Chapter 10: The Human Nervous System

• What is a Stimulus?

  A stimulus is a signal or event that triggers a response in an organism.
• What can a stimulus be?

  A change in the environment
• What is the Stimulus detected by?

  A Receptor
• What is a Receptor?

  Detect the change in the environment and start a signalling process within the body
• Where are Recptors found?

  All over the body
• What is a Receptor's signal picked up by?

  A neurone (nerve cell)
• What is a Neurone (Nerve Cell)?

  A specialized cell that transmits electrical signals in the nervous system.
• What are the 3 types of neurone (nerve cell)?

  • Sensory Neurone
  • Relay Neurone
  • Motor Neurone
• What is the sensory neurone?

  Carries the signal in the form of an electrical impulse to the central nervous system (CNS).
• What is the relay neurone?

  (in the CNS)

  Relays the electrical impulse from the sensory neurone to the appropriate motor neurone.
• What is the motor neurone?

  Anothe type of nerve cell that carries the electrical impulse from the CNS to an effector.
• What is an Effector?

  A muscle or gland that brings about an action n respnse to the change in the internal or external environment.
• What is the response?

  Any action that helps the organism to avoid the harmful situation.
• What is the Central Nervous System (CNS)?

  the part of the nervous system where information is processed.

  The brain & the spinal cord
• What are the coordination centres?

  Areas that recieve and process information from receptors.
• What is homeostasis?

  The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function, in response to internal and external changes
• What is a nerve?

  A bundle of hundreds or even thousands of neurones
• What are neurones?

  Basic cells of the nervous system that carry minute electrical impulses around the body
• What is a reflex arc?

  They bring about reflex actions. They involve the sense organ, sensory neurone, relay neurone and motor neurone
• What is a reflex?

  A rapid automatic response of the nervous system that does not involve concious thought.
• What is the endocrine system?

  A system of glands that produce and secrete hormones into the bloodstream to regulate various bodily functions.
• What is the receptor that detects Light?

  Eyes
• What is the receptor that detects sound?

  Ears
• What is the receptor that detects Temperature?

  Skin
• What is the receptor that detects Pain?

  Skin
• What is the receptor that detects Smell?

  Nose
• What is the receptor that detects Taste?

  Toungue/Nose
• What are examples of sense organs?

  • Eye
  • Ear
  • Nose
  • Skin
• What are examples of Effectors?

  • Salivary Glands
  • Skeletal Muscles
  • Pancreas
• What are examples of Coordinators?

  • Brain
  • Spinal Cord
• What does a Relay Neurone look like?

  A relay neuron, also known as an interneuron, is a type of neuron that connects sensory neurons to motor neurons. It has a cell body with dendrites and an axon.

  CNS —> CNS

  
• What does a Motor Neurone look like?

  A motor neuron has a cell body, dendrites, and an axon.

  CNS —> Effector

  
• 1. Dendrite
  2. Soma
  3. Nucleus
  4. Axon
  5. Myelin Sheath
  6. Schwann Cell
  7. Node of Ranvier
  8. Axon Terminal

  Label the parts of a nerve cell (Neurone)

  
• What does a Sensory Neurone look like?

  A sensory neuron has a cell body with long extensions called dendrites and an axon.

  Receptor —> CNS

  
• What is the order of the Nervous System?

  Stimulus —> Receptor —> Sensory Neurone —> Relay Neurone —> Motor Neurone —> Effector —> Response
• 1. Stimulus
  2. Receptor
  3. Sensory
  4. Cell Body of Sensory Neurone
  5. Relay
  6. Synapse
  7. Spinal Cord
  8. Motor
  9. Muscle


  Label the Reflex Arc

  
• Is a Reflex Action a conscious thought?

  No. You don't have to think about it.
• Examples of Reflex Actions

  • Blinking - prevents dust from getting in our eyes (infection)
  • Sneezing - Moves bacteria out of lungs (infection)
  • Flinching - Move away from danger
  • Gag Reflex - Stop choking
  • Squinting - Protects retina
  • Pupil Dialation/Contraction- Protects retina
• Describe the Reflex Arc:

  While walking barefoot, Mark trod on a pin. He immediately lifted his foot up to take his weight off of the pin.

  Pain from pin —> Skin —> Sensory Neurone —> Relay Neurone —> Motor Neurone —> Muscle in leg —> Lifts foot off ground
• What are Synapses?

  Tiny gaps between neurones