Human Body: Organs, Systems, Health, and Disease

Organs and Organ Systems

Organs

Organs are complex structures composed of various types of tissue. They perform single or similar functions.

Organ Transplant

Organ transplant is the replacement of a damaged organ or tissue. A common problem is rejection.

Organ Systems

• Nutrition:
  • Digestive system: Digests food and absorbs nutrients.
  • Respiratory system: Exchanges O2 and CO2.
  • Circulatory system: Transports substances throughout the body.
  • Excretory system: Removes metabolic waste, such as urine.
• Interaction:
  • Nervous system: Receives stimuli and sends instructions.
  • Endocrine system: Produces hormones.
  • Locomotive system: Enables movement and provides protection.
• Reproduction:
  • Reproductive system: Creates new life.

Health and Illness

Concept of Health

Health is a state of complete physical, mental, and social well-being.

Determinants of Health

• Environment
• Lifestyle
• Genetics

Concept of Illness

Indicators

• Symptoms
• Signs

Classification

• Non-infectious (non-transmissible): Cardiovascular diseases, respiratory diseases, diabetes, cancer.
• Infectious: Transmitted directly or indirectly via a vector.
• Pathogens: Bacteria, viruses, fungi, protozoa.

Defenses Against Illness

External (Non-specific)

• Physical: Skin, mucous membranes.
• Chemical: Secretions that block pathogens.
• Biological: Bacterial flora (natural antibiotic).

Internal Defenses

• Innate immunity:
  • Phagocytosis: Phagocytes engulf pathogens, forming pus.
  • Inflammation: Swelling, reddening, action of macrophages.
• Acquired immunity (specific against antigens):
  • Lymphocyte B cells: Plasma cells produce antibodies, and memory cells store information.
  • Lymphocyte T cells: Produce enzymes to destroy damaged cells and antigens.

Illness Prevention and Treatment

Prevention

Preventative Measures

Vaccination: Introducing deactivated antigens promotes the production of lymphocytes, antibodies, and memory cells.

Personal Habits

• Hygiene
• Lifestyle

Treatment

Medicines:

• Antibiotics: Inhibit bacterial growth.
• Antivirals: Kill viruses.
• Antisera: Used for animal bites.
• Fungicides: Kill or inhibit fungal growth.

White cells: Phagocytes, macrophages, lymphocytes B and T.

Organ Systems: Detailed Functions

Nutrition

• Digestive: Mouth, tongue, teeth, stomach, small and large intestines.
• Circulatory: Heart, arteries, veins.
• Respiratory: Nostrils, lungs, bronchioles, trachea, larynx, and pharynx.
• Excretory: Kidneys, bladder, urethra, ureters.

Reproduction

• Female: Ovaries, uterus, vagina, vulva, fallopian tubes.
• Male: Testicles, penis, urethra.

Interaction

• Nervous: Sense organs, brain, nerves.
• Endocrine: Hypothalamus, pituitary, thyroid, parathyroid glands, ovaries, testicles, pancreas.
• Locomotor: Bones and muscles.