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Flashcards in Blood and blood cells Deck (16):
1

what are the 6 main functions of the blood?

- transport
- heat distribution
- immunity
- haemostasis
- support
- maintain homeostasis

2

what are the 4 major components of blood?

- plasma
- red blood cells
- white blood cells
- platelets

3

what is the importance of haemoglobin?

transport of oxygen to tissue cells and transport of carbon dioxide to lungs

4

what is the basic structure of haemoglobin?

- 4 polypeptides each with a haem group
- 2 alpha chains, 2 beta chains
- each haem group contains Fe2+ which binds to an oxygen

5

what does haemoglobin carry carbon dioxide in conjunction with?

carbonic anhydrase

6

what adaptation does haemoglobin have in foetuses?

higher affinity for oxygen to take oxygen from the mother's blood

7

what are the essential features and functions of the erythrocyte?

- transport oxygen and carbon dioxide
- biconcave disk
- no organelles
- 120 day lifespan
- removed by macrophages
- dependent upon dietary iron
- produced in bone marrow
- production is stimulated by erythropoietin release from kidneys

8

define anaemia

low blood haemoglobin concentration

9

what are the major subclasses and causes of anaemia?

- microcytic (small MCV): ion deficiency - menstruation, GIT lesions, cancers
- normocytic (normal MCV): acute blood loss
- macrocytic (large MCV): vitamin B deficiency, folic acid deficiency during pregnancy

10

what are the major functions of leukocytes?

fight infections:
- lymphocytes produce antibodies
- neutrophils and monocytes are phagocytic
- eosinophils are involved in allergic responses
- basophils produce heparin

11

what are the major functions and main features of T-lymphocytes?

- cellular immunity
- produced in bone marrow and "educated" in thymus
- activated lymphocytes produce chemotaxins, lymphotoxin and interferon
- sub-groups include regulatory cells, helper cells and cytotoxic cells

12

what are the major functions and main features of B-lymphocytes?

- humoral immunity (antibody production)
- primary response occurs after a dormant period where it peaks then falls
- secondary response is greater, quicker and longer due to memory cells
- passive immunity can be acquired from injected antibody

13

what are the main features of monocytes?

- appear later
- become macrophages in tissue
- stimulate repair
- ingest, store and modify antigens and present them to lymphocytes

14

what are the main features of platelets?

- many organelles but no nuclei
- granules
- surface receptors initiate activation
- adhere to exposed collagen
- release granules to recruit and activate platelets
- involved in clot formation
- involved in haemostasis (prevention of blood loss)

15

what are the major functions of plasma?

- carrying cells
- carrying other key components: nutrients (glucose, lipids, amino acids), hormones (thyroxine, cortisol, erythropoietin), proteins (clotting factors, albumin, globulins), inorganic ions (Na+, K+, Ca2+), products of metabolism (urea, lactic acid)

16

in what ways do antibodies reduce infection

- precipitation: assist phagocytosis
- agglutination: clump cells together
- opsonisation: coat pathogen in antibody and mark for destruction by phagocytes
- neutralisation: prevent attachment of microorganisms to tissue