Part One – Answers

Pulse- change in diameter of the arteries following heart contractions.

Artery- a blood vessel that carries blood from the heart to the body.

Veins- blood vessels that carry blood from the body to the heart.

Interstitial- refers to the space between cells.

Sinus- a body cavity or air space surrounding an internal organ.

Plasma- the fluid portion of the blood.

Tissues- groups of cells that work together to perform specialized tasks.

Erythrocytes- red blood cells that contain hemoglobin and carry oxygen.

Anemia- the reduction in blood oxygen due to low levels of hemoglobin or poor red blood cell production.

Leukocytes- white blood cells.

Pus- protein fragments that remain when white blood cells engulf and destroy invading microbes.

Platelets- component of blood responsible for initiating blood clotting.

Antibodies- proteins formed within the blood that reacts with antigens.

Antigen- a substance, usually protein in nature that stimulates the formation of antibodies.

Serum- the liquid that remains after the solid and liquid components of blood have been separated.

Components of Blood – Answers

  1. Blood is a liquid tissue composed of 55% fluid and 45% blood cells or formed elements.

  1. Plasma is the liquid portion of blood. It is composed of approximately 90% fluid along with blood proteins, glucose, vitamins, minerals, dissolved gases, and waste products of cell metabolism.
  1. The three groups of proteins found in the plasma of blood are albumins, globulins, and fibrinogens. The albumins work together with inorganic minerals to maintain body fluid levels by drawing water via osmosis back into the capillaries. The globulins assist in protecting the body from foreign invaders. The fibrinogens play an important role in blood clotting.

Erythrocytes

  1. Erythrocytes are red blood cells whose job is to carry oxygen and carbon dioxide.
  1. Hemoglobin is an iron-containing protein that significantly increases the ability of the red blood cells to carry oxygen. Due to the presence of hemoglobin, red blood cells can increase their carry capacity by a factor of 7.Oxyhemoglobin is a compound formed when oxygen molecules bind with iron molecules in the hemoglobin.

  1. Red blood cells are biconcave in shape which increases their surface area for gas exchange by 20 to 30%.
  1. Erythrocytes live for approximately 120 days and they are produced in the bone marrow by stem cells.
  1. As red blood cells age their outer membranes become brittle and can rupture as the cells travel through narrow capillaries. The liver and spleen monitor the age of red blood cells and remove them and the debris from the blood. As they are broken down hemoglobin is released and the iron from the hemoglobin is recovered and stored in the bone marrow for future use and the heme is changed into bile pigments.
  1. Anemia is a condition characterized by low energy levels that result from deficient levels of haemoglobin or red blood cells. The most common cause of this deficiency is hemorrhage or heaving bleeding. Anemia can also be caused by a deficiency of dietary iron.

Leukocytes

  1. A major difference in structure between red blood cells and white blood cells is the presence of a nucleus in white cells and the absence of the nucleus in red cells.
  1. One method of fighting invaders is through the process of phagocytosis. The leukocytes squeeze out of the capillaries and into the tissue where the microbe (invader) is located and engulfs the microbe. Once it has ingested the microbe the leukocyte will release digestive enzymes that will digest the microbe and itself. The left over material is known as pus.
  1. The other method used by leukocytes is the formation of special proteins known as antibodies which interfere with invading microbes and toxins.

Platelets

  1. Platelets are similar to red blood cells in that they both are produced in the bone marrow and neither contain a nucleus
  1. Platelets are formed when small fragments of cytoplasm break away from a large cell in the bone marrow called a megakaryocyte. Platelets play a crucial role in blood clotting. They break open when they come in contact with the sharp edge of a broken blood vessel and release chemicals which begin the blood clotting process.