Question

1.Review and discuss the components of the cardiovascular system that play a role in the body’s defenses, as well as their endocrine-related regulatory mechanisms as necessary. (Hint: the heart and blood vessels generally do not have well-characterized body defense roles. Also, the question should address extracellular body defense components as well, not just cellular body defense components.)

2. Discuss the components of innate and adaptive immunity, including a thorough review of their structures and functions. In addition, explain how autoimmune disorders and metastasizing cancers represent a failure of the two types of immunity, and reference the components previously described in this response as appropriate.

Answer 1

Cardiovascular system consist of heart, blood vessels and blood. The three main functions of this system is transport of oxygen, nutriens and hormones to the cells and removal of metabolic wastes.

Heart:

Heart consists of 4 chambers:

• left and right atria - recieve blood from venous system.
• left and right ventricle - pumps blood into arterial system.

the right atrium and ventricle are seperated from left atrium and ventricle by a muscular wall or septum. This septum prevents mixing of blood from two sides of heart.

Blood vessels:

it form a tubular nework that permits blood to flow from heart to all the living cells of the body and then back to the heart. Arteries carry blood away from the heart, whereas veins return blood to the heart. Arteries and veins are continous with each oher through smaller blood vessels.

Blood:

blood consists of formed elements that are suspended and carrried in a fluid called plasma. the formed elements- erythrocytes, leucocytes, and platelets- function respectively in oxygen transport, immune defence and blood clotting. plasma contains different types of protiens and many water soluble molecules.

  The circulatory system protects against blood loss from injury and against foreign microbes or toxins introduced into the body.
a. Clotting. The clotting mechanism protects against blood loss when vessels are damaged.
b. Immune. The immune function of the blood is performed by the leukocytes (white blood cells) that protect against
many disease-causing agents (pathogens).

The circulatory system contributes to both hormonal and temperature regulation.
Hormonal - The blood carries hormones from their site of origin to distant target tissues, where they perform a variety of regulatory functions.

Innate immunity:

Innate immunity includes both external and internal defenses. These defenses are always present in the body and represent the first line of defense against invasion by potential pathogens. Innate immunological defenses are the first employed to counter the invasion and spread of infection. If these defenses are not sufficient to destroy the pathogens, lymphocytes may be recruited and their specific actions used to reinforce the nonspecific immune defenses. innate immunity include :

external defence: by means of skin as a protective layer

internal defence:

• phagocytes : ingest and destroy bacteria, cellular debris, denatures protiens and toxins
• interferons: inhibit replication of virus
• complement protiens: promote destruction of bacteria, enhance inflammatory response
• endogenous pyrogens: secreated by leucocyes and other cells, produce fever

Adaptive immunity:

it is the second line of immunity that is acquired by a person over time. It is possible by the help of antigen produced by the lymphocytes to kill invading micro organism through a procces called antigen antibody interaction.