Cardiovascular System

The Heart

Blood Flow Through the Heart

Heart Valves

Control of the Heartbeat Sinoatrial node (SA node) – “pacemaker” of the heart – Regulates the contraction of the entire heart Atrioventricular node (AV node) – Relays electrical impulses to the ventricles SA node and AV node work together to create a heartbeat

Control of the Heartbeat Pulse – a series of pressure waves within an artery caused by the contraction of the left ventricle

Activity Determining Heart Rate – Have a partner take your pulse for 15 seconds while seated. – Calculate beats per minute. – Have a partner take your pulse for 15 seconds while standing. – Calculate beats per minute. – Jog in place for one minute. Have your partner take your pulse for 15 seconds after jogging. – Calculate beats per minute. Was your pulse different in each situation? What might cause your heartbeat to change in each situation?

Self Quiz!

Heart Problems Atherosclerosis – a disease characterized by the build up of fatty materials on the interior walls of coronary arteries Atherosclerosis or blood clots can cause heart attacks

Heart Attack (myocardial infarction)

Blood

Blood Types

Blood Typing Game cine/bloodtypinggame/index.html cine/bloodtypinggame/index.html

Blood Disorders Sickle Cell Anemia Anemia Hemophilia

The Body’s Defense Systems Immune System!

Pathogen Any agent that causes disease – Bacteria – Viruses – Fungus – Protist – Parasite

First Line of Defense Barriers – Skin Physical barrier – Mucus membranes Mucus traps pathogens

Second Line of Defense Nonspecific Immunity Inflammatory response – suppresses infection

Second Line of Defense Temperature response – moderate fever may slow bacterial and viral growth Prolonged or very high fever are dangerous – Destroys important proteins – Can lead to death

Immune System: Specific Defenses Recognize pathogens Immune response Memory and immunity

Recognize Pathogens Antigen – any substance that the immune system can recognize and react with Antigens cause Lymphocytes (B cells and T cells) to react Lymphocytes bind to antigen and start attack (immune response)

Immune Response Helper T cell engulfs pathogen – helps other cells recognize antigens Killer T cells (cytotoxic T cells) recognize and destroy infected cells Plasma cells make defensive proteins called antibodies Antibodies bind to specific antigens on the pathogen – makes them inactive

Immunity Memory cells are created after an immune response Next time body exposed to pathogen, antibodies produced very quickly to protect

Disease Reminder: Pathogen = Any agent that causes disease – Bacteria – Viruses – Fungus – Protist – Parasite

Infectious Diseases Bacterial – Strep throat – Cholera – Necrotizing fasciitis (flesh eating disease) Virus – Chicken pox/ shingles – HIV – Ebola Fungus – Athletes foot Protist – Malaria Parasite – Tapeworm

Strep Throat Bacterial infection Caused by streptococcus Treated with antibiotics

Cholera Waterborne disease Transmitted through fecal matter Severe dehydration Can be fatal

Flesh Eating Disease Necrotizing fasciitis Destroys skin, fat, tissue Immunocompromised

Chicken Pox Varicella zoster virus Highly contagious Skin rash Vaccine Can develop into shingles – Herpes zoster

HIV Human Immunodeficiency Virus (HIV) Causes the condition AIDS (Acquired Immunodeficiency Syndrome) Spread through bodily fluids

Ebola Ebola hemorrhagic fever RNA virus Often fatal

Athlete’s Foot Fungal infection of the feet Scaling, flaking, itching of skin Transmissible

Malaria Common in the tropics Mosquitos are vectors Caused by plasmodium

Tapeworm Parasite Contaminated food Live in digestive tract

Activity Simulating an epidemic