80 
ANATOMY. 
of the os hyoides. Its use is to pull the os 
hyoides downward, or the thyroid cartilage 
upward. 
3. The crico-thyroideus arises from the 
side and fore part of the cricoid cartilage, and 
is inserted by two portions ; the first into the 
lower part of the thyroid cartilage; the se- 
cond into its inferior cornu. Its use is to puli 
forward and depress the thyroid, or to elevate 
and dr..w backward the cricood cartilage. 
Muscles situated between the lower jazv and 
os hyoides laterally. 
They are five in number. Three proceed 
from the styloid process of the temporal bone, 
from which they have half of their names; 
and two from the pterygoid process of the 
sphenoid bone. 
The three from the styloid process are, 
1. The stylo-glossus arises chiefly from 
the styloid process, and is inserted into the 
root, side and tip of the tongue. Its use is to 
draw the tongue laterally and backward. 
2. The stylo-hyoideus arises from the infe- 
rior part of the styloid process, and is inserted 
into the os hyoides between its base and cor- 
nu. Its use is to pull the os hyoides to one 
side and a little upward. 
3. The stylo-pharyngeus arises from the root 
of the styloid process, and is inserted into the 
side of the pharynx and back of the thyroid 
cartilage. 
The two from the pterygoid process are, 
1 . The circumfiexus, or tensor palati, arises 
chiefly from the spinous process of the sphe- 
noid bone, then runs over the hook of the in- 
ternal pterygoid process, and spreads into a 
broad membrane, which is inserted into the 
velum pendulum palati. Its use is to stretch 
the velum. 
2. The levator palati arises chiefly from 
the extremity of the pars petrosa of the tem- 
poral bone, and is inserted into the velum 
pendulum palati. Its use is to draw the ve- 
lum upward and backward. 
Muscles situated about the entry to the fauces. 
There are two on each side, and a single 
©nr: in the middle* 
The- two on each side are, 
1. The constrictor isthmi faucium arises 
from the side of the tongue : thence running 
upwards before the amygdala, it is inserted 
into the middle of the velum pendulum pa- 
lari. Its use is to draw the velum towards 
the root of the tongue. 
2. The patato-p h aryn geus arises chiefly 
from the middle of the velum pendulum pa- 
lati, thence passing within the posterior arch 
behind the amygdala 1 it is inserted into the 
edge of the upper and back part of the thy- 
roid cartilage. Its use is to draw the uvula 
’ and velum downward and backward. 
The one in the middle is. 
The azygos uvulae arises from the extremity 
ef the su ure, which joins the palate bones, 
and is inserted into the tip of the uvula. Its 
use is to raise tiie uvula upwards and for- 
wards. 
Muscles situated on the posterior part of the 
pharynx. 
Of these there are three pair. 
1 . The constrictor pharyngis inferior arises 
from the side of. the thyroid, and from the 
cricoid cartilage, and is inserted into the white 
line on the middle of the pharynx. Its use 
is to compress that part of the pharynx which 
it covers. 
2. The constrictor pharyngis medius arises 
chiefly from the appendix and cornu of the 
cs hyoides, and is inserted into the middle ot 
the cuneiform process of the os occipitis, and 
is joined to its fellow at a white line in the 
middle back part of the pharynx. Jts use is 
to compress that part of the pharynx which 
it covers. 
3. The constrictor pharyngis superior arises 
above from the cuneiform process of the os 
occipitis lower down, from the pterygoid pro- 
cess of the sphenoid bone, and from the up-' 
per and under jaw, near the last dentes mo- 
lares. It is inserted into a white line in the 
middle of the pharynx. Its use is to com- 
press the upper part of the pharynx. 
Muscles situated about the glottis. 
They consist generally of four pair of small 
muscles, and a single one. 
1. The cryco-ary frenoideus posticus arises in 
the back part of the cricoid cartilage, and is 
inserted into the posterior part of the base of 
the arytenoid cartilage. Its use is to open 
the rirna glottid is. 
2. The crico-arytanoideus lateralis arises 
from the cricoid cartilage laterally, and is in- 
serted into the side of the base ot the aryte- 
noid cartilage. Its use is to open the rnna 
glottid is. 
3. The thyreo-arytsenoideus arises from the 
under and back part of the middle of the thy- 
roid cartilage, and is inserted into the aryte- 
noid cartilage, higher up than the crico-ary- 
taenoideus lateralis. Its use is to pull the 
arytenoid cartilage forward. 
*4. The arytarioideus obliqnus arises from 
the base of one arytenoid cartilage and cross- 
ing its fellow, is inserted near the tip of the 
other. When both act, they pull the aryte- 
noid cartilages towards each other. 
The single muscle is, 
The arytienoideus transversus arises from 
the side ot one arytenoid cartilage, and is 
inserted in the same manner into tiie other. 
Its use is to shut the rima glottidis. 
Besides these there are a few disgregated 
muscular fibres on each side, which, from 
their general direction, are named the thyreo- 
epiglotlidei, and arytano-epiglottidei. 
Muscles situated in the fore part of the ab- 
domen. 
These consist of three broad layers on each 
side; always a long one, and generally also 
a short one, on each side the linea alba. 
The three layers are, 
1. The obliques descendens externus arises 
by eight heads from the lower edges of an 
equal number of inferior ribs at a little dis- 
tance; from their cartilages, and is inserted 
into the whole length of the linea alba, and 
into the anterior extremity of the os ilium. Its 
use is to support and compress the' abdomen, 
and to bend the loins. 
2: The obliquus ascenders interims arises 
from all the spine of the ilium, from the os 
sacrum, the three undermost lumbar verte- 
brae, and from Poupart’s ligament. It is in- 
serted into the cartilago ensiformis, and into 
the cartilages of the seventh and those of all 
the false ribs. Its -use is to assist the former, 
but to bend the trunk in an opposite direc- 
tion. 
3. The transversalis arises from the inner 
part of the cartilages of the seven lower ribs, 
from the spine of the os ilium internally, and 
from the tendon of the external oblique mus- 
cle. It is inserted into the cartilago ensi- 
formis, and into the whole length of the linea 
alba. Jts use is to compress the abdominal 
viscera. 
The long muscle in the middle is 
The rectus abdominis, which arises from 
the symphysis pubis, and is inserted into the 
cartilages of the three inferior true ribs. Its 
use is to compress the fore part of the belly, 
and to bend the loins. 
The short muscle in the middle is the I 
pyramidalis arising along with the rectus, and 
inserted into the linea alba, half-way between 
the os pubis and umbilicus. Its use seems to 
be to assist the rectus. 
Muscles about the male organs of generation, j 
Each of the testes has one muscle. 
The cremaster arises from the lower part ] 
of the internal oblique, and after having 
pierced the ring of the external, descends 
upon the spermatic chord, and is inserted I 
into the tunica vaginalis of the testis. Its usp 
is to elevate that gland. 
The penis has three pairs of muscles. 
1 . The erector penis arises from the tu- 
berosity of the ischium, and is inserted into 
the membrane covering the corpora cavernosa | 
penis. Its use is to compress the crus penis. 
2. The accelerator urinae, or c-jaculator 
seminis, arises from the sphincter ani and 
membranous part of tire urethra, and from 
the crus penis. It is inserted into a line in 
the middle of the bulb. Its use is to drive 
the urine or semen forward. 
3. Transversus perinei arises from the 
tough fatty membrane covering the tuberosity ; 
of the. ischium, and is chiefly inserted into the j 
accelerator urinax Us use is to dilate the ; 
bulb. 
There is often a fourth muscle named 
4. Transversus perinei alter, which arises j 
behind the former, runs more forward, and is 
inserted into the fore part of the accelerator | 
u rinse. Its use is to assist the former. 
Muscles of the anus. 
The anus has a single muscle, and one I 
pair. The single muscle is ' 
Tiie sphincter ani, which arises from the , 
skin and fat surrounding the verge of the 
anus, and is inserted, before, into the peri- 
neum, aeceleratores urinae, and transversi 
perinei ; behind, into the extremity of the 
os coccygis. Its use is tb close the anus. 
The levator ani arises extensively within 
the pelvis, and is inserted into the sphincter 
ani, &c. Its chief use is to draw the rectum 
upward. 
Muscles of -the female organs of generation. 
The clitoris has one pair. 
The erector clitoridis arises internally from 
the crus of the ischium, and is inserted into 
the crus and body of the clitoris. Its use is 
to draw the clitoris downward and backward.. 
The vagina has one pair. 
The sphincter vagina- arises from the • 
sphincter ani, and from the back of the va- 
gina, and is inserted into the crus and body 
of the clitoris. Its use is to contract the 
mouth of the vagina. 
The transversus perinei, sphincter ani, ansE 
