Blood Flashcards
What are the functions of blood?
Carriage of physiologically active compounds, clotting, defence, thermoregulation, maintenance of ECF pH.
Where is the blood found in a regular healthy person?
5 litres, 1L in lungs, 3L in systemic venous circulation, 1L in heart and arterial circulation.
What makes up blood?
Plasma, red blood cells, white blood cells, and platelets.
What are the different types of plasmas proteins and what do they do?
Albumin - binds drugs, steroid hormones, lipids, TRANSPORTATION. (Most abundant) Generates oncotic pressure.
Globulins - alpha beta and gamma(antibodies- protect from infection). TRANSPORTATION, carry lipids and fat soluble vitamins.
Fibrinogen - small fraction of total number, initiating clotting if blood vessel wall is damaged.
Always found within circulation, taking molecules/nutrients around the body.
What is oncotic pressure?
Like osmotic pressure, pull of water into vessel lumen.
Water, Na and glucose (interstitial fluid) moves across capillary into plasma in vessel lumen. Helps maintain plasma volume. Capillary hydrostatic pressure favours fluid out of capillary. Plasma protein conc. favours fluid into capillary.
What is hypoproteinaemia? Causes?
Abnormally low levels of circulating plasma protein. Causes: starvation, liver disease, intestinal diseases, kidney disease (plasma proteins filter through seive and are lost in urine. Lost colloid oncotic pressure.
What is haematopoiesis?
Formation of blood cells, all come from a single population of stem cells in the bone marrow. Can become a non-committed stem (create myeloid cells) cell OR a lymphocyte (lymphoid cell).
What are myeloid cells?
Cells that aren’t lymphocytes.
What are RBCs (erythrocytes) ?
Most abundant blood cell. 120 day lifespan - spleen breaks it down. Biconcave shape, no nucleus, very flexible. Densely packed with haemoglobin, protein concerned with gas transport (oxygen). When O2 binds to haemoglobin, BRIGHT RED (fully saturated with O2). (Arterial blood)
Venus blood - Bluey reddy purple colour.
What is erythropoiesis? What is it controlled by?
Red blood cell production. Controlled and accelerated by erythropoietin (formed in kidney). Increased secretion when O2 levels in kidney are low (hypoxia). Eg of negative feedback - restores oxygen delivery.
Renal Disease
Kidney disease, normally coupled with anaemia. Deficient in red blood cell production.
What are Leukocytes?
White blood cells, have nucleus, larger than RBCs, involved in defence.
What are neutrophils
Most abundant type of white blood cells, 100 billion produced every day! If increased levels, a bacterial problem.
What is Leukopoiesis?
Formation of white blood cells, controlled by CYTOKINES (proteins/peptides? A complicated process - whole family of white blood cells.
What are cytokines?
Proteins/ peptides that are involved in the synthesis of white blood cells.
Increased number of lymphocytes means?
Viral infection.
What are platelets?
Component of blood. Membrane bound fragments of cytoplasm. Life-span of 10 days. Function: stick to damaged endothelial cells to create a bridge across a gap in a blood vessel. (Initiating blood clot). Important in allowing blood clots to form.
What is haematocrit?
Blood measuring process. Measures RBCs in blood. Changes viscosity of blood.
What is Bilirubin?
Breaks down RBCs, formed in liver, ‘yellow’ colour of plasma. Build up of this in blood (eg liver disease)= JAUNDICE.
What does viscosity mean?
How thick/sticky blood is compared to water. Depends on haematocrit - more haematocrit increases viscosity. Thicker blood - problems, harder for heart to pump blood around. Increase in temp decreases viscosity. Flow rate reducing (sitting about) = increased opportunity for cell adhesion so increased viscosity of blood (problems faced on long haul flights etc).
Which cells are involved in blood clotting?
Platelets
What does the net movement of fluid between interstitial space and vessel lumen depend on?
2 things:
Blood pressure (favours movement out of vessel)
Oncotic pressure (favours movement into vessel)
What does abnormally low levels of plasma proteins result in?
Hypoproteinaemia
What is the difference between myeloid cells and lymphoid cells?
Lymphoid: all lymphocytes
Myeloid: all other blood cells (erythrocytes, eosinophils, basophils, monocytes, neutrophils) - come from ‘uncommitted stem cell’
