Human Body Systems


Human Body Systems

The body systems this page will include are;

  • Digestive System
  • Respiratory System
  • Circulatory System
  • Nervous System
  • Excretory System

  • Main goal: Understanding what each system does and what organs do what. Memorization of organs.

    Digestive System

    Mouth: Saliva in the mouth begins the process of chemically breaking down food, chewing helps physically break down food into smaller pieces.

    Esophagus: A long tube that connects the mouth to the stomach. Food goes down the Esophagus.

    Stomach: In the stomach, specialized acids dissolve the food chemically.

    Small Intestine: Digestive juices break all remaining food, letting the nutrients enter the bloodstream.

    Large Intestine: The remianing matter and water enter the Large Intestine, water is absorbed by stool.

    Food then gets excreted.

    Types of Digestion

    There are 2 types of Digestion.

    Mechanical Digestion: The physical breaking of food, like the teeth and tongue.

    Chemical Digestion: The dissolving of food into nutrients usuable by the body, this is done by Enzymes and stomach acid.

    More Parts

    Pancreas: Helps control sugar levels in blood.

    Liver: Stores useful nutrients, but has many more functions.

    Gallbladder: Aids in digesting fat.

    Peristalsis is how food moves through the body.

    Circulatory System

    2 Circits of the Circulatory System

    The job of the circulatory system is to deliver nutrients from your digestion, to each cell in your body, transport oxygen, and excret.

    This system has 2 CIRCUITS
  • 1. One circut sends blood to the lungs, for gas exchange. The oxygenated blood returns to the heart.
  • 2. The other circuit sends blood from the lungs to the rest of the body. Deoxygenated blood returns to the heart, so it can be sent to the lungs again.

  • Blood Vessels

    Arteries: Vessels that carry blood away from the heart, to all the parts of your body

    Veins: Vessels that carry blood from all the parts of your body to the heart

    Capillaries: Specialized blood vessels that are located between the arteries and the veins that allow the diffusion of nutrients and gasses.

    Blood

    Red Blood Cells: Carries oxygen.

    White Blood Cells: Fights infections.

    Platelets: Cells that help to stop bleeding at a cut.

    Plasma: Transports nutrients to your cells, and carries waste away

    The Heart

    The heart is made up of 4 chambers that pump the blood to different parts of the body.

    Atria: Recieves the blod from veins, are on top, and sends blood to a ventricle.

    Ventricles: Recieves the blood from an Atrium, are on the bottom, and sends blood to arteries.

    Right Side: Recieves deoxygenated blood from the body, sends it to the lungs.

    Left Side: Recieves oxygenated blood from the lungs and then sends it to the body.

    Respiratory System

    Main parts

    Trachea: Brings air from your mouth/nose to your lungs, passage for air.

    Bronchi: Two main branches of the airway (trachea) that lead into the lungs.

    Bronchioles: The bronchi then divides into smaller branches (bronchioles) then finally connecting to tiny alveoli.

    Alveoli: Tiny air-filled sacs in the lungs; the site of gas exchange.

    Lungs: A spongy organ that contains structures.

    Diaphram: Large muscle below the lungs.

    Inhalation
  • Pulls diaphram down
  • Expanding rib cage

  • Exhalation
  • Pulls diaphram up
  • Contracts rib cage

  • Gas Exchange

    When air is inhaled, it travels down the Trachea, into the bronchi, where it enters the lungs. The air travels through bronchioles and ends up in the alveoli.

    Excretory System

    Main parts

    Kidneys: Your body has 2 kidneys. They filter blood.

    Uterers: Each kidney is connected to the bladder, Urterers bring urine to the bladder.

    Bladder: Stores Urine.

    Urethra: Urine is excreted through here.

    Kidneys are made up of tiny filtering units called Nephrons. They have a system that filters out toxins like Urea from the blood. Urea is one of the main waste products.

    Nervous System

    The nervous system is divided into 2 main systems: the Central Nervous System, and the Peripheral Nervous System.

    Peripheral Nervous System

    The peripheral nervous system is divided into 2 main subsystems:
  • The Autonomic Nervous System
  • The Somatic Nervous System

  • Autonomic System: Controls subconcious movement of the body like; sweating, digesting, breathing. Think Automatic!

    Somatic System: Controls voluntary movement of the body. Concious decisions. It connects the Central Nervous System to the skeletal muscles. Also responsible for controlling reflexes.

    The Nervous System is made up of nerves that transmit signals throughout the body. Nerves are composed of neurons. There are 2 important parts of a neuron.
  • Dendrites: Recieves messages
  • Axons: Sends messages

  • Reflexes are involuntary movements that bypass the path to the CNS. For example; when your hand touches a hot stove, your arm will move before your brain tells it to. That's a reflex!