general blood review ch.18

What is the fundamental purpose of the circulatory system?

The fundamental purpose of the circulatory system is to transport substances from place to place in the body.

What structures make up the circulatory system?

The heart, blood vessels, and blood.

What does the term cardiovascular system refer to?

Only the heart and blood vessels.

What is the study of blood called?

Hematology.

What are the three major functions of the circulatory system?

Transport, protection, and regulation.

How does blood transport oxygen and carbon dioxide?

Blood carries oxygen from the lungs to all tissues and carries carbon dioxide from the tissues to the lungs for removal.

What does blood transport from the digestive tract to body tissues?

Nutrients.

Where does blood carry metabolic wastes?

To the kidneys for removal.

What does blood transport from endocrine cells to target organs?

Hormones.

What role does blood play in transporting stem cells?

It transports stem cells from bone marrow and other origins to tissues where they lodge and mature.

How does blood contribute to protection through inflammation?

Inflammation helps limit infection.

What do white blood cells destroy?

Microorganisms and cancer cells.

What do antibodies and blood proteins do?

They neutralize toxins and help destroy pathogens.

How do platelets help protect the body?

They secrete factors that initiate blood clotting and other processes that minimize blood loss.

How do blood capillaries help regulate fluid distribution?

By absorbing or releasing fluid.

How do blood proteins help regulate pH?

They buffer acids and bases to help stabilize pH.

How does blood flow help regulate body temperature?

Blood can be routed to the skin for heat loss or retained deeper in the body to conserve heat.

What type of tissue is blood?

A liquid connective tissue consisting of cells and an extracellular matrix.

How much blood does an adult generally have?

About 4 to 6 liters.

What is the extracellular matrix of blood?

Blood plasma.

What are the formed elements of blood?

Red blood cells, white blood cells, and platelets.

Are all formed elements actually cells?

No. Platelets are cell fragments.

What are erythrocytes?

Red blood cells (RBCs).

What are leukocytes?

White blood cells (WBCs).

What are the three types of granulocytes?

Neutrophils, eosinophils, and basophils.

What are the two types of agranulocytes?

Lymphocytes and monocytes.

What is hematocrit?

The percentage of total blood volume made up of erythrocytes.

What percentage of blood volume is normally made up of erythrocytes?

About 37% to 52%.

What is the buffy coat?

A narrow cream- or buff-colored layer containing white blood cells and platelets.

What percentage of blood volume does the buffy coat make up?

About 1%.

What percentage of blood volume is plasma?

About 47% to 63%.

What substances are found in blood plasma?

Water, proteins, nutrients, electrolytes, nitrogenous wastes, hormones, and dissolved gases.

What is serum?

The fluid remaining after blood clots and the solids are removed.

How is serum different from plasma?

Serum lacks the clotting protein fibrinogen.

What is the most abundant solute in plasma by weight?

Protein.

What are the three major categories of plasma proteins?

Albumin, globulins, and fibrinogen.

What is the smallest and most abundant plasma protein?

Albumin.

What are the functions of albumin?

It transports solutes, buffers pH, and contributes to viscosity and osmolarity.

What are the three subclasses of globulins?

Alpha, beta, and gamma globulins.

What are the functions of globulins?

Solute transport, clotting, and immunity.

What is fibrinogen?

A soluble precursor of fibrin.

What is the role of fibrin in blood clotting?

It forms the framework of a blood clot.

Where are most plasma proteins produced?

The liver.

Which major plasma proteins are not produced by the liver?

Gamma globulins.

Where do gamma globulins come from?

Plasma cells descended from B lymphocytes.

What are nitrogenous wastes?

Toxic end products of catabolism.

What is the most abundant nitrogenous waste in plasma?

Urea.

What is urea a product of?

Amino acid catabolism.

What do the kidneys do with nitrogenous wastes?

They normally excrete them at a rate that balances their production.

What nutrients does plasma transport from the digestive tract?

Glucose, amino acids, fats, cholesterol, phospholipids, vitamins, and minerals.

What dissolved gases are found in plasma?

Oxygen, carbon dioxide, and nitrogen.

Which ion makes up about 90% of plasma cations?

Sodium ions.

Why is sodium important in blood?

It is important for osmolarity and can influence blood pressure.

What is viscosity?

The resistance of a fluid to flow resulting from the cohesion of its particles.

What is another way to describe viscosity?

The thickness or stickiness of a fluid.

How viscous is whole blood compared with water?

About 4.5 to 5.5 times as viscous.

Why is whole blood more viscous than water?

Mainly because of red blood cells.

How viscous is plasma compared with water?

About twice as viscous.

Why is plasma more viscous than water?

Mainly because of its proteins.

Why can abnormal blood viscosity be dangerous?

Blood that is too viscous or flows too easily can put a strain on the heart.

What is blood osmolarity?

The total molarity of dissolved particles that cannot pass through the blood vessel wall.

What does movement of fluid between blood and tissue depend on?

A balance between filtration outward and reabsorption by osmosis.

What governs the rate of reabsorption?

The relative osmolarity of the blood compared with the tissue fluid.

What happens if blood osmolarity is too high?

The bloodstream absorbs too much water and blood pressure becomes elevated.

What happens if blood osmolarity is too low?

Water remains in the tissues, causing edema, and blood pressure may drop dangerously low.

What mainly contributes to blood osmolarity?

Sodium ions, proteins, and erythrocytes.

What is colloid osmotic pressure (COP)?

The contribution of proteins to blood osmotic pressure.

What can happen if colloid osmotic pressure becomes too low?

Fluid is lost into the tissues.

What is hemopoiesis?

The production of blood, especially its formed elements.

What are hemopoietic tissues?

Tissues that produce blood cells.

Where do the first hemopoietic tissues of the human embryo form?

In the yolk sac.

What are blood islands?

Cell clusters that form in the yolk sac and produce primitive stem cells.

Where do primitive stem cells migrate during embryonic development?

To the bone marrow, liver, spleen, and thymus.

What happens to RBC production in the liver and spleen after birth?

The liver and spleen stop producing RBCs soon after birth.

Which organ continues producing lymphocytes for life?

The spleen.

Where are all seven types of formed elements produced from infancy onward?

The red bone marrow.

Where else are lymphocytes produced?

The thymus, tonsils, lymph nodes, spleen, and mucous membranes.

What is blood formation in the bone marrow called?

Myeloid hemopoiesis.

What is blood formation in lymphatic organs called?

Lymphoid hemopoiesis.

What do all formed elements arise from?

A common type of hemopoietic stem cell (HSC), also called a pluripotent stem cell.

What are colony-forming units (CFUs)?

More specialized cells that develop from hemopoietic stem cells and can produce one class of formed elements.

Where does most of the water in blood plasma come from?

Absorption from the digestive tract.

Where do plasma electrolytes and organic nutrients come from?

The digestive tract.

Where do plasma gamma globulins come from?

Connective tissue plasma cells.

Where do most other plasma proteins come from?

The liver.