BIOL 220: CH. 22 - THE CIRCULATORY SYSTEM: BLOOD

What does the circulatory system consist of?

The circulatory system consists of the heart, blood vessels, and blood.

What is the cardiovascular system?

The cardiovascular system refers specifically to the heart and blood vessels.

What is hematology?

Hematology is the study of blood.

What are the main functions of the circulatory system?

• Transport

• Protection

• Regulation

What are the transport functions of the circulatory system?

The circulatory system transports:

• oxygen and carbon dioxide

• nutrients from the digestive tract

• waste products from metabolism

• hormones

• stem cells to other tissues

What protective roles does the circulatory system serve?

It provides protection by:

• causing inflammation to limit the spread of infection

• destroying cancer cells

• neutralizing toxins

• initiating blood clotting

How does the circulatory system regulate the body?

It regulates:

• fluid distribution and blood pressure

• stabilizes the pH of extracellular fluid

• helps maintain body temperature

What is the average volume of blood in the human body?

The average volume of blood in the human body is 4 to 6 liters.

What are the components of blood?

• Erythrocytes (RBCs)

• Leukocytes (WBCs)

• Platelets

What are platelets, and what is their function in the blood?

Platelets are fragments of certain bone marrow cells that are essential for blood clotting and preventing excessive bleeding.

What are the types of leukocytes (WBCs)?

• Neutrophils

• Eosinophils

• Basophils

• Lymphocytes

• Monocytes

What can WBCs be divided into?

• Granulocytes

• Agranulocytes

Granulocytes

Contain specific granules (protein containing secretory vesicles) and include three types of WBCs.

Agranulocytes

Lack specific granules and include two types of WBC.

What WBCs are considered granulocytes?

• Neutrophils

• Eosinophils

• Basophils

What WBCs are considered agranulocytes?

• Lymphocytes

• Monocytes

Choose all that are included in the cardiovascular (not circulatory) system.

• Heart

• Blood vessels

What are the main components of blood plasma?

The main components of blood plasma are

• water

• proteins

• nutrients

• electrolytes

• waste

• hormones

• gases

What is the primary component of blood plasma?

Water is the primary component of blood plasma.

Which type of molecules in blood plasma help with clotting and immune responses?

Proteins in blood plasma, such as fibrinogen and immunoglobulins, help with clotting and immune responses.

What nutrients are transported by blood plasma?

Blood plasma transports nutrients like glucose, amino acids, and lipids.

What role do electrolytes play in blood plasma?

Electrolytes in blood plasma help maintain:

• pH balance

• osmotic pressure

• nerve and muscle function

What type of waste products are carried in blood plasma?

Blood plasma carries waste products such as urea and carbon dioxide for removal from the body.

Which chemical messengers are transported by blood plasma?

Hormones are transported by blood plasma as chemical messengers to regulate various body functions.

What gases are dissolved in blood plasma?

Oxygen and carbon dioxide are the main gases dissolved in blood plasma.

What is blood plasma primarily composed of by weight?

Blood plasma is primarily composed of proteins by weight.

What roles do proteins in blood plasma play?

Proteins in blood plasma are involved in:

• clotting

• pathogen defense

• the transport of solutes

Where are most blood plasma proteins produced?

Most blood plasma proteins are produced by the liver, except for some globulins.

What is the function of albumin in blood plasma?

Albumin helps:

• transport solutes

• buffers pH

• contributes to viscosity and osmolarity

What functions are associated with globulins in blood plasma?

Globulins are involved in:

• solute transport

• clotting

• immunity

What is the role of fibrinogen in blood plasma?

Fibrinogen is the precursor to fibrin, which forms the framework of blood clots.

What are nitrogenous wastes?

Nitrogenous wastes are toxic byproducts of protein catabolism that need to be excreted from the body to maintain health.

What is urea, and how is it processed in the body?

Urea is a nitrogenous waste produced during the breakdown of amino acids.

• It is excreted through the kidneys in the form of urine.

What types of nutrients are found in blood plasma?

Blood plasma contains glucose, amino acids, fats, cholesterol, vitamins, and minerals, which are essential for the body’s functions.

What are electrolytes, and which one is the most abundant in blood plasma?

Electrolytes are charged ions in blood plasma, with sodium (Na⁺) making up 90% of the total electrolytes.

What is the viscosity of blood compared to water?

Blood is approximately five times more viscous than water, which affects its flow through blood vessels.

How do viscosity disorders impact blood flow?

• A deficiency in red blood cells (RBCs) or proteins results in higher blood flow.

• An excess of RBCs or proteins causes slower blood flow, potentially straining the heart and increasing the risk of heart disease.

What is osmolarity in the context of blood?

Osmolarity refers to the solute concentration in blood, which influences water absorption and blood pressure.

How does high osmolarity affect blood pressure?

High osmolarity leads to increased water absorption into the bloodstream, which raises blood pressure.

What components contribute to blood osmolarity?

Sodium and proteins, particularly through colloid osmotic pressure, are key contributors to blood osmolarity.

What is the process of creating new blood cells called?

The process of creating new blood cells is known as blood production.

What happens when the body experiences a significant loss of blood?

Blood loss can lead to a decrease in oxygen delivery and the need for the body to regenerate blood components quickly.

What happens to red blood cells as they age?

As red blood cells age, they die and are removed from circulation by the spleen or other organs.

How are plasma components managed in the body?

Plasma components are either used in various bodily functions or excreted as waste.

What are hemopoietic tissues, and what do they do?

Hemopoietic tissues are tissues responsible for producing blood cells, such as bone marrow.

What role does the spleen play in blood-related processes?

The spleen helps filter old red blood cells, store blood, and fight infections.

What is the function of the thymus in the body?

The thymus is involved in the development of T-cells, which are critical for the immune system.

What is the role of bone marrow in the body?

Bone marrow is a primary site of blood cell production, including red blood cells, white blood cells, and platelets.

What role does the liver play in blood production before birth?

Before birth, the liver serves as a primary site for blood production.

What are erythrocytes, and what are their primary functions?

Erythrocytes, or red blood cells (RBCs):

• pick up oxygen to deliver it to tissues

• pick up carbon dioxide to unload it into the lungs

What happens to the nucleus and organelles in erythrocytes?

Erythrocytes lose their nucleus and organelles as they mature.

How do erythrocytes generate energy?

Erythrocytes rely on anaerobic fermentation for energy, avoiding aerobic respiration to conserve oxygen for delivery.

What is the composition of the cytoplasm in erythrocytes?

• The cytoplasm contains hemoglobin, which makes up about 33% of its composition and gives red blood cells their color.

• It also contains carbonic anhydrase, an enzyme that catalyzes the conversion of carbon dioxide and water into carbonic acid.

What role do glycolipids play on the surface of erythrocytes?

Glycolipids on the surface of erythrocytes are involved in blood typing.

What is the clinical significance of red blood cells (RBCs) and hemoglobin?

The clinical significance lies in the amount of oxygen a person can carry, which is directly influenced by RBC and hemoglobin levels.

What does hematocrit measure?

Hematocrit measures the percentage of blood composed of red blood cells.

What is hemoglobin concentration, and how is it assessed?

Hemoglobin concentration refers to the amount of hemoglobin in whole blood and is used to evaluate oxygen-carrying capacity.

What is the significance of RBC count?

RBC count indicates the number of red blood cells in the blood, with values generally being higher in men.

Why are RBC values higher in men?

Androgens stimulate RBC production, and men do not experience periodic menstrual RBC loss as women do.

What factors influence RBC levels in relation to body fat?

RBC levels are inversely proportional to body fat percentage, which may point to evolutionary adaptations.

How many new RBCs are produced daily, and where does this occur?

Approximately 100 billion new RBCs are produced daily in the bone marrow.

Where does the breakdown of RBCs begin?

The breakdown of RBCs begins in the spleen and continues in the liver.

What is RBC homeostasis regulated by?

RBC count is regulated by a negative feedback mechanism.

What happens when the RBC count is low?

When the RBC count is low, hypoxemia, or low blood oxygen levels, occurs.

How do the kidneys respond to hypoxemia?

The kidneys detect hypoxemia and increase erythropoietin (EPO) output, which leads to increased RBC production.

What is EPO?

EPO stands for erythropoietin, a hormone that stimulates the production of red blood cells.

How long does it take for RBC levels to return to normal after hypoxemia is detected?

It takes a few days for RBC levels to return to normal after hypoxemia is detected.

What are other causes of hypoxemia?

Other causes of hypoxemia include:

• low atmospheric oxygen

• lethargy that turns into increased activity (such as exercise)

• conditions like emphysema, which cannot be corrected

What is blood doping?

Blood doping is the practice of increasing the number of red blood cells in the bloodstream to enhance athletic performance by improving oxygen delivery to muscles.

How does blood from higher altitudes improve performance?

Blood from higher altitudes contains more red blood cells due to lower oxygen levels in the atmosphere, and when used in sports, it can enhance oxygen delivery to muscles, improving endurance and performance.

What is polycythemia?

Polycythemia is the overproduction of red blood cells (RBCs).

What can cause polycythemia?

Polycythemia can be caused by:

• cancer of the bone marrow

• dehydration

• emphysema (often from smoking)

• high altitude

• excessive exercise

What are the dangers of polycythemia?

The dangers of polycythemia include:

• high blood pressure

• increased blood viscosity, which can lead to congested vessels and heart strain

• it can also result in embolism, stroke, or heart failure

What is anemia?

Anemia is a condition where the RBC count is lower than normal.

What causes hemorrhagic anemia?

Hemorrhagic anemia is caused by excessive bleeding or too much blood loss.

What is hemolytic anemia?

Hemolytic anemia occurs when there is destruction of red blood cells (RBCs).

What causes inadequate erythropoiesis in anemia?

Inadequate erythropoiesis in anemia can be caused by kidney failure, which leads to a lack of erythropoietin (EPO).

What is nutritional anemia?

Nutritional anemia, such as iron deficiency anemia, occurs when there is a lack of iron in the diet.

How does nutritional anemia affect the ability to carry oxygen?

Nutritional anemia reduces the ability to carry oxygen because of the insufficient number of RBCs or low hemoglobin levels.

What type of allele causes sickle cell anemia?

Sickle cell anemia is caused by a genetic, recessive allele.

What is the effect of being a heterozygote for sickle cell?

Heterozygotes for sickle cell have resistance to malaria.

What is the change in hemoglobin that leads to sickle cell anemia?

Sickle cell anemia is caused by one amino acid change in hemoglobin, where normal glutamic acid is replaced by valine.

What is the difference between glutamic acid and valine in terms of their properties?

Glutamic acid is hydrophilic, whereas valine is hydrophobic.

How does the change in hemoglobin affect red blood cells?

The change in hemoglobin causes red blood cells to cave in on themselves, resulting in a sickle shape.

What are the characteristics of sickled red blood cells?

Sickled red blood cells are rigid, sticky, and pointed.

What is the effect of sickled red blood cells on oxygen?

Sickled red blood cells have low binding to oxygen.

What is one consequence of sickled red blood cells clumping together?

Sickled red blood cells can agglutinate and clump together, blocking small blood vessels.

What health problems are associated with sickle cell anemia?

Sickle cell anemia can lead to heart failure, kidney failure, and joint pain.

How does the lysis (destruction) of red blood cells in sickle cell anemia contribute to the disease?

The lysis (destruction) of red blood cells causes a fatal positive feedback loop in sickle cell anemia.

An individual has their blood tested and the results indicate an abnormally high viscosity. What general condition of the blood could cause this?

Polycythemia.

What are the genetic antigens found on the surface of red blood cells?

The genetic antigens on the surface of red blood cells are glycolipids, which determine blood type.

What are the four blood types based on antigens?

The four blood types are A, B, AB, and O.

What antigen does Type A blood have?

Type A blood has A antigen only.

What antigen does Type B blood have?

Type B blood has B antigen only.

What antigens does Type AB blood have?

Type AB blood has both A and B antigens.

What antigens does Type O blood have?

Type O blood has neither A nor B antigens.

What happens if a RBC contains the Rhesus factor?

It will be a positive blood type.

What happens if a RBC does not contain the Rhesus factor?

It will be a negative blood type.

What does plasma contain?

Plasma contains antibodies against the antigens of the original blood type.

What is the function of antibodies in the blood?

Antibodies protect the blood from foreign substances and blood that do not match.