CHp 17 blood

Question 1

Why is blood is considered a connective tissue

Answer 1

(1) embryologically, it has the same origin (mesodermal) as do the other connective tissue types and (2) blood connects the body systems together bringing the needed oxygen, nutrients, hormones and other signaling molecules, and removing the wastes

Question 2

Functions of blood

Answer 2

Transports respiratory gases, nutrients, hormones
Protects against foreign invading microbes
Helps regulate body temp
Prevents loss of excess blood (by clotting)

Question 3

Blood characteristics

Answer 3

Sticky, opaque fliud
Scarlet (oxygen rich) to dark red (oxygen poor)
More dense and viscous than water
slightly alkaline (pH 7.35-7.45)

Question 4

Components of blood

Answer 4

Plasma 55% of whole blood, least dense
Buffy coat <1% of whole blood, leukocytes and platelets
Erythrocytes 45% of whole blood (hematocrit) most dense component

Question 5

Formed elements

Answer 5

Platelets 250,000-400,000
WBCs 5,000-9,000
RBCs 4.2 million - 6.2 million

Question 6

Average blood mass

volume males v females

Answer 6

8% body mass
Males: 5-6 liters
Females 4-5 liters

Question 7

Hematopoiesis

Answer 7

blood production
begins in early embryo (yolk sac); liver and spleen
after birth all blood cells originate in bone marrow

Question 8

Red Blood Cells

Answer 8

Biconcave, anucleate disc, salmon colored, 7-8 µm
“bags of hemoglobin”
Small size and biconcave shape provide huge surface area to volume; suitable for gas exchange
Lack mitochondria and generate ATP by anaerobic mechanisms, do not consume any of the oxygen they carry, making them very efficient O2 transporters

Question 9

RBC lifespan

Answer 9

100-120 days; unable to synthesize new proteins, grow, or divide
Lose flexibility, become rigid and fragile, hemoglobin degenerates

Question 10

Granulocytes

Answer 10

Neutrophils, eosinophils, basophils

Question 11

Agranulocytes

Answer 11

Lymphocytes, monocytes

Question 12

Which WBCs are most numerous? Least?

Answer 12

Never Let Monkeys Eat Bananas

neutrophils are most numerous, lymphocytes, monocytes, eosinophils, basophils

Question 13

Which WBC will increase during allergic reaction?

Answer 13

Eosinophils and basophils

Question 14

Which WBC will increase during parasitic infections?

Answer 14

Eosinophils

Question 15

Platelets

Answer 15

Fragments of megakaryocytes

Essential for blood clotting, form temporary plug that seals break in blood vessel lining