
|
What is the endoderm?
|
The internal germ layer that gives rise to the epithelium of the gastrointestinal tract and its derivatives (thyroid, trachea, bronchi, lungs, liver, pancreas).
Remember the endoderm is the inner layer and gut tube. |
|
|
What is gastrulation?
|
The coordinated movements of cells in the embryo (morphogenetic movements) that generate the three germ layers
|
|
|
What is the Epithelial-Mesenchymal transition
|
In epithelia, cells are tightly attached to each other by cell-cell junctions (such as adherens junctions mediated by cadherin cell adhesion proteins), forming cell sheets. Epithelial cell sheets provide barriers between body compartments. In mesenchyme, individual cells attach to a network of extracellular matrix proteins (such as collagens and fibronectin) and are able to migrate individually. At certain points in development, epithelial cells can disperse to become mesenchyme (e.g., formation of mesoderm and neural crest) and vice-versa (e.g., formation of mesothelial (serous) membranes such as peritoneum).
|
|
|
During development epithelial cells will disperse and become mesenchyme cells, the formation of what is produced?
|
The formation of mesoderm and neural crest
|
|
|
During development mesenchyme cells will disperse and become epithelial cells, the formation of what is produced?
|
The formation of mesothelial membranes such as peritoneum (membrane that covers the lining of the abdominal cavity)/
|
|
|
What is cleavage?
|
The division of cells in the early embryo.
|
|
|
During early stages of embryo growth, cells will move into the _________ _______ and become the mesoderm and endoderm cells.
|
Blastopore Slit
|
|
|
Explain what is meant by
If you don't use your ectoderm, you may endoderm swallowing or inhaling, which is quite mesoderm in-between the sheets. |
Ectoderm(Condom)-
Gives rise to what you see, protects your head (cranium bones) and you can feel it. Mesoderm- it is messy because blood is messy and remember blood is connective tissue. Also anything that is in the middle (in between the sheets). Endoderm-anything that you inhale or swallow ends up here. |
|
|
What is the notochord?
|
This is a primitive structure that is formed during early embryo development by the mesoderm. This was the backbone of primitive chordates.
|
|
|
What is the morula stage?
|
This is when the embryo has 16 cells
|
|
|
What is the blastocyst stage?
|
This is when the morula starts filling with liquid.
|
|
|
What is the trophoblast?
|
This forms the outer layer of the blastocyst and will contribute nothing to the body but will provide nutrients for the embryo
|
|
|
When the blastocyst enters the uterus it is digested and what is left? What will these cells form?
|
The inner cell mass is left and will form the entire embryo and trophoblast.
|
|
|
What contains the totipotent embryonic stem cells?
|
The inner cell mass
|
|
|
After the blastocyst attaches to the uterine wall, what will start secreting HCG?
|
The syncytiotrophoblast
|
|
|
In the oviduct, what in the egg attracts the sperm for fertilization?
|
The corona radiata
|
|
|
What is the function of FSH?
|
This induces follicle growth in the ovaries
Induces follicles to stay in ovaries and develop into corpus luteum |
|
|
What happens when there is a peak of LH?
|
Ovulation
|
|
|
What increases LH in the ovaries?
|
Estrogen
|
|
|
What is difference between pluripotency and totipotency ?
|
Totipotent Stem Cells
These are the most versatile of the stem cell types. This cell is totipotent, meaning it has the potential to give rise to any and all human cells, such as brain, liver, blood or heart cells. It can even give rise to an entire functional organism. Pluripotent Stem Cells These cells are like totipotent stem cells in that they can give rise to all tissue types. Unlike totipotent stem cells, however, they cannot give rise to an entire organism. |
|
|
What is so unique about embryonic stem cells?
|
They are capable of self-renewal via asymmetric divisions
|
|
|
What helps in telling a stem cell "you become differentiated and you stay a stem cell"?
|
Niche
|
|
|
The length of a full-term pregnancy is usually how long?
|
About 266 days
|
|
|
When is the onset of conception usually taken from?
|
The onset of conception is usually measured from the LMP.
(Remember ovulation happens, after day 14 of LMP). |
|
|
What week is the end of the embryonic period?
|
8 weeks
|
|
|
When are most of the organs formed in developing of the fetus? There will be some differentation but Dr. de Roberts said most of the organs will be formed at what point?
|
Week 8
|
|
|
What transports nutrients and gases from maternal circulation for embryonic survival and fetal growth, is developed from the trophoblast, is the root system for the umbilical vessesl and produces progesterone and estrogen.
|
The placentae
|
|
|
What is the most significant developments in the 12-38 weeks (fetal period)?
|
Great increase in length of the body
Lungs grow and support breathing for air Fat stores develop (help survive till takes in food and nursing). |
|
|
All ____ _____ developed in first trimester?
|
Major organs
|
|
|
Fetus may survive if born prematurely at the end of the ____ trimester, this depends on of course the ______.
|
Second
Lungs |
|
|
How do we estimate fetal age?
|
Crown to Rump
Biparietal diameter -Skull diameter Head circumference Weight |
|
|
How can Crown to Rump be determined?
|
From ultrasound
|
|
|
Why is using the weight of the fetus not the best tool for determining fetal age?
|
Because sometimes there is metabolic diseases (diabetes) from the mother which can lead to some discrepancies.
|
|
|
When are signs of ossifications first seen? trimester or week?
|
1st
12 weeks |
|
|
What generally is present/happens in the 9-12 week stage of embryo development?
|
Head comprimises half of CRL
External genitals appear the same Primary ossification centers start Intestinal coils visible in umbilical cord |
|
|
What generally is present/happens in the 13-16 week stage of embryo development?
|
Body begins growing faster than the head
Limb movments occur but not perceived Genitalia may be differentiated Female ovaries have differentiated Rapid growth |
|
|
What generally is present/happens in the 17-20 week stage of embryo development?
|
Brown fat forms
Growth slows down Quickening (fetal movements begin to be felt) Genitalia can be differentiated Skin covered by vernix caseosa |
|
|
What generally is present/happens in the 21-25 week stage of embryo development?
|
Rapid eye movement
surfactant secretion begins in alveoli -lungs in contact with fluid, to get around surface tension the surfactant will be used. Lungs developed Nervous system begins to get wired |
|
|
Why are babies placed in incubators?
|
Baby doesn't have enough surfactant to support for the lungs to be fully expanded.
|
|
|
What generally is present/happens in the 26-29week stage of embryo development?
|
The magic 27-babies can survive enough surfactant
CNS has developed to support breathing and control body temp. Eyelids open Fetal spleen is important at this time for hematopiesis and then bone marrow will take over at week 28. |
|
|
What generally is present/happens in the 30-34 week stage of embryo development?
|
Normal weight fetus usually survive at this point
|
|
|
What generally is present/happens in the 35-38 week stage of embryo development?
|
Testes in scrotum
Head is still the largest region Can orient to light Nervous system can carry out some integrative functions |
|
|
What fetal growth factors are determined by the placenta?
|
Glucose
Amino acids Insulin, HGH, Insulin |
|
|
Smoking and alcohol consumption tend to produce intrauterine growth retardation and _____infants with low birthweights?
|
Low
|
|
|
How can uteroplacental blood flow affect fetal growth?
|
Decreased supply to the fetus
|
|
|
What are the four ways of assessing fetal status?
|
Amniocentesis
-Cells are shed into the amniotic sac CVS Cell cultures Percutanous umbilical cord blood Ultrasound CT and MRI Fetal monitoring |
|
|
What is a teratogen?
|
□ An environmental agent that can causes developmental disruptions following maternal exposure
|
|
|
What trimester is the most sensitive to teratogens?
|
The first
|
|
|
What is a prion?
|
This is a infectious agent composed primarily of protein
|
|
|
What is an polymorphism?
|
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species
|
|
|
The most common source of genetic variation is what?
|
The single nucleotide variants (SNPs)
|
|
|
What are two uses of polymorphisms?
|
They are genetic markers within families and individuals
-Linkage analysis Find out the rough location of the gene relative to another DNA sequence called a genetic marker, which has its position already known. |
|
|
The sicke cell disease will replicate in the ____ and release H+, causing decrease in pH (more acidic).
|
RBC.
|
|
|
What is the heterozygote advantage?
|
HbS heterozygotes (carriers) show no evidence of Sickle Cell anemia, but are resistant to Malaria!
|
|
|
What aspects of fetal development does alcohol adversely affect in 1st trimester?
|
Facial features and brain development
-Decreased height and weight=3rd -Increased risk of spontaneous abortion=2nd |
|
|
Which cells are especially sensitive to the effects of alcohol exposure resulting in cranial and facial defects in FAS?
|
Neural crest cells
|
|
|
What are the three discriminating facial features of Fetal Alcohol syndrome?
|
Short palpebral fissures (separation between the upper and lower eyelids)
Smooth philtrum (extending from the nose to the upper lip) Thin upper lip |
|
|
What is not essential for a diagnosis of FAS?
Pre and/or postnatal growth deficiency Specific pattern of facial anomalies Evidence of a CNS dysfunction Enzymatic changes in the cells in the liver |
Enzymatic changes in the cells in the liver
|
|
|
Which of the following is a possible mechanism of alcohol's effect on the brain?
Changes in microtubule system with neuronal axons Excessive proliferation of neural crest cells Induction of heightened production of neurotransmitters resulting in increased synaptic function. Disruption of the development of supporting cells for the neurons resulting in changes in cell signaling and myelination |
Disruption of the development of supporting cells for the neurons resulting in changes in cell signaling and myelination
|
|
|
During neurulation, the primitive streak will begin to shrink and begin sending cells upwards. The neural plate will become the ______, and is created by the thickening of the ectoderm.
|
Brain
|
|
|
What part of the ectoderm germ layer make the CNS?
|
The neural tube; the neural tube is formed due to neural folds closing on themself.
|
|
|
What part of the brain will have the Rhombomeres, which is innervated by the 12 cranial motor nerves?
|
The Hindbrain
|
|
|
There is an organizer center in between the mid and hind brain, what is this called?
|
Isthmic inducing center
|
|
|
The forbrain has what two ventricles?
|
Telencephalon-olfactory
Diencephalon-optic |
|
|
The midbrain has what ventricle?
|
Mesencephalon- oculomotor (control eye movement)
|
|
|
There are two forms of birth defects with the incomplete closure of the neural tube, not closing the anterior or the posterior. Which causes spina bifida and which causes the baby to die?
|
Baby will die if the anterior neural tube isn't closed.
The baby will have spina bifida if the posterior is not closed. |
|
|
What protein and where is this taken from to see if the neural tube wasn't closed?
|
The AFP protein taken from the mother's blood.
AFP is made in the fetus' liver and will then go into the cerebrospinal fluid. If the neural tube is open it will then enter the amniotic cavity and enter the mothers blood. |
|
|
What is a morphogen?
|
A signaling molecule that can diffuse in the embryo, inducing distinct cell fates at different concentrations. Usually emanates from an organizing center.
|
|
|
What is a growth factor?
|
Secreted proteins that bind to cell surface receptors and cause changes in cell proliferation differentiation. Examples are Epidermal growth factor (EGF), Fibroblast growth factor (FGF), Insulin-like growth factor (IGF), and TGFβ.
|
|
|
What is the TGF(beta) superfamily?
|
the largest family of growth factors in humans (30 different ones). Frequently they inhibit cell proliferation and induce cell differentiation. Examples are Bone Morphogenetic Proteins (BMP) and TGFβ-1 to 3.
|
|
|
What is Dorsal, Ventral, Anterior and Posterior in regards t the body?
|
Dorsal-Back
Ventral-Belly Anterior-Head Posterior-Feet |
|
|
What is the homeodomain?
|
A 60 amino acid DNA-binding domain present in Hox and other DNA-binding proteins.
|
|
|
What is the homebox?
|
Nucleic acid sequence encoding a homeodomain. Homeobox sequences have been highly conserved through evolution, and can be detected by nucleic acid hybridization across species. There are many homeobox genes (170 in the human genome, of which only 40 are Hox genes).
|
|
|
What are hox gene complexes?
|
Clusters of about 10 coordinately expressed Hox genes related to the Drosophila Antennapedia homeobox. Four gene complexes present in humans, each Hox cluster is in a different chromosome.
|
|
|
The homeobox is a nucleic acid sequence that endoces the _____
|
Homeodomain
|
|
|
What period (weeks) in the development of an fetus, is the most sensitive to teratogens?
|
The 4th to 8th week-organ formation
|
|
|
The primitive node is an organizing center that induces _______ to thicken and become the brain. Also the primitive node is equivalent of the Spemann's organizer.
|
ectoderm
|
|
|
When the primitive streak is formed, what two germ layers will come out from the primitive streak?
|
The mesoderm and endoderm
|
|
|
The CNS is formed from the folding and closure of what?
|
The neural tube
|
|
|
Where do cranial nerves I-III originate from?
|
Cranial nerve one originates from telencephalon (olfactory)
Cranial nerve two originates from diencephalon (optic) Cranial nerve three originates from mesencephalon (occulamotor) Tel mom I can smell, Diencephalon can see, and Mesencephlaon let her see |
|
|
What organizing center induces the formation of the cerebellum?
|
The Isthmic inducing center
|
|
|
Neuropore non-closure can be detected with what in the mothers serum?
|
AFP protein;
AFP is made in fetus liver. If neuropore not closed, passes then through cerebrospinal fluid, to the amniotic fluid and then to mothers serum |
|
|
What is used as a signaling center in embryo development, but will later disappear?
|
The notochord
|
|
|
Paraxial mesoderm (mesenchyme) forms what?
|
Somite
|
|
|
From the lateral plate mesoderm, what layer surrounds the gut and what surrounds the body wall?
|
Parietal-body wall
Visceral-Gut The two layers are connected by the dorsal mesentary |
|
|
In what mesoderm do the blood islands form?
|
The lateral mesoderm and in the visceral layer
|
|
|
The heart and blood vessels are formed where?
|
In the blood islands of the lateral visceral mesoderm, problems at this point (around day 21) can cause cardiac malformations
|
|
|
What gives the dermatome and myotome its importance?
|
Importantly, each dermatome and myotome is innervated by nerves originating in the CNS next to the original somite, even after extensive cell migrations during embryonic development. This segmental body organization is important in neurological diagnosis in the adult
|
|
|
During week of twos, the inner cell mass will form two epithelial cells, whcih are ?
|
Hypoblast and epiblast
|
|
|
During the week two , there are two cavities formed, which are?
|
Amniotic cavity and blastocyst cavity
|
|
|
Of the two trophoblasts, cytrophoblast and syncytiotrophoblast created during the week of twos, whicih secretes the HCG?
|
Syncytiotrophblast
|
|
|
The hypoblast will disapperar later on after embryo development, what does the hypoblast do?
|
Provide nutrients for the embryo
|
|
|
If the primitive streak doesn't disappear what can form?
|
A tumor
|
|
|
What are the three cases for identical twins?
|
Two cells separate at the two cell state.(each baby has own placenta)
Inner cell mass split into two(babies share placenta) Gastrulation (two embryos within a single amnion) |
|
|
In the primitive streak epiblast cells will undergo ______- _____ transition
|
Epithelial-Mesenchymal transition
|
|
|
How does the cell get rid of cAMPs?
|
Cyclic AMP phosphodiesterase will cleave cAMPs and give rise to 5'AMP
|
|
|
What acts as an intermediate for adenylate cyclase and receptors?
|
G proteins
|
|
|
Describe the G protein pathway?
|
Hormone binds to receptor
Causes conformation change in receptor Now forms a 5 protein complex between receptor and g protein The changed receptor is recognized by the G protein The G alpha will then change conformation The G alpha will then release the GDP G alpha will then pick up GTP from medium When the G alpha has GTP it will dissociate G protein from receptor G ALPHA will then recognize and activate the adenylate cyclase to convert ATP to cAMPs |
|
|
How can two cells have different responses to the same ligand?
|
Different signals are generated by the same ligand-receptor complex in different cell types
Different downstream targets exist in different cell types. For a common signal generated by a common ligand-receptor complex --Has different response proteins |
|
|
Why do cells have extra receptors?
|
§ The strength of biological response to a ligand in intact cells is proportional to the number of occupied receptors
|
|
|
Why are claratin coats used?
|
Need to get piece of receptor into a cell to pass on the signal
Need to get a piece of ligand into cell Degradation is part of the termination Lower the amount of receptors, is the way we lower the sensitivity |
|
|
What happens if you can't cleave GTP?
|
There will be huge levels of signal transduction
|
|
|
How does cAMP activate Cyclic AMP dependent kinase PKA?
|
In absence of cAMPs in cell is found with regulatory subunits that inhibit catalytic subunit
The cAMPs will make this an active enzyme Steps -Follow the illustration □ Activated § Turn off --Class illustration |
|
|
Explain the pathway of DAG?
|
Ligand binds
Go through G protein pathway G alpha will activate PIP-PDE PIP-PDE will cleave PIP to make DAG DAG activates protein kinase C - PKC --Is usually bound to membrane --DAG will bind to PKC and activate the PKC Phosphorylated kinase How to Turns off Ligand removed- no more DAG Remove DAG --DAG is part of a constant cycle that will continually make more PIP. ---This will form a pool of substrate |
|
|
Besides using agonists and antagonists, how else could you regulate the signal transduction pathway?
|
Increase the levels of cAMP.
|
|
|
How can PKA stmulate gene expression?
|
CREB will bind CRE
--Not active yet Once it CREB is phosphorylated(via ligand binding, then G protein, adenylate cyclase, cAMPs will then activate PKA, the PKA will phosphorylates CREB) , it can recruit additional cofactors and turn on tranx |
|
|
Which kinase is bound to the membrane PKA or PKC?
|
PKC
|
|
|
Give the pathway of CAM?
|
Calmodulin (same in bacteria and humans)-Binds calcium and modulates activity
When binds calcium, calmodulin changes conformation -Active form Then binds to an inactive protein (CAM Kinase) When Calmodulin binds to CAM kinase and then can cause CAM kinase to become active (CAM Kinase) CAM kinase then can phosphorylate proteins |
|
|
The placenta is derived from the ____ and provides nutrients and gases from maternal circulation to embryo. The placenta also produces ______
|
Synatrophoblast
Progesterone |
|
|
What is crucial during fetal growth?
|
Lungs grow and can support breathing for air
Fat stores develop Progressive wiring of nerve and muscle Great increase in weight and length |
|
|
How can you estimate fetal age via ultrasound?
|
Weight, head circumference
biparietal diameter (Diameter of skull) CTR |
|
|
What centers happen in the 9-12 week period of development?
|
Primary ossification centers appear in cranium and long bones
|
|
|
At what point do external genitalia differentiate?
|
Week 14
|
|
|
When does female uterus develop?
|
WEEK 18
|
|
|
When does surfactant secretion begin in alveoli?
|
Week 24
|
|
|
What is used for production of RBC (hematopoiesis) in fetus before bone marrow?
|
Spleen
|
|
|
What factors can affect fetal growth?
|
Amino acids
Glucose availabilty Insulin, HGH and IGF |
|
|
Alcohol and smoking can produce _________ _____ _______ in the fetus.
|
Intrauterine growth retardation
|
|
|
What are some methods for assessing fetal status?
|
Amniocentesis
-See what chromosmoes CVS Cell cultures Percutaneous umbilical cord blood Ultra sound MRI and Tomography Fetal monitor |
|
|
Are there more or less SNP in the sex chromosomes?
|
Less
|
|
|
What accounts for the most genetic variation and in what region does it occur the most?
|
SNPs
Non coding |
|
|
What RNA polymerase is found within the Nucleolus, makes rRNA and is alpha amanitin sensitive?
|
I
|
|
|
What RNA polymerase is found within the nucleus, is Alpha-Amanitin sensitive and makes mRNA and some snRNA
|
II
|
|
|
What RNA polymerase is found in nucleus, makes tRNA, snRNA and small rRNAs is intermediate sensitive for alpha-amanitin?
|
III
|
|
|
What is the function of CpG islands?
|
They are proximal promoter elements that have Sp1 tranx factors and can recruit basal pol II to form the PIC
|
|
|
What two domains make up the tranx factors?
|
DNA binding and activator/repressor domain
|
