bài giảng DÒNG HỒNG cầu (phần 2)

Erythrocytes RBCsDisc-shaped cell with thick rim 7.5 µ M diameter & 2.0 µ m thick at rim Major function is gas transport lost all organelles during maturation and has biconcave shape wh

Focus on RBCs:

Figure 16-5c: Bone marrow

Erythropoiesis

Chapter 18 The Circulatory System: Blood

Centrifuging blood forces formed elements to

separate from plasma

Hematocrit is % of blood volume that is composed of

RBC

Erythrocytes (RBCs)

Disc-shaped cell with thick rim

7.5 µ M diameter & 2.0 µ m thick at rim

Major function is gas transport

lost all organelles during maturation and

has biconcave shape which gives RBCs increased surface area/volume ratio

increases diffusion rate of substances in & out of cell 33% of cytoplasm is hemoglobin (Hb)

Hemoglobin is the red pigment that gives RBC its color

O2 delivery to tissue and CO2 transport back to lungs cytoplasm contains enzyme, carbonic anhydrase (CAH)

produces carbonic acid (H 2 CO 3 ) from CO 2 and water CAH has an important role in gas transport & pH balance

RBC Structure

Small and highly specialized disc

Thin in middle and thicker at edge

Figure 19–2d

Erythrocytes on a Needle

RBCs vs WBCs

Focus on RBCs:

Figure 16-7a, b: Bone marrow

RBC variation and irregularity

anisocytosis poikilocytosis

anisocytosis (aniso = unequal)

various sizespoikilocytosis (poikilo = various)

various shapes

- heredirary elliptocytosis

- iron def anemia

- myelofibrosis with myeloid metaplasia

- megaloblastic anemia

- sickle cell anemia

- normal (<10% of cells)

- hereditary spherocytosis

- acquired hemolytic anemia (e.g AIHA)

- physical or chemical injury

- heat

(target cells)

- liver disease (obstructive jaundice)

- post splenectomy

- hemoglobinopathies (hypochromic anemias)

thalassemia Hgb C disease Hgb H disease

beta thalassemia relative increase of cell membrane > “target” formation

“helmet cell”

(irregular surface spicules)

irregularly spiculated cells

with bulbous/rounded ends of spicules

- abetalipoproteinemia

- liver disease

(crenated cells, burr cells)

regularly contracted cells with smooth surface

(may be associated with reduced ATP of RBCs)

bite cells

Removal (“bites”) of membrane by splenic macrophages

- G6PD deficiency

(teardrop cells)

- thalassemia

- myelofibrosis

(sickle cells)

- sickle cell anemia

Sickle-Cell Diseased

Erythrocyte

lined up RBCs in a row

- multiple myeloma

inorganic iron-containing granules (Pappenheimer bodies)

- sideroblastic anemia

abnormally trapped iron in mitochondria forming a ring around nucleus

Heinz bodies

denatured hemoglobin

- G6PD deficiency

Hypochromia Pencil Cells