Balance Flashcards
State 3 systems involved with balance.
Visual. Vestiubular. Somatosensory.
How do electrical signals travel to the brain in the ear?
Via the vestibular branch of the vestibulocochlear nerve.
What do the axons of the nasal retina synapse with?
Lateral geniculate nucleus in both sides of thalamus.
After the lateral geniculate nucleus of the thalamus, where do the electrical signals go?
Primary visual cortex/occipital lobe.
Why can the nasal aspect of the left eye still be seen if the left eye is damaged?
Nasal portion of the left eye seen by the right eye. But, the peripheral vision of left eye lost.
Do the nasal axons or temporal axons crossover at the brain?
Nasal axons.
State 3 aspects of the somatosensory system.
Touch and proprioception (awareness of position and movement of body). Pain. Temperature.
What is meant by proprioception?
Awareness of position and movement of body
What receptors detect pain?
Nociceptors.
What receptors detect temperature?
Thermoreceptors.
Which receptors detect touch and proprioception?
Mechanoreceptors.
State the 3 types of somatosensory fibres.
Non-myelinated fibres. Small myelinated fibres. Large myelinated fibres.
Which horn recieves information from the motor cortex of the brain, the anterior (ventral) or posteriod (dorsal) horn?
Anterior (ventral) horn.
Which horn processes information from external sensory sources to the brain, the anterior (ventral) or posterior (dorsal) horn?
Posterior (dorsal) horn.
State the 2 pathways of the somatosensory system?
Medial lemniscal (posterior pathway). Spinothalamic pathway (anterior pathway).
What is the medial lemniscal pathway responsible for?
Pressure. Vibration. Fine touch. Proprioception.
What is meant by proprioception?
The perception or awareness of the position and movement of the body.
Which pathways don’t enter the brain?
Invountary reflexes - invove an interneuron instead.
State 2 factors affecting sensory coding.
Receptive fields (small receptive field increases resolution). Stimulus resolution controlled by lateral inhibition (ensures pinpoint of exact location). Stimulus strength and duration (determined by frequency of nerve firing).
State 2 of the 4 mechanoreceptors for touch.
Meissners corpuscles. Merkel discs. Ruffini corpuscles. Pacinian corpuscles.
State the name of the mechanoreceptors for proprioception.
Proprioceptors.
State 3 types of proprioceptors.
Muscsle spindles. Golgi tendon organ. Joint receptors.
What are the channels which change detect changes in heat?
Thermoreceptors - transient receptor potential changes.
What are the three types of nociceptors (pain)?
Thermal - sense extremely cold/hot temperatures. Mechanical - sense excess pressure and deformation. Polymodal - sense combination.
How many orders of neurone are there in the somatostatic pathway?
- 1st order - sensory receptors converts stimui. 2nd order - cell body in spinal cord or brainstem. 3rd order - cell body in thalamus. 4th order - cell body in sensory cortex.
