Anatomy Flashcards Preview

Hematology and Oncology > Anatomy > Flashcards

Flashcards in Anatomy Deck (20)
Loading flashcards...
1
Q

Erythrocytes

A

Carries O2 to tissue and CO2 to lung (chloride-HCO3- on surface to sequester HCO3-)
Large surface area to volume ratio; anucleave and biconcave

Lifespan: 120 days
Source of energy: glucose (90% glycolysis, 10% HMP shunt)

2
Q

Erythrocytosis
Anisocytosis
Poikilocytosis

A

Erythrocytosis: polycythemia (increased hematocrit)

Anisocytosis: varying sizes

Poikilocytosis: varying shapes

3
Q

Reticulocytes

A

Immature erythrocytes; marker of erythroid proliferation

4
Q

Platelets

A

Primary hemostasis - aggregates with other platelets and interacts with fibrin to form plug

Small cytoplasmic fragments from megakaryocytes

Dense granules (ADP, calcium)
Alpha granules (vWF, fibrinogen)

1/3 store in spleen
Thrombocytopenia or platelet dysfunction results in petechiae

5
Q

Leukocytes

A

Defense against infections

2 groups:
Granulocytes (basophils, eosinophil, neutrophils)
Mononuclear (lymphocytes, monocytes)

Normally 4000 - 10 000 cells

6
Q

WBC Differential

A
Neutrophils (54-62%)
Leukocytes (25-33%)
Monocytes (3-7%)
Eosinophils (1-3%)
Basophils (0-0.75%)
7
Q

Neutrophils

A

Acute inflammation (bacterial); phagocytic

Multilobed nucleus

Small, numerous granules: alkaline phosphatase, collagenases, lysozyme, lactoferrin

Large azurophilic granules (lysozymes): acid phosphatase, peroxidase, beta-glucuronidase

Hypersegmented polyps (>5 lobes) - Vitamin 12 or folate deficiency

Increased bands reflect myeloid proliferation (bacterial infections, CML)

8
Q

Monocyte

A

Differentiate into macrophages

Large, kidney-shaped nucleus
“Frosted glass” cytoplasm

9
Q

Macrophages

A

Phagocytose bacteria, cell debris, old RBC; scavenges damaged cells and tissues

Long half life; activated by gamma-interferon

Can function as APC cell (MHC-II)
CD14 as cell surface

10
Q

Eosinophil

A

Helminthic infection (major basic protein)

Bilobe nucleus
Large eosinophilic granules of uniform size

Highly phagocytic for antigen-anttibody complexes

Produces histaminase/arylsulfatase (helps limit reaction after mast cell degranulations

11
Q

Causes of Eosinophilia

A

[NAACP]

Neoplastic
Allergy
Asthma
Collagen vascular disease
Parasite (invasive)
12
Q

Basophil

A

Mediates allergic reaction

Densely basophilic granules with heparin (anticoagulant), histamine (vasodilator) and leukotrienes (LTD4)

13
Q

Mast cells

A

Mediates allergic reaction (resemble basophils but not the same cell); metachromasia of cytoplasm

Bind Fc portion of IgE -> cross-links upon antigen binding -> degranulation of histamine, heparin, eosinophil chemotactic factor

Type I hypersensitivity reaction

Cromolyn sodium prevents mast cell degranulation (asthma prophylaxis)

14
Q

Dendritic cells

A

Antigen-presenting cells (express MHC II and Fc receptors)

Skin = Langerhan cells

15
Q

Lymphocyte

A

Adaptive immunity
B and T cells

Round, densely staining nucleus with small amount of pale cytoplasm

16
Q

B lymphocytes

A

Humoral immune response
From bone marrow stem cells; mature in marrow

Migrates to peripheral lymphoid tissue (lymph node, white pulp of spleen, unencapsulated lymphoid tissue)

Differentiate into plasma cells when encountered antigens -> produce antibodies and memory cells

Can function as APC (MHC II)

17
Q

Plasma cells

A

Produce large amounts of antibody specific to an antigen

Off-center nucleus, clock face chromatin distribution, abundant RER and well developed Golgi

Multiple myeloma - plasma cell cancer

18
Q

T lymphocytes

A

Cellular immune response
From bone marrow stem cells -> mature in thymus

Differentiate into cytotoxic (CD8+, MHCI) and helper (CD4+, MHCII), and regulatory T cells
CD28 (costim signal) for T-cell activation

Majority circulating lymphocytes are T cells

19
Q

Blood group: antigens and antibodies

A

Group A: A antigen on RBC, anti-B in plasma

Group B: B antigen on RBC, anti-A on plasma

Group AB: A and B antigen on RBC, no antibodies in plasma - “universal recipient” of RBC; “universal donor” of plasma

Group O: no antigen on RBC, anti-A and anti-B antibodies in plasma - “universal donor” or blood, “universal recipient” of plasma

Incompatible blood transfusions can cause immunologic response, hemolysis, renal failure, shock and death

Anti-A and B antibodies - IgM (do not cross placenta)

20
Q

Rh antigens

A

Rh antigen on RBC surface

Rh- mothers exposed to fetal Rh+ make IgG anti-Rh factors

Subsequent pregnancies -> cross placenta and cause hemolytic disease of newborn (erythroblastosis fetalis)

Tx: Rho(D) immune globulin for mother at first delivery to prevent initial sensitization of Rh- mother to Rh antigen