19.3 RBCs

Question 1

hemoglobin (Hb)

% of RBC proteins

Answer 1

red pigment that binds and transports oxygen & CO2. Hb accounts for 95% of RBC’s intracellular proteins

Question 2

RBC count

in males? females?

Answer 2

number of RBCs per microliter

males: 4.5-6.3 million RBCs
females: 4.2-5.5 million RBCs

Question 3

blood of an average adult contains ___ RBCs

Answer 3

25 trillion

Question 4

RBCs account for ___ of cells in the human body

Answer 4

1/3

Question 5

rouleaux

Answer 5

stacks of red blood cells formed in narrow blood vessels

Question 6

RBC diameter

Answer 6

7.8 micrometers

Question 7

RBC thickness

Answer 7

2.85 micrometers

center narrows to .8 micrometers

Question 8

lifespan of RBC

Answer 8

<120 days

Question 9

because RBC’s lack _____ & _____ they cannot divide or synthesize structural proteins

Answer 9

nuclei and ribosomes

Question 10

RBCs also lack _____, so they obtain energy through anaerobic metabolism of glucose

Answer 10

mitochondria

Question 11

nromal ranges of Hb content (males/females)

Answer 11

male: 14-18 g/dl
female: 12-16 g/dl

Question 12

Hb structure

Answer 12

• quaternary
• 2 alpha chains, 2 beta chains
• each chain is a globular protein subunit and contains single molecule of heme

Question 13

heme

Answer 13

non-protein pigment complex

-holds iron ion, interacts w/ oxygen to form oxyhemoglobin (HbO2)

Question 14

oxyhemoglobin (HbO2)

Answer 14

hemoglobin molecule whose iron is bound to oxygen

-bright red

Question 15

deoxyhemoglobin (HbO2)

Answer 15

hemoglobin molecule whose iron is not bound to oxygen

-dark red

Question 16

fetal hemoglobin

Answer 16

binds to oxygen more readily, can “steal” oxygen from maternal bloodstream

Question 17

hydroxyurea/butyrate

Answer 17

stimulate production of fetal hemoglobin in adults

Question 18

each RBC contains ______ Hb molecules

Answer 18

280 million

Question 19

carbaminohemoglobin

Answer 19

Hb bound to CO2

Question 20

anemia

Answer 20

• results from low hematocrit, reduced Hb content of RBCs, or low RBC count
• interferes with oxygen delivery
• weakness, lethargy, confusion.. organ function deteriorates

Question 21

RBC travels ____ miles in 120 days

Answer 21

700

Question 22

% of RBCs replaced each day?

Answer 22

1%

Question 23

how many new RBCs enter bloodstream each second?

Answer 23

3 million

Question 24

hemoglobinuria

Answer 24

red-brown urine resulting from large number of broken down RBCs

Question 25

hematuia

Answer 25

presence of intact RBCs in urine | -result of kidney damage of damaged vessels along urinary tract

Question 26

biliverdin

Answer 26

organic compound with green color.. result of heme unit being stripped of iron

Question 27

bilirubin

Answer 27

converted from biliverdin - orange-yellow pigment - excreted in bile - causes jaundice if not excreted properly

Question 28

bilirubin gets converted to pigments _____ & _____, which are converted to _____ & _____ when exposed to oxygen

Answer 28

- urobilinogens & stercobilinogens | - urobilins (yellow) & stercobilins (brown)

Question 29

transferrin

Answer 29

plasma protein that binds to iron in bloodstream

Question 30

iron is stored in two protein-iron complexes:

Answer 30

ferritin & hemosiderin

Question 31

only site of RBC production in adults

Answer 31

red bone marrow

Question 32

erythropoiesis (occurs in what tissue?)

Answer 32

RBC formation.. occurs in myeloid tissue (red bone marrow)

Question 33

myeloid tissue location

Answer 33

vertebrae, sternum, ribs, skull, scapulae, pelvis, and proximal limb bones

Question 34

hematologists

Answer 34

blood specialists

Question 35

hemocytoblasts

Answer 35

multipotent stem cells.. produce: 1. myeloid stem cells (divide into RBCs and several classes of WBCs) 2. lymphoid stem cells (divide into various lymphocytes)

Question 36

stages of RBC maturation

Answer 36

1) proerythroblast, 2) basophilic erythroblast, 3) polychromatophilic erythroblast 4) normoblast, 5-7) reticulocyte - ->mature RBC

Question 37

reticulocytes make up __% of RBC population in blood

Answer 37

0.8%

Question 38

erythropoiesis requires adequate supplies of (three things)

Answer 38

amino acids, iron, & vitamins (B12, B6, & folic acid)

Question 39

in order to absorb vitamin B12, we need

Answer 39

intrinsic factor (produced in stomach)

Question 40

causes of pernicious anemia

Answer 40

possible causes: B12 deficiency, problem with intrinsic factor production, or problem with absorption of B12 bound to intrinsic factor

Question 41

erythropoiesis is indirectly stimulated by

Answer 41

T4, androgens, and GH

Question 42

hypoxia

Answer 42

low oxygen levels in tissues

Question 43

EPO 2 major effects:

Answer 43

1) stimulates cell division rates in erythroblassts and in stem cells that produce erythroblasts, 2) speeds up RBC maturation by accelerating Hb synthesis

Question 44

blood doping & EPO administration

Answer 44

can raise hematocrit to 65+, placing intolerable strain on the heart

Question 45

elevated hematocrit (may reflect erythrocytosis or leukocytosis)

Answer 45

polycythemia

Question 46

Reticulocyte count (retic.) is elevated

Answer 46

reticulocytosis

Question 47

elevated RBC count

Answer 47

erythrocytosis/polycythemia

Question 48

MCV (mean corpuscular volume)

Answer 48

(normal = 82-101 cubic micrometers) elevated: macrocytic depressed: microcytic

Question 49

MCHC (mean corpuscular hemoglobin concentration)

Answer 49

(normal = 27-34 pg/microliter) elevated: hyperchromic depressed: hypochromic