Unit 3: Hematology Flashcards
Define “extracellular fluid” and “interstitial fluid”.
How are these fluids related?
Extracellular fluid- fluid surrounding cells
Interstitial fluid- fluid surrounding most body cells except for blood cells
[[plasma surrounds blood cells]]
[interstitial fluid, along with plasma, makes up extracellular fluid]
Describe the major functions of the blood.
~TRANSPORTER: transporting oxygen, Co2, nutrients, metabolic wastes, heat, hormones
RBC- transporter
WBC- defense/immunity
Platelets- blood clotting
Describe the general composition of the blood.
55% plasma
~largely made of water, also salts, proteins, and other variable substances
45% cellular/ formed elements
~erethrocytes/leukocytes/platelets
Describe the composition of plasma. ‘
Pay particular attention to the protein types found in the plasma in terms of identity, proportion, and function
~~~3 types of proteins [8% of plasma]
a. albumins [60%] - osmotic balance, bind/release hydrogen ions = weak buffers to stabilize pH, transport
b. globulins [36%] - [immunoglobulins] - immunity/ immunological protection
c. fibrinogens [4%] - blood clotting (coagulation)
92% of plasma = water & salts
water- solvent for carrying substances
salts- osmotic balance, pH buffering, regulating membrane permeability
What are the formed elements?
make up 45% of blood
cells/ cell fragments
~erethrocytes/leukocytes/platelets
-erythrocytes dominate
Describe the structure, quantity and function of erythrocytes.
Structure: biconcave disc shape with hemoglobin
Quantity: 4.5-6 million RBC in a microliter of blood
Function: transporting oxygen
What is anemia?
A condition in which the blood doesn’t have enough healthy red blood cells
Describe the structure, quantity and function of hemoglobin.
Structure: quaternary protein structure; heem group & central iron atom
Quantity: 2/3 of the entire internal contents of RBC
Function: attaches oxygen (gives RBC oxygen transporting ability)
Explain the relationship between oxygen concentration and hemoglobin-oxygen binding affinity.
if oxygen is attached, hemoglobin shape changes each time; each shift > binding affinity to oxygen changes
Explain how pH, temperature, carbon dioxide and 2,3-DPG affect hemoglobin.
How do these factors contribute to oxygen distribution?
increase Co2
low ph
increase temp
increase 23 DPG
23 DPG - tissue metabolite
this all shifts the oxy hemoglobin shift
pH-
Low pH (acidic), > hemoglobin has reduced oxygen-binding affinity.
High pH (more alkaline), hemoglobin has a higher affinity for oxygen and readily binds to it, allowing for efficient oxygen uptake.
Temp-
Higher temperature, > reduces hemoglobin’s oxygen-binding affinity, promoting the release of oxygen.
Cooler environments, > hemoglobin has a higher affinity for oxygen and binds to it more readily.
Co2-
Increased CO2 levels lower the pH (increase acidity) in the blood > reduces hemoglobin’s oxygen-binding affinity
Lower Co2 Levels > the pH is higher, and hemoglobin has a higher affinity for oxygen, allowing for efficient oxygen uptake.
2,3 DPG-
In tissues with lower oxygen levels > 2,3-DPG levels increase, promoting the release of oxygen from hemoglobin
Describe where erythrocytes are produced and how their production is regulated.
~RBC are products of stem cells in the bone marrow
~Regulated by the endocrine system
~regulatation is influenced by a hormone called erythropoietin produced by the kidney
Describe where, when and how erythrocytes are removed from circulation. What is the destiny of the decomposition product of hemoglobin?
they will be disassembled/recycled through the spleen / other organs making up the reticuloendothelial system
[globin & iron recycled; heme eliminated]
May be discarded as bile from liver > large intestine > urobilinogen
Some ends in blood stream > kidneys discard
Describe the structure and function of platelets.
Tiny fragments that prevent blood loss
-clotting
-forming clogs
-vasoconstriction
Describe the three steps in hemostasis [stopping of bleeding].
A. Vasoconstriction
B. Platelet plug
C. Fibrin clot formation- chemical reaction regulated by series of proteins within plasma
Describe the two different pathways leading to clot formation. How are the different pathways activated, how fast are they (comparatively), and what are the common steps (starting from prothrombin)?
- Extrinsic pathway
~the initiating protein is tissue thromboplastin (triggered by injury without any foreign body contact)
~quicker - Intrinsic pathway
~mediated by initiating plasma protein Hageman’s factor (triggered by exposure to foreign bodies)
~slower
both pathways converge on prothrombin
(names confusing; based on initiating protein and where it came from)
What is the significance of a multi-stepped pathway leading to the formation of a blood clot?
How are calcium and vitamin K related to blood clotting?
How are blood clots removed?
Multi step pathway ensures that clots only form when needed, such as to stop bleeding from a cut or injury.
1) gives multiple points for the potential of blocking the pathway = more control
2) each step is a potential amplifying step ; each step amplifies the next step
Calcium: needed cofactor to make enzyme functional
to convert fibrinogen to fibrin
Vitamin K is necessary for acting as a coenzyme, to make enzyme functional
Blood Clot Removal:
The body has a natural process, called fibrinolysis, that breaks down the clot and restores normal blood flow.
[plasmin breaks down fibrin]
What is erythroblastosis fetalis?
Is this disorder harmful to the mother?
To the fetus?
condition in which a baby’s red blood cells are destroyed due to an incompatibility between the mother’s and baby’s blood types, typically involving the Rh factor.
~does not directly harm the mother biologically. However, mother can develop antibodies against the fetus’s incompatible blood cells, which may affect future pregnancies if not managed. Fetus may be treated as a disease and attacked- may not survive
~can be harmful to the fetus- can lead to severe anemia, jaundice, and other health problems; can be life-threatening to the fetus.
How are the ABO blood type and the Rh blood types similar?
How are they different?
~Both ABO and Rh blood types involve antigens on the surface of RBC
~They determine blood compatibility for transfusions and are inherited genetically.
differences—
ABO Blood Type: categorizes blood as A, B, AB, or O based on the presence of A and B antigens on the red blood cells.
It doesn’t involve the Rh factor.
Rh Blood Type: focuses on the Rh factor, which can be Rh-positive (+) or Rh-negative (-);separate from the ABO blood type.
ABO blood type deals with A and B antigens, while Rh blood type deals with the Rh factor (+ or -).
Why is type AB blood the “universal recipient”?
Why is type O blood the “universal donor”?
AB is the universal recipient bc they have no antibodies to A, B or Rh in their blood
O is the universal donor bc has no antigens [will not trigger an immune response]
How are coagulation and agglutination similar? How are they different?
Describe specifically how agglutination occurs.
coagulation- blood clotting; fibrinogen associated reaction
agglutination- clumping of cells; antibody-based reaction
Define “antigen” & “antibody”
antigens- recognizable molecules that antibodies can bind to
antibodies-globulin proteins in the plasma w/ specific binding properties
Define “agglutination.”
clumping of cells
[antibody-based reaction]
occurs when an antigen (molecule capable of triggering the adaptive immune response) is mixed with the corresponding antibody at a suitable pH/temperature.
Interstitial fluid and blood plasma collectively make up ________ _______ .
extracellular fluid
The fluid surrounding most of the body cells (except for blood cells) is
interstitia fluid
