Blood Flashcards
Describe the major constituents of blood; roughly how much blood does a healthy adult have
- Average person = 5L of blood
- Plasma (more viscous than water) = proteins & nutrients = ~ 55% of blood
- Cellular components ~ 45%
patients with low red blood cell count will present with what symptoms?
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.
which type white blood cell count will be high when a patient is experiencing allergy?
elevated eosinophils or basophils; could be due to an exaggerated immune response to an allergen
what is the function + structure of a neutrophil
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
Which WBC is most common in a blood sample?
Neutrophils aka polymorphonuclear (PMN) leukocytes, are the most abundant cell type in human blood.
Which test would you carry out for a suspected infection in blood?
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.
Which is the quickest buffer system to react to changes in pH
Chemical buffer in plasma i.e. carbonic acid/bicarbonate system
Which is largest store of fluid in body?
Intracellular fluid - ICF is the largest store of fluid in body
Which is the main stimulus for the sense of thirst?
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
what is the function of a eosinophil + what type of granules do they contain?
- 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
what is the function of a basophil
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
what is the function of platelets
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.
what is a young red blood cell called, where are red blood cells (eurythrocytes) made
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
where do T cells mature
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.
what kind of stem cell do all blood cells develop from?
hematopoietic stem cell from bone marrow they are pluripotent
