Blood Flashcards
(28 cards)
What is the average circulating volume in an adult male?
5L overall
1L in lungs
3L in systematic
venous circulation
1L in heart and arterial circulation
What are the 6 functions of blood?
Carrying physiologically active compunds - hormones enzymes nutrients
Clotting
Defence
Carrying gas
Thermoregulation
Maintenance of ECF pH
What % water is plasma?
95%
What is plasma used for?
Used to circulate biologically active molecules and compounds
What are the 3 plasma proteins sub-categories?
Albumin
Globulins
Fibrinogen
What does albumin do?
Transports lipid and steroid hormones
Helps create colloid oncotic pressue
What does Globulins do?
Alpha/beta transports lipids and fat-soluble vitamins
Gamma type are antibodies
What is fibrinogen ?
Clotting factor
What is causes the colloid oncotic pressure?
Plasma proteins do not readily cross the capillary wall.
These proteins displace water and create an osmotic potential. This creates a pressure that can pull water from the interstitial space into the lumen/plasma.
When the water moves, chemicals and nutrients move to, however this only changes the volume, not the concentration.
What are erythrocytes and what is its lifespan? Function? Normal circulating levels?
Red blood cells
120 days
Carries O2
Levels between 4 and 6x10^12/L
What is erythropoiesis
Red blood cell formation
Controlled and accelerated by protein erythropoietin
What does erythropoietin do? What factors cause its secretion to be enhanced?
Speeds up differentiation of pluripotent stem cells to Erythroblasts (immature RBC)
Secretion is enhanced when O2 delivery to kidneys is reduced due to either a hemorrhage, anemia, cardiac dysfunction or lung disease
What are leukocytes?
White blood cells - several types of them
Neutrophils - function and half life? Normal levels?
Phagocytic function - entraps bacteria and forms the 1st line of defense
has a 6 hour half life
Normal levels are 68% of WBC population (2.5-2.7x10^-9/L)
Eosinophils - function - normal levels?
Attacks pathogens too large for neutrophils such as parasites
Numbers increase rapidly during allergenic response
Normal levels are 1.5% of population (0.1-0.44x10^-9/L)
Basophils function? Normal levels?
Relases histamine and heparin - triggers inflammation
Normal levels are 0.5% of population (0.1x10^-9/L)
Monocytes - function and life span? Normal levels?
Largest white blood cell
72 hours life span
Are “pre” macrophages that migrate to spleen, liver, lungs and lymph nodes
Normal levels are 5% (0.2-0.8x10^-9/L)
What are macrophages? Life span?
Mature monocyte that has migrated from the blood to the connective tissue
Can reside for up to 3 months.
Is phagocytic.
Lymphocytes - normal levels? Function?
25% (1.3-3.5x10^-9/L)
Are key componants of immune system - respond to viruses - have B and T cells
What is Leukopoiesis?
White blood cell formation
How does Leukopoiesis occur?
More complex than erythropoiesis
Controlled by a cocktail of cytokines - growth stimulating factors and interleukins
Cytokines released by endothelial cells, fibroblasts and mature white cells, and stimulate mitosis and maturation of leukocytes
The cocktail is dynamic and changes its composition to suit which specific cell type is needed at any given moment.
What are platelets? Are they nucleated? What governs formation? Life span?
Membrane bound cell fragments (from megakaryocytes)
Rarely nucleated
Formation governed by Thrombopoietin
Has life span of 10 days
What do platelets adhere to and function of them?
Adhere to damaged vessel walls and exposed connective tissue to mediate blood clotting
DO NOT adhere to healthy intact endothelium.
What is the haematocrit?
% of RBC to whole blood content
