Special Senses Flashcards
What does CN I innervate?
CN I innervates olfactory mucosa of superior nasal cavity
How do CN I fibres pass from the olfactory bulb to the olfactory mucosa?
Via the cribriform plate
What is retronasal breathing vs. orthonasal breathing?
Retronasal smell creates flavour from smell molecules in foods or drinks shunting up through the nasal passages when chewing. Orthonasal smell is the perception of smell molecules that enter directly through the nose and up the nasal passages.
What can cause unilateral anosmia?
Meningioma or anterior cranial fossa trauma
Which parts of the cortex does the olfactory tract carry sensory neurons to?
Primarily piriform cortex but also orbital cortex.
Piriform cortex is part of temporal lobe: amygdala, parahippocampal gyrus.
Where are most taste receptors found?
On the tongue, some found in palate/pharynx
What senses taste in anterior 2/3 of tongue?
CN VII - Facial nerve via the Chorda tympani nerve
What senses taste in the posterior 1/3 of the tongue?
CN IX Glossopharyngeal nerve
What type of papillae are found in anterior 2/3 of tongue?
Fungiform
What type of papillae are found at the 2/3rd boundary of the tongue?
Filiform - NO taste buds
What type of papillae are found in posterior 1/3 of tongue?
Vallate
What are the 5 types of taste that receptors can sense?
Sweet, sour, salty, bitter, umami
What sensory nucleus do the cranial nerves carrying taste synapse on when they come into the brainstem?
Nucleus solitarius
What cranial nerves does taste sensation from the tongue travel via?
CN VII (Chorda tympani) and CN IX
What cranial nerves carry sensory innervation from the tongue?
CN Vc (Lingual branch) and CN IX
What is the Fovea Centralis?
Region of greatest visual activity
What are the three layers of the eye?
1) Retina (Photo-receptive/sensory region)
2) Choroid (vascular)
3) Sclera (white outer layer)
What is the optic papilla?
Blind spot where the optic nerve comes together
What does fundoscopy do?
Allows examination of retina
What is the optic nerve called after the optic chiasm?
Optic tract