Lecture 6- Blood

Question 1

Transport functions of blood

Answer 1

delivery of oxygen and nutrients, transport of metabolic wastes for elimination, and transport of hormones.

Question 2

Regulatory functions of blood

Answer 2

maintaining body temperature, maintaining pH and maintaining fluid balance.

Question 3

Protective functions of blood

Answer 3

preventing blood loss and fighting infections.

Question 4

What are the three layers of blood?

Answer 4

Blood plasma and dissolved elements

Buffy coat (white blood cells and platelets)

Erythrocytes (red blood cells)

Question 5

What does blood hematocrit represent?

Answer 5

Percentage of erythrocytes in whole blood

Low hematocrit - lack of RBCs (anemia)

High hematocrit- elevated number of RBCs (polycythemia)

Question 6

What does blood plasma consist of?

Answer 6

mostly water (90%) and solutes including nutrients, gases, hormones, wastes, products of cell activity, ions, and proteins.

Question 7

What are the Formed elements of blood?

Answer 7

erythrocytes (red blood cells)

leukocytes (white blood cells)

platelets

leukocytes are complete cells: erythrocytes have no nucleus, and platelets are cell fragments.

Question 8

Erythrocytes

Answer 8

small cells that are biconcave in shape, lack nuclei and most organelles, and contain mostly hemoglobin

size and shape of erythrocytes provide a larger surface area for gas exchange

Question 9

Hemoglobin

Answer 9

protein consisting of four polypeptide chains, globin proteins, each with a ring-like heme

Each heme contains an iron atom that oxygen binds to

Question 10

Oxyhemoglobin

Answer 10

Oxygen diffuses into the blood in the lungs and binds to hemoglobin, forming bright red blood

Question 11

Deoxyhemoglobim

Answer 11

At body tissues, oxygen detaches from iron, forming dark red blood

Question 12

Carbaminohemoglobin

Answer 12

When carbon dioxide carried in the blood is bound to amino acids on the globins

Question 13

Arterial blood gas analysis

Answer 13

Only done for critical illnesses or respiratory disease

mostly used to determine how well gas exchange is functioning in the lungs

Question 14

Pulse oximetry

Answer 14

estimates percentage of hemoglobin that is oxygen-saturated based on the absorption of light at two different wavelengths

Question 15

Hematopoiesis

Answer 15

Blood cell formation

Occurs in red bone marrow

Question 16

Myeloid stem cells

Answer 16

able to make platelets, erythrocytes and some kinds of leukocytes

Question 17

Lymphoid stem cells

Answer 17

Able to make lymphocytes

Question 18

Erythropoietin

Answer 18

formation of erythrocytes, begins when a hematopoietic stem cell is transformed to a proerythroblast.

Question 19

Reticulocyte

Answer 19

Immature erythrocyte

ejects most organelles, the nucleus degenerates, and the cell assumes its biconcave shape.

Question 20

What controls erythrocyte production?

Answer 20

Hormone erythropoietin ( produced in kidneys)

Question 21

What triggers erythropoietin production?

Answer 21

loss of red blood cells

insufficient hemoglobin

reduced availability of oxygen

Question 22

Dietary requirements for erythrocyte formation

Answer 22

iron

vitamin B12

and folic acid

proteins

lipids

carbohydrates.

Question 23

Anemia

Answer 23

Deficiency in red blood cells

Question 24

What can cause anemia?

Answer 24

Blood loss (hemorrhagic anemia)

Not enough red blood cells produced (iron deficiency)

Too many red blood cells destroyed (sickle cell anemia)

Question 25

Polycythemia

Answer 25

excess of red blood cells due to oxygen deficiency or disease

Question 26

What happens when erythrocytes die or are destroyed?

Answer 26

Heme is split from globin

globin is broken down to amino acids

iron from heme is salvaged.

What remains of the heme is degraded to bilirubin, which isultimately secretes in bile to the intestine for removal from the body.

Question 27

Blood doping

Answer 27

artificially inducing polycythemia to try to get an advantage in athletic competitions, typically by injecting synthetic erythropoietin.

High altitude training can also cause temporary polycythemia.