Blood Flashcards
Approximately what is the total volume of fluid in the human body
42 litres (3 - plasma, 2.5 - blood cells, 28 - interstitial fluid and 14 - extracellular fluid
What are the three types of blood cells (general) including the scientific names
Red blood cells - erythrocytes
White blood cells - leokocytes
Platelets - thrombocytes
What is polycythaemia and how is it treated
When a person has higher then average hematocrit. This is treated by blood letting
If a red blood cell takes up too much water what does it become (and what if it loses its water)
Too much water = HYPOtonic
Too little water = HYPERtonic
What are the 4 classes of blood loss
Class 1 - up too 15% (no medical)
Class 2 - 15-30% (saline drip)
Class 3 - 30-40% (saline solution + blood)
Class 4 - more than 40% (aggressive resuscitation)
What are the three stages of haemostasis
Vascular spasm
Formation of the platelet plug
Formation of the blood clot
What are platelets and what organelles do they contain
Colourless fragments that break off megakaryocytes
They contain mitochondria, smooth ER and cytoplasmic granules (not a nucleus)
How do platelets form the platelet plug
Platelets become sticky in the presence of von willibrand factor which is secreted by megakaryocytes and platelets. This von willibrand factor binds to exposed collagen in damaged cells then the platelets bind and begin to release serotonin attracting more platelets
Why do blood clots eventually dissolve
Plasmin trapped inside of blood clots causes them to eventually dissolve
What is the coagulation cascade
Von Willibrand factor makes platelets sticky. Platelets that have stuck together then release Von Willibrand factor causing more too stick etc…
Roughly how many red blood cells are in 1 micro litre of blood
5 million
What proportion of blood vessels are capillaries and how much of the total volume of blood do they hold
99% of blood vessels are capillaries and they only hold around 5% of the total blood volume
What is the bone marrow
Stem cells which can become Red blood cells (in multiple stages of the process between stem cell and RBC) and the support tissue called the stroma
What is the stroma (part of the bone marrow) composed off
Fibroblast-like reticular cells
Collagenous fibres
Extracellular matrix
What are haemoglobin’s 2 constituent groups
Haem - which is an Fe2+ ion bound to a polypeptide chain
Globin - is a protein made of 4 polypeptide chains
What constitutes the lymphatic system
Bone marrow
Thymus
Encapsulated tissue
What do natural killer cells do (immune system)
Eliminate virus-infected and tumour cells as well as secrete interferons which can prevent viral replication or attract macrophages
