1) Hematopoiesis Flashcards
1
Q
Blood is what type of tissue?
A
Connective tissue
2
Q
The two main functions of blood
A
Transport nutrients and oxygen throughout the body; remove metabolic waste to maintain stable internal environment
3
Q
Composition of blood
A
55% Plasma, 45% Formed elements (44% RBCs, 1% Platelets)
4
Q
Which cells contain hemoglobin
A
Erythrocytes/red blood cells
5
Q
Which cells function for oxygen and carbon dioxide transport
A
Erythrocytes or red blood cells
6
Q
In the centrifuged blood sample, where can you find platelets and WBCs?
A
Buffy coat or the layer between plasma and erythrocytes
7
Q
Cells involved in defense against foreign antigens
A
Leukocytes or white blood cells
8
Q
Part of blood involved in hemostasis
A
Platelets
9
Q
Two classifications of erythropoiesis
A
Primitive and Definitive
10
Q
Describe the RBCs in primitive erythropoiesis
A
Nucleated and immature
11
Q
Process of differentiation of cellular blood elements that have mature features
A
Definitive erythropoiesis
12
Q
Erythropoiesis that occurs in later embryos and adults
A
Definitive
13
Q
Erythrocytes in definitive erythropoiesis are
A
Anucleated
14
Q
Early (primary) sites of hematopoiesis
A
Placenta, yolk sac, and AGM (aorto-gonado-mesonephros system) are the early sites. Later, hematopoiesis migrates to fetal liver through the AGM.
15
Q
Where do definitive hematopoietic stem cells arise before colonization of the embryonic liver?
A
AGM
16
Q
Stages of Hematopoiesis (Blood Cell Development)
A
Megaloblastic > Hepatic > Medullary
17
Q
Stage that occurs as early as 19 days post fertilization
A
Megaloblastic Stage
18
Q
Where does megaloblastic hematopoiesis (3-5wks) occur?
A
Mesoderm of yolk sac
19
Q
At __ weeks, yolk sac production of RBCs cease in the ________ stage of hematopoiesis
A
6 weeks; hepatic stage
20
Q
What organ takes over as main source of blood cells in the medullary phase?
A
Bone marrow
21
Q
Peak of erythro- and granulo- poiesis in humans
A
Medullary stage (3-5 mos AOG)
22
Q
Where hematopoiesis first occurs
A
Yolk sac
23
Q
Fate of hemangioblast or angiogenic cluster cells, which came from the mesenchyme
A
Endothelial cells and/or primitive blood cells (first vessel-like structure in embryo)
24
Q
Less understood but recognized major source of hematopoietic clusters
A
Placenta
25
The placenta has more progenitor stem cells than what organ
Fetal liver
26
Placental hematopoiesis overlaps with BOTH yolk sac and fetal liver hematopoiesis (T/F)
T
27
At what age does hematopoiesis shift from yolk sac and placenta to the liver?
4th week
28
All blood cell types can differentiate in the liver, except one. What is this cell type and in what organ does it differentiate?
T-cells in the thymus
29
When does the medullary phase (BM) occur?
By 21st week AOG
30
What is the bone marrow made of?
Mesenchymal cells composed of reticular cells providing support for developing hematopoietic cells which reside in the bony core
31
Main sites of medullary or bone marrow hematopoiesis
Sternum, pelvis, proximal ends of long bones
32
At what age does fat start to appear in marrow of long bones
5-7 years of age
33
Composition of yellow marrow
Reticular cells and adipose
34
Function of yellow marrow
Storage of fat and hematopoietic cells
35
Red marrow can compensate by producing 10x more than its normal activity in increased physiologic demand, despite regressing and being replaced by yellow marrow
Amen
36
Hematopoiesis deals with __ and __ of the cellular components of blood
Production and destruction
37
Hematopoiesis occurring in the bone marrow
Medullary HP
38
Hematopoiesis outside the bone marrow
Extra medullary hematopoiesis
39
The main function of liver is
Production of transport proteins (not HP)
40
The liver serves as a filter for blood where it gathers, transfers, and aliminates substances in the form of what?
Bile
41
A yellow byproduct of heme synthesis that is transported to the intestines after conjugation by the liver
Bilirubin
42
What cells line the sinusoids if the liver? Describe also their functions.
Kupffer cells are macrophages (remove cellular and foreign debris) and also function in CHON synthesis.
Stellate cells are the main storage of retinol. They play a role in the liver's toxicity mechanism.
43
The largest lymphoid organ is ___, containing ___ mL of blood.
Spleen; 350
44
Describe the layers of the spleen
Outer later covered by peritoneum; inner layer with trabeculae sent inward by CT capsule to divide the spleen
45
____ pulp surrounds the central ____ pulp
Red; white
46
This may be observed in cases of hereditary spherocytosis, thalassemia, malaria, and myeloproliferative disease
Hypersplenism
47
Describe the layers of the thymus
Outer cortex densely packed with small lymphocytes and macrophages
Inner medulla which is less cellular and a waiting zone for mature T cells
48
Protein that functions for the maturation of T lymphocytes
Thymosin
49
A defect in chromosome 22, this disease is also known as congenital hypoplastic thymus. It is characterized by recurring infections, failure to thrive, and eventually death in infancy.
DiGeorge Syndrome
50
Describe the structure of the lymph node
Medulla - plasma cells
Germinal centers - B-lymphocytes
Paracortex - T-lymphocytes
51
Functions of the lymph node
Formation of lymphocytes from GCs
Immunoglobulin processing
Filtration from lymphatics
52
Describe the percentages of formed elements produced in HP
60% Granulocytes, 20% RBCs, 10% lymphocytes, monocytes, platelets
53
Myeloid:erythroid ratio
3:1
54
Location of differentiation of erythrocytes
Outer vascular sinus layer (proximal to Fe-laden macrophages)
55
Location of differentiation of granulocytes
Deep in cord of sinusoids of BM
56
Location of differentiation of platelets
Vascular walls of sinusoids
57
Three components of HSCs
Pluripotent SCs, Progenitor or committed SCs, and Mature SCs
58
Enumerate the characteristics of a fully differentiated cell
Decrease in proliferative potential
Loss of nucleoli or decrease in nuclear size
Condensation of chromatin (resulting in a change in shape and extrusion of nucleus in the case of RBCs)
Cytoplasmic changes (decrease in basophilic character, increase in cytoplasm, appearance of granules)
59
Requirements for blood cell differentiation
Stromal cells and cytokines
60
Stromal cells
Fibroblasts, endothelial cells, adipocytes
61
Proteins that regulate cell activities
Cytokines
62
Substances that promote cell growth
Growth factor
63
All growth factors are cytokines
Amen
64
Cytokines that function for stem cell and progenitor proliferation
Interleukins (IL-3) and stem cell factor
65
Cytokines for RBC development
EPO
66
Cytokines for granulocyte-monocyte precursors
GM-CSF
67
Granulocyte-committed progenitors
G-CSF
68
Monocyte-macrophage progenitors
M-CSF
69
Four types of hematopoietic responses
Hypoxia -> RBC
Infection -> granulo- and mono- cyte
Antigen -> lymphocyte
Hemorrhage -> platelets
70
Average RBC lifespan
120 days
71
Organs that release EPO in response to hypoxia
Kidney and liver
72
Where is iron absorbed in the body?
Duodenal enterocytes of the small intestines
73
Phases of Erythropoiesis
Ribosome synthesis -> hemoglobin accumulation -> ejection of nucleus and formation of leukocytes -> maturation to erythrocytes
74
Marrow stromal cells and IL-3 stimulate GM-CSF and SC factor
Erythropoietin-independent stage
75
Manager of RBC production and destruction balance
Hepcidin control
76
Needed for DNA synthesis and replication
Vitamin B12 and Folic Acid
77
Needed for hemoglobin synthesis
Fe
78
Where is folic acid absorbed?
Duodenum and proximal jejunum
79
Where is Vit B12 absorbed
Ileum
80
Macrophages engulf senescent RBCs and break them into _&_ and then _&_
Globin and heme; iron and biliverdin
81
Term for reduced oxygen-carrying capacity of the blood
Anemia
82
Anemia due to blood loss from injury or undiagnosed bleeding ulcer
Hemorrhagic
83
Anemia due to blood loss in transfusion reactions and certain infections
Hemolytic
84
Anemia due to destruction or inhibition of red marrow by drugs, IR, or toxins
Aplastic
85
Anemia due to inadequate intake of a certain compound, leading to microcytes
Iron deficiency
86
Dietary deficiency of Vit12 or inadequate production of IF for its absorption forming macrocytes
Pernicious anemia
87
Absence or anomaly in one globin chain
Thalasseia
88
Excess of RBCs leading to viscous blood
Polycythemia
89
Using amoeboid motion, WBCs can squeeze between vessels to tissues to attack foreign antigen in a process called what?
Diapedesis
90
The main function of WBCs is in ____
Tissues
91
Earliest form of granulocyte
Myeloblast
92
Granulocyte precursor where nucleoli had disappeared
Myelocyte
93
Granulocyte precursor where cell differentiation stops
Metamyelocyte
94
WBCs that increase in allergic reaction and parasitic infection
Eosinophil
95
WBCs that function in vasodilation by releasing histamine
Basophils
96
____ function in humoral immunity; _____ for cellular
B lymphocytes; T lymphocytes
97
Cytotoxic T-cells
CD8
98
Helper T-cells
CD4
99
Lymphopoiesis is amplified by
Antigens
100
Heavy chain rearrangement occurs in ____; light chain in____
pro-B and pre-B; pre-B and immature B
101
Mature B lymphocyte specialized for antibody production
Plasma cell
102
A basophil found in connective tissue; releases histamine and other substances during allergic and inflammatory reactions
Mast cell
103
What happens to lymphoid T-cell progenitors in the thymus?
They acquire cell surface characteristics and commit to being either CD4 or CD8 cells
104
Final maturation stage of T cells
Exposure to antigen in peripheral lymphoid organs
105
Low leukocyte count
Leukopenia
106
Abnormally high or abnormally low numbers of immature WBCs
Leukemia
107
Increased in infectious mononucleosis (EBV)
Monocytes
108
Most WBCs are immature; seen in myeloid leukemia or severe infections
Left shift
109
Shift to more mature WBCs, hypersegmentation of PMNs, seen in pernicious anemia and Vit B deficiency
Right shift
110
Increase in leukocyte numbers
Leukocytosis
111
Leukocytosis in acute inflammation, pyogenic bacterial infection, tissue necrosis
Increased PMNs
112
Leukocytosis in asthma, parasites, drugs, skin diseases, adenocarcinoma
Eosinophils
113
Leukocytosis in viral diseases and chronic inflammation
Monocytosis
114
Lymphocytosis is caused by
Collagen vascular disease, inflammatory bowel disease, tuberculosis
115
Excessive leukocytic response, shift to the left in response to a certain condition
Leukemoid reaction
116
Protein regulating platelet production
Thrombopoietin
117
Necrosis or apoptosis are processes also involved in hematopoiesis
Amen
118
Stem cell marker
CD34, c-kit, rhodamine, Hoechst dyes
119
B-cell markers
CD19, 20, 22, 79a
120
T-cell markers
CD3, 2, 5, 4/8
121
Natural Killer cell markers
CD16, 57, 56
122
Study of blood
Hematology
