Hematology Flashcards
What divisions do our fluid compartments have?
Intracellular and extracellular and within extracellular there is interstitial fluid, plasma, and some other small compartments
What is interstitial fluid?
Fluid occupying the space between cells with the same constituents as plasma EXCEPT for large proteins which are present at a lower concentration
Where does interstitial fluid come from?
It’s derived from capillary filtration
What maintains membrane potential?
Sodium ATPase (3 Na out 2 K in)
What are the total osmotic pressures of the three important fluid types to each other?
Interstitial fluid is hypoosmotic to plasma and interstitial fluid is isosmotic to intracellular fluid
What type of cells have blood capillaries with the greatest permeability? How about the least?
Hepatocytes and brain cells.
How do cells that are not small enough to pass through even pores in the capillaries with increased permeability pass through?
Through intercellular clefts
How does the molecular weight of a substance relate to its permeability?
The larger a substance is the lower its permeability is.
What is colloid osmotic pressure/oncotic pressure?
Osmotic pressure caused by the presence of proteins
What is the effect of an increase of oncotic pressure on water movement?
It increases water movement, but notably protein concentration increases rarely happen so this does not often happen.
What three major proteins are in the plasma that contribute to colloid osmotic pressure?
Albumin, globulin, fibrinogen. Other proteins vital but not related to oncotic pressure.
What are the role of albumins?
They are the most abundant plasma proteins and act as nonspecific carrier proteins to prolong half-lives by binding loosely and protecting from enzymes. They also contribute to oncotic pressure.
What are the role of globulins?
Proteins with specificity like specific carrier proteins, enzymes, and immunoglobulins
What are the role of fibrinogens?
Blood clotting! It polymerizes into long fibrin threads.
What are the Starling forces?
Forces that affect fluid movement in and out of capillaries. Outward pressure is capillary pressure + outward pressure, and inward pressure is interstitial fluid pressure and plasma colloid osmotic pressure.
What is the net movement of fluid in the capillaries?
0.3 mmHg towards the Interstitial compartment
What is the order of key plasma protein contribution to Starling forces?
Albumin, globulins, fibrinogen
What does the interstitial compartment contain?
Collagen fibres for structure and proteoglycan (hyaluronic acid and protein) filaments to create a semi permeable gel when trapping interstitial fluid. Also a very small amount of free flowing fluid
How does movement of solutes occur in the interstitial compartment?
Molecular diffusion slightly slower than in fluid.
What is edema? What are the two main causes?
An edema is an increase in the pocket of free fluid in the interstitial compartment which can be caused by an increase in oncotic pressure. Proteins can flux due to a disruption in protein concentration across a membrane and blocked lymph fluid accumulation.
What does the presence of proteoglycans, collagen fibres, and gel formation in the interstitial compartment ensure?
Uniform fluid distribution in the body, maintenance of optimal intracellular distance for diffusion, and mechanical support (adhesion proteins)
How does flow from the capillaries into the lymph system work?
Most blood flows directly back to the heart but due to Starling forces some gets pushed into the lymph system, a one-way series of valves. It transports fluids and macromolecules and is a function of interstitial fluid pressure, with increased pressure increasing flow.
What is the role of lymph nodes?
They filter lymph and contain phagocytic cells which remove foreign blood contaminants and cancer cells before draining into the veins. This is why infection causes swollen lymph nodes.
What disease causes edema?
Elephantiasis caused by worms. Block lymphatic flow.
What are the important small fluid compartments and what do they do?
Cerebrospinal fluid: cushioning
Intraocular fluid: eyeball pressure
Fluid compartment of GI tract: space
Fluids compartment of lung: lubrication for slippage of lung
Fluids compartment of pericardial cavity, peritoneal cavity, joint spaces, bone and cartilage etc: lubrication
What is haemopoiesis?
The production of blood cells
Fill in the blanks: Pluripotent stem cells can differentiate into two types of cells, _ stem cells and _ stem cells. The former can further differentiate into _, _, and _, while the later can further differentiate into _, _, _, _, _, and _.
Lymphoid, myeloid, NK cells, B lymphocytes, T lymphocytes, erythrocytes, platelets, monocytes, neutrophils, eosinophils, basophils.
Where are myeloid stem cells located?
Bone marrow
The derivatives of the lymphoid system can be grouped as?
lymphocytes
What controls the production of blood cells?
Cytokines which control the proliferation and differentiation of blood cells. They are committed progenitor cells past the myeloid/lymphoid state.
What increases the production of all hemopoietic stem cells?
Interleukins/stem cell factor