Cardiovascular system II Flashcards
Erythropoiesis- Production of RBC- ~15 days
Production and Maturation
Bone marrow»_space;> Blood
Plurpotent hematopoietic > Proerythroblast > Erythoblast > Reticulocyte > Erythocryte
Regulation of Erythropoiesis
Hormonal (Negative Feedback Axis)
Kidney becomes hypoxic (renal arterial oxygen drops) triggering EPO release
What causes Hypoxia?
Haemorrhage or Injury
-Iron deficiency-
-High Altitude or Lung Disease (Pneumonia
O2 sensor protein- Hypoxia-inducible Factor
Low oxygen > to bone marrow to red blood cells
Oxygen levels drop - high demand for oxygen, what happens?
Stimulant for Erythropietin to be released by kidney
High number of Erythropeietin >
High number of Erythrocytes whihc increase O2
Blood becomes…
thicker - harder to flow through the vessels
Whats another word for RBC?
Erythrocytes
Hormone which is release in demand of oxygen:
Erythropoietin (EPO)
What is Erythropoietin made of and where is it secreted?
glycoprotein hormone naturally produced by the peritubular cells of the kidney
Regulation of Erythropoiesis
Hormonal -Ive feedback Axis
Kidney becomes hypoxic (renal arterial oxygen drops) triggering EPO release
Erythropoietin (EPO) stimulate the red bone marrow to produce erythrocytes
Erythrocytes increases O2 transport to the kidney and block EPO release
Why do males have more red blood cells/ more RBC than females per mcL?
More testostrone compared to women
Why does more testostrone means bigger supply of oxygen?
Testosterone enhances EPO production,
(result in higher RBC in Males)
High EPO: Erythrocytes mature faster
Increase haematocrit, dehydration and blood viscosity (clotting, stroke, heart failure)
What is the importance of Iron in blood?
Nutrients
Iron: Dietary
65% in Hb
Bound with protein and stored as ferritin and haemosiderin
How is Iron transferred?
Transported by binding with transferrin
Substrates, like amino acids, lipids and carbohydrates
Folic acid & Vitamin B12 – DNA synthesis/Development of RBC
Life cycle RBC
how many days?
100-120
What happens in the RBC cycle?
Cannot grow, divide and replicate (no nucleus)
-Get older and fragile and degenerate
-trapped/macrophage in spleen- RBC breakdown
-Iron- recycled & stored
Heme
Degraded to bilirubin, yellow pigment-Liver secretes bilirubin in bile (in intestine)-urobilinogen-stercoblin, brown pigment excreted in faeces
Globin
metabolised into aminoacids & recycled
RBC: What could go wrong?
- Anaemia
- Blood loss
- RBC deficiency
- Sickle cell anaemia
- Thalassemia
Anaemia:
Sign of problem and risk
(Low Oxygen- Hypoxia- Growth, Development and Metabolism of several cells)
Symptoms of Anaemia
Fatigue, Pallor, Dyspnoea & chills
Blood Loss:
Haemorrhagic (acute, chronic): Blood loss, replace blood; treat cause
RBC deficiency:
Iron deficiency: RBC turning microcytes lacking Iron-Hb production. Treat or manage with Iron supplements
Renal: lack of EPO; supplement with synthetic EPO
Pernicious: Autoimmune condition-destroy B12 absorption; without B12 RBC cannot divide (or) and they become macrocytes: Treat or manage with either dietary or supplement B12.
Aplastic: Injury to Red Bone Marrow/ Drugs: Chemotherapy, Radiation, chemicals: Transfusion and stem cell transplantations