Blood

Question 1

what is the function of blood?

Answer 1

TRANSPORT!

• erythrocytes carry oxygen to cells
• carries nutrients, waste and hormones
• carries leukocytes that help defend against infection and defense proteins like antibodies
• carries platelets that work with clotting factors to prevent bleeding
• carries heat and regulation of blood flow to help regulate body temperature

Question 2

What is the composition of blood?

Answer 2

Plasma and formed elements (erythrocytes, leukocytes, and thrombocytes)

Question 3

Plasma

Answer 3

90% water along with dissolved compounds
*Proteins-albumin, antibodies, clotting proteins.
Proteins help maintain osmotic pressure
*Albumin-60% of plasma proteins
*Antibodies-immune proteins produced by B-lymphocytes that help defend against infection
*Fibrinogen-precursor for the clotting protein fibrin
*Electrolytes-sodium, potassium, calcium, magnesium, chloride, bicarbonate

Question 4

Thrombocyte (Platelets)

Answer 4

irregular shaped cell fragments from megakaryocytes

*Play a key role in blood clotting

Question 5

Erythrocyte (Red blood cell)

Answer 5

biconcave shape, no nucleus or organelles

• Transport oxygen and to a lesser extent carbon dioxide
• Last 120 days and are then destroyed by the spleen or liver
• Contains hemoglobin-protein that binds and carries oxygen
• Made of 4 polypeptides and 4 heme groups
• Enzymes in cytoplasm-glycolytic enzymes to carry out glycolysis, carbonic anhydrase converts CO2 to HCO3

Question 6

Leukocyte (white blood cell)

Answer 6

Protects against infection, initiates inflammation, destroy cancerous cells, functions in tissue repair

Question 7

What are the types of leukocytes?

Answer 7

Granulocytes- neutrophil, eosinophil, basophil

Agranulocytes-monocyte, lymphocyte

Question 8

Granulocyte

Answer 8

leukocytes with cytoplasmic granules

Question 9

Agranulocyte

Answer 9

leukocytes without cytoplasmic granules

Question 10

Neutrophil

Answer 10

60-70% of leukocytes in blood, have a multi-lobed nucleus

*function as phagocytic cells are the first on the scene of infection and triggers inflammation

Question 11

Eosinophil

Answer 11

1-4% of leukocytes in blood, bi-lobed nucleus and granules stained bright red
*associated with allergies and parasite infections

Question 12

Basophil

Answer 12

<1% of leukocytes in blood, have dark blue staining cytoplasmic granules that release histamine to promote inflammation

Question 13

Monocyte

Answer 13

2-6% of leukocytes in blood, large nucleus curved into a U-shape
*travel into the tissue and mature into macrophages

Question 14

Lymphocyte

Answer 14

25-33% of leukocytes in blood, have a small rim of clear cytoplasm surrounding the round large nucleus
*functions are important for the specific adaptive immune defenses

Question 15

Hemopoiesis

Answer 15

production of blood cells and platelets that occurs in bone marrow

Question 16

erythropoiesis

Answer 16

production of new erythrocytes
*rate of production is controlled by erythropoietin produced by the kidneys in response to hypoxia (low blood oxygen levels)

Question 17

Hemostasis

Answer 17

prevents the loss of blood when blood vessels are damaged

• Three phases-
  1. vascular spasm-blood vessels constrict to diminish blood flow and loss
  2. platelet plug formation-broken or damaged blood vessels cause platelets to become sticky and cling to site, activated platelets release chemicals that attract other platelets
  3. coagulation-formation of a network of fibrin fibers that seals the blood vessel