Ascending Pathways Flashcards
What are three examples of ascending pathways?
Spinothalamic
Medial lemniscus
Trigeminothalamic
What are the two types of senses?
Special and general senses
What is a special sense?
Localised sense by their respective sensory organ
How many special senses are there?
5
Which nerves carry the special senses?
Cranial nerves
What are the five special senses?
Olfaction
Vision
Taste
Hearing
Vestibular
Which cranial nerve carries olfaction?
CN1 - olfactory
Which cranial nerve carries vision?
CN2 - optic
Which cranial nerves carry taste?
CN7 - facial
CN9 - glossopharyngeal
Which cranial nerve carries hearing?
CN8 - vestibulocochlear
Which cranial nerve carries vestibular?
CN8 - vestibulocochlear
What are general senses?
Senses that are spread throughout the body
What are examples of general senses?
Interoception
Exteroception
Proprioception
What is interoception?
Awareness of internal environment
Pain, temperature, touch pressure of viscera
What is exteroception?
Awareness of external stimuli
Pain, temperature, touch pressure of external world
What is proprioception?
Position sense/awareness of space occupied by joints/tendons/ligaments
What are general senses detected by?
Sensory receptors e.g. nociceptors, thermoreceptors, mechanoreceptors, chemoreceptors, baroreceptors
What is a dermatome?
Area of skin of skin supplied by a particular spinal nerve in the PNS
How many dermatomes are there in the human body?
31
What information is the spinothalamic pathway involved in?
Pain, temperature, crude touch
What information is the medial lemniscus pathway involved in?
Fine touch, conscious proprioception
What information is the spinocerebellar pathway involved in?
Proprioception
How many orders of neurons are there in ascending somatosensory pathways?
Three orders of neurons
Where is the first order of neurons located in ascending pathways?
Dorsal root ganglion
Where is the second order of neurons located in ascending pathways?
Grey matter of spinal cord
Where is the third order of neurons located in ascending pathways?
Ventral posteromedial nucleus of thalamus
Which four cranial nerves make up the trigeminothalamic tract?
Trigeminal
Facial
Glossopharyngeal
Vagus
Where do the trigeminothalamic nerve tracts synapse?
Trigeminal nuclear complex
Where do the trigeminothalamic nerve tracts project to?
Post central gyrus / primary sensory cortex
