Blood and Hematopoiesis Flashcards
functions of blood
- deliver O2 and nutrients
- transport waste and CO2
- transport hormones and regulatory substances
- homeostasis by being buffer, coagulation, thermoreg
- protect via transport of immune cells and components
components of blood
- formed elements
2. plasma
what are the formed elements of blood?
- cells: erythrocytes (RBCs) and leukocytes (WBCs)
- cell fragments: thrombocytes (platelets)
all form hematopoeitic stem cell
what is in the plasma element of blood?
protein rich, fluid ECM
components of centrifuged blood
RBCs = 45% plasma = 55% buffy coat (leukocytes and platelets) = 1%
what is the hematocrit?
volume of packed RBCs in a sample
what is the composition of plasma?
- water = 90%
- plasma proteins = 7-8%
- other solutes
water as plasma component
solvent for many solutes, provides optimal pH and osmolarity
what are the plasma proteins?
- albumin
- globulins
- fibrinogen
albumin
most prominent plasma protein made in liver exerts concentration gradient helps maintain osmotic pressure is carrier protein for hormones, metabolites, drugs
loss to tissues brings fluid with it = edema
2 types of globulins
- immunoglobulins
2. nonimmuneglobulns
immunoglobulins
gamma globulins
part of immune system
secreted by plasma cells (become activated B cells)
nonimmuneglobulns
alpha/beta
produced by liver
maintain osmotic pressure
carrier proteins
fibrinogen
made in liver
soluble
transforms into insoluble protein fibrin for clots
other plasma solutes
electrolytes, non protein N substances, nutrients, blood gasses, regulatory substances
erythrocytes
- anucleated, no typical organelles
- bind and deliver O2 to tissues, remove CO2
- bicancave disc to allow max surface area
- 120 day life span
what is the size of a RBC
7.8 um
where are RBCs produced?
in red bone marrow via erythropoiesis
what is hemoglobin?
protein involved in binding, transporting, and releasing O2 and CO2
structure of hemoglobin
4 polypeptide chains of globin, 4 iron containing heme groups (each binds one molecule O2)
most common is 2 alpha and 2 beta chains
what are the two groups of leukocytes?
- polymorphonuclear granulocytes
2. monomuclear agranulocytes
polymorphonuclear granulocytes
specific granules, multilobed nuclei, azurophilic granules
neutrophils, eosinophils, basophils
monomuclear agranulocytes
no specific granules, rounded nuclei, azurophilic granules
lymphocytes (B and T lymphocytes and NK cells), monocytes
neutrophil characteristics
most common leukocyte, 12-15 um, small faint lavender granules in cytoplasm, dark several lobed nuclei, granules contain lysozyme and peroxidases
function of neutrophils
1st response to infection (acute inflammation), phagocytose bacteria (pus)
eosinophil characteristics
1-5% leukocytes, 12-15 um
cytoplasm: large, coarse acidophilic granules caontaining peroxidase, histiminase, and arylsulfatase (infalmm effects)
nucleus: light, bilobed
function of eosinophils
defense of parasitic infection (helminths), associated with allergies, chronic inflammation
basophil characteristics
least abundant leukocyte, 12-15 um,
cytoplasm: large, coarse basophilic granules (obscure nucleus)
nucleus: light, obscured
functions of basophils
regulating immune response to parasites, release histamine for allergies
lymphocyte characteristics
26-28% leukocytes, 6-18 um
cytoplasm: narrow blue rim
nucleus: dark, takes up all of cell
function of lymphocyte
T lymphocyte: adaptive, cell mediated immunity, mature in thymus
B lymphocyte: adaptive, humoral immunity, produce antibodies
NK cells: innate, kill virally infected and malignant cells
monocyte charcteristics
3-9% leukocytes, 12-20 um
cytoplasm: grey, foamy
nucleus: dark, large, kidney/oval/ horseshoe shaped
function of monocytes
differentiate to macrophages in tissue -> phagocytic cells in antigen presentation
thrombocytes
derived form megakeryocytes (small bits of cytoplasm separates)
small, disc shaped, 2-3 um, form blood clots and repain tears in BV walls
monophyletic theory of hematopoiesis
all blood cells are derived from a common pluripotental stem cells (hematopoietic stem cell) which can self renew or differentiate into any 1 blood cell lineage
common myeloid progenitor
- megakaryocytes
- erythrocytes
- granulocytes
- monocytes
common lymphoid progenitor
- NK cells
- T lymphocytes
- B lymphocytes
steps in erythrpoiesis
- proerythroblast
- basophilic erythroblast
- polychromatophilic erythroblast
- orthochromatic erythroblast
- polychromatophilic erythrocyte
proerythroblast
large, 12-20 um, large spherical nucleus with 1-2 nucleoli, cytoplasm = mildly basophilic
basophilic erythroblast
nucleus 10-16 um, more heterochromatin, cytoplasm strongly basophilic (free ribos synthesizing hemoglobin)
polychromatophilic erythroblast
cytoplasm = acidophilic (hemoglobin) and basophilic (ribosomes), overall grey/lilac, smaller nucleus, coarse heterochromatin, checkerboard
orthochromatic erythroblast
small, compact, densely stained nucleus, eosinopilic cytoplasm (hemoglobin), no longer capable of division
polychromatophilic erythrocyte
reticulocyte
no nucleus, some polyribosomes still present (some basophilia), can be in BS
thrombopoiesis
HSC-CMP-MEP-MKP-megakaryoblast-megakeryocyte-platelets
megakaryoblast
large, 30 um, nonlobed nucleus undergoes endomitoses
megakaryocyte
50-70 um, complex multilobed nucleus, scattered azurophilic granules, polyploid (64N)
located near sinusoids in bone marrow, send cytoplasmic extensions that break off as platelets
where is bone marrow located
medullary cavity and spaces of spongy bones
what does bone marrow consist of?
sinusoids, hematopoietic cords (developing blood cells, megakaryocytes, macrophages, mast cells, adipocytes)
