The Heart and Blood Vessels

The Heart and Blood Vessels

• The human heart and lungs' structure and function should be well-understood, including respiratory adaptations.
• The heart is an organ that pumps blood in a double circulatory system.
• The right ventricle pumps blood to the lungs for gas exchange.
• The left ventricle pumps blood to the rest of the body.
• Knowledge of blood vessels is limited to the aorta, vena cava, pulmonary artery and vein, and coronary arteries.
• Knowledge of the lungs is restricted to the trachea, bronchi, alveoli, and capillary network surrounding the alveoli.
• The natural resting heart rate is controlled by a group of cells in the right atrium acting as a pacemaker.
• Artificial pacemakers are electrical devices that correct irregular heart rates.
• The body contains three types of blood vessels: arteries, veins and capillaries.
• The structure of blood vessels relates to their functions
• Use can be made of simple compound measures such as "rate" to carry out rate calculations for blood flow.

Blood

• Blood is a tissue of plasma, red and white blood cells, and platelets.
• It is important to know the function of each of these blood components.
• Different types of blood cells are found in diagrams or photographs.
• The adaptations of each blood cell explain its function.

Coronary Heart Disease

• Advantages and disadvantages of treating cardiovascular diseases: drugs, mechanical devices, or transplant need evaluation.
• Coronary heart disease involves fatty material buildup inside coronary arteries, which narrows them.
• Narrowed arteries reduce blood flow, resulting in a lack of oxygen for the heart muscle.
• Stents are used to keep the coronary arteries open
• Statins lower blood cholesterol levels, slowing fatty material deposit.
• Faulty heart valves prevent full opening or may develop leaks.
• Faulty valves have consequences and can be replaced with biological or mechanical valves.
• In heart failure a heart and/or lungs can be transplanted.
• Artificial hearts can keep patients alive while waiting for transplant or to allow the heart to rest as an aid to recovery.

Health Issues

• Describe the health/disease relationship and interactions between different types of disease.
• Health is physical and mental well-being.
• Communicable and non-communicable diseases are major causes of ill health.
• Other factors influence health: diet, stress, and life situations.
• Defects in the immune system increase susceptibility to infectious diseases.
• Viruses living in cells can be the trigger for cancers.
• Immune reactions from pathogens can trigger allergies like skin rashes and asthma.
• Severe physical ill-health leads to depression and mental illness.

Lifestyle and Non-Communicable Diseases

• It is important to be prepared to discuss the human and financial cost of non-communicable diseases to individuals, communities, nations.
• Lifestyle factors including diet, alcohol, and smoking affect the incidence of non-communicable diseases at all levels
• Risk factors are linked to an increased rate of disease, either by lifestyle or internal factors.
• Causal mechanisms have been proven for some risk factors.
• Cardiovascular disease is impacted by diet, smoking, and exercise.
• Obesity is indicated as being a risk factor for Type 2 diabetes.
• Alcohol affects the liver and brain function.
• Smoking affects lung disease and lung cancer.
• Smoking and alcohol effects the unborn babies.
• Carcinogens, including radiation, are risk factors for cancer.
• Many diseases are caused by interacting factors. Understand the principles of sampling as applied to scientific data regarding risk factors
• Information can be translated between graphical and numerical forms from charts, graphs, and tables with risk factor considerations

Cancer

• Cancer is results from changes in cells leading to uncontrolled growth and division.
• Benign tumors are growths of abnormal cells in one area, contained within a membrame
• Cancer is caused by malignant tumor cells.
• Malignant tumors invade tissues and spread via the blood, forming secondary tumors
• Lifestyle and genetic risk factors have been identified for various types of cancer.

Communicable Diseases

• Diseases caused by viruses, bacteria, protists, and fungi are spread in animals and plants.
• The ways that infections are spread can be reduced or prevented.
• Pathogens cause infectious disease and may be viruses, bacteria, protists, or fungi.
• Pathogens may infect plants and animals, spread by contact, water, or air.
• Bacteria and viruses reproduce rapidly.
• Bacteria produce toxins that damage tissue.
• Viruses live and reproduce inside cells, causing cell damage.

Viral Diseases

• Measles is a viral illness characterized by fever and a red skin rash.
• Complications can arise making Measles a serious and sometimes fatal illness
• Most young children are vaccinated against measles because of the seriousness.
• Measles is contracted by inhalation of droplets from sneezes and coughs.

Human Defense Systems

• Key non-specific defense systems for the human body include; skin, nose, trachea, bronchi, and also, stomach.
• The immune system defends the body when pathogens enter.
• White blood cells defend against pathogens by phagocytosis, antibody production, and antitoxin production.

Vaccination

• Vaccination prevents illness and reduces the spread of pathogens by immunizing a large population.
• Vaccination uses small amounts of dead or inactive pathogens to stimulate white blood cells to produce antibodies preventing infection
• White blood cells quickly respond the the correct antibodies if the same pathogen re-enters the body.

Response to Exercise

• The human body reacts to exercise as more energy is demanded To supply the muscles with more oxygenated blood, heart rate, breathing rate, and breath volume all increase with exercise.
• If insufficient oxygen is supplied, then anaerobic respiration takes place inside the muscles.
• Incomplete glucose reaction causes lactic acid build up, creating what is called an oxygen debt.
• Vigorous activity over long periods of time causes muscles to become fatigued and stop contracting efficiently.
• (Only HT) Oxygen debt causes blood flowing transports the lactic acid where the liver converts it back into glucose.
• The extra oxygen needed to react with accumulated lactic acid and remove it from the cells is the actual oxygen debt.