Transcript Human Touch and Pain Receptors
Human Touch and Pain Receptors
• Somoesthetic sensations – Sensations associated with skin receptors • Proprioception – Perception and position of the body including limbs
3 Receptor Types
• Mechanoreceptors – Pressure, force, vibration • Thermoreceptors – Temperature • Nociceptors – Tissue damaging stimuli
• Modality – Energy form of stimulus • Sensory neurons convert energy from stimulus into another form of energy.
• Receptor potentials – Graded responses caused by closing and opening of ion channels. – Number activated and frequency of APs generated correlated to stronger stimulus intensity perceived.
• Detect stimuli • Two main forms: – Specialized structure on peripheral end of afferent neuron.
– Separate cell that communicates via chemical synapses with associated afferent neuron.
• Respond to surrounding tissue, not air temp.
• Warm receptors – Respond to temps 35-45 °C – Beyond 45 °C APs decrease rapidly – Above 45 °C nociceptors also.
• Cold receptors – Respond to to temps 20-35 °C – Below 25 °C APs decrease rapidly – Below 10 °C also nociceptors – Also respond to temps above 45 °C • Paradoxical cold receptors
• 3 Types – Mechanical – Thermal – Polymodal
• Brain integrates info from different sensory systems. • Combination of thermoreceptors and mechanoreceptors.
B ody Part Receptor Density (cm 2 )
Fingertip, palm surface Back of finger One eye 60 pain, 100 touch 100 pain, 9 touch 90,000,000!!!!!!!!!
• Write a methods, results, and introduction.
• Answer ALL questions. • This may be done within the results section or introduction. Make sure you include a section with answers to questions that you don’t answer within the intro or results sections.
• You do not have to replicate the figures from the pdf for today. Just staple that to your lab report.
• Successfully establishes the physiological concepts of the lab.
• Effectively presents the objectives and purpose of the lab.
• States hypotheses AND provides logical reasoning for them.