General Sensory Mechanisms II Flashcards
What are the three physiological types of somatic senses?
Mechanoreceptive
Thermoreceptive
Pain
What is exteroreceptive sensation?
Sensation that is from the surface of the body
What are proprioceptive sensations?
Sensations that refer to the physical state of the body. They include:
Position sensations
Muscle and tendon sensations
Pressure sensations
Equilibirum
What are deep sensations?
Sensation to deep pressure, pain and vibrations.
What are the three physiological types of somatic senses?
Mechanoreceptive
Thermoreceptive
Pain sense
What are visceral sensations?
Sensations of the body, specifically to sensations from internal organs.
What are the three differences among touch, pressure and vibration?
- Touch sensation generlly results from the stimulation of tactile receptors in the skin or tissues immediately beneath the skin.
- Pressure sensation generally results from the deformation of deeper tissues.
- Vibration sensation results from rapidly repetitive sensory signals, but some of the same types of receptors as those for touch and pressure are used.
What are the three neuron pathways?
Primary sensory neurons
Secondary neurons
Tertiary neurons
Where do primary sensory neurons arise from?
External receptors.
They travel through the dorsal roots of the spinal cord.
What do primary sensory neurons synapse with?
Secondary neurons
Where are seconday neurons comprised of?
Tracts in the spinal cord and brainstem.
Where do secondary neurons usually terminate?
In the thalamus.
What do secondary neurons synapse with?
Tertiary neurons.
What is the route of tertiary neurons?
From the thalamus to the primary sensory cortex.
What do tertiary neurons travel through in order to get from the thalamus to the primary sensory cortex?
The internal capsule
What are the two ascending pathways?
A pathway for conscious perception
A pathway for unconscious perception
What are the two pathways of conscious perception?
Spinothalamic system
Medial lemniscal system
What are the four pathways of unconscious perception?
Spinocerebellar
Spino-olivary
Spinotectal
Spinoreticular
What are the two tracts in the spinothalamic system?
Lateral spinothalamic tract
Anterior spinothalamic tract
What sensations are carried by the lateral spinothalamic tract?
Pain and temperature
Where does the lateral spinothalamic tract go before synapsing with secondary fibers?
It ascends or descends 1-2 spinal cord segments before synapsing with secondary fibers.
What does the term “decussate” mean?
To cross over
What kinds of axons make up the lateral spinothalamic tract traveling in the lateral column of the spinal cord?
Secondary aons