Neurons and the main parts of the brain

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Neuron drawing (model, not to scale): one neuron, with four parts marked W to Z. branching extensions that receive messages from other neurons; holds the nucleus and the other organelles of the neuron; a long, tube-like fiber that carries the impulse away from the cell body; an insulating wrap around part of fiber Y that speeds the impulse.

2. 1.

   Ari reads a neuron drawing. The job column says part Y is a long, tube-like fiber that carries the impulse away from the cell body. What is part Y?

   • The axon
   • The myelin sheath
   • The dendrites
   • The cell body

3. Use this

   Neuron drawing (model, not to scale): one neuron, with four parts marked W to Z. Part | letter | job: ? | W | branching extensions that receive messages from other neurons; cell body | X | holds the nucleus and the other organelles of the neuron; axon | Y | a long, tube-like fiber that carries the impulse away from the cell body; axon terminals | Z | endings at the far end of the fiber that release chemicals onto the next cell.

4. 2.

   Bo reads the neuron drawing. The job column says part W has branches that receive messages from other neurons. What is part W?

   • The axon
   • The cell body
   • The dendrites
   • The axon terminals

5. Use this

   holds the nucleus and the other organelles of the neuron; an insulating wrap around part of fiber Y that speeds the impulse; a long, tube-like fiber that carries the impulse away from the cell body; endings at the far end of the fiber that release chemicals onto the next cell.

6. 3.

   Esme studies another neuron. The job column says part Z sits at the far end and releases chemicals onto the next cell. What is part Z?

   • The dendrites
   • The myelin sheath
   • The axon terminals
   • The axon

7. Use this

   Brain drawing (model, not to scale): a side view of the brain, with the spinal cord leaving below and four parts marked W to Z. Part | letter | job: cerebrum | W | the large, folded top part; handles thinking, the senses and planned movement; cerebellum | X | the small ridged part at the back, under the top part; helps with balance and coordination; ? | Y | the stalk that links the brain to the spinal cord; helps keep breathing and heart rate going; spinal cord | Z | a long column of nerve tissue in the backbone that passes messages between the brain and the body.

8. 4.

   Kira reads the brain drawing. The job column says part Y is the stalk that links the brain to the spinal cord and helps keep breathing going. What is part Y?

   • The cerebellum
   • The brainstem
   • The spinal cord
   • The cerebrum

9. Use this

   branching extensions that receive messages from other neurons; holds the nucleus and the other organelles of the neuron; a long, tube-like fiber that carries the impulse away from the cell body; endings at the far end of the fiber that release chemicals onto the next cell.

10. 5.

    Milo reads a labeled neuron drawing. Which job belongs to part Z, the axon terminals?

    • It wraps the fiber to speed the impulse
    • It releases chemicals onto the next cell
    • It holds the nucleus of the neuron
    • It receives messages from other neurons
12. 6.

    Noah reads a labeled brain drawing. Which job belongs to part X, the cerebellum?

    • It helps with balance and coordination
    • It keeps breathing and heart rate going
    • It does the thinking and stores memories
    • It links the brain to the spinal cord
13. 7.

    Pia reads the labeled brain drawing. Which job belongs to part Y, the brainstem?

    Use the picture in question 6.

    • It helps with balance on a bike
    • It stores memories and plans thoughts
    • It helps keep breathing and heart rate going
    • It plans the movement of the fingers
14. 8.

    Signal path in one neuron (model, not to scale). Ren traces a signal through one neuron. Which part goes in the blank box?

    • The myelin sheath
    • The cell body
    • The axon terminals
    • The next neuron
15. 9.

    “(model, not to scale). Boxes in order:” Tala brushes a hand against a prickly pinecone, and the hand pulls away. Which neuron goes in the blank box?

    • A muscle fiber
    • A glial cell
    • A motor neuron
    • A sensory neuron
16. 10.

    Zee watches the reflex path after a hand pulls away from a pinecone. Which neuron carries the message out from the spinal cord to the muscle?

    • A motor neuron
    • A glial cell
    • A sensory neuron
    • A receptor