Blood And Hematopoiesis

Question 1

Erythrocytes (Red blood cells)

Answer 1

• most numerous, 120 day life span
• biconcave disk, increases surface area facilitating gas exchange
• no nuclei or organelles
• filled with hemoglobin
• flexible membrane allows for movement

Question 2

Spherocytosis

Answer 2

Spleen filters blood. Macrophages bite off bad portion of cytoskeleton, left with smaller RBC and less surface area

Question 3

Leukocytes (WBCs)

Answer 3

Neutrophils, monocytes, eosinophils, basophils, b and t lymphocytes, and NK cells

Question 4

Neutrophils

Answer 4

• Granule
• nucleus is 3-5 lobes
• life span 6-8 hrs in blood, days in tissue
• can survive anaerobic
• phagocytize by internalizing bacteria in phagosomes which fuse to granules and destroy bacteria
• Pus
• lysozyme and myeloperoxidase, digestive enzymes

Question 5

Eosinophils

Answer 5

• granules (major basic protein)
• large, reddish staining
• bilobed nucleus
• few hours to several day span
• mediate allergic reactions and prot cat from parasites
• granules have crystalline core

Question 6

Basophils

Answer 6

• granules (histamine, heparin)
• dark blue
• bilobed nucleus
• mediate allergic rxn in tissues
• anaphylaxis is a type 1 hypersensitivity rxn

Question 7

Lymphocytes

Answer 7

• small, round. Thin rim of pale cytoplasm
• t cell-cell mediated
• b cell-humoral immunity, diff into plasma
• life span of days to years
• cytoplasm is larger when activated

Question 8

Monocytes

Answer 8

• kidney or oval shaped nucleus.
• precursor of macrophages, osteoclasts, and microglia (phagocytic, antigen presentation)
• life span few hours in circulation, differentiate in tissue

Question 9

Platelets

Answer 9

Cytoplasmic fragments of megakaryocytes, participate in blood clotting.
-complex with granules and organelles

Question 10

Hematopoiesis

Answer 10

Blood making. Begins in bone marrow. Myeloid stays there, lymphoid goes to thymus spleen or lymph nodes.

Question 11

Erythropoiesis

Answer 11

• 1 week w 3-5 cell divisions
• erythropoietin prod. by kidney is the growth factor.
• polyribosomes are blue, hemoglobin red.
• less nucleus means more hemoglobin is made, nucleus spat out when done

Question 12

Granulopoiesis

Answer 12

• takes 2 weeks
• GCSF (granulocyte colony stimulating factor)
• acquire azurophillic and specific granules
• precursors similar until myelocyte stage granules characteristics define them

Question 13

Monocytes development

Answer 13

• early stages are mono last and promonocyte
• final differentiation occurs in tissue after monocytes migrates from blood
• differentiate into variety of phagocytic cells in different tissues

Question 14

Megakaryoblasts

Answer 14

• Large cell with single lobed nucleus.
• endomitosis (replication without division) gives rise to polyploid megakaryocyte.
• thrombopoietin is the growth factor

Question 15

Proplatelets

Answer 15

• Swollen extension of megakaryocyte cytoplasm,
• penetrate capillary endothelium and exposes in circulating blood
• platelets bud off cytoplasm of megakaryocyte