Optional Bonus Activity for Final Exam

  1. Identify all the structures involved in the conduction system of the heart.

The structures involved in the conduction of the heart are the SA and AV node, the bundle of His; the bundle branches and the Purkinje fibers. These structures all work together to make the heart pump and generate an electrical signal which cause the nerve cells to fire.

  1. What are the two major forces that drive gas exchange at capillaries?

The two major forces are the concentrations of both oxygen and carbon dioxide and the pH level at the capillary site. A combination of these factors is what drives gas exchange at the capillaries. The blood capillary surrounds the alveolus, and the exchange between the oxygen and the carbon dioxide takes place in between these two structures. Oxygen is taken in by the alveolus from the capillary while carbon dioxide is pushed out from the alveolus into the capillary.

  1. Briefly explain the function of the spleen.

The spleen acts as a filter for the blood, and as a part of the immune system by managing red and white blood cells, as well as platelets. Red blood cells which are no longer useful are destroyed in the spleen while white blood cells and platelets are stored there.

  1. Briefly explain how an antibody function.

An antibody is a protein, which works by stopping intruders into the body, which can cause ill health. Some of these intruders include bacteria and viruses. When such substances enter the body the immune system springs into action by using antibodies.

  1. How does the inflammatory response work?

Inflammation takes place when tissues are injured by such things as an injury, such as by wounds, abrasions, cuts and heat. These affected cells cause a spill out of plasma into the tissues which release chemicals that cause the affected areas to become swollen. In addition, warmth and redness may be found at the site of the imflammation.

  1. What is the difference in antibody mediated immunity and cell mediated immunity?

Cell-mediated immunity is an immune response that does not involve antibodies, but rather involves the activation of various chemicals in response to an antigen (Pross 318). In antibody mediated immunity, B-lymphocytes are made active to form plasma cells. These cells produce antibodies which are targeted to a specific antigen (Pross 316).

  1. What is the function of surfactant?

The main function of a surfactant is to lower the surface tension between a liquid and a gas. The surface tension is the amount of pressure which is exerted on the top of the liquid by the surrounding gaseous environment.

  1. What is reflux in the digestive system?

Reflux is a mechanism which causes stomach contents to re-enter the esophagus of the digestive system. This causes long periods of food exposure on the esophagus and can in bad cases deteriorate the lining of the esophagus and cause unwanted ulcers and inflammation of the lining causing much discomfort to the individual suffering from reflux.

  1. For lipids, carbohydrates and proteins, list all the enzymes each one uses for digestion.

    Lipase is the enzyme used to digest lipids or fats. Pepsin is the protein-digesting enzyme of the stomach. The digestion of carbohydrates is accomplished by amylase found in saliva.

  2. In the digestive system what is the function of lacteals?

The function of lacteals is to absorb dietary fats. This type of capillary is found in the small intestine. Fats which are broken up into triglycerides is accomplished by the lacteals.

  1. What is a glomerulus?

The glomerulus is composed of a network or cluster of capillaries, which filters plasma content for various toxins.

  1. Why is reabsorption by the nephron important for overall homeostasis?

Reabsorption is important in homeostasis because it plays a role in maintaining the balance of chemicals and water in and around the cells of the kidney. Homeostasis is the scientific word meaning balance. Keeping the balance of chemicals in and out of the kidneys is essential to good health.

  1. How does the hormone ANH affect the function of the kidneys?

The hormone ANH functions in the regulation of the kidney and aldosterone secretion. An increase in ANH causes a much greater output of urine, salt in the urine, and potassium concentrations in the urine.

  1. Briefly describe the RAAS pathway.

The RAAS is one of the most complex and important systems in controlling blood pressure. In addition, the RAAS pathway increases the amount of extracellular fluid within the body.

  1. Identify all the different fluid compartments of the body.

The intracellular fluid compartment is the fluid within cells, and the extracellular fluid compartment is the fluid outside of cells. About 2/3rds of the fluid are in the ICG, while 1/3 of the fluid is in the ECF.

  1. Briefly explain the thirst mechanism.

If the amount of water in the body falls below a certain point or the osmolite concentration becomes too high, the brain signals thirst (Fitzsimons 3).

  1. Briefly explain how a buffer system works.

A buffer is simply a mixture of a weak acid and its related base or a weak base and its related acid. It serves to balance pH levels. Adding a base to an acid, for example, would be considered one way of buffering it, and in this case increasing the pH level.

  1. What is the difference between acidosis and alkalosis?

Acidosis is an increased amount of acid in the tissues and body fluids. Alkalosis is an increased amount of base or alkaline condition in the tissues and body fluids.

  1. Briefly explain the entire process of spermatogenesis (2 points)

Spermatogenesis is the process by which immature germ cells in the testes are nourished with blood and certain chemicals by other cells in tubules, and the process by which these cells mature and then are transported to a different location.

  1. Briefly explain the entire process of oogenesis (2 points)

Oogenesis is the process by which an immature egg cell which is in the ovary is nourished and then released. After it is released it is ready for cell division and into a mature egg.

  1. Where does fertilization of the egg occur in the female reproductive tract?

Fertilization usually occurs in the fallopian tube which joins the ovary to the uterus.

  1. What is a teratogen?

It is a factor which causes a malformation of the embryo.

  1. What is the free radical theory of aging

The free radical theory of aging supports the idea that a free radical, or an atom with one electron in its outer shell, accumulates in the body over time causing damage and/or aging.