Blood 1 Flashcards by Lucy Day

How does blood contribute to homeostasis?

Serves as:
- The vehicle for transporting materials to & from cells

Buffering changes in pH
Carrying excess heat to the body surface for elimination
Plays major role in body’s defence system
Minmising blood loss when a blood vessel is damaged

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Why is blood crucial for the survival of cells?

Cells need constant supply of O2 & removal of CO2
Cells can only survive & function only in a narrow pH & temp range
Cells must be protected against disease causing microorganisms

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Why is O2 important for cells?

It supports their energy generating chemical reactions - which produce CO2

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What is the total amount of fluid in the body?

42 litres

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How is the 42 litres of body fluid divided around the body?

Intracellular volume = 28L
Extracellular vol = 14L
Plasma vol = 3L
Red cell vol = 2.5L

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How much of your body fluid does blood make up?

5.5L

(Plasma 3L and Red cell 2.5L)

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How does circulation support the need of tissues?

Transports nutrients to tissues
Transports waste products away from tissues
Carries hormones from one part of the body to another
Maintains appropriate environement in all tissue fluids for optimal survival & func of cells

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What is the composition of blood?

Plasma (3L - 55%)
Formed elements (2.5L - 45%)
- Red cells (erythrocytes)
- White cells (leukocytes)
- Platelets (thrombocytes)

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What is another name for red cells?

Erythrocytes

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What is another name for white cells?

Leukocytes

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What is another name for platelets?

Thrombocytes

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What is the haematocrit?

The proportion of red cells in the blood volume - is approx 45%

When blood is spun the RBCs pool at the bottom so can count them

Males = 42% - 52%
Females = 37% - 47%

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How will Anaemia, Polycythaemia and Dehydration change the haematocrit?

Anameia = 35%

Polycythaemia = 70%

Dehydration = 70%

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Why does the Haematocrit look the same in Polycythaemia and Dehydration?

Polycythaemia - total blood volume stays the same however the amount of RBCs increases from 45% to 70%

Dehydration - total blood volume dec (to lets say 65% of normal), so the RBC vol stays the same but the total vol of blood dec, therefore is 70%

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What can your blood proportions help to determine?

Whether you are healthy or not

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What is an external factor that can affect the proportion of RBCs in your blood?

Altitude

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What can cause anaemia?

Blood loss, e.g. haemorrhage

Haemolytic disease, e.g. sickle cell

(Causes haematocrit to dec)

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What causes Polycythaemia?

Secondary factor/physiologic i.e. hihg altitude

Polycythaemia vera = bone marrow tumours (a type of blood cancer that causes production of too many RBCs)

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What % of world pop suffer from anaemia?

40%

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What are 3 major causes of anaemia?

Dietary iron deficiency
Micronutrient deficiencies
Iron absorption

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How does dietary iron deficiency cause anaemia?

Diagnosed by low haemoglobin - low serum ferritin response to iron supplements

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How does micronutrient deficiencies cause anaemia?

Haemoglobin synthesis dec due to lack of vitamin B12 or folic acid

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How does low iron absorption cause anaemia?

A lack or riboflavin alters level of iron absorption

Riboflavin is involved in RBC production and transportation of oxygen to the cells

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What is polycythaemia also known as?

Erythrocytosis

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What is Polycythaemia?

Having a high concetration of RBCs in you blood

What are the symptoms of of Polycythaemia?

- A ruddy complexion - Headache - Blurred/patchy vision - Confusion - Stroke or coma (extreme)

What are the subtypes of Polycythaemia?

Absolute erythrocytosis Apparent erythrocytosis

What is absolute erythrocytosis?

Rasied red cell mass - normal plasma volume

What is apparent erythrocytosis?

Normal red cell mass - reduced plasma volume

What is the treatment for Polycythaemia (erythrocytosis)?

Venesection (blood letting)

What is the Congenital primary cause of Polycythaemia (erythrocytosis)? (Caused by an abnormality in the red cells)

Congenital --> Abnormal erythropoietin cell receptor, von Hippel Linda protein or proline dehydroxgenase enzyme

What is the Acquired primary cause of Polycythaemia (erythrocytosis)? (Caused by an abnormality in the red cells)

Acquired: - Polycythaemia vera - Myeloproliferative Disease

What are the Congenital secondary causes of Polycythaemia (erythrocytosis)? (Caused by an abnormality outsdie of the RBCs)

Congenital: - Inherited High Erythropoietin - Abnormal haemolgobin with increased O2 affinity - Decreased levels of metabolites

What are the Acquired secondary causes of Polycythaemia (erythrocytosis)? (Caused by an abnormality outsdie of the RBCs)

Acquired: - Conditions causing low O2 levels: chronic lung disease, congenital heart disease, sleep apnoea - Kidney disease: tumours, cysts, block to urine flow, kidney transplants - Liver diease

What are the Idiopathic secondary causes of Polycythaemia (erythrocytosis)? (Unknown cause)

Idiopathic erythrocytosis

What are the 3 main components of the blood?

- Plasma --> 55% - Buffy coat --> leukocytes & platelets less than 1% of blood vol - Erythrocytes --> 45% of whole blood vol

What is the role of plasma?

Transport of substances

What is the role of the Buffy coat?

Leukocytes --> Defence Platelets --> Clotting

What is the role of erythrocytes?

Transport of gasses

What are the plasma components?

- Water (90%) Solutes: - Proteins (8%) - Albumin - Globulins - Fibrinogen - Others

What role does water play in plasma?

- Makes up 90% of plasma vol - Prrovides dissolving & suspending medium for solutes & formed elements

What role do proteins play in plasma?

Account for 8% of plasma (by weight); Most are synthesised by liver

What role does albumin play in plasma?

60% of plasma proteins; Largely responsible for plasma osmotic pressure

What role do globulins play in plasma?

36% of plasma proteins; Include: - Clotting proteins - Antibodies secreted by certain leukocytes during the immune response - Proteins that bind to lipids - Fat-soluble hormones & metal ions to transport these substances in the blood

What role does fibrinogen play in plasma?

Important in the formation of blood clots

What role do the other molecules play in plasma?

Enzymes, hormones & antibacterial proteins

Albumins: Where is it made and what is its function?

Source: Liver Function: Major contributors to colloid osmotic pressure of plasma; carriers for various substances

Globulins: Where is it made and what is its function?

Source: Liver & lymphoid tissue Function: Clotting factors, enzymes, antibodies, carriers for various substances

Fibrinogen: Where is it made and what is its function?

Source: Liver Function: Forms fibrin threads essential to blood clotting

Transferrin: Where is it made and what is its function?

Source: Liver & other tissues Function: Iron transport

Others in the plasma: Where is it made and what is its function?

Source: various Function: Enzymes, hormones & antibacterial proteins

What is hypotonic?

Cell swells & loses shape

What is hypertonic?

Cells collapse but rigid cytoskeleton remains intact

What are the components in plasma that are transported?

- Nitrogenous waste products - Organic nutrients - Electrolytes - Cations - Anions - Respiratory gases

What are nitrogenous waste products?

By-products of metabolism, such as ureas, uric acid and creatine

What are organic nutrients?

Materials absorbed from the intestines & used by cells throughout the body; Includes glucose and other simple sugars, amino acids, fatty acids, glycerol, triglycerides, cholesterol and vitamins

What are cations?

Sodium, potassium, calcium, magnesium (important in neuromuscular signaling), and trace metals (important in normal enzyme activity)

What are anions?

Chloride (important in neuromuscular signalling), bicarbonate and phosphate (important in maintenance of normal plasma pH)

What are respiratory gases?

O2 and CO2; most O2 and some CO2 is bound to Hb in erythrocytes A sig fraction of CO2 is found in the plasma in the form of bicarbonate

What are the 5 blood cell types that can derive from a Myeloid stem cell?

- Platelets - Eosinophil - Basophil - Neutrophil - Macrophage

What are the 2 types of stem cells that derive fro, a haematopoietic stem cell?

- Myeloid stem cell - Lymphoid stem cell

What is the type of blood cell that derives from a lyphoid stem cell?

A lymphocyte