Card Set Information
What does the the somatosensory system do?
tells us what the body is up to and what's going on in the environment by providing bodily sensations such as
What are the two different kinds of skins?
Hairy skin and Glabrous skin.
What is glabrous skin?
Skin that does not have hair follicles but contains lager numbers of sensory receptors than do other skin areas.
What is hapsis?
Hapsis is the ability to identify objects with touch. It is the perception of fine touch and pressure.
What is proprioception?
It is the perception of the location and movement of limbs/ body.
What is nociception?
Perception of pain and temperature.
What does a rapidly adapting receptor do?
It responds briefly to the beginning and end of a stimulus on the body.
What does a slowly adapting receptor do?
It responds as long as the sensory stimulus is on the body.
Where does input go into the spinal cord?
What is a dorsal-root ganglion neuron?
They carry sensory information from the skin to the central nervous system.
What are the characteristics of proprioceptive and haptic neurons?
They are large and well-myelinated axons. Fast
What are the characteristics of nociceptive neurons?
They are small axons with little or no myelination and are slow.
What is deafferentation?
Loss of incoming sensory input usually due to damage to sensory fibers.
The dorsal spinothalamic track takes what kind of information?
Haptic and proprioceptive information
How does the dorsal spinothalamic track go?
Axons from dorsal- root ganglion neurons enter the spinal cord and ascend until they synapse in the dorsal column nuclei. They cross over at the brainstem
What kind of information does the ventral spinothalamic tract carry?
It cares nociceptive information.
How does the ventral spinothalamic tract go?
Axons from the dorsal-root ganglion neurons enter the spinal cord. They synapse onto another neuron which crosses over right away in the spinal cord to the contralateral side. Than to the brain.
What are the stimuli for pain?
prostaglandin and substance p
Where do the pain impulses go?
To the dorsal horn.
What is a pain gate?
A neural circuit in which activity in haptic pathways diminishes the activity in nociceptive pathways.
What are the two different types of pain?
Fast bright pain and slow nagging pain.
What is referred pain?
Pain felt on the surface of the body that is actually due to pain in one of the internal organs.
What are the painkilling chemicals in the brain and nervous system?
opioid peptides or endorphins
How were endorphins studied?
Through the use of naloxone.
how do endorphins inhibit pain?
They inhibit the release of substance P
What are the vestibular organs?
the 3 semicicirular canals and otolith rogans
What do the vestibular organs allow you to do?
They allow you to sense gravity, tells you the position of the body in relation to gravity, and signal changes in direction and speed of movements of the head.
What are the two main somatosensory areas in the cortex?
The primary somatosensory cortex and the secondary somatosensory cortex.
What is the somatosensory homunculus?
representaion of the somatic sensory system in the cortex. Operates horizontally. Functions controlled vertically. Hands and face have the most innervation.
What does the secondary somatosensory cortex do?
Involved in integrating information from the sensory and motor systems.
What are teh effects of damage to the somatosensory cortex.
results in impaired sensory thresholds, proprioception, hapsis, and simple movements.