Blood Lecture Flashcards
Circulatory vs Cardiovascular Systems
Circulatory: heart, blood and blood vessels
Cardiovascular: heart and blood vessels
What are the functions of the circulatory system?
Transport: oxygen, nutrients, waste, and hormones
Protection: inflammation, limit spread of infections, destroys microorganisms, pathogens, and cancer cells, and initiates clotting
Regulation: fluid balance, stabilizes extracellular fluid pH levels and temperature control
What are components and properties of blood?
-Blood is a connective tissue consisting of cells and an extracellular matrix. Adults have 4-6L of blood.
-Plasma is the matrix of blood
-The formed elements are red blood cells, white blood cells, and platelets
Describe blood plasma
Plasma is the liquid portion of blood with three main plasma proteins that are formed by the liver (except globulin):
1. Albumin: small and most abundant. Contributes to blood osmolarity, viscosity, and influences blood pressure
2. Globulins: antibodies, provide immune system functions
3. Fibrinogen: precursor of fibrin threads that help form blood clots
Other components of plasma:
1. Nitrogenous compounds: free amino acids from dietary protein, tissue breakdown, and waste
2. Nutrients such as glucose, vitamins, fats, cholesterol and minerals
3. Dissolved oxygen, CO2, and nitrogen
4. Electrolytes: Sodium makes up 90% of plasma cations
What is the structure and function of erythrocytes?
Structure: disc shaped cell with thick rim; all organelles are gone. The blood type is determined by surface glycoproteins and glycolipids. It is bendable.
Function: Gas transportation
- carry oxygen from lungs to cell tissues, and brings back CO2 to lungs
- With most organelles lost, RBC has an increased diffusion rate of substances .
-Hemoglobin, 33% of the cytoplasm, aids in oxygen delivery
What is the structure and function of hemoglobin?
Structure: 2 alpha and 2 beta protein chains that make up a total of 4 chains, which is a globin. It also contains 4 heme groups where iron helps bind oxygen to the center of it
Function: oxygen delivery and CO2 transport to lungs
Describe the life cycle of erythrocytes
- Kidney detects low oxygen and secretes EPO
- EPO stimulates hemopoietic tissues to make RBC in red bone marrow
- New RBC after 2-3 days and they live for about 90 days
- RBC rupture in narrow channels of the spleen and liver where macrophages eat the membranes and the heme is excreted through bile
Explain the general function of leukocytes (WBC)
-the least abundant formed element
-protects against microorganisms and other pathogens
-prominent nucleus and organelles for protein synthesis
-all WBC have granules from lysosomes, but some WBC have specific granules that aid in defense (granulocytes)
-they spend only a few hours in the bloodstream before migrating to connective tissues
Neutrophil
-granulocyte
-most abundant
-aggressively antibacterial and phagocytize (eat) bacteria or throw acid
Lymphocyte
-second most abundant
-immune memory
-produces antibodies
-destroy cancer cells
-provide long term immunity because it moves from blood to tissue fluid to lymph and to blood again
Monocytes
-middle abundant
-leave blood stream to phagocytize pathogens
-antigen presenting cells to activate other immune cells
-transform into macrophages and live for several years
Eosinophil
-second to least abundant
-granulocyte
-active during parasitic infection
Basophil
-least abundant
-granulocyte
-secrete histamine: increases blood flow to injury
-secrete heparin: mobilizes other WBC
Describe leukopoiesis (WBC formation)
-all WBC form from hemopoietic stem cells
-WBC do not stay in blood stream
-granulocytes leave blood stream after 8 hours and live 5 days longer
How does the body control bleeding?
- Vascular spasm: blood vessel constricts
- Platelet plug: platelets stich to collagen fibers and recruits more platelets until the plug is full
- Cogulation: convert fibrinogen to fibrin to hold platelet plug in place
- Clot retraction
