64 DISSECTION OF THE NECK. 
2. The Hyoid Bone lies just anterior to the larynx. 
Determine its shape by feeling through the muscles 
covering it. The body is a short transverse bar of 
bone, and from it two horns — posterior cornua — 
may be felt passing posteriorly to the thyroid cartil- 
age of the larynx. “Two longer anterior horns pass 
to the base of the skull to be attached to the temporal 
bone. 
3. The Sterno-mastoid Muscles forma pair of broad 
muscular bands arising from the anterior end of the 
sternum, and passing obliquely forward, diverging 
from each other, to be inserted into the mastoid por- 
tion of the temporal bone. 
Cut these muscles at the sternal insertion, and re- 
flect them forward. 
4. The Sterno-hyoid Muscles, one on each side, lie 
along the ventral mid-line of the neck. Separate the 
two along the mid-line, and the trachea will be ex- 
posed. Each isa flat band arising from the anterior 
end of the sternum and the ist rib, and inserted into 
the hyoid bone. 
Cut the sterno-hyotds at the anterior end and reftect 
backwards. 
5. Sterno-thyroid Muscles, one on each side of the 
neck. Each is a slender band of muscle arising from 
the anterior end of the sternum with the sterno-hyozds, 
and passing obliquely forward to be inserted into the 
side of the thyroid cartilage of the larynx. 
Cut the sterno-thyrords at the antertor end and re- 
Hlect backwards ; the trachea will be fully exposed. 
6. The Thyroid Glands are two oval bodies lying 
one on each side of the trachea just posterior to the 
larynx. Usually these are entirely separated from each 
other (differing in this respect from the same struct- 
