BLOOD Flashcards
(33 cards)
BLOOD
Is a connective tissue.
Regulation
- pH (acid/base) by buffers
- temperature by vasodilation and vasoconstriction, supply of blood to sweat glands
- blood osmotic pressure and water content of tissues (involves protein and dissolved ions)
Transport
- blood gases: oxygen and carbon dioxide - nutrients from the digestive system
- heat and waste products from cells
- hormones from endocrine cells to target tissues
Protection
- blood clotting - preventing blood loss
- white cells, antibodies and other proteins (interferon, complement etc.) protect against disease
Is made up of 55% plasma and 45% red blood cells
Never Let Monkeys Eat Bananas
Type of white blood cells (leucocytes) can be remembered in order of abundance in blood by using the acronym
Neutrophil Lymphocyte Monocyte Eosinophil Basophil
BLOOD PLASMA
Makes up 55% of blood.
Consists of:
- Water 91.5%
- Proteins 7 %
- Other solutes 1.5%
FORMED ELEMENTS
45% of blood
Consist of
• red blood cells (RBCs) - Erythrocytes
• white blood cells (WBCs) - Leukocytes
• platelets - Thrombocytes
Production of formed elements
• Occurs in the red bone marrow
• Haemopoiesis - production of formed elements of blood
• Erythropoiesis - production of red blood cells also known as erythrocyte
Erythrocytes – red blood cells
- are biconcave discs
- contain no nucleus (lost in their development)
- contain haemoglobin, a protein that carries oxygen
PLATELETS
In the formed elements
are fragments of cells that do not have a nucleus. Among other actions, they release chemicals that promote blood clotting when blood vessels are damaged. Platelets are the functional equivalent of thrombocytes, nucleated cells found in lower vertebrates that prevent blood loss by clotting blood.
POSITIVE FEEDBACK SYSTEM!
HAEMOPOIESIS
Production of formed elements in the blood.
Occurs in red bone marrow.
ERYTHROPOIESIS
production of red blood cells also known as erythrocyte
Occurs in red bone marrow.
HAEMATOCRIT
% that makes up red blood cells.
Normal values:
42% +/- 5% (female)
47% +/- 5% (male)
LEUKOCYTES
White blood cells (never let a monkey eat bananas)
5 types
Granulocytes:
Neutrophil. Eosinophil. Basophil
Agranulocytes:
Lymphocyte. Monocyte
NEUTROPHIL
Granulocyte white blood cell
Phagocytosis. Destruction of bacteria with lysozyme, defensins, and strong oxidants, such as superoxide anion, hydrogen peroxide, and hypochlorite anion.
EOSINOPHIL
Granulocyte white blood cell.
Allergies and kills parasites
Combat effects of histamine in allergic reactions, phagocytise antigen–antibody complexes, and destroy certain parasitic worms.
BASOPHIL
Granulocyte white blood cell.
Mast cells of connective tissue, release histamine, heparin etc., involved in inflammation.
Liberate heparin, histamine, and serotonin in allergic reactions that intensify overall inflammatory response
LYMPHOCYTE
Agranulocyte white blood cell
T Cells
• Attack invading viruses, cancer cells and transplanted tissue cells
B cells
• B cells can become plasma cells which generate antibodies and help mediate an immune response
Natural Killer cells
• Attack a wide variety of infectious microbes and spontaneous tumour cells
Mediate immune responses, including antigen–antibody reactions. B cells develop into plasma cells, which secrete antibodies. T cells attack invading viruses, cancer cells, and transplanted tissue cells. Natural killer cells attack wide variety of infectious microbes and certain spontaneously arising tumour cells.
MONOCYTE
Agranulocyte white blood cell
Phagocytosis and antigen presentation
Phagocytosis (after transforming into fixed or wandering macrophages).
GRANULYTES
Leukocytes (white blood cell) that displays conspicuous granules with distinctive colouration that can be recognised under a light microscope.
ARANULOCYTES
Leukocytes (white blood cells) that possess cytoplasmic granules, the granules are not visible under a light microscope because of their small size and poor staining qualities.
PLATELETS - THROMBOCYTES
Essential for blood clotting.
HAEMOSTASIS
- Haemostasis is a term used to describe the series of responses that stop bleeding from a damaged blood vessel
- Reduces haemorrhage (loss of blood from a vessel) through clot formation
- Initiates tissue repair
• Clot formation involves three steps:
- vascular spasm
- platelet plug formation
- blood clotting (coagulation)
VASCULAR SPASM
When arteries or arterioles are damaged, the circularly arranged smooth muscle in their walls contracts immediately, a reaction called vascular spasm.
This reduces blood loss for several minutes to several hours, during which time the other heamostatic mechanisms go into operation. The spasm is probably caused by damage to the smooth muscle, by substances released from activated platelets, and by reflexes initiated by pain receptors
PLATELET PLUG
Initially, platelets contact and stick to parts of a damaged blood vessel, such as collagen fibres of the connective tissue underlying the damaged endothelial cells. This process is called platelet adhesion.
2 Due to adhesion, the platelets become activated, and their characteristics change dramatically. They extend many projections that enable them to contact and interact with one another, and they begin to liberate the contents of their vesicles. This phase is called the platelet release reaction. Liberated ADP and thromboxane A2 play a major role by activating nearby platelets. Serotonin and thromboxane A2 function as vasoconstrictors, causing and sustaining contraction of vascular smooth muscle, which decreases blood flow through the injured vessel.
3 The release of ADP makes other platelets in the area sticky, and the stickiness of the newly recruited and activated platelets causes them to adhere to the originally activated platelets. This gathering of platelets is called platelet aggregation. Eventually, the accumulation and attachment of large numbers of platelets form a mass called a platelet plug.
COAGULATION
Blood clotting
- Blood normally remains liquid in the blood vessels
- In contact with foreign surfaces coagulation takes place
- Coagulation is the formation of a clot made up of protein fibres (fibrin) which traps the formed elements
- Plasma without its clotting proteins forms a yellow liquid called serum
PHAGOCYTOSIS
fag′-ō-sĪ-TŌ-sis; phago- = to eat) is a form of endocytosis in which the cell engulfs large solid particles, such as worn-out cells, whole bacteria, or viruses
SERUM
Plasma without its clotting proteins forms a yellow liquid called serum.
