<p>REFLEX ACTION MECHANISM, for instance, patellar reflex = knee-jerk</p><p>Striking the patellar tendon with a reflex hammer [4] just below the patella [11] stretches [1] the quadriceps muscle. This produces a signal (an afferent [9] impulse) which travels back, through a sensory neuron, to the spinal cord [3] and synapses [5] in the spinal cord, completely independent of any higher centre [10]. From there, a motor neuron [6] conducts an efferent [8] impulse back to the quadriceps muscle, triggering [7] contraction. This contraction, coordinated with the relaxation of the flexor hamstring [2] muscle causes the leg to kick. This reflex is a reflex of proprioception [12] which helps maintain posture and balance, allowing to keep one's balance with little effort or conscious thought. The patellar reflex is a clinical and classic example of the monosynaptic reflex arc. The bipolar sensory neuron synapses directly on a motor neuron in the spinal cord. </p><p>1.- To pull something so that it becomes longer 7.- To make something function 2.- A muscle at the back of the upper part of your leg 8.- An impulse that comes 3.- A set of nerves that connect the brain to other nerves 9.- An impulse that goes in the body (it's made of gray and white matter) 4.- A tool with a rubber part at the top that a doctor uses 10.- The brain, for instance to hit a tendon and test a reflex 5.- To establish a connection between nerve cells 11.- The kneecap or knee bone 12.- Perception of your own position or 6.- A nerve cell that conducts an impulse movement THE FIVE SENSES</p><p>STIMULUS Receptor Type Organ Sense</p><p>Cones and rodes Light Photoreceptors Eye Sight or vision in the retina.</p><p>Sound Receptor cells in Inner ear Hearing or audition vibrations cochlea.</p><p>Contact, Receptors and Mechanoreceptors pressure or nerve endings of Skin Touch puncture the dermis.</p><p>Specific Changes of receptors in the Thermoreceptors Skin Touch temperature dermis.</p><p>Substances Receptor cells in Olfactory dispersed in the olfactory Smell epithelium the air epithelium Chemoreceptors Molecules Receptor cells in dissolved in Tongue Taste taste buds water or saliva</p>