Infectious diseases and the stress response

• Infectious diseases causes


  • Virus
  • Bacteria
  • Fungi
  • Parasite
• Transmission of infectious diseases


  • Foodborne
  • Direct contact
  • Airborne
  • Animal/insect
• Common symptoms of infectious diseases

  • Fever
  • Diarrhea
  • Coughing
  • Muscle pain
  • Fatigue
• Examples of infectious diseases


  • Influenza
  • Tuberculosis
  • Measles
  • Chickenpox
  • Chlamydia
  • Meningitis
  • COVID
  • Hepatitis A, B, C
  • Mumps
  • Diphtheria
  • Pneumonia
  • Common Cold
  • Giardia
  • Malaria
  • Dengue Fever
  • Norovirus
  • HIV
  • Gastroenteritis
  • Ebola
  • Elephantitis
• Components of innate immunity

  • Granulocytes
  • Monocytes
  • Natural killer cells
• Types of granulocytes


  • Basophils-allergic reactions, asthma
  • Eosinophils-parasitic and cancer
  • Neutrophils-first responder
• Components of adaptive/specific immunity

  • Lymphocytes - B-cells-antibody production, T-cells-destruction of pathogen
• Hormones involved in stress response

  • Epinephrine & norepinephrine (catecholamines)
  • Glucagon
  • Cortisol
  • Aldosterone
  • Antidiuretic hormone
• Effects of stress hormones

  • Increased metabolic rate
  • Glycogen breakdown
  • Glucose production
  • Release of fatty acids
  • Protein degradation
  • Sodium reabsorption/retention
  • Water reabsorption/retention
• Chronic stress results in excess cortisol levels for extended period of time resulting in muscle breakdown, insulin resistance, hyperglycemia, and compromised immunity cortisone.
• Causes of chronic obstructive pulmonary disease (COPD)

  • Chronic bronchitis
  • Emphysema
• Emphysema


  Alveoli walls are destroyed, losing lung elasticity
• Chronic bronchitis


  Continuous inflammation and mucus secretion in the airways results in narrowing of bronchi and bronchioli
• Acute respiratory distress syndrome (ARDS)


  • Lung injury causing lung edema and dyspnea (shortness of breath)
  • Characterized by hypoxemia, hypercapnia, hypoxia, acidosis, and cyanosis
  • Results in headache, confusion, heart arrhythmias, and coma
• Acute stress response (burns)


  Tissue damage increases the need for proteins for recovery, damaged tissue may result in loss of fluids, and impaired oxygen delivery can result in tissue death and organ damage
• Degrees of burns


  • 1st degree: damage to epidermis
  • 2nd degree: damage to epidermis and dermis
  • 3rd degree: damage to epidermis, dermis, and underlying tissue
• Acute inflammation


  • C-reactive protein, fibrinogen, and blood clotting proteins are released to repair damaged tissue
  • Anti-inflammatory agents are released once the issue is resolved
• Chronic inflammation


  • Immune response and stress response are prolonged, resulting in damaged tissue, muscle mass loss, vital sign irregularities, and potential organ failure and chronic diseases
• Septic shock


  The last stage of sepsis, where severe blood pressure drop happens and organs start shutting down one by one
• 1 in 5 people die from septic shock