Superior colliculus

Relay nuclei · detail

Tectal target of retinal fibres arriving through its brachium; the superficial layers map the contralateral visual field and the deep layers drive reflex saccades and head-orienting movements through the pontine and midbrain gaze centres.

Traced from the start

  1. Temporal hemiretinaNasal hemiretinaMacula and papillomacular bundle
  2. Optic nerve (CN II)
  3. Optic tract
  4. Superior colliculus

Detail

Input
Retinotectal fibres from the optic tract, plus V1 and the frontal eye field
Output
Tectospinal tract, paramedian pontine reticular formation, rostral interstitial nucleus of the MLF
Function
Reflex saccades and orienting to a novel stimulus

When it goes wrong

Destruction of V1 with intact retinotectal pathway

Blindsight: the patient denies seeing but can localise or track a stimulus in the blind hemifield

Practise this structure

1 question in the bank tagged Brainstem.