L1.3: Overview of Human Body Systems

• Organ Systems

  • Respiratory System
  • Urinary System
  • Nervous System
  • Muscular System
  • Reproductive System
  • Skeletal System
  • Lymphatic System
  • Integumentary System
  • Digestive System
  • Endocrine System
  • Cardiovascular System
• Functions

  • Forms the external covering of the body for protection against external forces.
  • Waterproofs the body, and cushions and protects deeper tissues from injury.
  • Produces vitamin D with the help of sunlight. Excretes salts in perspiration and helps regulate body temperature.
  • Location of the cutaneous nerve receptors.

  Organs

  • skin, hair, fingernails


  Integumentary System
• Functions

  • Composed of specialized cells called muscle fibers whose predominant function is to contract.
  • The mobility of the body as a whole reflects the activity of the skeletal muscles.
  • These muscles are distinct from hollow organs or the muscles of the heart.
  • Nearly all movement in the body is a result of muscle contraction.
  • There are about 600 muscles in the human body.
  • Maintains posture
  • Produces heat

  Organs

  • skeletal muscles


  Muscular System
• • “MTB”
  • Muscles to bones
  • Muscles, tendons, bones
  • Meaning, muscles are connected to the bones by tendons


  Muscular system
• Functions

  • It supports the body and provides a framework that the skeletal muscles use to cause movement.
  • Protective function that encloses cavities.
  • Ex: Thoracic cavities and the ribs.
  • The skeleton’s cavities (bone marrow) are the sites of blood formation while the hard substances of the bones are the warehouse for minerals.

  Organs

  • bones, cartilages, and joints


  Skeletal System
• Functions

  • Fast-acting control system that responds to both external and internal stimuli.
  • Sensory receptors detect changes and send messages (nerve impulses) to the central nervous system which assesses the information to activate the body’s appropriate effectors (muscles/glands).

  Organs

  • brain, spinal cord, nerves, and sensory receptors

  Parts

  • Central Nervous System: Contains the brain and the spinal cord
  • Peripheral Nervous System: Contains the sensory receptors


  Nervous System
• Functions

  • Made up of glands that Secretes chemical molecules, called hormones, into the blood which controls body activities.
  • Similar with nervous, but a slow-acting controlling system
  • Body functions controlled by hormones include:
  • Growth, reproduction, and use of nutrients.

  Organs

  • pituitary, thyroid, parathyroids, adrenals, thymus, pancreas, pineal, ovaries, and testes.


  Endocrine System
• Functions

  • Cardio = heart; Vascular = vessels (blood vessels).
  • Cardiovascular systems deliver oxygen, nutrients, hormones, and other substances, and pucks up wastes like CO2
  • Blood acts as a carrier.
  • White blood cells and chemicals are protectors against the body’s foreign invaders.
  • The heart propels blood out of its chamber to be transported to all body tissues.

  Organs

  • Heart: pumps blood which contains oxygen, nutrients, hormones, carbon dioxide, wastes
  • Blood vessels: transports the blood


  Cardiovascular/Circulatory System
• Functions

  • Complements the cardiovascular system by returning leaked fluids back to the bloodstream.
  • Lymph nodes and other lymphoid organs cleanse the blood and house white blood cells involved in immunity.

  Organs

  • lymphatic vessels, lymph nodes, and lymphoid organs (spleen and tonsils), thymus


  Lymphatic System/Immune System
• Functions

  • Supplies the body with oxygen and removes carbon dioxide
  • Gases are exchanged through the thin walls of the alveoli.

  Organs

  • Nostrils, nasal cavity, pharynx, larynx, trachea, bronchi, lungs, diaphragm, alveoli


  Respiratory System
• Functions

  • Breaks down food and delivers nutrients to the blood to be utilized by the body cells.
  • Excretes undigested food as feces.
  • Ingestion, digestion, absorption, excretion
  • MAJOR FUNCTIONS: absorb nutrients and reabsorb water.
  • Liver: produces bile that breaks down fats.
  • Pancreas: delivers digestive enzymes to the small intestine.

  Organs

  • Oral cavity, pharynx, esophagus, stomach, intestines, rectum, accessory digestive organs (liver, gallbladder, pancreas, even the teeth)


  Digestive System
• Functions

  • Production of waste by-products.
  • Nitrogen-containing wastes: results when the body cells break down proteins and nucleic acids.
  • Urea and uric acid.
  • The urinary system removes such waste by flushing them from the body in urine.
  • Maintains the body’s water and salt (electrolyte) balance, regulates the acid-base balance of the blood, and helps regulate normal blood pressure.

  Organs

  • kidneys, ureters, bladder, and urethra.


  Urinary/Excretory System
• Functions

  • To produce offspring

  Organs [Female]

  • Ovaries, Fallopian tube, Uterus, Cervix, Vagina, Mammary glands

  Organs [Male]

  • Seminal vesicle, Prostate gland - the only organ which grows as a person ages, Vas deferens, Testis, Penis, Urethra, Scrotum


  Reproductive System