Nervous System Physiology Part 6 Flashcards
How many separate sensory areas are located in the anterior parietal lobe? What are they called?
There are two separate sensory areas:
* Somatosensory area I
* Somatosensory area II
What is the reason for the division into somatosensory area I and area II?
There is a distinct and separate spatial orientation of the different parts of the body in each of these two areas.
Which somatosensory area is more extensive and of much more importance for somatosensory perception? What term often refers to this area?
Somatosensory area I. In popular usage, the term “somatosensory cortex” almost always means area I.
What side of the body does each lateral side of the somatosensory cortex primarily receive sensory information from?
Almost exclusively from the opposite side of the body.
List the characteristics of somatosensory area I regarding the sensory projection system.
- Specific
- Specific, point to point
- Cause to specific sense and nerve impulses
List the characteristics of somatosensory area II regarding the sensory projection system.
Non-specific
* Common pathway, dispersion
* Maintain and change the excitability
What is the somatosensory cortex responsible for?
It is responsible for processing sensory input from various parts of the body.
Which body parts are represented by the largest areas in the somatosensory corte
The lips (greatest), face, and thumb.
How is the size of a body part’s representation in the somatosensory cortex determined?
By the number of specialized sensory receptors in that body part.
Which body areas are represented by relatively small regions in the somatosensory cortex
The trunk and lower parts of the body.
the somatosensory cortex, where is the head represented?
In the most lateral portion of somatosensory area I.
In the somatosensory cortex, where is the lower body represented?
Medially
What causes pain in the body?
Pain occurs when tissues are being damaged.
Why does the body react to pain stimuli?
To remove the pain stimulus
What is the pain ascending pathway?
It involves primary afferents with nociceptor endings synapsing on ascending neurons after entering the CNS.
Which neurotransmitters are involved in the pain ascending pathway?
Glutamate and the neuropeptide substance P.
How is pain suppressed by the descending pathway from the brain?
Descending inputs from the brainstem stimulate interneurons to release endogenous opiate neurotransmitters.
What effect do endogenous opiate neurotransmitters have?
They inhibit neurotransmitter release from afferent pain fibers and inhibit ascending neurons.
How does morphine affect pain pathways?
Morphine inhibits pain similarly to endogenous opiates by acting on opiate receptors.
What are the types of pain?
Fast and slow pain, deep pain, visceral pain, referred pain, and inflammatory pain.
What are the subtypes of inflammatory pain?
Hyperalgesia, allodynia, and pain from cytokine and growth factor release
What are the two major types of pain?
- Fast pain
- Slow pain
How quickly is fast pain felt after a painful stimulus is applied?
About 0.1 second.
How quickly does slow pain begin after a painful stimulus?
Begins only after 1 second or more and then increases slowly over many seconds and sometimes even minutes.
