Introduction to Blood COPY Flashcards
What are the functions of blood?
- Carriage of physically active
- Compounds
- Clotting
- Defence
- Gas transport
- Thermoregulation
- Maintenance of ECF pH
How much of the blood is plasma?
50%
How much of the plasma is water>
95%
What can be said about the quantity of biologically active compounds within the blood?
Kept at a relatively constant level
What are the three categories of plasma protein?
- Albumin
- Globin
- Fibrinogen and other clotting factors
What is albumin used for?
Transport of steroids and lipids - it is the most abundant plasma protein
What is Globulin used for?
Alpha and beta globulin have the same function as albumin
Gamma globulin acts like anti-bodies
What can be said about the volume and the concentration of the fluid in the plasma?
Concentration stays the same since water passes into the plasma, but therefore volume changes
What is Oncotic pressure/ colloidosmotic pressure?
Osmotic pressure exerted by proteins in the vessel lumen, usually pulls water into the circulation
What is meant by hyrdostatic pressure and which direction of fluid movement does it favour?
Favours the movement of water from the capillary to the interstitial fluid (hyrdostatic pressure is greater in the capillary) It is defined as the pressure created by fluid due to the force of gravity - increases with depth
What is hypoproteinaemia?
Abnormally low levels of protein circulating in the plasma
What causes hypoproteinaemia?
Prolonged starvation - breakdown of plasma proteins
Liver failure - reduced synthesisKidney disease - sieve holes are bigger
Intestinal disease - reduces the amino acids used for synthesis
What are the two classifications of blood cells?
Myeloid, lymphoid
Where do all myeloid cells come from?
Undifferentiated stem cells -> Differentiated progenitor cells -> Myeloid cells
How long does it take a reticulocyte to form a rbc (both found in the circulation)
24 hours
Where do you find all immature blood cells?
Bone marrow
What colour does the red blood cell (most abundant type of blood cell) adopt when the haemoglobin binds to oxygen?
Bright red
What is the life span of a red blood cell?
120 days
What organelles does a rbc not contain?
Nucleus, ribosome, mitochondria
What is the name given to red blood cell formation?
Erythropoiesis
What is erythropoiesis controlled by?
Erythropoietin
Where is erythropoietin secreted from?
Peritubular capillary cells - kidney cells (85%)
Hepatocyte cells - (15%)
When is erythropoietin secretion enhanced?
When oxygen delivery to the kidneys is reduced - hypoxia
What might be the cause of hypoxia?
Haemorrage, anaemia, cardiac dysfunction, lung disease
What is the name given to white blood cells?
Leukocytes - involved in the defence against pathogens
What type of cells are granulocytes?
Cytoplasms are granular : polymorphonucleated cells
Examples include - neutrophils, eosinophils, basophils
What is the function of neutrophils? And what is their life span?
Phagocytic and can engulf bacteria in nets
They have a half life of 6 hours
FORM PUSS
When are Eosinophils useful?
Number increases rapidly during an allergic response
They attack pathogens too large for neutrophiils and other defence cells - parasites
What is the function of basophils?
Release heparin and histamine : trigger inflammation
Heparin : Reduces blood viscosity - most highly negatively charged biological molecule known to mankind
Histamine : Involved in inflammation and pruritus (itching)
Describe the size of a monocyte?
The largest white blood cell
Describe what kind of cell is derived from monocytes?
Macrophages
What is the difference in phagocytic activity between phagocytes and macrophages?
Monocytes are less phagocytic
What is the name given to the immune system that has memory?
The adaptive immune system
What type of cells are lymphocytes?
White blood cells - Adaptive immune system - B cells and T cells
What controls leukopoiesis?
Cytokines ( proteins/peptides) - controls mitosis and cell maturation
Give two examples of cytokines
Colony stimulating factors
Interleukins
Where are cytokines released from?
Endothelial cells, mature white blood cells and fibroblasts
(A cell in connective tissue which produces collagen and other fibres.)
What might a bacterial infection give rise to?
Neutrophils
What might a viral infection give rise to?
Lymphocytes
How can the differential white cell count be used in diagnosis?
Allows you to tell the difference between infection types, since cytokine cocktail is dynamic
What are platelets?
Membrane bound cell fragments, rarely nucleated
What governs platelet formation?
Thromboprotein
What is the function of a platelet?
Attaches to damaged vessel walls and exposed connective tissue to mediate blood clotting?
What is a haematocrit defined as?
The percentage of red blood cells to the whole blood
Which is thicker plasma or whole blood?
Whole blood
What does viscosity depend on?
The temperature
The haematocrit (50% increase gives rise to 100% increase in viscosity)
Flow rate (decreased flow rate increases viscosity)
