Blood Flashcards
What is blood?
Connective tissue that consists of cells and a liquid extracellular matrix (plasma)
What is interstitial fluid?
The fluid that bathes body cells
Main 3 functions of blood
- Transportation.
Oxygen, nutrients, hormones, heat and waste products
- Regulation.
> homeostasis of all body fluids
pH through the use of buffers
body temperature
blood osmotic pressure influences the water content of cells
- Protection.
> Blood clots
White blood cells protect against disease
Blood plasma consists of mainly water and some solutes (mainly proteins). Name the 3 plasma proteins.
- Albumins
- Globulins
- Fibrinogen
Which plasma protein can develop into antibodies or immunoglobulin?
Globulins
An antigen is a…?
Foreign substance in the body
Name some other solutes present in blood plasma.
Waste, nutrients, electrolytes, gases, enzymes, hormones
Name the 3 main formed elements in blood (the blood cells)
- Red blood cells
- White blood cells
- Platelets
Where are the majority of plasma proteins produced?
Liver
What is the primary function of albumins?
Maintain osmotic pressure
Primary function of globulins?
Attack bacteria and viruses; transport iron, lipids and fat-soluble vitamins
Primary function of fibrinogens?
Essential in blood clotting
What’s another name for red blood cells?
Erythrocytes
What’s another name for white blood cells?
Leukocytes
What are platelets (or thrombocytes)?
Cell fragments (no nucleus) that promote blood clotting
What is haemopoiesis?
The process by which the formed elements of blood develop
(primary site is red bone marrow in adults)
Blood cells are formed from pluripotent haematopoietic stem cells that can develop into many different cells. Pluripotent cells are differentiated into two groups - what are they?
- Myeloid stem cells
- Lymphoid stem cells
Haemopoitetic growth factors stimulate and regulate differentiation and proliferation of various blood cells. What are the 3 growth factors?
- EPO (erythropoietin)
- TPO (thrombopoietin)
- Cytokines (local hormones of bone marrow)
What is haematocrit?
The proportion of blood that is made up of red blood cells
What is anaemia?
Deficiency in the number of quality red blood cells
What is polycythaemia?
When the body produces too many red blood cells
Haemoglobin is?
The oxygen-carrying protein in RBCs
Haeme - one haeme pigment attached to each polypeptide chain; each haeme contains an iron ion (Fe2+) that can combine with one oxygen molecule
Globin - protein consisting of 4 polypeptide chains
Function of haemoglobin?
Transport of O2, CO2 and nitric oxide
Normal haemoglobin range is 12 to 16g/100ml of blood for adult females and 13.5 to 18g/100ml of blood for adult males. A deficiency of what nutrients can lead to decreased production of haemoglobin?
Vitamin B12 or folic acid
How long do RBCs live?
120 days because they wear out from bending and cannot repair due to lack of organelles.
Worn out cells are removed by macrophages in the spleen and liver.
Outline the 4 main steps in red blood cells production (erythropoiesis)
- Proerythroblast starts to produce haemoglobin.
- Reticulocyte is formed.
- Reticulocytes leave the bone marrow into the blood.
- In 1-2 days, they eject the remaining organelles to become a mature RBC.
Where are the receptors that detect low oxygen levels in the body?
Kidney
White blood cells are classified based on the presence of cytoplasmic granules. What are the two classes of WBCs?
- Granuloctyes
- Agranulocytes
Name the 3 types of granulocytes (BEN).
- Basophils
- Eosinophils
- Neutrophils
Name the 2 types of agranulocutes (ML).
- Monocytes
- Lymphocytes
Broad function of WBCs?
Combat pathogens by phagocytosis or an immune response
Neutrophils function (granular)
(2 - 5 lobes connected by thin strand)
- release lysozymes
- release strong oxidants
- release defensin proteins which poke holes in bacterial cell walls
Basophils function (granular)
(irregular, s-shaped, bi-lobed nuclei)
- involved in inflammatory and allergic reactions
- release heparin, histamine and serotonin
- account for allergic reactions
Eosinophils function (granular)
(2 or 3 lobes connected by a thin strand)
- release histaminase which slows down inflammatory response caused by basophils
- attack parasitic worms
Lymphocytes function (agranular)
(Dark, oval to round nucleus)
B Cells - destroy bacteria and inactivate their toxins
T Cells - attack viruses, fungi, transplanted organs, cancer cells and some bacteria
Natural Killer Cells - attack many different microbes and some tumour cells
What do Monocytes (agranular) do?
(kidney or horse-shoe shaped)
Enlarge and differentiate into macrophages
Fixed macrophages or wandering which take longer to get to the infection site than neutrophils but arrive in larger numbers to destroy microbes and clean up dead tissue.
What is chemotaxis?
The chemical attraction of WBCs to a disease or injury site
What is leukocytosis vs leukopenia?
Leukocytosis = high WBC
Leukopenia = low WBC
[note: only 2% of total WBC population is in circulating blood at any given time. The rest are in lymphatic fluid, skin, lungs, lymph nodes and spleen]
What is thrombopoiesis?
The process of making platelets
Which cells are stimulated to produce platelets in bone marrow?
Myeloid cells
What is haemostasis? What are the 3 main mechanisms used?
The process to prevent and stop bleeding
- vascular spasm
- platelet plug formation
- blood clotting (results in formation of fibrin threads)
An enzyme converting soluble fibrinogen into insoluble fibrin is called…?
Thrombin
A network of insoluble fibrin fibres in which the blood formed elements are trapped is called?
Blood clot
The extrinsic and intrinsic clotting cascade culminates in the production of what?
Prothrombinase
To reduce blood loss from minor damage to a small blood vessel, what is formed?
Platelet plug
What are the key steps in clotting?
- Formation of prothrombinase
- Prothrombinase and Ca2+ convert prothrombin into thrombin
- Thrombin converts soluble fibrinogen into insoluble fibrin threads
What is the general shape of a red blood cell and why?
Biconcave disk to increase surface area (can carry more haemoglobin)
No nucleus or other organelles (some mitochondria)
