The Brainstem, Cranial Nerves And The Visual Pathway Flashcards
Location of midbrain
Most superior part of brainstem
2 parts of the midbrain
Tectum
Tegmentum
Location of Tectum
Smaller part of the midbrain located dorsal of the cerebral aqueduct
Tectum
Contains 2 pairs of rounded bumps = colliculi
Role of superior colliculi
Involved in regulating eye movements and reflexes associated with visual stimuli, such as turning or moving the head quickly when something quickly enters our field of vision
Role of inferior colliculi
Involved sound location, pitch discrimination and reflexes associated with auditory stimuli, such as turning our head on hearing a loud noise
Location of tegmentum
Larger part of midbrain located ventrally of cerebral aqueduct
What separates the tegmentum and Tectum
Cerebral aqueduct
Which colliculi are involved with visual stimuli
Superior colliculi
Which colliculi are involved with auditory stimuli
Inferior colliculi
Substantia nigra
Important in motor control by producing dopamine
Cerebral peduncles
On most ventral surface of tegmentum
Large white matter bundles that connect the midbrain to the thalami
Red nuclei
Support motor control of limbs
What 3 structures does the tegmentum contain
Substantia nigra
Cerebral peduncles
Red nuclei
Which nuclei does the midbrain contain
Nuclei of the oculomotor (CN III) and trochlear (CN IV) nerves
Edinger-Westphal nuclei (involved in pupillary light reflex)
Pons
Large, rounded middle part of the brainstem
Contains the Pneumotaxic and aponeustic centres involved in regulation of breathing
Which artery lies on the ventral surface of the pons
Basilar artery
Middle cerebellar peduncles
Large white matter connections to the cerebellum on the dorsal surface of the pons
What is located on the ventral surface of the pons
Basilar artery
What is located on the dorsal surface of the pons
Middle cerebellar peduncles
Where is the fourth ventricle situated
Dorsal surface of pons between 2 middle cerebellar peduncles
Which nuclei are in the pons
Nuclei of the trigeminal (CN V), abducens (CN VI), facial (CN VII), vestibulocochlear (CN VIII) nerves
Which centres are involved in the regulation of breathing
Pneumotaxic and Apneustic
Where are the Pneumotaxic and apeneustic centres located
Pons
Location of medulla oblongata
Connects pons to spinal cord
Anterior median fissure
Groove on ventral surface of medulla oblongata that separates the 2 medullary pyramids
Medullary pyramids
2 distinct lumps on ventral surface of medulla separated by anterior median fissure
Which tracts run through the medullary pyramids
Corticospinal tracts
Medullary olives
Prominent ridges immediately lateral to the medullary pyramids
2 nuclei in the dorsal column medial lemniscus
Fasciculus gracilis
Fasciculus cuneatus
Dorsal column medial lemniscus
Sensory nerve pathway in dorsal part of medulla
Which fibres decussate in the medulla
Corticospinal
Dorsal column medial lemniscus
Where do the corticospinal tracts decussate
Medulla
Where do the dorsal column medial lemniscus decussate
Medulla
Which nuclei are in the medulla
Nuclei of the Glossopharyngeal (CN IV), vagus (CN X), accessory (CN XI) and Hypoglossal (CN XII) nerves
Medulla
Contains vital centres responsible for regulating respiration, heart rate, blood pressure and initiating vomiting
Where are the centres responsible for regulating respiration, heart rate, blood pressure and initiating vomiting located
Medulla
Bulbar palsy
This term refers to dysfunction of the cranial nerves that arise from the medulla (glossopharyngeal, vagus, accessory and hypoglossal). Symptoms include difficulty speaking and swallowing, excessive saliva production, wasting and fasciculations of the tongue and an absent gag reflex. Causes include diseases which affect peripheral nerves such as motor neurone disease and Guillain-Barré syndrome.
Which part of the brainstem do nerves affected by bulbar palsy originate in
Medulla
Is the olfactory nerve sensory or motor
Sensory
Is the optic nerve sensory or motor
Sensory
Is the oculomotor nerve sensory or motor
Motor + parasympathetic
Is the trochlear nerve sensory or motor
Motor
Is the trigeminal nerve sensory or motor
Both
Is the abducens nerve sensory or motor
Motor
CNS origin of the olfactory nerve
Cerebrum
CNS origin of the optic nerve
Diencephalon
CNS origin of the oculomotor nerve
Midbrain
CNS origin of the trochlear nerve
Midbrain
CNS origin of the trigeminal nerve
Pons
CNS origin of the abducens nerve
Pons
Which skull base Foramen does the olfactory nerve exit
Cribriform plate
Which skull base Foramen does the optic nerve exit
Optic canal
Which skull base Foramen does the oculomotor nerve exit
Superior orbital fissure
Which skull base Foramen does the trochlear nerve exit
Superior orbital fissure
Which skull base Foramen does the abducens nerve exit
Superior orbital fissure
Which skull base Foramen does the ophthalmic branch of the trigeminal nerve exit
Superior orbital fossue
Which skull base Foramen does the maxillary branch of the trigeminal nerve exit
Foramen rotundum
Which skull base Foramen does the mandibular branch of the trigeminal nerve exit
Foramen ovale
3 branches of trigeminal nerve
Ophthalmic
Maxillary
Mandibular
Function of the olfactory nerve
Olfaction (smell)
Function of the optic nerve
Sight
Function of the oculomotor nerve
Eye movements (SR, IR, MR, IO)
Eyelid opening (LPS_
Pupillary constriction
Accommodation
Function of the trochlear nerve
Eye movement (SO)
Function of the abducens nerve
Eye movements (LR)
Function of the ophthalmic branch of the trigeminal nerve
Sensation from upper 1/3 of face - as far as top of head to anterior surface of the eye
Function of the maxillary branch of the trigeminal nerve
Sensation from the middle 1/3 of face - including most of the internal nasal cavity, upper teeth and palate
Function of the mandibular branch of the trigeminal nerve
Sensation from the lower 1/3 of face - including general sensation to anterior 2/3 of the tongue, mandibular teeth and gums
Motor to the muscles of mastication
Motor to tensor tympani muscle
Where are the olfactory bulbs located
Superior surface of the Cribriform plate either side of the crista galli
Where are the olfactory cortices
Temporal lobes
V1 branch of trigeminal nerve
Ophthalmic
V2 branch of trigeminal nerve
Maxillary
V3 branch of trigeminal nerve
Mandibular