THE JOINTS. 
rod 
4 
wal 
one, extends from the internal tuberosity of the femur to 
the internal tuberosity of the tibia. 
sular ligaments must be cut in order 
to see the crucial ligaments, which 
are short, and cross each other in 
the region of the intercondylar notch. 
The posterior crucial extends from 
the caudal margin of the head of 
the tibia to the mediocranial angle 
of the intercondyloid notch of the 
femur. The anterior crucial extends 
from the summit of the tibia to the 
caudolateral angle of the intercondy- 
loid notch. The tibio fibular ligament 
is very short, extending from the 
head of the fibula to the outer tu- 
berosity of the tibia. In addition to 
these ligaments, there are four 
bands uniting the menisci to the 
bones. The menisci or semilunar 
cartilages are two biconcave car- 
tilaginous plates, about one milli- 
meter thick, interposed between the 
condyles of the femur and tibia. 
The synovial membrane isa very 
thin transparent sheet lying within 
the capsular sheath of the joint. It 
secretes the white glairy synovia. for 
lubricating the joint. The synovial 
fluid and membrane may be demon- 
strated by cutting open a fresh joint 
The anterior and cap- 
Fic. 46. CaupaLt ASPECT 
OF KNEE-JOINT WITH 
CaPpsuLAR LIGAMENT 
Cut. 
ac, Anterior crucial liga- 
ment; ar, articular sur- 
face of condyle of 
tibia; cn, condyle of 
femur; cp, capsular 
ligament cut along the 
line Jg and reflected 
proximad ; ex, external 
lateral ligament; fb, 
fibula; fm, femur; in, 
internal lateral liga- 
ment; Ig, cut edge of 
capsular ligament; pc, 
posterior crucial liga- 
ment; pl, posterior ex- 
ternal ligament of the 
meniscus; sm, medial 
or internal meniscus; 
sme, lateral or exter- 
nal meniscus; ¢f, tibio- 
fibular ligament; 1b, 
tibia. 
obtained from the butcher-shop (Fig. 44). 
All other freely movable joints are similar in structure to 
the knee-joint, but have no menisci and fewer ligaments. 
