Lecture C1 Flashcards
RBC were first described by _____ (date?)
Leeuwenhoek (1695)
RBC and WBC were described by ____ (date?) by using different stains
Beale (1863)
Paul Ehrlich did what?
-studied stained blood corpuscles & identified them microscopically
Techniques to study blood (2)
-centrifugation: separate blood cells into different density
-blood smear
blood smear steps (4)
- prick finger & collect blood
- drop of blood on slide
- use second slide to thinly spread drop & dry
- view under microscope
composition of whole blood
-plasma: 55%
-erythrocytes/RBC: 44%
-Buffy coat: <1%
plasma of blood is mostly ____ & also contains _____
-water
-proteins and other solutes
Buffy coat of blood centrifugation contains ____ (2)
platelets, leukocytes
hematopoiesis (def.)
making all blood cells
hematopoiesis occurs in ____ during development and aging
different locations
In the early embryo, blood cells are made in _____. In the second trimester, blood cells are made primarily in ____ and ___ helps out.
-yolk sac mesoderm
-liver
-spleen
In the third trimester, blood cells are made in ____ as the _____ starts to develop in the medullary cavities of the bone
-bones (bone marrow)
-bone marrow
Before puberty, ______ contributes to hematopoiesis. After puberty, it shifts to ____
-all the bones
-axial bones (vertebra, sternum, rib)
In the embryo, hematopoiesis occurs first in _____ and later at _____ (3)
-yolk sac blood islands
-aorta-gonad mesonephros (AGM) region, placenta, fetal liver
Hematopoiesis in each location favours the production of _____
specific blood lineages
In adults, _____ (2) are the primary hematopoiesis sites
bone marrow and thymus
HSC stands for _____
Hematopoietic stem cells
The majority of functional adult HSCs reside in the ____
bone marrow
Within the bone marrow, HSCs can be located in either _____ regions, where they interact directly or indirectly with _____ that comprise HSC niches
-perivascular or endosteal
-different types of cells
HSC niches keep HSC in ____ and activates them when _____
-quiescence
-needed
extra-medullary hematopoiesis is what? happens when?
-blood cell formation outside bone marrow
-when sick
cells that forms HSC niches
perivascular stromal cell
stromal cell secrete ____ (2)which maintain HSC niche
-SCF, Cxcl2
All blood cells arise from a single type of ______ in the bone marrow
-pluripotent hemopoietic stem cell
pluripotent hemopoietic stem cell are rare, proliferate ___, and forms two lineages: _____
-slowly
-lymphoid cells
-myeloid cells
lymphoid cells produces _____
lymphocytes
myeloid cells produces ____ (3)
erythrocytes, platelets, some leukocytes (eosinophils, basophils, neutrophils, monocytes)
shape of RBC is maintained by ___
spectrin
spectrin (def.)
a unique cytoskeleton protein forming a scaffold that holds the PM in shape
spectrin mediates the interaction between _____
actin filaments and the plasma membrane
spectrin forms long, flexible ____, binding to a junctional complex (with _____ ) and the network is anchored to PM by ____ (2)
heterodimers and heterotetramers
-F-actin
-ankyrin, adducin
hereditary anemias can be due to mutations in ____ and causes RBC to be ____
-spectrin
-easily lysed
Advantages of biconcave shape of RBC
-high SA to V ratio causes hemoglobin close to cell surface for gas exchange
-flexibility
-minimal tension when the volume of cell alters
How RBC get their biconcave shape?
myosin interacts with spectrin-actin complex on membrane to cause contraction/tension leading to biconcave shape
inhibition of myosin & actin interaction in RBC results in ____
loss of biconcave shape
leukocytes aka ____
white blood cells
leukocytes are split into 2 groups based on ______
the density of their cytoplasmic granules
two groups of leukocytes
-granulocytes
-agranulocytes
granulocytes characteristics
-type of WBC with cytoplasmic granules
-has lobulated nucleus
agranulocytes characteristics
-type of WBC without granules
-spherical, slightly bent nucleus
types of granulocytes (3)
-neutrophil
-eosinophil
-basophil
types of agranulocytes (2)
-lymphocyte
-monocyte
_____ primary granules or_____
-Azurophilic
-lysosomes
Primary granules description? role? contain?
-large, dense vesicles
-killing and degrading engulfed microorganisms
-proteases and antibacterial proteins
Secondary granules description? role?
-smaller, less dense vesicles
-secretion of ECM-degrading enzymes like collagenases, delivery of bactericidal proteins to phagolysosomes, insertion of new PM components
nuclear morphologies of WBC are ____; some cells can be ____
-varied
-polynucleated
Possible reasons that WBC have polymorphic nuclei (3)
-flexibility when passing through small gaps
-low lamin A:B ratio similar to Progeria causing lobulated nucleus
-formation of extracellular traps by extending nuclear membrane
Formation of neutrophil extracellular traps has two pathways: _____
-NETosis (slow cell death)
-Non-lytic NETosis (rapid release from live cells)
NETosis involves ______ (4)
-disassembly of nuclear envelope
-chromatin decondensation
-PM rupture
-release of NETs (DNA which is gooey and can trap bacteria)
Non-lytic NETosis involves _____
-expulsion of nuclear chromatin
-extracellular assembly of NET (that traps bacteria)
-this produced anucleate cell that can eat bacteria but is not dead
Lymphocytes size? shape of nuclei? description?
-6-15 um in diameter in circulation
-spherical nucleir
-smallest leukocytes
lymphocytes are separated into 3 groups based on _______
cluster of differentiation or CD marks
3 groups of lymphocytes
-T cells, B cells, and natural killer (NK) cells
T lymphocytes differentiate where? B cells, NK cells?
-thymus
-bone marrow
platelets also called ____
thrombocytes
platelets size? function? interesting characteristic?
-2-4 um in diameter
-promote blood clotting (has granules with clotting proteins)
-not a cell but cell fragments; anucleated
Platelets originate by fragmentation from mature ______
-megakaryocytes
megakaryoblast mature to form _____
megakaryocytes
megakaryoblast size? megakaryocytes size?
-25-50 um
-up to 150 um
megakaryocytes have several _____ and one has a _____ nucleus from _______
-nucleoli (plural for nucleolus-ribosome production)
-polyploid
-endomitosis
endomitosis (def.)
repeated rounds of DNA replication without cytokinesis
Polyploidization in megakaryocytes results from a ______
-late reversal of cytokinesis
megakaryocytes lack of cleavage furrow is due to lack of ____
myosin
Platelets originate by ______
fragmentation from mature megakaryocytes
