Exam 1: Blood Flashcards
1
Q
Components of Blood
A
- formed elements: cells and all things derived from them
- — erythrocytes, leucocytes, platelets
- plasma
- proteins, ions (electrolytes), nutrients, gases, waste products et al.
2
Q
Physical Characteristics of Blood
A
- viscous
- temperature: about 38°
- arterial blood has a pH of 7.35 – 7.45.
- — slightly alkaline
3
Q
Functions of Blood
A
- distribution functions: transport of O2, nutrients, metabolic waste (urea, CO2), and hormones
- regulatory functions: body temperature, pH, fluid volume
- protective functions: preventing blood loss, preventing infection (antibodies, WBC’s, Complement)
4
Q
Plasma
A
- serum + clotting factors
- – serum: plasma without the clotting factors/proteins
- is over 90% water
- makes up over half of blood
- over 100 different dissolved solutes
- – mostly proteins
- – albumin is the most abundant plasma protein
- contains globulins
- — alpha, beta, and gamma
5
Q
Albumin
A
- most abundant plasma protein (58%)
- carrier: assisting other molecules through the circulation
- an important buffer to maintain pH
- helps maintain osmotic pressure
6
Q
Gamma Globulin
A
- include antibodies
- important for immune function
- make up about 38% of all globulins
7
Q
Erythrocytes
A
- red blood cells
- made in red bone marrow
- – found in spongy bone (caps of long bones and flat bones)
- anucleate, biconcave discs containing hemoglobin
- function in the transport of respiratory gases, deliver oxygen to cells
8
Q
Hematocrit
A
- percentage of total blood volume made up of RBC’s
- — usually about 45%
- centrifuge blood
- — RBCs go to the bottom bc they are heaviest - fill the bottom 45% of test tube
- — white blood cells and platelets are in the middle - but only make up about 1% of blood
- — plasma is the lightest and fills the top 55% of the test tube
9
Q
Hemoglobin
A
- a protein consisting of two α and two β polypeptide chains, each of which is bound to a molecule of the pigment heme in the center of the hemoglobin
- – iron is found in the heme
- O2 binds easily and reversibly to the iron in the heme so each hemoglobin molecule can bind with four molecules of oxygen
- CO2 binds to the globin.
10
Q
Hematopoiesis
A
- blood cell production
- all formed elements originate from stem cells found in the red bone marrow called hemocytoblasts
- proerythroblasts are committed to becoming RBC’s.
11
Q
Erythropoietin
A
- hormone that leads to red blood cell production
12
Q
Erythrocytosis (polycythemia)
A
- too many red blood cells
- blood becomes thick and sluggish, high viscosity
- may lead to blocked capillaries
- often found in smokers
- – not getting enough oxygen, which signals the kidneys to make more red blood cells
13
Q
Red Blood Cell Formation
A
- hypoxic conditions stimulate certain kidney cells to release erythropoietin hormone
- erythropoietin is transported to the bone marrow and hastens the maturity of RBC’s
- during the maturation process, the nucleus and other organelles are ejected and become stippled reticulocytes which enter the bloodstream
- erythrocytes last about 4 months at which time they are engulfed by macrophages (WBC’s) and are stripped of their iron for reuse.
- — some of the heme is degraded into bilirubin which is picked up by liver cells and secreted in bile.
14
Q
Anemia
A
- usually defined as a decrease in the amount of red blood cells or hemoglobin in the blood.
- it can also be defined as a lowered ability of the blood to carry oxygen.
Types:
- hemorrhagic anemia
- hemolytic anemia
- aplastic anemia
- iron-deficiency anemia
- pernicious anemia
- thalassemia
- sickle-cell anemia
15
Q
Microcytic vs Macrocytic anemia
A
- Microcytic: RBCs are smaller than they normally are
- –ex: iron deficiency - iron is hard to absorb, so you preserve it as much as you can while you have it
- Macrocytic: RBCs are larger than they normally are
16
Q
Hemorrhagic Anemia
A
- refers to loss of blood from the vessels.
- — a wound which leads to significant blood loss from the body
- — or a wound that leads to internal bleeding
17
Q
Hemolytic Anemia
A
- refers to the rupture of RBC’s.
- – example: malaria - the virus affects red blood cells and causes them to burst when the virus reproduces
18
Q
Aplastic Anemia
A
- is the inability of bone marrow to manufacture RBC’s
- caused by some antibiotics, but cause is often unknown
19
Q
Iron-Deficiency Anemia
A
- is the inadequate intake or absorption or loss of Fe necessary to make heme.
- microcytic
20
Q
Pernicious Anemia
A
- is a deficiency of vitamin B12 necessary for DNA replication and cell division.
- usually people have enough B12 in diet, but not enough intrinsic factor
- — older people are more likely to have pernicious anemia: not producing enough intrinsic factor in their stomach
- — need intrinsic factor to get B12 into the system through the stomach
- B12 is important for mitosis/cell division
- — red bone marrow is a very active site for cell division, so a lack of B12 leads quickly to a lack of red blood cells
21
Q
Thalessemia
A
- genetic disorder affecting red blood cells
- most commonly found in people of mediterranean descent
- causes the body to make less hemoglobin
- — improper oxygen transport
- — destruction of red blood cells - less circulating red blood cells than there should be
22
Q
Sickle Cell Anemia
A
- genetic disorders affecting RBC’s.
- african descent
- beta chain is affected by a genetic defect - only one amino acid different from normal cell
- — cause RBC to have a curved (sickle) shape instead of being circular
- RBCs bunch up at beginning of capillary beds and starve tissues of blood
23
Q
Leucocytes
A
- nucleated
- account for less than 1% of the total blood volume
- — the normal number is from about 4,000 to 11,000 WBC’s per mm3.
- some WBC’s are capable of slipping through capillary walls by amoeboid motion (a process called diapedesis) where they are able to engulf infectious agents by phagocytosis.
- 2 major categories: granulocytes and agranulocytes
24
Q
Granulocytes
A
- visible cytoplasmic granules
- neutrophils
- eosinophils
- basophils
25
Q
Neutrophils
A
- cytoplasm stains a lilac color with a mixture of basic and acidic dyes
- the most numerous of the WBC’s (about 60%).
- about twice the size of RBC’s
- have nuclei variably consisting of 3 to 6 lobes
- — polymorphonuclear leukocytes
- phagocytes
- — are able to leave the bloodstream and enter infected tissue where they ingest and destroy bacteria
- the number of neutrophils increases dramatically with acute bacterial infections.
26
Q
Eosinophils
A
- cytoplasm stains red or orange with the acidic dye eosin
- make up about 1 – 4% of all WBC’s
- has a bilobed nucleus
- their major function is to produce toxic proteins against certain parasitic worms
- they are also important in allergic responses by phagocytizing immune complexes.
27
Q
Basophils
A
- cytoplasm stains blue-purple with the basic dye methylene blue
- account for
28
Q
Agranulocytes
A
- Lymphocytes
- Monocytes
29
Q
Lymphocytes
A
- the second most numerous of the WBC’s (20 to 40%)
- most are not found in the bloodstream, but are enmeshed in lymphoid tissue
- — where they are necessary for the specific immune response
- T cells respond directly against infected cells
- B cells give rise to plasma cells that produce antibodies
- memory cells: responsible for a more immediate reaction to the same antigen at the time of a later infection
- — secondary response
- — both T and B have memory cells
- lymphocytes are the primary constituents of lymphatic tissue
- — this tissue is found in tonsils, lymph nodes and the spleen.
30
Q
Monocytes
A
- are the largest of the WBC’s
- account for about 2 to 8% of the total
- have a kidney or U-shaped nucleus
- during infections, they leave the blood and migrate to the infected tissue
- — where they differentiate into macrophages (clark kent –> superman)
31
Q
WBCs fight off substances by…
A
- releasing chemicals such as heparin (an anticoagulant) and histamine (a vasodilator)
- phagocytosis
- antibody production
32
Q
Leukocytosis
A
- a high number of leucocytes
- — a count of over 11,000/mm3
- occurs normally in response to infection
33
Q
Leukopoiesis
A
- the production of WBCs
- hemocytoblasts may become
- — lymphoid stem cells: committed to becoming lymphocytes
- — myeloid stem cells: committed to becoming all other types of WBC’s
34
Q
Leukopenia
A
- a leukocyte disorder
- an abnormally low white blood cell count
35
Q
Leukemia
A
- a leukocyte disorder
- a cancerous condition involving WBCs
36
Q
B and T cell maturation
A
- T cell: mature in thymus gland
- B cell: mature in bone marrow
37
Q
Infectious Mononucleosis
A
- a leukocyte disorder
- is a virus infection of B lymphocytes
- usually seen in teens and young adults
- transmitted through infected saliva.
38
Q
AIDS
A
- a leukocyte disorder
- a viral infection of T lymphocytes.
39
Q
Platelets
A
- aka thrombocytes
- are fragments of large cells called megakaryocytes
- thrombopoietin: regulates platelet formation
- normal platelet count is 250,000 to 400,000 per mm3.
- stick to exposed collagen and other platelets in damaged blood vessel walls
- — temporarily forming a plug to protect against blood loss
- — Aspirin makes platelets less sticky.
- release molecules to start the clotting process
- stimulate neutrophils to destroy bacteria.
40
Q
Macrophages
A
- actively phagocytize pathogens
- — hunters: eat foreign bacteria
- — either wandering: go out and catch food (like a lion)
- — or fixed: lie in wait for the foreign organism to come near (like a spider)
- clean up cellular debris
- — scavengers
- important in activating lymphocytes.
41
Q
ABO Blood Groups
A
- ABO blood groups are based on the presence or absence of two antigens or agglutinogens
- — specific glycoproteins on the RBC membrane surface
- — type A and type B.
- preformed antibodies called agglutinins act against these two antigens
- — formed during fetal development, do not need to be exposed to the antigen to have the antibody to it
- — found in the plasma
- — anti-A and anti-B
- a person possesses agglutinins for the type of antigen that is not found on her RBC membrane
- — type A blood has A antigen and anti-B agglutinins
- — type B blood has B antigen and anti-A agglutinins
- a person with neither antigen is Type O
- — and has both anti-A and anti-B agglutinins
- a person with both antigens is Type AB
- — and has neither anti-A nor anti-B agglutinins
42
Q
If a blood transfusion is given to someone with a different ABO blood type….
A
If RBC’s with certain antigens are transfused into blood containing antibodies against those antigens, a clumping or agglutination will occur and may be fatal
- Type O is called the universal donor
- — since there is no antigen to attack, all types will accept this blood
- Type AB is called the universal receiver since no antibodies occur in the plasma.
- — AB blood recognizes both A antigens and B antigens as belonging to self
43
Q
Rh Blood Type
A
- People carrying the Rh antigen on their RBC membrane are called Rh+, those without the antigen are called Rh-
- . No preformed antibodies in the plasma, but a transfusion involving Rh+ to an Rh- recipient stimulates antibody production in the recipient
- — no reaction takes place the first time because antibodies build up very slowly
- But on subsequent exposures to the antigen, hemolysis occurs.
- — Untreated, a second pregnancy involving an Rh- mother and an Rh+ fetus may result in abortion because of the mother’s immediate immune response to the mixing of maternal and fetal blood
- — this is called hemolytic disease of the newborn
44
Q
Coagulation
A
- Blood clotting is a complex, multistep process that results in a complex substance called prothrombin activator being formed
- — prothrombin activator converts a plasma protein called prothrombin into an enzyme called thrombin.
- — vitamin K is necessary for the activation of prothrombin.
- Thrombin catalyzes the joining of fibrinogen molecules (present in the plasma) to a fibrin mesh
- — the fibrin mesh traps blood cells and effectively seals the hole until the blood vessel can be permanently repaired.
45
Q
- Thrombus
2. Embolus
A
- a clot that forms and persists in an unbroken blood vessel
- a thrombus that has broken away and is floating freely in the bloodstream
46
Q
- Clotting Factors
2. Anticoagulants
A
- Factors that enhance clot formation
2. Factors that inhibit clotting
47
Q
- thrombocytopenia
- impaired liver function occurs when
- hemophilia
A
- a deficiency of circulating platelets
- the liver is unable to synthesize some of the clotting factors.
- refers to several hereditary bleeding disorders in which certain clotting factors are missing
- — a sex-linked disease causing a deficiency of factor VIII is the most common
48
Q
Diagnostic blood tests
A
- a differential white blood cell count may indicate the kind of infection involved.
- prothrombin time assesses the amount of prothrombin present in the blood.
- a SMAC (Sequential Multiple-channel Analyzer Computer) is a blood chemistry profile.
- a Complete Blood Count (CBC) includes counts of all formed elements as well as hemoglobin and hematocrit
