about AIDs/HIV
- AIDS is one of the fastest growing virus in the world!!
- no cure for AIDS
- In Africa, it is one of the highest places with AIDS, women, men, children and unborn children.
- exchanged through body fluids.
- The HIV virus causes AIDS by attacking the helper T cells.
- The helper T cells signal other cells to the presence of pathogens. When there are not enough helper T cells for this part of the immune response, the immune response becomes deficient
- To help prevent AIDS is to get tested!!!
Chapter Five
Cardiovascular System: Heart and Blood Vessels
Overview of the Cardiovascular System
The two parts of the cardiovascular system-
- Heart- pumps blood
- Blood vessels- keeps the blood flowing
The Type of Blood Vessels
The type of blood vessels-
- The arteries: From the Heart- the arteries carry blood away from the heart and to have strong walls.
- The Capillaries: Exchange- Have thin walls, is where exchanging can occur
- The Veins: To the Heart- the veins carry blood to the heart and it has thinner walls than the arteries and contains valves. About 70% of blood is in the veins so the blood acts as a blood tank.
The Heart is a Double Pump
- The heart is a cone-shaped, muscular organ located between the lungs.
- The heart is a double pump because the right ventricle of the heart sends blood through the lungs, and the left ventricle sends blood throughout the body. The valves keep the blood flowing in the right direction so no flows are going backwards.
- The atrium receives oxygen-poor blood from the body and the ventricle pumps it into the pulmonary circuit (lungs).
- The atrium receives oxygen-rich blood from the lungs, and the ventricle pumps it into the systemic circuit.
- Each heartbeat is called a cardio cycle.
- Systole, the working phase refers to contraction of the chambers and the diastole, the resting phase refers to relaxation of the chambers.
- “Lub” occurs when increasing pressure of blood inside a ventricle forces the cusps of the AV valve to slam shut.
- “Dub” occurs when the ventricles relax, and blood in the arteries pushes back, causing the semilunar valves to close.
- Electrocardiogram (ECG) is a recording of the electrical changes that occurs in myocardium during a cardiac cycle.
Features of the Cardiovascular System
- The pulse rate indicates the heartbeat rate. The pulse arte is usually 70 beats per minute but can vary.
- Blood pressure moves blood in arteries
- Blood flow is slow in the capillaries
- Blood flow in veins returns blood to the heart
Two Cardiovascular Pathways
• The cardiovascular system is divided into the pulmonary circuit and the systemic circuit.
- The pulmonary circuit: exchange of gases
- The systemic circuit: exchanges with tissue fluid
- The largest artery is the aorta, which receives blood from the heart.
- The largest vein is the superior and inferior venae cavae, returns blood to the heart.
Exchange at the Capillaries
- At the end arterial end of a cardiovascular capillary, blood pressure is greater than osmotic pressure; therefore, water leaves the capillary.
- Lymph is tissue fluid contained within lymphatic vessels.
- The lymphatic system is a one-way system, and fluid is returned to blood by way of a cardiovascular vein.
Cardiovascular Disorders
• Cardiovascular disease is the leading cause of death in the western countries.
Disorders of the Blood Vessels
Hypertension and atherosclerosis lead to stroke due to an artery blocked by a blood clot. Another possibility is an aneurysm, a burst blood vessel.
• High blood pressure
• Stroke, heart attack, and aneurysm
• Dissolving blood clots
• Treating clogged arteries
Disorders of the Heart
Heart failure is when the heart no longer pumps as usual. Heart failure is a growing problem because people who did die from heart attacks are now surviving and are left with damaged hearts.
Picture Reference:
http://www.mhhe.com/biosci/ap/dynamichuman2/content/gifs/0140.gif
http://kvhs.nbed.nb.ca/gallant/biology/blood_vessels.html
http://www.livescience.com/images/human_heart_graphic_03.jpg
Chapter six
Cardiovascular system: Blood
Blood: An overview
-The functions of blood fall into three categories
1. Transport
2. Defense
3. Regulation
• Blood is the primary transport medium
• Blood defends the body against invasion by pathogens in several ways.
• Blood has regulatory functions
-Composition of Blood
• Blood is a tissue and is classified as a liquid cell.
• The cells and cell fragments are called formed elements. The cell and cell fragments are suspended in a liquid are called plasma.
1. Formed Elements
• Red blood cells, white blood cells and platelets
• Red blood cells are larger than white blood cells and there are million of red blood cells and only ten of thousands of white blood cells.
2. Plasma
• The composition of plasma is 91% water and 9% of various salt (ions) and organic molecules
• The most abundant organic molecules in blood are plasma protein.
• The function of plasma protein is to maintaining homeostasis.
• Three major type of plasma proteins:
- Albumins- most plasma osmotic pressure
- Globulins- three types: alpha, beta and gamma globulins. The alpha and beta both help transport substance in the blood like iron hormones and cholesterol. The gamma globulin is important in fighting disease.
- Fibrinogen- is a plasma protein that is active in formation of blood clots.
• Red blood cells are highly specialized for oxygen transport.
• The red blood cells lack a nucleus but have hemoglobin (Hb) instead.
• Hemoglobin makes blood the color red.
• Have a biconcave shape because RBC (red blood cells) does not have a nucleus during maturation.
• Hemoglobin allows RBC to transport oxygen.
• Red blood cells are produced in bone marrow.
• Three disorders that are associated with RBCs are: anemic, sickle-cell disease and hemolytic diseases of the newborn.
White Blood Cells and Defense Against Disease
• Are large have a nucleus, does not have hemoglobin, and are translucent unless strained.
• Fights infections and is important to the immune system.
Type of white blood cells
1. Granular leukocytes- (neutrophils, eosinophils, basophils)
2. Agranular leukocyte- (lymphocytes, monocytes)
- Granular Leukocytes- neutrophils account for 50%-70% of all white blood cells, are first to respond to an infection. Eosinophile respond in the event of a parasitic worm infection or an allergic reaction. Basophils respond to an asthma attacks.
- Agranular Leukocyte- lymphocyte account 25%-35% of white blood cells. Lymphocyte are of two types: B (plasma cell) and T (cytotoxic T cells) cells. Monocytes are the largest of white blooc cells and take up residence in the tissues.
Disorders
• SCID
• Leukemia
• EBV
All blood cells are produce within red bone marrow from stem cells and live up to 120 days and are destroyed in the liver and spleen.
Platelets and Blood Clotting
• Platelets result from fragmentation of megakaryocytic in the red bone marrow.
• Platelets function in blood clotting.
Blood Typing and Transfusions
• Blood transfusion is transfer of blood to another person’s blood.
ABO Blood Groups
• ABO blood typing determines the presence of absence of type A antigen and type B antigen on the surface of red blood cells.
• Type A Blood
• Type B Blood
• Type AB Blood
• Type O Blood
• Agglutination
Blood Typing and Transfusions
• Blood transfusion is transfer of blood to another person’s blood.
ABO Blood Groups
• ABO blood typing determines the presence of absence of type A antigen and type B antigen on the surface of red blood cells.
• Type A Blood
• Type B Blood
• Type AB Blood
• Type O Blood
• Agglutination
Rh Blood Groups
• Must be considered when transfusing blood.
• Very important during pregnancy because an Rh- mother may form antibodies to the Rh antigen while carrying or after the birth of an Rh+.
Homeostasis
• Homeostasis depends upon the cardiovascular system because it serves the needs of the cells.
Picture References:
http://z.about.com/f/p/440/graphics/images/en/19192.jpg
http://www.britannica.com/eb/art-88528/Blood-is-made-up-of-red-blood-cells-white-blood
http://www.lymphomation.org/images/leukocytes-normal.gif
http://media.allrefer.com/s4/l/p0014535-blood-clotting.gif
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f21-7a_abo_blood_types_c.jpg
http://faculty.southwest.tn.edu/rburkett/urinar31.jpg
Chapter seven
Microbes, Pathogens, and You
• Microbes perform valuable services but they also cause diseases.
- The body has three line of defenses against invasion:
- Barrier to entry mean that the body has body cavities like skin and mucous membranes to prevent any harm against the body or having anything enter the body to cause harm.
- First responders mean that the white blood cells are the first to act to fight against the diseases.
- Specific defenses overcome an infection by killing the particular disease-causing agent that has entered the body.
Bacteria
- Are single-celled prokaryotes and do not have a nucleus.
- Have three common shapes:
- Bacillus has a rod shape.
- Coccus has a spherical shape.
- Spirillum is curved.
- Bacteria have cell wall that contains a unique amino-disaccharide.
- Are independent cells that are metabolically competent.
- Can reproduce rapidly under favorable conditions, doubling their numbers every 12 minutes.
- The growth of bacteria causes diseases.
- Viruses bridges the gap between the living and the nonliving
- Are non-cellular- not composed of cells.
- Causes diseases (cold, flu, measles, chicken pox)
- Four times smaller than a bacterium.
- Can emerge and cause new diseases in the human body.
- Are protein
- There are three types of prion diseases: spontaneous, acquired and genetic.
- Has two parts: an outer capsid (protein unit) and inner core of nucleic acid.
- Can emerge and cause new diseases.
The Lymphatic System
- The lymphatic system consists of lymphatic vessels and the lymphatic organs.
- The lymphatic system is closely associated with the cardiovascular system.
- Has four major functions that contribute to homeostasis:
- Lymphatic capillaries absorb excess tissue fluid and return it to the bloodstream.
- In the small intestines, lymphatic capillaries called lacteals absorb fats in the form of lipoproteins and transport them to the bloodstream.
- The lymphatic system is responsible for the production, maintenance, and distribution of lymphocytes.
- The lymphatic system helps defend the body against pathogens.
Lymphatic Vessels
- Form a one-way system first to the capillaries, then the vessels and so the ducts.
- The fluid in the lymphatic vessels is called lymph.
- The lymphatic system has two ducts:
- Thoracic duct-returns lymph collected from the body below the thorax, the left arm, and left side of the head and neck into the left subclavian vein.
- Right lymphatic duct-returns lymph from the right arm and right side of the head and neck into the right subclavian vein.
- Are divided into those that are primary: red bone marrow and the thymus gland; and the secondary: lymph nodes and spleen.
- The primary lymphatic organs
- Red bone marrow produces all types of blood cells.
- Thymus gland is located in the thoracic cavity between the trachea and the sternum, superior to the heart.
- The thymus has two functions:
- The thymus gland produces thymic hormones
- Immature T lymphocytes migrate from the bone marrow through the bloodstream to the thymus, where they mature
- Secondary lymphatic organs
- Organs are the spleen, the lymph nodes, and other organs like tonsils and the appendix.
- The spleen filters blood. The largest lymphatic organ.
- Lymph nodes, which occur along lymphatic vessels, filter lymph.
- Lymphatic nodules are concentration of lymphatic tissue not surrounded by a capsule
- The tonsils are patches of lymphatic tissue located in a ring about the pharynx.
- Peyer’s patches located in the intestinal wall
Immunity, the ability to combat diseases and cancer, includes lines of defense. Two lines of defenses are: barriers to entry and inflammatory response.
Barriers to Entry
The body has built in barriers, both physical and chemical, that serve as the first line of defense against an infection by pathogens.
- Skin and mucous membranes
- The skin prevents infections from entering the body.
- Mucous membrane lines the respiratory, digestive, reproductive, and urinary tracts are also physical barriers to entry by pathogens.
- Chemical barriers
- The chemical barriers to infection include the secretions of sebaceous (oil) glands of the skin. It contains chemicals that weaken or kill certain bacteria on the skin.
- Perspiration, saliva, and tears contain an antibacterial enzyme called lysozyme.
- Resident bacteria
- Created by the normal flora, microbes that usually reside in the mouth, intestine, and other areas.
- Prevent potential pathogens from taking up residence.
The inflammatory response exemplifies the second line of defense against invasion by a pathogen.
- Is usually recognized by its four characteristic symptoms: redness, heat, swelling, and pain.
- Protective Proteins
- The complement system is composed of a number of blood plasma proteins.
- Certain other complement proteins join to form a membrane attack complex that produces holes in the surface of bacteria and some viruses.
- Interferons are proteins produced by virus-infected cells as a warning to no infected cells in the area.
When nonspecific defenses fall to stop an infection, a specific defense comes into play.
How Specific Defense Works
- Specific defenses respond to antigen, which are molecules the immune system recognizes as foreign to the body. Antigens are large molecules like proteins.
- Specific defenses primarily depend on the action of lymphocytes, which differentiate as either B cells or T cells.
- B Cells and antibody-medicated Immunity
- The receptor on a B cell is called a B cell receptor (BCR).
- Most of the cloned B cells become plasma cells.
- Characteristics of B cells:
- Antibody-medicated immunity against pathogens
- Produced and mature in bone marrow
- Directly recognize antigen and then undergo clonal selection
- Clonal expansion produces antibody-secreting plasma cells as well as memory B cells.
- Structure of an Antibody
- The basic unit which composes antibody molecules is a Y-shaped protein molecule with two arms.
- Classes of Antibodies
- There are five different classes of circulating antibodies.
- T cells and cell-medicated Immunity
- For a T cell to recognize an antigen, the antigen must be presented by an antigen-presenting macrophage, along with an HLA.
- The two main type 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.
Immunity occurs naturally through infection or is brought about artificially by medical intervention. The two type of acquired immunity are active and passive.
Active Immunity- the individual alone produces antibodies against an antigen
- Immunization involves the use of vaccines, substances that contain an antigen to which the immune system responds.
- After a vaccine is given, it is possible to follow an immune response by determining the amount of antibody present in a sample of plasma; this is called the antibody titer.
- Passive immunity occurs when an individual is given prepared antibodies or immune cells to combat a disease.
- Is short-lived because the antibodies are administered to and not made by the individual.
Allergies
- Allergies are hypersensitivities to substances, such as pollen, food, or animal hair, the ordinarily would do no harm to the body.
- The response to these antigens is called allergens.
- An immediate allergic response can occur within seconds of contact with the antigen.
- Tissue rejection occurs when the immune system recognizes a tissue as foreign.
- Autoimmune disease-cytotoxic T cells or antibodies mistakenly attack the body’s own cells as if they bear foreign antigens.
- Myasthenia gravis- antibodies attach to and interfere with the functioning of neuromuscular junctions, and muscular weakness results.
- Multiple sclerosis (MS)- t cells attack the myelin sheath of nerve fibers, and this causes various neuromuscular symptoms.
- Systemic lupus erythematosus (SLE)- has various symptoms prior to death due to kidney damage from the deposition of excessive antigen-antibody complexes.
- Rheumatoid arthritis- the joints are affected.
- When a person has an immune deficiency, the immune system is unable to protect the body against disease. AIDS is an example.
- Severe combined immunodeficiency disease (SCID)- both antibody and cell-mediated immunity are lacking or inadequate.
http://www.esa.int/images/General_Bacteria_L.jpg
http://www.worsleyschool.net/science/files/virus/page.html
http://www.stanford.edu/group/virus/prion/2005priya/molecularbio.html
http://www.longevity.ca/info_theory_of_cell.htm
http://diverge.hunter.cuny.edu/~weigang/Images/17-08_clonalselect_1.jpg
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