Compendium Review # 1 for unit 2

TABLE OF CONTENTS
CHAPTER 5

CARDIOVASCULAR SYSTEM: HEART AND BLOOD VESSELS

1. Overview of the Cardiovascular System
a. Functions and circulation

b. Lymphatic system

2. Types of Blood Vessels

a. Arteries
b. Capillaries
c. Veins
3. The Heart is a double pump
a. Passage of blood
b. Heartbeat
c. Electrocardiogram

4. Features of the Cardiovascular System

a. Pulse
b. Blood flow

5. Two Cardiovascular Pathways

a. Pulmonary Circuit
b. Systemic Circuit
6. Exchange at the Capillaries
7. Cardiovascular Disorders
a. Blood vessels
b. Heart

CHAPTER 6

CARDIOVASCULAR SYSTEM: BLOOD
8. Blood: An Overview
a. Functions

b. Composition
9. Red Blood Cells and Transport of Oxygen

a. Carry oxygen
b. Transport carbon dioxide
c. Bone marrow
d. Disorders
10. White Blood Cells and Defense against diseases
a. Types

b. Disorders

11. Platelets and Blood Clotting
a. Clotting
b. Disorders
12. Blood Types and Transfusions

a. blood groups

b. RH groups

13. Homeostasis

CHAPTER 7
LYMPHATIC SYSTEM AND IMMUNITY

14. Microbes, Pathogens and You
a. Bacteria
b. Viruses
c. Prions
15. Lymphatic System
a. Vessels
b. Organs
16. Nonspecific Defenses

a. Barriers

b. Inflammatory Response

17. Specific Defenses
a. How defense works
18. Acquired Immunity
a. Active
b. Passive
19. Hypersensitivity Reaction
a. Allergies

b. Tissue Rejections

c. Disorders

AIDS SUPPLEMENT
20. Origin and Prevalence of HIV
21. Phases of HIV Infection
a. Category A
b. Category B

c. Category C

22. HIV Structure and Life Cycle

a. Life Cycle
b. Transmission and Prevention

c. Testing and Treatment

OVERVIEW OF THE CARDIOVASCULAR

Functions of the cardiovascular system include contractions of the heart generates blood pressure and moves blood, vessels transport the blood, exchanges at capillaries refreshes blood and tissue fluid, and the heart and blood vessels regulate blood flow. The lymphatic system is of assistance to the cardiovascular system. The lymphatic vessels collect excess tissue fluid and return it to the cardiovascular system.

THE TYPES OF BLOOD VESSELS

The arteries take blood away from the heart, they have the thickest walls, which allows them to withstand blood pressure. Capillaries are where exchange of substances occur. Veins take blood to the heart. Veins have weaker walls with valves that keep blood flowing in one direction. Illustration of the difference of an artery and a vein.*

THE HEART IS A DOUBLE PUMP
The major portion of the heart is the myocardium, which consists largely of cardiac muscle tissue. The pericardium is a thick, membranous sac that supports and protects the heart. The septum is the internal wall that separates the heart into right and left sides. Each side has an atrium (upper chamber) and ventricle (lower chamber). The illustration here shows the external anatomy of the heart.*

The next illustration* shows the internal anatomy of the heart and shows the passage of blood. Oxygen poor blood enters the right atrium through the superior and inferior vena cavas. The right atrium sends blood through the tricusppid valve to the right ventricle. The right ventricle sends blood through the pulmonary semilunar valve into the pulmonary trunk. The trunk, carries oxygen poor blood and divides into two pulmonary arteries, which go to the lungs. Four pulmonary veins, which carry oxygen rich blood to the left atrium, which sens the blood through the bicuspid valve to left ventricle and that sends

blood through the aortic semilunar valve into the aorta to the body. This illustration* helps us "see" the heartbeat. The SA node (pacemaker) initiates the heartbeat, the AV node conveys stimulus to the ventricles, the heart sound "lub-dup" are due to closing of the atrioventricular valves, followed by closing of the semilunar valves.

An elecocardiogram (ECG) is a recording of the electrical changes that occur in myocardium during a cardiac cycle.

FEATURES OF THE CARDIOVASCULAR

The surge of blood entering arteries can be felt as our pulse because of the rhythmic expansion and recoil of an arterial wall.

This illustration* addresses blood pressure. Blood pressure is the pressure of blood against the wall of a blood vessel. A sphygmomanometer is used to measure blood pressure. The systolic pressure is the highest arterial pressure and the diastolic pressure occurs while the heart ventricles are relaxing. Blood pressure accounts for the flow of blood in the arteries. In the capillaries blood flow is slow and it is where exchange of nutrients and wastes in the tissues occurs. In the veins, blood flow returns to the heart.

TWO CARDIOVASCULAR PATHWAYS

The pulmonary circuit, exchange of gases, blood travels to and from the lungs.

The systemic circuit, exchanges with tissue fluid, the aorta divides into blood vessels that serve the body's organs and cells. As shown in this illustration.*

EXCHANGE AT THE CAPILLARIES

Two forces primarily control movement of fluid through the capillary wall. Blood pressure causes water to move from capillary to tissue fluid. Osmotic pressure tends to cause water to move in the opposite direction. Both of these are shown in the illustration shown here.*

CARDIOVASCULAR DISORDERS

Cardiovascular disease is the leading cause of death in the Western countries.

Hypertension and atherosclerosis can lead to stroke, heart attack or aneurysm.

Healthy diet, regular exercise, maintaining proper weight, and not smoking help protect against cardiovascular disease.

CHAPTER 6

CARDIOVASCULAR SYSTEM: BLOOD

BLOOD: AN OVERVIEW

The functions of blood are: 1. the transport of oxygen, hormones, and nutrients to cells
2. to transport carbon dioxide, and other wastes from cells 3. to fight infection and has various regulatory functions 4. maintain blood pressure 5. regulates body temperature 6. keeps the pH of body fluids within normal limits. These help maintain homeostasis.
Blood also has 2 components: formed elements and plasma. Formed elements are red and white blood cells and platelets. Plasma is 91% water. Its proteins, produced by the liver, maintain osmotic pressure, help regulate pH and transport molecules. For example some functions of the plasma are to transport immunity and blood clotting.

RED BLOOD CELLS AND TRANSPORT OF OXYGEN

The illustration to the left show the structure of red blood cells.*

Red blood cell production is controlled by the oxygen concentration of the blood. When oxygen decreases, the kidneys increase their production of erythropoietin, and more red blood cells are produced. These are produced in the bone marrow.

Blood doping is any method of increasing the normal supply of RBC'S for the purpose of delivering oxygen more efficiently, reducing fatigue, and giving athletes a competitive edge.
Disorders involving red blood cells include anemia, hemolysis (rupturing of red blood cells), sickle cell disease, hemolytic disease of the newborn.

WHITE BLOOD CELLS AND DEFENSE AGAINST DISEASE

White blood cells are classified into granular leukocytes and agranular leukocytes. Some of these have noticeable granules and some do not have noticeable granules.

Granular leukocytes include neutrophils, eosinophils, and basophils.

Neutrophils account for 50-70% of white blood cells. Neutrophils are abundant and respond first to infections. They phagocytize pathogens. See illustration to left.*

These increase in number in the event of parasitic infection or an allergic reaction.
See illustration.*

The basophil releases histamine associated with allergic reactions. Histamine dilates blood vessels, but constricts the air tubes that lead to the lungs. Like during an asthma attack.

Agranular leukocytes include lymphocytes and monocytes.

Monocytes are the largest of white blood cells. They can become macrophages that phagocytize pathogens and cellular debris. See illustration.*

Lymphocytes are responsible for specific immunity. See illustration.*

All blood cells are produced in the red bone marrow from stem cells. These cells live about 120 days and are eventually destroyed in the spleen and liver.

PLATELETS AND BLOOD CLOTTING

Platelets are a result from fragmentation megakaryocytes in the red bone marrow. Platelets function in blood clotting. Platelets are produced at a rate of 200 billion a day.



Platelets and two plasma proteins, function in blood clotting, an enzymatic process that results in fibrin threads, which trap red blood cells.

Disorders relating to blood clotting are hemophilia and thrombocytopenia.

BLOOD TYPING AND TRANSFUSIONS

Blood transfusion is the transfer of blood from one individual to another.

Blood typing involves determining the ABO blood group and whether the person is Rh- or Rh+

Type A blood is type A surface antigens, plasma has anti B antibodies.

Type B blood is type B surface antigens, plasma has anti A antibodies.
Type AB blood is both type A and type B surface antigens, plasma has neither anti A nor anti B antibodies.
Type O blood is neither type A nor type B surface antigens, plasma has neither anti A nor anti B antibodies.

Agglutination occurs if the corresponding antigen and antibody are put together.

RH antigen must also be considered when transfusing blood. It is very important during pregnancy because an Rh- mother may form antibodies to the Rh antigen while carrying or after the birth of an Rh+ child. These antibodies can cross the placenta to destroy the red blood cells of any subsequent Rh+ child.

HOMEOSTASIS

Homeostasis depends upon the cardiovascular system because it serves the needs of the cells. Several other boy systems are also critcal to cardiovascular systems function: 1. digestive system supplies nutrients 2. respiratory system supplies oxygen and removes carbon dioxide from the blood 3. nervous and endocrine systems are involved in maintaining blood pressure 4. lymphatic system returns tissue fluid to the veins 5. Skeletal muscle contraction and breathing movements propel blood in the veins.

CHAPTER 7

LYMPHATIC SYSTEM AND IMMUNITY

MICROBES, PATHOGENS, AND YOU

Microbes perform valuable services, but they also cause disease.

Bacteria are prokaryotic cells that live and reproduce independently of host cells and cause disease by multiplying in hosts and also by producing toxins.

Viruses are noncellular particles, consisting of a protein coat and a nucleic acid core, take over the machinery of the host in order to reproduce and can emerge and cause new diseases the human body has difficulty combating.

Prions, proteinaceous infectious particles, cause a group of degenerative diseases of the nervous system, also called wasting diseases. A common example is mad cow disease. However, the incidence of prion diseases in humans is very low.

THE LYMPHATIC SYSTEM

The lymphatic system consists of lymphatic vessels and lymph organs. Lymph vessels form a one way system, capillaries, vessels and ducts that take lymph to cardiovascular veins in shoulders. Lymph is usually a colorless liquid that is secreted by cells.

Primary lymphatic organs are: red bone marrow, thymus gland.

Seconday lymphatic organs are the spleen, lymph nodes, tonsiles, peyers patches and the appendix. Blood is cleansed of pathogens and debris in the spleen.

Lymph is cleansed of pathogens and debris in the nodes.

NONSPECIFIC DEFENSES

Immunity involves nonspecific and specific defense. Non specific are 1. barriers to entry, skin and mucous membranes. 2. Chemical barriers, secretion of sebaceous glands, perspriation, saliva and tears. 3. Resident bacteria, normal flora found in mouth, intestine and other areas.

Inflammatory reaction involves phagocytic neutrophils and macrophages and protective proteins.
See illustration.*

SPECIFIC DEFENSES

Specific defenses require B cells and T cells. See illustration.*

B cells undergo clonal selection with production of plasma cells and memory B cells, after, their B cell receptor combines with a specific antigen. Plasma cells secrete antibodies and eventually undergo apoptosis. Apoptosis is programmed cell death involving a cascade of specific cellular events leading to death and destruction of the cell. Antibodies are Y shaped molecules that have two binding sites for a specific antigen. Memory B cells remain in the body and produce antibodies if the smae antigen enteres the body at a later date. See Illustration.*

For a T cell to recognize an antigen, the antigen must be presesented by an antigen presenting macrophage, along with an HLA(human leukocyte antigen) Once T cells are actevited they undergo clonal expansion until the inllness has ben stemmed. Then they to undergo apoptosis. A few will remain as memory T cells.

The two main types of T cells are cytotoxic T cells and helper T cells. Cytotoxic T cells kill virus infected cells or cancer cells on contact because they bear a nonself protein. Helper T cells produce cytokines and stimulate other immune cells.

ACQUIRED IMMUNITY

Active immunity can be induced by vaccines and also depends upon the presence of memory cells in the body. Passive immunity is needed when an individual is in immediate danger of succumbing an infectious disease. Passive immunity is short lived. Monoclonal antibodies have various functions from detecting infections to treating cancer. Cytokines are a form of passive immunity used to treat AIDS and to promote the boldy's ability to recover from cnacer.

HYPERSENSITIVITY REACTIONS

Allergic responses occur when the immune system reacts vigorously to substances not mormally recongnixzed as foreign. Immediate allergic responses are due to the activity of antibodies. Delayed allergic respinses are due to the activity of T cells.

Tissuse rejection happens when the immune system recognixes a tissue as being foreign.

Autoimmune siorders occur when the immune system reacts to tissues or organs of the individual as if they were foreign

AIDS SUPPLEMENT

ORIGIN AND PREVALENCE OF HIV

Acquired immunideficiency syndrome (AIDS) is cause by a virus known as a human immunodeficiency virus (HIV). There are two main types of HIV, HIV-1, HIV-2. HIV-1 is the most widespread.

AIDS is a pandemic because the disease is prevalent in the entire human population aroun the globe.

PHASES OF AN HIV INFECTION

Category A: Acute Phase - in this phase a person has no apparent symptoms, is highly infectious and has a CD4 T cell count that hs\as never fallen below 500 cells per mm3 of blood. During first few weeks of infections some people develop flulike symptoms.

Category B: Chronic Phase - A person in this category would have a CD4 count between 499 and 200 cells per mm3. Some symptoms could be yeast infections, prolonged diarrhea, thick sores on the tongue or shingles.

Category C: AIDS - A person in this category is diagnosed with AIDS. CD4 count falls below 200 cell per mm3, or has developed oe or more of the 25 AIDS defining illnesses. Like: pnewmocystis jiroveci pneumonia, fungal infection of the lungs. Mycobacteruim tuberculosis, bacterial infection nodes or lungs. Toxoplasmic encephalitis, a protozoan parasitic infection, often seen in the brain. Kaposi's sarcoma, canceer of the blood vessels. Invasive cervical cancer.

Death usually follows in tew to four years after AIDS diagnosis.

HIV STRUCTURE AND LIVE CYCLE

The life cycle of an HIV virus includes transmission to a new host.

TRANSMISSION AND PREVENTION OF HIV

HIV is transmitted by sexual contact with an infected person. Also, neddle sharing amon intravenous drug users. A less common mode is through blood transfusions of infected blood.

HIV TESTING AND TREATMENT FOR HIV

There is not a specific test for the HIV, instead the test is done to detect the presence of HIV antibodies in the body.

There is no cure for AIDS, but a treatment called highly active antiretroviral therapy is usually able to stop HIV replication to such an extent that the viral load becomes undetectable.

There are no real vaccines yet as of today. In 2006 26 vacines were undergoing human trials around the world. None of these would be a cure, the vaccine would be a preventive measure that helps people who are not yet infected escape infection or slow down the progression of the disease upon future infection. No results from these tests will be done until about the year 2010.