immune system 1

Question 1

Pathogens

Answer 1

A pathogen is a disease causing agent that must be able to colonize the host, live in/on the host, avoid immune response, replicate using host resources, and leave to spread to a new host.

Question 2

Types of pathogens

Answer 2

The types of pathogens include parasitic worms (ex: tapeworms), parasitic protozoa (ex: amoebas), fungi (ex: mold), eubacteria (ex: e. coli), viruses (ex: HIV), and prions (ex: mad cow disease).

Question 3

How are pathogens removed from the body?

Answer 3

Some ways that pathogens are removed from the body are through the shedding of skin cells, coughing, and the flushing of bodily fluids.

Question 4

Mucous membranes

Answer 4

Mucous membranes act as physical barriers for exposed areas of the body. These membranes secrete sticky mucus containing enzymes, glycoproteins and lysozymes, that attack bacterial cell walls. They have antiseptic properties that reduce the growth of microbes.

Question 5

Skin

Answer 5

The skin being dry, having microbes living atop of it, and its secretion of sweat and oils inhibits the growth of bacteria. The top layer of skin is dead which prevents viruses from infecting the skin, since they need living materials to feed off of.

Question 6

Platelets

Answer 6

Platelets are involved with clotting blood when blood vessels break. When a blood vessel is damaged, platelets send out signals that trigger an immediate travel to the injured area in order to form clots and stop the bleeding.

Question 7

What are the benefits of blood clotting when skin is cut?

Answer 7

One of the benefits of blood clotting is that it protects the wound’s surrounding tissues. Another benefit of blood clotting is that it provides a provisional matrix allowing cells to migrate to the injured area during the repair process.

Question 8

Atheromas

Answer 8

Atheromas are fatty deposits caused by high blood concentrations of cholesterol and fats in the arteries. These deposits build up over time and eventually block arteries which leads to cardiovascular issues.

Question 9

Coronary arteries

Answer 9

Coronary arteries are the main source of blood to the heart. Coronary arteries allow for the heart to contract which circulates blood throughout the whole body.

Question 10

Coronary thrombosis

Answer 10

Coronary thrombosis is the clotting within a blood vessel that blocks the blood vessel entirely. If a coronary artery is blocked, the cells in that part of the heart die and a heart attack occurs. Smoking, hypertension, and stress may increase the risk of coronary thrombosis.

Question 11

Blood clotting

Answer 11

Blood clotting is a result of multiple reactions that are triggered by damage to a blood vessel. First, inactive clotting factors are activated by platelets. This triggers the conversion of inactive prothrombin into active thrombin. Then, thrombin catalyzes the reaction that converts soluble fibrinogen into insoluble fibrin. The fibrin then creates a clump of blood to form a clot.