Week 5 - Autonomic nervous system/mechanisms of pain

• Mechanoreceptors • Chemoreceptors • Thermoreceptors • Nociceptors • Photoreceptors • Osmoreceptors • Proprioceptors

• Detects change in position of receptor - Stretch, pressure, touch

• Detect change in concentration of chemicals - C02, glucose

• Detect change in temperature - Hot/cold

• Detects tissue damage - Burns/trauma

• Detects change in light - Only found in the retina of the eye

• Detects change in osmotic pressure (blood pressure) - Found in the hypothalamus

• Its the sense of orientation or body position, so that means you can locate a body part without looking at it • Helps maintain posture and coordination of body movement

• Touch • Pain • Temperature • Vibration • Motion (Proprioceptors)

• Acute • Chronic • Somatic • Visceral • Referred • Phantom

It begins suddenly and is usually sharp in quality. It serves as a warning of disease or a threat to the body. Acute pain might be caused by many events or circumstances, including: Surgical Pain. Traumatic Pain, example: broken bone, cut, or burn.

A disease in its own way - not a warning to prevent injury. It has a poor response to pain relief and it persists for months beyond the time of healing

It results from nociceptor activation in the skin tissue and muscle and is activated by pressure and temperature

it results from nociceptor activation of thoracic, pelvic and abdominal organs and is activated by pressure, stretching and chemical changes.

Pain felt in a place different to where it has originated as a result of shared sensory nerve pathways that supply different tissue

Ongoing sensation (Pain, itching, tingling) perceived by the brain to be located in the part of the body no longer there. The person may still experience the sensation (Intermittent or constant) despite amputation.

The decrease in perception of a nerve impulse even though the stimulation is constant

• Receives a continual supply of sensory input from sensory receptors which monitor the internal body environment to achieve homeostasis • Operating via reflex arcs in the hypothalamus, brain stem and spinal cord. • Motor signals are sent to autonomic effectors, which are subconsciously regulated and include • Smooth muscle • Cardiac muscle • Certain glands

The sympathetic and parasympathetic nervous systems

• The autonomic nervous system is a component of the peripheral nervous system that regulates involuntary physiologic processes including heart rate, blood pressure, respiration and digestion • It contains three anatomically distinct divisions: sympathetic, parasympathetic and enteric.

- Decreased myelin so conduction of impulses slows (NI = Voluntary movements slow, Reflexes reactions slower and less intense and Slower at processing of thoughts • Loss of some synaptic connections (NI= Memory is reduced and takes longer to learn new information) • Size & volume of the brain reduces (NI= Motor control of precise movements diminishes which means it takes longer to carry out actions and more prone to falls) • Autonomic NS becomes less efficient (NI= Blood pools in the feet/legs. Vasoconstriction delayed, so the older person may feel dizzy, unless they get up slowly)