Blood- The River Of Life Flashcards
Blood characteristics
Approx 8% body weight
5-6 Litres Males
4-5 Litres Females
Functions and what is Transported
Transport, Defence, Homeostasis
Gasses, Nutrients, Fats, Wastes, Hormones
Blood and defence
Contains immune cells and antibodies
Thrombocytes seal breaches in skin
What is it made of?
55% plasma
-92% water, 8% albumin and solutes
45% formed elements
-99.9%erythrocytes, then leukocytes and thrombocytes
Plasma vs serum
Serum is clotted plasma.
They are different and some tests require plasma while others require serum.
Plasma proteins
Produced mostly by the liver
60% Albumin -plasma osmotic pressure -carrier molecule: free fatty acids, some drugs and steroids 35% Globulins -Antibodies (immunoglobulins) -TRANSPORT PROTEINS 4% Clotting factor -Fibrinogen = most abundant 1% Regulatory -Enzymes, Hormones
Electrolytes
Sodium ions
-most abundant cation intercellular. Water balance. Muscle and nerve function
Chloride ions
-most abundant cation extracellular.
Potassium ions
-most abundant cation extracellular. Nerve and muscle activation
Calcium ions
-healthy bones and teeth, blood clotting, nerve transmission and muscle contraction
Phosphate ions
-health bones and teeth. Buffer intracellular fluid
Bicarbonate ions
-buffer extracellular
How is the efficiency of pulmonary gas exchange determined?
Blood collection for analysis
- venipuncture
- capillary puncture
- arterial puncture
Why term them formed elements? Not cells?
Only leukocytes are full cells
Erythrocytes have no nuclei or organelles
Platelets are cell fragments
Where do the formed elements come from
Haematopiesis
Haematopoietic stem cells give rise to all the formed elements
-abundant in umbilical cord
Haemotopoeisis occurs where
This is the production of erythrocytes.
At the end of long bones and in flat, irregular bones.
Skull, sternum, vertebra, pelvis, ribs
Bone marrow that no longer produces blood cells is called patty yellow marrow.
Fate of RBCS
Last around 100-120 days
Macrophages phagocytose worn out RBCs in the spleen, liver, and bone marrow
Broken into haem and globin. Iron from haem is recycled, the rest of the haem is broken down into bilirubin excreted in bile. Globin is broken into amino acids and released into blood stream.
Name of immature erythrocyte
Reticulocyte
What is erythropoietin and what does it do
A hormone released by the kidneys which stimulates the production of red blood cells (erythropoiesis)
Leukocytes
Less than 1% total blood volume
“Leukocyte rolling” is them moving out of blood to infection
Two categories: Granulocyte & Agranulocyte
Neutrophils, eosinophil, basophil. Leukocyte, monocyte>macrophage
Neutrophil
40-75% leukocytes Also known as polymorphonuclear Usually first to arrive Active against BACTERIA mainly Phagocytic Lifespan 30min-10hours
Eosinophils
Modulators of the immune response> help reduce inflammation
Active agains PARASITIC WORMS too big to be phagocytosed
Bilobed nuclei
Basophils
Induce inflammatory response by releasing histamine> vasodilation> inflammation
This also attracts other leukocytes
Leukocytes
20-50% leukocytes
Crucial to specific immunity> most in lymphoid tissue not blood stream
Three types: T cell (viruses and tumours), B cell and cytotoxic cell
Large round nuclei
Monocytes
2-10%
Largest leukocyte (differentiate in phagocytes in tissue)
Actively motile
Large, purple, kidney shaped nuclei
VIRUSES, intracellular bacteria, parasites, chronic infections
Platelets
Formed from glial cells (remember the supporting neuronal cells
Lots of granules, lysosomes and mitochondria
Haemostasis
- Vascular spasm
- Platelet plug formation
- Coagulation> fibrin threads
Clot retraction and repair
Clot retraction
-Contraction of actin and myosin in platelets> squeezes serum from clot
Clot repair
-platelet derived growth factor (PDGF) stimulates division of smooth muscle and fibroblasts
-vascular endothelial growth factor (VEGF) stimulates endothelial cells to multiply and restore lining
Blood disorders
Leukocytosis- increased numbers
- maybe due to infection or marrow abnormality
Leukopenia- decreased numbers
Leukaemia
-bone marrow occupied by cancerous leukocytes, immature, nonfunctional WBCs
Thrombocytosis- too many
-results on thrombosis (clotting in vessels)
Thrombocytopenia
-results in bleeding
