Blood Flashcards

1
Q

Describe the major constituents of blood; roughly how much blood does a healthy adult have

A
  • Average person = 5L of blood
  • Plasma (more viscous than water) = proteins & nutrients = ~ 55% of blood
  • Cellular components ~ 45%
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2
Q

patients with low red blood cell count will present with what symptoms?

A

anaemia:
Tiredness.
Weakness.
Shortness of breath.
Pale or yellowish skin, which might be more obvious on white skin than on Black or brown skin.
Irregular heartbeat.
Dizziness or lightheadedness.
Chest pain.
Cold hands and feet.

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3
Q

which type white blood cell count will be high when a patient is experiencing allergy?

A

elevated eosinophils or basophils; could be due to an exaggerated immune response to an allergen

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4
Q

what is the function + structure of a neutrophil

A

Function - motile cells, leave circulation and migrate to site of action (Acute phase inflammation; they’re one of the first responders)

  • Controlled by expression of adhesion molecule on their surface and interactions with molecules expressed on endothelial cells
  • L-selectin and integrins have binding affinity to endothelial cell ligands like intracellular-adhesion molecule 1/2 (ICAM1/2) - enable antibacterial and homing function of neutrophils
  • Phagocyte utilise variety of surface receptors to recognise infectious agents that can be killed within lysosomes (bacteriolytic enzymes)
  • Specific receptors - produced by complement system pathway
  • phagocytosis
  • degranulation (a process which releases antimicrobial cytotoxic or other molecules from secretory vesicles called granules)

*the release of nuclear material in the form of neutrophil extracellular traps (NETs)

structure:
* Most common granulocyte, identified by multilobed nucleus - polymorphonuclear or polymorphs
* Structure - multilobed nucleus with distinctive granules
* Specific granules (2ary) - small, not visible under light microscopy - contain enzymes, complement activators and antimicrobial peptides
Azurophilic granules (1ary) - large and numerous - contain MPO (myeloperoxidase) helps to generate bactericidal compounds

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5
Q

Which WBC is most common in a blood sample?

A

Neutrophils aka polymorphonuclear (PMN) leukocytes, are the most abundant cell type in human blood.

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6
Q

Which test would you carry out for a suspected infection in blood?

A

Blood culture;

this test tries to identify what type of bacteria or fungi caused infection in the blood. Blood cultures are collected separately from other blood tests. They are usually taken more than once from different veins. It can take several days to get the results of a blood culture.

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7
Q

Which is the quickest buffer system to react to changes in pH

A

Chemical buffer in plasma i.e. carbonic acid/bicarbonate system

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8
Q

Which is largest store of fluid in body?

A

Intracellular fluid - ICF is the largest store of fluid in body

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9
Q

Which is the main stimulus for the sense of thirst?

A

Subtle changes in plasma osmolality are the most potent stimulus for thirst. In response to increases in osmolality, osmoreceptors activate release of the neurohormone vasopressin (also known as antidiuretic hormone). The released vasopressin acts on the kidneys to conserve water to correct the hyperosmolar state

extra reading: most potent hormonal stimulus for thirst is angiotensin II (AngII), which is generated when the rate-limiting enzyme renin is secreted

n.b.
* Osmolarity is moles of solute per L
* Osmolality moles of solute per Kg

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10
Q

what is the function of a eosinophil + what type of granules do they contain?

A
  • Eosinophils are able to express and to secrete a large variety of mediators (cytokines, granule proteins, lipid mediators).
  • Eosinophils are putative antigen presenting cells and play a role in mast cell activation, T cell communication and function.
  • Eosinophilic granules in their cytoplasm:
  • Specific granules - eosinophil peroxidase and eosinophil-derived neurotoxin - have cytotoxic action
  • Azurophilic granules - lysosomal acid hydrolases - important for dissolving pathogens
    Associated with allergic reaction, parasitic infections and chronic inflammation
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11
Q

what is the function of a basophil

A

Basophils are circulating blood granulocytes that are mainly involved in hypersensitivity (atopic) and anaphylactic reactions2–5; they stem from CD34+ hematopoietic progenitor cells in bone marrow

  • Least numerous WBCs
  • Lotta large, basophilic granules in their cytoplasm:
  • Specific granules - heparin, histamine, leukotrienes, IL-4/3 etc.
  • Azurophilic - lysosomal enzymes
    Function similar to mast cells (innate and adaptive immunity) - resident cells in tissues

respond to allergies/parasites

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12
Q

what is the function of platelets

A

platelet= complex anucleated cell

primary function: hemostasis{is the mechanism that leads to cessation of bleeding from a blood vessel} thrombosis (clotting), and wound healing

through a complex activation process leading to integrin activation and formation of a “core” at the site of injury

other roles: immunity and communication with other cells and tissue in the vessel.

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13
Q

what is a young red blood cell called, where are red blood cells (eurythrocytes) made

A

Reticulocytes are slightly immature red blood cells. A reticulocyte count is a blood test that measures the amount of these cells in the blood. In the presence of some anemias, the body increases production of red blood cells (RBCs), and sends these cells into the bloodstream before they are mature.

RBCs are made in the bone marrow and released into the circulation

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14
Q

where do T cells mature

A

T cells mature in the thymus

Precursors of T cells migrate from the bone marrow and mature in the thymus. This process is similar to that for B cells, including the sequential rearrangement of antigen receptor gene segments.

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15
Q

what kind of stem cell do all blood cells develop from?

A

hematopoietic stem cell from bone marrow they are pluripotent

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16
Q

granulocytes are: basophils, neutrophils + eosinophils. What is their journey from a hematopoietic stem cell?

A

hematopoietic stem cell—>myeloblast
–>myelocyte
which then becomes eithers of the 3

16
Q

where are RBCs broken down since they don’t have a nucleus to programme cell death

A

Old or damaged RBCs are removed from the circulation by macrophages in the spleen and liver, and the hemoglobin they contain is broken down into heme and globin. The globin protein may be recycled, or broken down further to its constituent amino acids, which may be recycled or metabolized.

17
Q

what is the shape of erythrocytes maintained by

A

the shape of erythrocytes (RBCs) is maintained by internal + peripheral membrane proteins; they provide a strong but flexible structure

18
Q

what is IL-8 (interleukin 8) role + which WBCs/cells in general release it

A

IL-8 is involved in neutrophil activation, and is released from several cell types in response to inflammation, including monocytes, macrophages, neutrophils, and intestine, kidney, placenta, and bone marrow cells

19
Q

mast cells release _____

A

mast cells release histamine

When mast cells detect a substance that triggers an allergic reaction (an allergen), they release histamine and other chemicals into the bloodstream. Histamine makes the blood vessels expand and the surrounding skin itchy and swollen.

20
Q

C-reactive protein (CRP) blood test is an indicator of what?

A

C-reactive protein (CRP) test - generic marker of inflammation

21
Q

what do we mean by haematocrit?

A

% of rbc in blood

22
Q

what does MCV mean on blood results

A

(Mean Corpuscular Volume): size of red blood cells

if they small its an indication of anaemia

23
Q

MCH vs MCHC on blood test mean

A

MCH quantifies the amount of hemoglobin per red blood cell.
MCHC indicates the amount of hemoglobin per unit volume. In contrast to MCH, MCHC correlates the hemoglobin content with the volume of the cell.

24
Q

blood glucose tests (fasting, non-fasting, glucose tolerance tests) what is the international standard units for blood glucose measurements

A

molar concentration mmol/L