Yarn Brain

I had first planned to make this brain for Halloween, (zombie bait), but the biologist in me wanted to make this anatomically correct so it took me a bit longer to make. I am not a neuroanatomist so I can't guarantee the accuracy of this brain. I made it based on Google image searches which actually proved to be a bit of a challenge since most brain model images are in cross section (sagittal section) so you only see half of it and you need to extrapolate into 3D.

I made my brain all one colour, but if you want to use it as a teaching tool, you can make each of the parts a different colours. Also the midbrain and brain stem is connected to the cortex with a magnet so you can pull it out and see the parts.

Yarn weight 3:

• Pink

Other:

• 2.25mm crochet hook
• Yarn needles
• Small knitting loom (eg. Knitting Nancy or a spool loom)
• Polyfil/fibrefil stuffing of some sort
• Sewing thread and needle
• 22 gauge wire, pliers and a magnet
• Elastic thread (white or pink)

Abbreviations:

Rnd round

ch(s) chain stitch(s)

sc single crochet

sl st slip stitch

st(s) stitch(s)

sc2tog decrease by crocheting 2 stitches together

I made my own spool loom from a small plastics tube, I cut a hole in the bottom and poked four nails into the rim. Knitting with this loom forms a cord with a diameter of approximately one centimetre. (Here is an Instructable on how to make a small knitting loom). I won't go into how to use a loom there are plenty of great instructions available for that (How to Loom Knit)

So with my homemade loom I knitted two lengths of cord approximately one meter in length.

I cut two pieces of elastic thread, roughly half the length of the two knitted cords made in the previous step, about 50cm. I tied one end of the elastic to one of the ends of the cord, threaded the other end of the elastic through the centre of the cord using a yarn needle. The elastic is pulled through the entire length of the cord, out the other end and tied to the yarn tail. This should cause the cord to form folds. Repeat with the other cord.

To form the cerebral cortex you need over 3 million years of human evolution. Though for a yarn cortex some sewing thread and a needle will do. I folded each cord about four times and sewed each length together forming the general shape of each hemisphere, albeit flat. I then lined up each hemisphere side by side and stitched together to top edge, leaving the bottom open, creating a bowl shape.

Make two:
With the pink yarn

Rnd 1: Magic Circle 6 .

Rnd 2: Work 2 sc in each sc around - 12 sts

Rnd 3: *2 sc in next st, sc in next st, rep from * around - 18 sts

Rnd 4: *2 sc in next st, sc in each of next 2 sts, rep from * around - 24 sts.

Rnds 5 -7: Sc in each sc around - 24 sts

Rnd 8: Sc in each sc around - 24 sts

Rnd 9: *sc2tog, sc, sc, sc, sc repeat - 20sts.

Rnd 10: *sc2tog, sc, sc, sc, repeat - 16sts.

Rnd 11: *sc2togsc, sc, sc, repeat -12sts.

Rnd 12: *sc2togsc, sc, repeat -8sts. Stuff

Rnd 13: *sc2tog in rest. Fasten off. Leave tail.

Brain Stem

For the brain stem, use the knitting loom to form a cord approximately 10cm long.

Pons

Make one

Rnd1: Magic Circle 6 6sts

Rnd2: 2sc in sc 12sts

Rnd3: sc insc 12sts

Rnd4: 2sc in first and 6th, sc in sc in rest 14sts

Rnd5: sc insc 14sts

Rnd6: sc2togin first and 6th 12sts

Rnd7: sc in sc 12sts

Rnd8: sc2tog in each 6sts

Rnd9: sc2tog in each. Fasten off. Leave tail. Press flat.

Thalamus

Make two

Rnd1: Magic Circle 6 6sts

Rnd2: 2sc in sc 12sts

Rnd3: 2sc in sc, sc. repeat in rest 18sts

Rnd4: sc in sc 18sts

Rnd5: sc2tog in sc, sc. repeat in rest 12sts

Rnd6: sc2tog in each 6sts. Stuff

Rnd7: sc2tog in rest. Fasten off. Leave tail

Pituitary Gland

Make two

Rnd1: ch2, 3sc in second ch from hook

Rnd2: sc in sc for first, sc2tog next 2, ch3.

Fasten off. Leave tail

Cut two pieces of wire 7.5cm (3 inches) in length. Bend each into a nearly closed circle, with the bottom part flatter and the ends folded back (see image 2 above).

Begin by crocheting: ch2, 3sc in second ch from hook.

Hold the piece you started crocheting in the previous step against the end of the wire and chain stitch around the wire starting at the top. (See these instructions for more information). Continue covering the length of the wire, once you reach the end, turn and sc in each chain for the first 7-8chs, sl st into next chain, tie off and weave in ends. You may need a dab of glue on each end to prevent the yarn from slipping. Repeat with the second wire. Stitch the two pieces together at the top like in image 4 above.

Corpus Callosum

Make one

Rnd1: Magic Circle10 10st(s)

Rnd2-15: sc in sc 10sts

Rnd16: sc2tog in each. Fasten off. Leave tail

Stitch a rare earth magnet to the centre of the corpus callosum.

Now that we have all of the parts, lets assemble.

• First stitch together the two Thalamus (?plural) at an angle, see above.
• Sew the two Pituitary Glands in between the Thalamus.
• Then attach the Thalamus to the top of the Brain Stem.

• Stitch together the Cerebellums the same way you did the Thalamus.
• Wrap the Pons around the Brain Stem, front to back and stitch the Cerebellum to the Pons.
• Place the Hippocampus around the Thalamus and stitch in place.
• Stitch the Corpus Callosum to the inside of the Cerebral Cortex, between where the two hemispheres come together in the middle (magnet facing out).
• Place the Hippocampus against the magnet inside the Cortex, with the Cerebellum at the back. The magnets should hold the two parts together, and can be pulled apart as needed.