REFLEX ACTION MECHANISM , for Instance, Patellar Reflex = Knee-Jerk

REFLEX ACTION MECHANISM, for instance, patellar reflex = knee-jerk

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.

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

STIMULUS Receptor Type Organ Sense

Cones and rodes Light Photoreceptors Eye Sight or vision in the retina.

Sound Receptor cells in Inner ear Hearing or audition vibrations cochlea.

Contact, Receptors and Mechanoreceptors pressure or nerve endings of Skin Touch puncture the dermis.

Specific Changes of receptors in the Thermoreceptors Skin Touch temperature dermis.

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