Blood Flashcards
Functions of blood (x3)
Transportation: O2, CO2, nutrients, hormones etc.
Regulation: pH buffer, body temperature, water content
Protection: blood clotting, WBCs + antibodies
Components of blood
Plasma (water, proteins, hormones, glucose etc.)
Leukocytes (WBCs, buffy coat)
Erythrocytes (RBCs)
What makes up the formed elements of blood?
WBCs and RBCs
Ways to obtain a blood sample (x3)
Venipuncture (drawn via a vacutainer –> need this bc venous system is under low pressure)
Finger/heel stick: constantly sued to monitor sugar levels, and with infants to assess blood factors (K+ etc.)
Arterial stick: used to analyze arterial blood gases
Characteristics of RBCs
Biconcave disc
Large SA
No nucleus –> more space for O2 transport
Lack mitochondria (generation of ATP anaerobically)
Hemoglobin (red colour)
Relevance of biconcave shape of RBCs
Shape comes from RBC ejecting its nucleus during development
Allows for more SA for diffusion
Characteristics of hemoglobin
Made up of 4 polypeptide chains (2 alpha and 2 beta)
Each chain has an iron-containing heme group
Each iron combines with 1 O2
Iron binds w O2 at the lungs and releases at tissues (then diffuses into interstitial fluid)
Hemoglobin and CO2
Carries CO2 in the globin part of the molecule
Hemoglobin and NO
Binds to NO (produced by endothelial cells)
Releases to cause vasodilation of SM cells
O2-Hb curve shifted right
Oxygen unbinds from hemoglobin more readily
Increased temp + CO2, decreased pH
O2-Hb curve shifted left
Oxygen is released from hemoglobin less readily
Decreased temperature + CO2 and increased pH
Steps of RBC production
Pluripotent stem cell –> myeloid stem cell –> proerythroblast –> reticulocyte (nucleus ejected) –> RBC
Key takeaways from RBC production
Cell decreases in size
Nucleus is removed
Cell becomes specialized
Cytoplasm fills with hemoglobin
Where does RBC production occur?
In red bone marrow
in long bone for infants
RBC production & aging
RBC production moves more axial & central (ribs + pelvis)
What happens when RBCs die?
Removed by spleen and liver (phagocytosed by macrophages)
Iron is recycled for formation of new RBCs
What happens if destruction of RBCs > production?
Anemia
RBC production homeostasis
Decreased O2 levels –> erythropoietin release from kidney –> stimulates red bone marrow –> more RBCs –> increased O2 carrying ability
How can hypoxia occur?
Decreased RBCs, decreased O2 availability, increased O2 demands
What is another way for erythropoietin to be released?
Renal a. stenosis
Less blood to kidney (kidney views it as decreased O2 –> release)
What happens during kidney failure?
Not enough erythropoietin produced –> decreased RBC production (can’t maintain homeostasis)
Characteristics of antigens
Any substance that causes an antibody response to be generated
Found on surface of RBCs
Where are antibodies found?
In the blood plasma
Antigens and antibodies
You don’t have the antibodies in your plasma that react with the antigens on your own RBCs
