SBI4U1Name: ______________________________

S H E E P  B R A I N   L A B

Purpose:
To study the structure and function of the mammalian (sheep) brain.

References:
"Nelson Biology 12" (chapter 9), dissection charts, models, internet, other texts.

Instructions - External Anatomy:

  1. Obtain a handout with diagrams of the brain from your teacher.

  2. Working in groups of two or three, select a sheep brain. The brain has been cut in half longitudinally (sagitally). Lay the brain flat on the dissecting tray so as to view the external surface.

  3. Identify the external structures indicated below on the brain. Then label the external anatomy diagram with all the structures.

      cerebellum, cerebral hemisphere, spinal cord, medulla oblongata, temporal lobe,
      parietal lobe, frontal lobe, occipital lobe

  4. Complete the table for the major external brain regions.
    STRUCTURE
    FUNCTION
    Frontal lobe

     
    Temporal lobe

     
    Occipital lobe

     
    Parietal lobe

     
    Cerebellum

     
    Medulla oblongata

     
    Cerebral hemisphere

     

  5. Observe the convolutions and fissures (indentations) on the surface of the brain. Define the following terms:
    Sulcus (singular) / Sulci (plural) 
    Gyrus (singular) / Gyri (plural) 

  6. Why does the brain have these sulci and gyri? ______________________________________

  7. What is the general name for the 3 protective membranes that cover the brain?
    _____________________________________________

  8. Which one of these membranes might be found closely adhering to the sheep brain?
    _____________________________________________

Instructions - Internal Anatomy:

  1. Turn the brain over in the dissecting tray so the internal structures are visible.

  2. Identify the internal structures indicated below on the brain. Then label the internal anatomy diagram with all the structures. (Note: the pituitary gland is usually not visible on the sheep brain)

      corpus callosum, medulla oblongata, pituitary gland, ventricle, pons, sulci, gyri, cerebral cortex,
      thalamus, hypothalamus, cerebellum, pineal gland

  3. Complete the table for the major internal brain structures.
    STRUCTURE
    FUNCTION
    Corpus callosum

     
    Cerebral cortex


     
    Thalamus

     
    Hypothalamus

     
    Pons

     
    Pituitary gland

     
    Pineal gland

     


Instructions - Pin Labelling / Worksheet Completion: (       /20 marks)

  1. Obtain FIVE coloured pins. Choose any five structures, internal or external, and gently place a pin in each region of the sheep brain. Be very accurate in your placement.

  2. Bring your completed worksheets/diagrams and your sheep brain with pins inserted to your teacher for a group evaluation. You will be evaluated on correct placement of your pins and the ability to state the function of each part (without use of worksheets). Your teacher will also ask you to identify THREE other structures and functions.

  3. After your evaluation, wash off the pins, return the brain to the bin, wash all equipment including the dissection tray and then wash your hands.