MCM Lectures 19-22 Flashcards
What is the apical most junction found between epithelial cells? This junction is maintained by what proteins?
Tight junction, occludins and claudins
Cell to cell junctions anchored by actin filaments
Adherens
Cell to cell junctions anchored by intermediate filaments
Desmosomes
Cell to matrix junctions anchored by intermediate filaments
Hemidesmosomes
Anchoring junction. That mediates cell to cell connections using actin
Cadherin
Anchoring junction. That mediates cell to matrix connections
Integrin
Classical cadherins and desmosomal cadherins are both examples of what kind of junction
Homophilic
Classical cadherin junctions require calcium to function while nonclassical cadherins do not. What are examples of nonclassical cadherins?
Desmoglein, desmocollin, hemidesmosome
Cells of similar type are able to stick together with highly selective regulation (especially important during development) thanks to a process dependent on what Homophilic cell adhesion molecules?
Cadherin
Anchoring protein that help link classical cadherins to the cytoskeleton (important in wnt pathways)
Beta-catenin
This structure is found just inferior to tight junctions between epithelial cells (adjacent to contractile actin)
Adhesion belt (zonula adheren)
hydrophilic medications are fast acting. what is an example of a hydrophilic medication?
epinephrine
the same hormone may elicit different responses in different tissue when bound to GPCRs. For examples, epinephrine causes what to happen in bronchial tissue, smooth muscle, and cardiac muscle?
bronchial- relax
smooth muscle- relax
cardiac muscle- contract
these two beta agonists are used to treat airway constricting conditions
albuterol, epinephrine
fatal drop in blood pressure can occur with too much vasodilation which is why these two medications should not be taken together
viagra- cGMP phosphodiesterase inhibitor
nitroglycerine- smooth muscle relaxation/vasodilation
antihistimines bind GPCReceptors which normally bind what?
the AA histidine
what 4 regulatory proteins cause a differentiated adult cell to revert to pluripotency?
sox2, oct4, nanog, lin28
what is a stem cell?
self renewing, slow dividing, primitive cell that gives rise to more specialized cell types through differentiation
term for a cells ability to give rise to all cells of an organism including embryonic and extra embryonic tissues.
totipotency (zygote)
term for a cells ability to give rise to all cells of the embryo and thus all adult tissues
pluripotency (ES cells)
term for a cells ability to give rise to different cell types within a given lineage
multipotency (adult stem cells)
term for a set of cells that is programmed to have a fixed number of divisions controlled by short range signals
founder stem cells
cell population that is mixed with stem cells yet divides frequently to leave basal layer and become incorporated more superficially (divide a limited number of times)
transit amplifying cells
divisional asymmetry describes the process of stem cell division where one daughter cell retain stem cell characteristics while the other has the ability to differentiate. this describes which theory of stem cell renewal?
asymmetric division
environmental asymmetry describes the process of stem cell division where both daughter cells are identical and environment alters one so it has the ability to differentiate. this describes which theory of stem cell renewal?
independent choice
theory of stem cell division stating an original strand of DNA is preserved generation to generation (second cell gets newly synthesized DNA) to prevent errors
immortal strand hypothesis
pluripotent stem cells can be obtained from which part of an embryo at which stage in development?
inner cell mass of the blastocyst
what is a teratoma?
embryonic stem cells alone (when they are not part of an embryo) are incapable of generating a body in full. the lack of organization leads to tumor formation that involves many different tissue types involved.
whats required to differentiate a cultured ES cell into an adipocyte? a neuron?
fat- RA, insulin, thyroid hormone
neuron- RA
what are advantages / disadvantages to using multi potent stem cells to treat a patient?
no immune response to patients own tissue however they have limited ability (cannot become ANY cell type) and limited longevity
what are advantages / disadvantages to using embryonic stem cells (via somatic cell nuclear transfer) to treat a patient?
they are pluripotent (live long and can become anything) however immune rejection is possible if they were obtained via IVF and can be hard to coax
what is SCNT?
somatic cell nuclear transfer is when the nucleus of a somatic cell is used to replace an oocyte nucleus to generate ES cells to be used in therapy
where are adult stem cells found
bone marrow, cord blood, skeletal and heart muscle, skin, colon, liver, prostate, mammary gland, eye, ear, fat
whats the name of the process which allows lost limb tissue in a newt that is differentiated muscle tissue to reenter cell cycle after cutting off a limb, de differentiate and become ES cells that can proliferate and form a new limb
regeneration
where does hematopoiesis occur in a developing fetus?
trimester 1- yolk sac
trimester 2- liver and spleen
trimester 3- bone marrow
where does hematopoiesis occur in an adult?
long bones: tibia, vertebra, pelvis, sternum, ribs, femur
more hematopoiesis occurs in which type of bone marrow?
red marrow
what are the components of red marrow?
bone, endothelial, hematopoeitic, sinusoids that allow mature blood cells to enter circulation
what is the primary component of yellow bone marrow?
adipocytes
what cells in bone marrow are responsible for producing short range regulatory molecules to induce colony stimulating factors?
stromal (reticular) cells