Ch 16 - Blood Flashcards
Functions of blood
transport, regulation, protection
Blood tissue type
only fluid tissue; connective tissue
____ is a nonliving fluid called ___
matrix; plasma
Formed elements
erythrocytes (RBCs); leukocytes (WBCs); platelets
spun tube of blood layers (bottom to top)
erythrocytes, WBCs, plasma
hematocrit
percent of blood volume that is RBCs
Buffy coat
thin, whitish layer between RBCs and plasma layers
Albumin
plasma protein; carrier of other molecules, blood buffer, contributes to plasma osmotic pressure
Which formed element has the only complete cells
WBCs
RBCs have no….
nuclei or other organelles
What provides erythrocytes with the flexibility to change shape?
the plasma membrane protein spectrin
Erythrocyte shape
biconcave disc
RBCs have no mitochondria bc..
ATP production is anaerobic, so they don’t consume O2 they transport
hemoglobin structure
four poly peptide chains - 2 alpha and 2 beta; four heme groups
Function of Erythrocytes
O2 loading in lungs; O2 unloading in tissues; CO2 loading in tissues
Erythrocyte O2 loading in lungs
produces oxyhemoglobin (ruby red)
Erythrocytes O2 unloading in tissues
produces deoxyhemoglobin, or reduced hemoglobin (dark red)
Erythrocytes CO2 loading in tissues
CO2 in blood binds to hemoglobin, producing carbaminohemoglobin
hematopoiesis
formation of all blood cells
Where does hematopoiesis occur?
red bone marrow
hematopoiesis stem cells (hemocytoblasts)
stem cell that gives rise to all formed elements; hormones and growth factors push cell toward specific pathway of blood cell development
erythropoiesis
process of formation of RBCs that takes about 15 days
Erythropoiesis stages (1-4)
(1) hematopoietic stem cell: transforms into myeloid stem cell; (2) myeloid stem cell: transforms into proerythroblast; (3) proerythroblast: divides many times, transforming into basophilic erythroblasts; (4) basophilic erythroblasts: synthesize many ribosomes, which stain blue
Erythropoiesis stages (5-8)
(5) polychromatic erythroblasts: synthesize large amounts of red-hued hemoglobin; (6) orthochromatic erythroblasts: eject most organelles, nucleus degrades, causing concave shape; (7) reticulocytes: still contain small amount of ribosomes; (8) mature erythrocytes: ribosomes degrade, transforming into mature RBC
