Human body systems

• Digestive System

  Converts food into simpler molecules that can be used by cells; absorbs food; eliminates waste
• The entire digestive process takes between 24 and 33 hours
• Organs/Components of the Digestive System


  • Mouth
  • Pharynx (throat)
  • Esophagus
  • Liver
  • Gall Bladder
  • Stomach
  • Pancreas
  • Small Intestine
  • Villi
  • Large Intestine (colon)
  • Appendix
  • Rectum
• Mouth


  • The first stop in the disassembly of your food; Mechanical digestion = chewing and Chemical digestion = enzymes found in saliva
• Pharynx (throat)


  • Epiglottis - Small flap that closes over the opening of the respiratory system when swallowing, preventing food from entering the airway
• Liver


  • Produces bile, a substance that helps break down fats
• Gall Bladder


  • Stores bile produced by the liver
• Stomach


  • Muscular pouch like organ where involuntary muscular churning and chemical digestion occurs
• Pancreas

  • Secretes enzymes to help break down carbohydrates, proteins and fats
• Small Intestine


  • Narrow muscular tube where digestion of food is completed with the help of enzymes secreted by the liver and pancreas
• Villi


  • Little projections in the lining of the small intestine that function in the absorption of digested food
• Large Intestine (colon)


  • Muscular tube where water and salts are absorbed; material spends 18-24 hours here
• Appendix


  • Tube like extension off of the large intestine
• Rectum


  • The last part of the digestive system, feces are eliminated from the rectum through the anus
• Digestive System


  • Muscular – contains smooth muscle
  • Nervous – gets signals that control the rate of digestion
  • Circulatory – broken down food travels through blood vessels to cells
  • Endocrine – hormones (ex. Insulin) control blood sugar levels
• Excretory System


  Eliminates waste products from the body
• Organs/Components of the Excretory System

  • Kidneys
  • Nephron
  • Ureters
  • Urinary Bladder
  • Urethra
  • Skin
  • Lungs
• Kidneys


  • Help maintain homeostasis by filtering blood to remove waste
• Nephron


  • Tiny filter that makes up the kidney, there are millions
• Excretory System


  • Circulatory – waste products are carried from the cells to the kidney through blood vessels
  • Endocrine – hormones are sent that control water levels and homeostasis
  • Respiratory – expels toxic CO2 out of body
• Respiratory System


  Provides oxygen needed for cellular respiration and removes carbon dioxide from the body
• Organs/Components of the Respiratory System


  • Nose and Mouth
  • Pharynx (Throat)
  • Larynx
  • Trachea (Windpipe)
  • Bronchi (singular: Bronchus)
  • Bronchioles
  • Alveoli
  • Diaphragm
• Respiratory System


  • Circulatory – brings O2 to the cells and CO2 back to the lungs
  • Excretory – part of the excretory system to get rid of toxic CO2 from the body
• Circulatory System


  Brings oxygen, nutrients and hormones to cells; fights infections; removes cell wastes; regulates body temperature
• Organs/Components of the Circulatory System

  • Heart
  • Blood Vessels
  • Arteries
  • Red Blood Cells
  • White blood cells
  • Platelets
  • Plasma
• Circulatory System


  Connected to almost all other systems since the circulatory system carries oxygen to all cells
• Skeletal System


  Supports the body; protects internal organs; allows movement; stores mineral reserves; provides blood cell formation
• Organs/Components of the Skeletal System

  • Bones
  • Red Marrow
  • Yellow Marrow
  • Joints
  • Cartilage
  • Ligaments
  • Tendons
• Skeletal System


  • Muscular system – bones and muscles work together for movement
  • Circulatory system and immune system – all blood cells (red and white) are made in the bone marrow
• Muscular System


  Produces voluntary movement; circulates blood, moves food through digestive system
• Organs/Components of the Muscular System

  • Cardiac Muscle
  • Skeletal Muscle
  • Smooth Muscle
• Muscular System


  • Works closely with the skeletal system
  • Circulatory – brings O2 to muscles and waste products such as lactic acid away
  • Nervous – how muscles contract
• Nervous System


  Recognizes and coordinates the body's response to changes in its internal and external environments
• Organs/Components of the Nervous System


  • Neurons (Nerve Cells)
  • Brain
  • Spinal Cord
  • Central Nervous System
  • Peripheral Nervous System
• Neurons (Nerve Cells)

  • Basic unit of structure and function of the nervous system; Long cell with 3 regions: Cell body, Dendrites, Axon
• Nervous System

  Works closely with the digestive system and muscular system
• Integumentary System

  Barrier against infections and injury; regulates body temperature; protects against ultraviolet radiation
• Organs/Components of the Integumentary System

  • Skin (Epidermis and Dermis)
  • Hair, Skin and Nails
  • Pigment of skin and hair
  • Sweat
  • Oil Glands
• Integumentary System

  Contains blood vessels and nerves
• Immune System

  Helps protect the body from disease; collects fluid lost from blood vessels and return it to the circulatory system