Cardiovascular System Lecture 2

Question 1

Describe an Erythrocyte
(4)

Answer 1

• Live ~ 120 days
• Biconcave disc, flexible, high SA:V
• No Nucleus or Oragnells
• Contain about 250 million Hb

Question 2

What is the Structure of Hemoglobin?

Answer 2

• 4 globin chains (2 Alpha/2 Beta)
• 4 hemes (each with iron ion in core

Question 3

What are the 2 HEME Bindings for Transport?

Answer 3

Oxygen: OXYHEMOGLOBIN

Carbon Monoxide: CARBOXYHEMOGLOBIN

Question 4

What are the 2 GLOBIN Bindings for Transport?

Answer 4

Carbon Dioxide: CARBAMINOHEMOGLOBIN

Hydrogen: DEOXYHEMOGLOBIN

Question 5

Erythropoiesis

Answer 5

Erythropoiesis is the process of making red blood cells in the body. It starts with stem cells, which turn into immature red blood cells, and these cells gradually mature into fully functional red blood cells. These red blood cells are essential for carrying oxygen from the lungs to the rest of the body and transporting carbon dioxide back to the lungs for exhalation. Erythropoiesis is regulated by a hormone called erythropoietin, which ensures that the body has enough red blood cells to carry oxygen effectively.

Question 6

What are macrophages?
Where are they found?

Answer 6

Type of Leukocyte that engulfs old or damaged erythrocyte

Found in the Spleen or Liver where blood is filtered

Question 7

Processing results in heme and globin portions of Hb being split into what? (3)

Answer 7

• Globin – broken down to amino acids – released and used for protein synthesis.
• Iron – transferred to liver and then red bone marrow – recycling to incorporate into new Hb.
• Rest of heme converted to bilirubin – sent to liver – released into small intestine as part of bile for fat digestion – large intestine bacteria process bilirubin and products end up in urine and feces for elimination.

Question 8

What is Homeostasis?
What is Negative Feedback?

Answer 8

• Physiological variables in a state of dynamic constancy; not static.
• Maintain within a set range over time.

Question 9

Balance between erythropoiesis – red blood cell removal.

Answer 9

Question 10

What is Hypoxia?

Answer 10

Hypoxia is a medical condition characterized by insufficient oxygen supply to body tissues and organs, which can result from various factors such as low oxygen levels in the blood, inadequate blood flow, anemia, or cellular inability to use oxygen.

Question 11

What happens to blood during altitude training?

Answer 11

• Creates hypoxia – erythrocyte production.
• Return to sea level for competition with elevated erythrocyte level

Question 12

What is Blood doping - Reinfusion?

Answer 12

• Remove erythrocytes and store.
• Creates hypoxia – erythrocyte production.
• After time, erythrocytes return to normal levels.
• Before competition reinfuse stored erythrocytes to get an elevated erythrocyte level

Question 13

Blood doping – Inject EPO

Answer 13

• Directly stimulate erythrocyte production in red bone marrow.
• Bypass kidney steps so hypoxia not needed.

Question 14

What is Hematocrit?
(Hct)

Answer 14

Hematocrit is a measure of the proportion of blood volume that is occupied by red blood cells, often expressed as a percentage.

Question 15

How do we Split Blood Volume?

Answer 15

Spin Blood sample into a centrifuge
(Blood Volume = BV)

Blood Volume is split into
* Plasma volume (PV).
* “Buffy coat” volume (leukocytes /platelets).
* Erythrocyte (RBC) volume

Question 16

How is Hct found?

Answer 16

Hct: percentage of blood volume that is erythrocyte volume

(Hct = RBC / BV).
* Average ~42 – 47%

Question 17

ratio in blood

Answer 17

Question 18

What is Anemia?

Answer 18

Anemia is a medical condition characterized by a deficiency in the number of red blood cells or a decrease in their ability to carry oxygen, leading to symptoms such as fatigue, weakness, and paleness.

Question 19

How is Hct different in someone who has Anemia?

What can it lead to?

Answer 19

Same Blood Volume (BV)
Hct and RBC volume is reduced

Observe:
* Lower oxygen-carrying capacity

Result:
* Can lead to hypoxia issues

Question 20

How can one get Anemia?
(4)

Answer 20

• Hemorrhagic – blood loss (wounds/ulcers/ menstruation).
• Nutritional – lack elements for erythrocyte formation (iron deficient; low iron levels).
• Developmental – damage in critical area (aplastic; red bone marrow).
• Hemolytic – erythrocytes destroyed
  (sickle-cell)

Question 21

What is Polycythemia?

Answer 21

Polycythemia is a medical condition characterized by an abnormally high number of red blood cells in the bloodstream, which can lead to an increased risk of blood clot formation and other complications.

Question 22

How is Hct different in someone who has Polycythemia?

What can it lead to?

Answer 22

Same Blood Volume (BV)
Hct and RBC volume is increased

Observe:
* Higher oxygen-carrying capacity.

Result:
* Can lead to blood viscosity and blood pressure issues

Question 23

How can one Get Polycythemia?
(3)

Answer 23

• Primary – bone marrow tumor.
• Secondary – some altitude living
  cultures, compensation for heart and lung disease.
• Induced – athletics

Question 24

What is “Relative” Polycythemia?

Answer 24

“Relative” polycythemia, also known as stress polycythemia or Gaisböck syndrome, is a condition where the concentration of red blood cells appears elevated due to a decrease in plasma volume, often associated with factors like dehydration, smoking, or stress.

Question 25

How is Hct different in someone who has “Relative” Polycythemia?

What can it lead to?

Answer 25

Reduced – BV, PV.
Same – RBC.
Increased – Hct

Observe:
* Higher oxygen-carrying capacity
.
Result:
* Could lead to blood viscosity and blood pressure issues – less likely as often a temporary state.

*Not a “true” polycythemia as there is no increase in erythrocytes

Question 26

How can one get “Relative” Polycythemia? (2)

Answer 26

• Dehydration.
• “Making weight” sports.