Respiratory, Circulatory, and Excretory Systems
Respiratory System
The respiratory system contains the airways and lungs. Its function is to capture the oxygen that our body needs and to expel the carbon dioxide produced.
- Respiratory: nasal cavities, pharynx, larynx, trachea, and bronchi.
- Lungs: two elastic, fluffy, pink bodies occupying almost the entire chest.
- Ribcage: This includes the spine, ribs, diaphragm, and sternum.
Respiratory Diseases
- Microorganisms:
- Cold and flu: virus.
- Pharyngitis, laryngitis, bronchitis, and pneumonia: Inflammation.
- Inhaling substances:
- Silicosis: miners.
- Bronchitis and lung cancer: tobacco.
- Asthma: Occurs when the fine walls of the bronchioles contract, decreasing their diameter.
Circulatory System
The circulatory system is responsible for getting nutrients and oxygen to all cells and collecting the waste substances produced, conducting them to the organs that are responsible for eliminating them.
Blood
Thick, viscous, red liquid that circulates through blood vessels. Formed by a liquid part: the plasma with cells in suspension: red blood cells, white blood cells, and platelets.
- Plasma: Transparent, yellow liquid in which blood cells float.
- Red Blood Cells: Disk-shaped cells without a nucleus. Their function is the transportation of oxygen from the lungs to all organs and tissues of the body.
- White Blood Cells: Cells with a nucleus, present in the blood, and slightly larger than red blood cells. Their mission is to defend the organism against infections.
- Platelets: Very small cells. Their mission is blood coagulation, which occurs when a blood vessel breaks.
Heart
A hollow organ, about the size of a fist, consisting of a specific muscle called the myocardium.
- Systole: Contraction of the heart.
- Diastole: Relaxation of the heart.
- Valves play an important role in maintaining the direction of blood flow inside the heart.
Blood Vessels
- Arteries: Blood vessels that carry blood from the heart to the organs.
- Veins: Vessels that return blood from the organs to the heart.
- Capillaries: Vessels that connect larger arteries and veins.
- Major artery: aorta.
- Major veins: superior vena cava, inferior vena cava, and pulmonary veins.
Lymphatic System
It is composed of lymph vessels and the lymph fluid that circulates through them.
- Lymph Nodes: Similar in shape to a pea, between 1 and 20mm in size, containing large numbers of white blood cells.
Circulatory Diseases
- Valves not closing properly: murmur.
- Blocked arteries: atherosclerosis, thrombosis, myocardial infarction, and stroke.
- Prevention: Avoid smoking, engage in physical activity, and maintain a balanced diet.
Excretory System
Excretion: The process by which the body eliminates toxic substances produced by cellular activity.
Kidneys
Dark red, bean-shaped organs, measuring 10 cm long, located on both sides of the spine, slightly below the waist. They regulate the amount of water and salts in our body to keep them constant.
- Nephron: Functional units of the kidneys. Each nephron is an independent unit of urine production.
- Urine: Yellowish liquid composed of water, salts, and urea, formed in the nephrons through filtration and then reabsorption.
Excretory Diseases
- Cystitis: Bladder infection.
- Kidney stones and kidney failure.