The glossopharyngeal, vagus and cranial accessory nerves (CN IX, X, XI) can be considered as a group, passing through the jugular foramen, and are commonly damaged together. Jointly, they supply: motor innervation to the pharynx and larynx (CN X, joined by fibres from the cranial root of XI) parasympathetic supply to the parotid gland (CN IX) and thoracic and abdominal viscera (CN X) taste from … Continue reading CN IX, X & XI

Swallowing is the process by which food from the mouth enters the oesophagus via the pharynx. It occurs in a specific sequence of phases to prevent food from entering the airway. Oral phase Mastication and moistening by saliva forms a soft and wet mass known as a bolus. The tongue forms a longitudinal trough (mediated by intrinsic muscles) and then is pushed up against the … Continue reading Swallowing

Malaria is a disease caused by protists, specifically, Plasmodium vivax, knowlesi, ovale, falciparum, or malaria. These pathogens are spread by female Anopheles mosquitos (which feed on blood), although males are important in giving off the hormone 20-Hydroxyecdysone, that helps the plasmodium grow. P. ovale and knowlesi are sympatric species. Risk factors pregnancy age immunosuppressed NOT sickle cell anaemia Life cycle In mosquitoes, Plasmodium exists as … Continue reading Malaria

Pupillary light reflex The pupillary reflex mediates pupil contraction in response to light. Afferent signals from CN II fibres are passed to the pretectal area of the brainstem and lead to stimulation of the Edinger-westphal nucleus. Consequently, parasympathetic CN III efferent fibres mediate constriction of the pupil via sphincter pupillae. Since afferent signals split bilaterally at the optic chiasm, the reflex is consensual where shining light … Continue reading Ocular reflexes

The optic nerve consists of about 1.2 million very fine retinal ganglion cell fibres. The nerve within the orbit is slightly sinuous to allow for eye movements and is covered by extensions of the three layers of the meninges and a fine layer of cerebrospinal fluid. The two optic nerves form a flattened cross, the optic chiasm, which overlies the tuberculum and diaphragma sellae to … Continue reading Visual pathway