Question

Donna does not feel the wound of her knee. In a normal situation, describe how this sensory input of a scraped knee wound result in the feeling of pain.

Answer 1

• When there is a wound on a knee , causes tissue damage , which is registered by microscopic pain receptors (nociceptors) in the skin.
• Each pain receptor forms one end of nerve cell and it is connected other end of spinal cord by a long nerve fiber or a axon .When pain receptor is activated , it send electrical signals up the nerve fiber.
• The nerve fiber bundled to form a peripheral nerve , through which electrical signal passes within the neuron and reach at the spinalcord in the neck.
• At the dorsal horn of spinal cord , electrical signals are transmitted from one neuron to another across junction ( synapses) by means of chemical messengers ( neurotransmitter).Signals are passed from spinal cord to brain.
• At the brain , signal pass into thalamus, which is the main sensory relay station.Signals are sent to the somatosensory cortex (responsible for physical sensation), the frontal cortex (in charge of thinking), and the limbic system (linked to emotions).
• At the end result , feeling of sensation of pain in the knee.
• If there is any damage to any of these sensory inputs, there will absence of pain.