Human Body Systems

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Human Body Systems
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Key Ideas

• How do the skeletal and muscular systems help the
  body maintain homeostasis?
• How does the integumentary system help the body
  to maintain homeostasis?
• How do the nervous and endocrine systems help the
  body to maintain homeostasis?
• How do the digestive and excretory systems help
  the body maintain homeostasis?
• How do the circulatory and respiratory systems
  help the body to maintain homeostasis?

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Skeletal/Muscular Systems

• These systems enable movement and provide support
  and protection for tissues and organs.
• Skeletal system has 5 main functions
• Support (give body shape and structure)
• Protection (protect internal organs)
• Movement (joints allow for motion)
• Mineral storage (calcium, phosphorus)
• Blood cell production (marrow)

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How do Muscles Cause Bones to Move?

• Muscles are attached to bones by tendons.
• Tendons are strips of very strong, flexible
  connective tissue.
• Pairs of muscles cause bones to move- one pair
  pulls and one pair pulls the other way (when one
  contracts the other relaxes).

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Three Main Kinds of Muscle Tissue

• Skeletal- are voluntary, you can control them.
  They help move the body.
• Smooth- involuntary, you cannot control them,
  found in blood vessels, digestive system,
  bladder.
• Cardiac- involuntary, found in heart, you cannot
  control.

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Integumentary System

• Functions of the skin
• Protection
• Disease prevention
• Temperature control
• Waterproofing

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Nervous System

• Consists of two main parts
• Central nervous system- Brain and spinal cord.
• Peripheral Nervous system- axillary nerves (arms,
  legs).

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The Neuron

• Nerve cells are the largest in the body.

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Types of Neurons

• Motor- transmit messages from the CNS to muscles
  and other organs.
• Sensory- transmit messages from the sensory
  organs to the CNS.

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Endocrine System

• Has five main functions
• Regulate metabolism.
• Maintain salt, water, and nutrient balance in the
  blood.
• Control responses to stress.
• Regulate growth, development, reproduction.
• Produce hormones.

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Digestive System

• The process of breaking down foods into molecules
  that the body can use.
• Uses both chemical and mechanical means.

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Excretory System

• The removal of metabolic wastes.
• Metabolic wastes include water, salts, CO2,
  nitrogenous wastes.
• Main organs are Kidneys, Ureters, and Bladder,
  and Lungs.

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Respiratory System

• The Respiratory System brings Oxygen into the
  body and and carries Carbon Dioxide out of the
  body.
• The Lungs are the main organs of the Respiratory
  System.

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Cardiovascular System

• What Is the Cardiovascular System?The heart,
  blood vessels, and blood make up the
  cardiovascular system.The cardiovascular system
  carries nutrients, oxygen, hormones, and wastes
  through the body and distributes heat to maintain
  homeostasis.

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Parts of the Circulatory System

• Arteries- carry blood away from the heart.
• Veins- carry blood to the heart.
• Capillaries- exchanges gases and nutrients from
  vessels to cells.

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The Immune System

• Disease is caused by a disruption in a human body
  system that leads to a corresponding disruption
  in homeostasis.
• Disease falls into two categories
• Infectious, can be transmitted from one organism
  to another. Infectious diseases are caused by
  pathogens.
• Non-infectious, cannot be transmitted from one
  organism to another.
• Pathogens can spread disease by air, contact with
  contaminated objects, ingesting contaminated
  food, by contact with a vector.
• A vector is an intermediate organism that
  transfers a pathogen from one organism to
  another.

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• We can avoid disease by practicing
• Good hygiene
• Living a healthy lifestyle
• Eating completely cooked meat
• Getting enough sleep
• Exercising
• Eating a balanced diet
• Drinking plenty of water

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How does the Immune System Work?

• Key Concept The Immune System consists of
  Organs, Cells, and Molecules that fight
  infection.
• Your body has organs, cells, and tissues that
  protect you from pathogens.
• The body system that fights off infection is the
  Immune System.

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Immunity

• Bodily Defenses
• Skin- is the bodies 1st line of defense.
• Skin prevents pathogens from entering the body.
• Oil/sweat make it difficult for pathogens to
  survive on the skins surface.
• Pathogens enter the body through openings in the
  skin (cuts, scrapes), eyes, nose , mouth, and
  ears.
• Tears, mucous, and tiny hairs help to trap and
  remove pathogens.