Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
What is a heme moiety |
Protoporphyrin 9 ring surrounding a single iron atom in its ferrous state |
|
|
Hemoglobin |
Globin chain surrounding a heme moiety a tetramer of these thus can carry 4 oxygen molecules Tetramer is highly soluble but individual Globin chains are insoluble |
|
|
Modulation of oxygen affinity to hemoglobin |
Protons(H+)-lower affinity of O2 thus more O2 available for tissue 2,3-biphosphoglycerate reduces oxygen affinity when bound to Hb Temperature - increase reduces O affinity decrease increases O affinity |
|
|
Embryological hemoglobin |
Hb Portland Hb Gower 1 Hb Gower 2 |
|
|
Gestational first appearance of fetal hemoglobin? |
10 to 11 weeks |
|
|
What mutation is responsible for sickle cell |
Change in 6th amino acid on chromosome 11 having B gene from Glutamate to Valine |
|
|
What are the findings of a sickle blood on a blood smear |
Elongated crescent shaped cells Target cells Nucleated red blood cells |
|
|
What are the effects HbS |
When passing through capillaries and have given off their oxygen they easily polymerisation that make the inside of the cell gelatinous 1 Increase in intracellular viscosity stiffening the RBC membranes 2 Calcium influx and potassium leaks out leading to dehydration 3 loss of pliability through capillaries leading to micro vascular occlusion and premature RBC destruction in liver and spleen and tissue ischaemia leading to progressive organ damage as well as acute pain 4 posses sticky membranes that are abnormally adherent to endothelium of small venules |
|
|
What other mutation can exist at position 6? |
HbC- Glutamate to Lysine |
|
|
Sickle cell syndromes |
Sickle cell trait-HbS/A-40/60 Sickle cell anemia- HbS/A-100/0 Sickle thalassemia minor-HbS/A-100/0 Sickle thalassemia major-HbS/A-60/40 Hemoglobin SC-HbS/A-50/0 and HbC-50 |
|
|
Clinical manifestations of sickle Cell anemia |
Hemolytic anemia Granulocytosis Reticulocytosis Painful crises Autosplenectomy within 18-36 months of life Splenic sequestration rare Renal papillary necrosis Renal failure Aseptic necrosis of bones and joints especially the femoral and humeral heads Chronic osteomyelitis caused by Salmonella Detachment of retinaRenal papillary necrosisRenal failureAseptic necrosis of bones and joints especially the femoral and humeral headsChronic osteomyelitis caused by SalmonellaHand-foot syndromeStroke in children infarctive leading to behavioral changesPriapismChronic lower leg ulcersAcute chest syndrome Painless haematuria in sickle cell trait Hand-foot syndrome Stroke in children infarctive leading to behavioral changes Priapism Chronic lower leg ulcers Acute chest syndrome Painless haematuria in sickle cell trait |
|
|
What are the features of the painful crises in sickle cell anemia |
Pain Tenderness Fever Tachycardia Anxiety |
|
|
What are the triggers of painful crises |
Infections - Malaria,UTI Fever Hypoxia Abrupt change in temperature Excessive exercise Anxiety Hypertonic dyes |
|
|
What is Isosthenuria |
Excretion of urine with specific gravity no more or no less than protein free plasma indicating renal papillary necrosis |
|
|
Acute chest syndrome |
Chest pain Cough Fever Tachypneoa Arterial O2 desaturation |
