Week 10 Haematological System Flashcards

1
Q

Haematopoeisis and Haemopoesis

A

Interchangeable terms —> describes formation of blood cells

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2
Q

Myelopoiesis

A

Formation of blood cells in the myeloid line (e.g., granulocytes, monocytes, erythrocytes, and platelets).

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3
Q

Lymphopoiesis

A

Formation of blood cells in the lymphoid cell line (e.g., B cells, T cells, and natural killer (NK) cells.

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4
Q

Haematopoietic stem cells (HSCs)

A

• The precursor cell to blood cells and begin the differentiation process.
• They are self-renewing and can make any blood cell in the body, (e.g., erythrocyte, B cell, T cell, etc.).
• They can also make other non-haematopoietic cells, when required, and are hence classed as pluripotent.
• HSCs are found predominately in the bone marrow in adults.

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5
Q

Haematopoietic Stem Cells vs Progenitor cells

A

BOTH
- Located in bone marrow
Heamatopoeitc Stem Cells
- High self renewal tendency
- Differentiate into progenitor cells
- Pluripotent
Progenitor Cells
- Limted self renewal tendency
- Differentiate into myeloid or lymphoid
- Multipotent

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6
Q

Site of haematopoiesis in an embryo

A

Yolk sac and then liver

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7
Q

Site of haematopoiesis in 3-7 month old foetus

A

Spleen

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8
Q

Site of haematopoiesis haematopoiesis in a 7-9 month old foetus

A

Begins to occur in bone marrow

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9
Q

Site of haematopoiesis between birth and maturity

A

Bone marrow and the tibia/femur

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10
Q

Site of haematopoiesis in adults

A

Bone marrow of the skull ribs and sternum

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11
Q

Types of WBCs

A

Neutrophils, Lymohocytes, monocytes eosinophil, basophil

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12
Q

Primary lymphoid organs

A

Where lymphocytes undergo ontogeny (get made and develop in mature B and T cells)
Thymus and Bone Marrow

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13
Q

Naive lymphocytes

A

Precursor lymphocytes that differentiate into effector lymphocytes
CD4 T cell —> Helper T Cell
CD8 T cell —> Cytotxic T cell
B Cell —> Plasma cell

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14
Q

Primary lymphoid organs

A

Thymus and bone marrow (where cells develop)

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15
Q

Secondary Lymphoid organs

A

Lymph nodes
Spleen
Mucosal associated lymphoid tissues MALT

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16
Q

Function of Lymph Nodes

A

Filters tissues borne antigens in regions rich with naive B and T cells —> allowing them to interact (which happens in the Cortex, paracortex and medulla of the lymph node)

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17
Q

Spleen Function

A

Filters blood born antigens
Has white pulp for immune response and red pulp for filtration

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18
Q

M-CSF

A

Stimulates the production and differentiation of monocytes and macrophages from hematopoietic stem cells

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19
Q

GM-CSF

A

Stimulates growth and maturation of WBC

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20
Q

G-CSF

A

Specifically stimulates the production and release of neutrophils from the bone marrow helping body fight infections

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21
Q

Thromboprotein

A

Regulates the production and maturation or platelets (thrombocytes)( from megakaryocytes in the bone marrow, marinating appropriate platelet levels in the blood

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22
Q

What does multipotent myeloid stem cell differentiate into

A

Myeloid progenitor and Lymphoid progenitor

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23
Q

What does myeloid progenitor differntiate into

A

Megakaryocyte —> Platelets
Erythroblast —> Reticulocytes —> RBC
Myeloblast —> Monocyte, Neutrophil, Basophil, Eosinophil

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24
Q

What does Lymphoid progenitor differntiate into

A

B-lymphocyte —> B plasma
T Lymphocyte
Natural Killer Cell

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25
Q

Function of RBCs

A

Nutrition (gas exchange)
Waste removal (pH and electrolytes; removal of carbon dioxide)
Thermoregulation (via vaso constriction and dilation)
Distribution (immune cells, cytokines, hormones and Immunoglobulins)

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26
Q

Bony Trabeculae in histology

A

Seen as thick pink stripes; structure of the bone itself

27
Q

Active Bone marrow in histology

A

Pink/purple cellular elements of the bone marrow

28
Q

Dissolved Fat in bones in histology

A

White spaces
In adults makes about about 30-70%

29
Q

Haeme synthesis

A
  1. Succinyl-CoA and glycine combine to form δ-aminolaevulinic acid (ALA).
  2. ALA is transported into the cytoplasm
  3. A series of enzymatic reactions in the cytoplasm and mitochondria lead to the formation of the porphyrin ring, known as porphobilinogen (PBG).
  4. Four PBG molecules combine to form hydroxymethylbilane (HMB), which is then converted into uroporphyrinogen III.
  5. Uroporphyrinogen III is converted to coproporphyrinogen III.
  6. Coproporphyrinogen III is further modified to form protoporphyrin IX.
  7. Iron is incorporated into protoporphyrin IX to produce heme.
30
Q

What is Haeme

A

• Haeme is a crucial component of haemoglobin and other hemoproteins, which play a vital role in oxygen transport and various biological processes.
• Haeme synthesis occurs in the mitochondria (early and late stages) and the cytoplasm of the cell (intermediate stages).

31
Q

Structure of Haemoglobin

A

Consists of 4 different protein chains (two alpha like sub units and two beta like subunits)
Each subunit contains iron

32
Q

Bohr Effect

A

Haemoglobin exhibits cooperativity, meaning that as one subunit binds to oxygen, it increases the affinity of the other subunits for oxygen. This enhances its oxygen-
carrying capacity.

33
Q

Turnover rates of RBCs, Granulocytes, and Platelets

A

RBC= 120 days
Granulocytes = mere hours
Platelets = 5-10 days

34
Q

Right shift/decreased O2 affinity factors

A

Increased pCO2
Increased H+
Increased temp
Increased 2-3DPG (has to do with lactate)
Think right=exercise

35
Q

Role of thymus

A

Site of development and maturation of t lymphocytes

36
Q

Role of Spleen
Including red and white pulp

A

Acts as a filter for blood, removing damaged or old blood cells, pathogens and cellular debris
White Pulp: Serves as the immune response centre, initiating and coordinating immune reactions against blood borne pathogens and antigens
Red Pulp: Primarily functions to filter and remove damaged or aged blood cells from the circulation as well as to store platelets

37
Q

Role of lymph nodes

A

Filter lymph to remove pathogens and antigens, innate immune reactions and facilitate activation of T and B cells

38
Q

Lymph Node Cortex

A

Outer region contains B cells and follicles

39
Q

Lymph nodes Medulla

A

Inner region contains plasma cells and macrophages

40
Q

Lymph node paracortex

A

Middle region constraint T cells and High endothelial venules

41
Q

Lymph node follicles

A

Contractions of B cells for antibody production

42
Q

Flow of lymph through lymph node

A
  1. Afferent vessels
  2. Subcapsular sinus
  3. Lymph flows into the cortex, where B and T cells enable cell mediated immune responses
  4. Lymph flows into the paracortex where T cells enable cell mediated immune responses
  5. Medulla (dendritic and macrophages process antigens)
  6. Exits via lymphatic vessels
43
Q

Iron types, where they come from, solubility and oxygen affinity

A

Fe3+
Source: Plants
Solubility: High
Oxygen Affinity: Low
Fe2+
Source: Animal Products
Solubility: Low
Oxygen Affinity: High

44
Q

How is Fe3+ converted to Fe2+

A

By a transporter protein called DNMT-1

45
Q

Iron Metabolism

A

Iron is converted to Fe2+ by DMT1 (if not already)
Ferroportin enables Fe2+ to travel from the enterocytes (cells in intestine) into the blood stream
When iron is not needed, Hepcidin is produced by the liver, and actively degrades Ferroportin, preventing more Fe2+ uptake into blood
Transferrin (a transporter protein) oxides iron into Fe3+, increasing solubility in blood

46
Q

How does Hypoxia effect Iron absorption

A

Increases levels of DMT1
Leads to decreased hepcidin
Leads to increased absorption of iron
(And thus more RBCs can be made)

47
Q

How does Increased EPO (erythropoietin) levels effect iron absorption

A

Leads to decreased hepcidin
Leading to increased released of iron into blood stream

48
Q

How does Inflammation effect iron absorption

A

Leads to increased hepcidin
Leading to decreased released of iron into blood stream

49
Q

How does Haemochromatosis (iron overload) effect iron absorption

A

Leads to decreased hepcidin
Leading to increased released of iron into blood stream

50
Q

DMT1

A

A membrane [protein that transports dietary iron into interstitial cells

51
Q

Ferroportin

A

A protein responsible for exporting iron from enterocytes (cells in intestine) into the blood stream

Channel protein facilitating absorption of iron into intestinal cells from the lumen

52
Q

Macrolytic Anaemia

A

MCV Value: >100
Causes: B12 deficiency, folate deficiency, alcoholic liver disease

53
Q

Normocytic anaemia

A

MCV Value: 80-100
Causes: Renal failure, anaemia of chronic disease, leukaemia

54
Q

Microcytic anaemia

A

MCV Value: <80
Causes: Iron Deficiency, anaemia of chronic disease

55
Q

Consequences and Clinical Presentation of thalassaemia

A

Consequences: RBCs are fragile and prone to haemolysis —> anaemia
Presentation: Pallor, Jaudice, Splenomegaly, Dyspnoea

56
Q

Consequences of Iron Overload

A

Cardiac complications: cardiomyopathy and heart failure
Liver damage: fibrosis, cirrhosis, impaired function
Endocrine disorders: growth and puberty delays, diabetes, thyroid dysfunction
Bone marrow suppression
Weakened immune system
Skin discolouration: bronze of slate gray hue

57
Q

Causes of iron deficiency

A

Chronic Blood loss
Diet
Malabsorption
Increased iron demand (ie pregnancy or growth)
Impaired iron recycling

58
Q

Prevelance and incidence of anaemia

A

24.8% of people globally, 47.4% of pre-school aged children
Most common cause is iron deficiency- 50% of cases

59
Q

Causes of Haemolytic Aaemia

A

Thalasseamia
Stress from mechanical Valve
G6PD deficiency
Thrombotic state

60
Q

Anaemia Investiagtions

A

CBE: for classification and aetiology (MCV)
Iron studies
B12/folate
LDH: Hugh may suggest haemolytic anaemia
Hb electrophoresis: suickle cell or thallassemia

61
Q

how to differeintate btwn iron deficiency anaemia and anaemia of chronic disease?

A

serum ferrotin
also a little bit total iron binding capacity

62
Q

the pattern of inheritance in Haemophilia A & B?

A

X Linked reccessive

63
Q

What gives rise to platelets

A

megakaryocytes