knee: Quick Facts

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Photos

An anatomical diagram comparing the human and bird (chicken) knee joints. The human skeleton highlights the knee area, with a detailed close-up showing the femur, tibia, patella, ligaments (ACL, PCL, patellar), meniscus, cartilage, tendons, and surrounding muscles. A smaller chicken skeleton also highlights the knee for structural comparison.

X-ray image showing a total knee replacement with a visible artificial joint implanted between the femur and tibia.

Medical illustration of a human knee joint in a parasagittal section just lateral to the midline, labeling ligaments, cartilage, meniscus, patella, synovial structures, and surrounding muscles and fat pads.

Diagram showing the knee jerk reflex: a reflex hammer strikes the patellar tendon below the knee, activating a stretch receptor in the quadriceps muscle. This sends a signal through a sensory neuron to the spinal cord, where it connects to a motor neuron. The motor neuron then signals the muscle to contract, causing the lower leg to kick forward. The diagram also illustrates the pathway of sensory and motor neurons and their connection in the spinal cord.

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Superficial arteries and veins of face and scalp, cardiovascular system, human anatomy, (Netter replacement project - SSC)

The Human Body

Muscles of facial expression, human anatomy, (Netter replacement project - SSC). Human face, human head.

Characteristics of the Human Body

Muscles of facial expression, human anatomy, (Netter replacement project - SSC). Human face, human head.

Characteristics of the Human Body

Male muscle, man flexing arm, bicep curl.

Facts You Should Know: The Human Body Quiz