quadriceps femoris muscle: Quick Facts

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Illustration of the human leg from the front showing major muscles, tendons, and ligaments of the thigh and lower leg, each labeled for anatomical reference.

Diagram showing the anterior view of human leg muscles, highlighting the rectus femoris muscle as a bipennate fibred muscle, the extensor digitorum longus as a unipennate fibred muscle, and the tibialis anterior muscle as a parallel fibred muscle, with muscle fibers and tendons labeled.

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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