Respiratory and Circulatory Systems: Anatomy and Diseases

Respiratory System

The respiratory system is formed by the ducts through which air circulates, and by small cavities called alveoli, which are capable of entering the bloodstream. At the same time, blood circulates CO2 through the tubes of the respiratory system.

Upper Respiratory Tract

• Nose and nostrils: Two cavities located in the center of the face. Function: To warm and moisten the air.
• Pharynx: Connects the mouth with the larynx and nasal passages. It also communicates through the auditory tube. It forms part of the respiratory and digestive tracts.
• Larynx: Formed by cartilage and bone, it connects the pharynx with the trachea. It contains the vocal cords, which vibrate with airflow to produce the voice.

Lower Respiratory Tract

• Trachea: A tube that goes from the pharynx to the bronchi, formed by C-shaped cartilaginous rings. Its function is to allow air to pass to the larynx and lungs.
• Bronchi and bronchioles: Bronchi are tubes that lead air from the trachea to the lungs.
• Lungs: Two spongy and elastic organs located in the thorax and protected by the ribs and the dorsal spine. The right lung is divided into three parts, and the left lung is divided into two.

Respiratory Problems

Common symptoms include coughing, cyanosis, and dyspnea.

Respiratory Diseases

• Nose and larynx:
  • Rhinitis: Inflammation of the nasal mucosa.
  • Sinusitis: Inflammation of the nasal mucosa.
  • Laryngitis: Inflammation of the nasal mucosa.
• Bronchi:
  • Acute bronchitis
  • Chronic bronchitis
  • Asthma
• Lungs:
  • Pulmonary emphysema
  • COPD (Chronic Obstructive Pulmonary Disease)
  • Bronchopulmonary cancer

Circulatory System

The circulatory system has different functions: to carry nutrients and oxygen to the cells, to carry hormones, to regulate body temperature, and to be involved in defending the body.

Anatomy of the Heart

The heart is a muscle that relaxes and contracts alternately.

• Atria: The upper chambers, one on the left and one on the right, separated by muscle.
• Ventricles: The lower chambers, one on the right and one on the left, separated by muscle tissue.

Parts of the Heart

Endocardium, myocardium, pericardium.

• Vena cava: Reaches the right atrium.
• Pulmonary artery trunk: Exits the right ventricle and is shaped like a T.
• Pulmonary veins: Reach the left atrium.
• Aorta artery: Exits the left ventricle and carries blood throughout the body.

Blood Vessels

• Arteries: Blood vessels that transport blood out of the ventricles.
• Veins: Vessels with fine, inelastic walls that collect blood and carry it to the heart.
• Capillaries: Fine vessels into which the arteries divide.

Blood Circulation

• Greater circulation: Begins in the left ventricle, which, when it contracts, ejects blood into the aorta artery.
• Lesser circulation: Blood goes from the right atrium to the right ventricle.

Cardiac Cycle

• Atrial systole: The atria constrict, and blood passes through the ventricles.
• Ventricular systole: The ventricles contract, and blood passes into the pulmonary arteries and aorta.
• General diastole: The atria and ventricles are dilated when the muscles relax, and blood returns to the entrance of the atria.

Diseases of the Circulatory System

• Angina pectoris: Lack of blood in the heart muscle.
• Arterial hypertension (AHT): Increased blood pressure.
• Hypercholesterolemia: Prevalence of cholesterol in the blood.
  • LDL: Low-density lipoprotein or "bad" cholesterol.
  • HDL: High-density lipoprotein or "good" cholesterol.
• Myocardial infarction: Impaired heart function.
• Varicose veins: Dilated veins. Symptoms include pain and heavy legs.

Other Conditions

• Hypoxia: Low oxygen levels.
• Hypercapnia: High CO2 levels.