Flashcards in Brainstem and cranial nerves Deck (50)
What does the pineal gland do?
Circadian rhythm generation for hormone release via secretion of melatonin - trained via the eye
What is the purpose of the superior colliculus?
Eye and neck movement
What is the purpose of the inferior colliculus?
Auditory response (protective reflex)
What is the only cranial nerve that emerges from the back the brainstem?
Trochlear nerve (CN IV)
What are the dorsal columns responsible for?
fine touch and proprioception
What muscle does the trochlear nerve innervate?
The superior oblique muscle
What makes the roof of the midbrain?
The superior and inferior colliculi (tectum)
What is CN I, where can you find it and what does it innervate?
Olfactory nerve (sensory)
Inferior surface of frontal lobes
Olfactory nerves pass through Cribriform plate -> olfactory bulbs -> olfactory tract
What is CN II, where can you find it and what does it innervate?
Optic nerve (sensory)
-> innervates retina
Crosses over at the optic chiasm
What are the mamillary bodies for and where are they?
In the hypothalamus; important in memory and part of the limbic system
What is CN III, where is it found and what does it innervate?
Midbrain, in the midline
Goes to superior, inferior and medial rectus and inferior oblique, levator palpebrae -> movement of eyeball
Pupillary constrictor and ciliary muscle (PNS); for constriction and accommodation
What is the purpose of the cerebellar peduncles?
Connects the cerebellum to the brainstem.
What are the main fibres in the cerebellar peduncles?
Corticospinal tract; communicates with alpha motor neurones -> musculature
How do you easily identify the pons?
Transverse bridging fibres (hides the corticospinal tract)-connects the cerebellum via the middle cerebral peduncles.
What is CN V?
Trigeminal nerve (ophthalmic, maxillar, mandibular);
Sensory; face, scalp, cornea, nasal and oral cavities, cranial dura mater
The smaller root is the motor (muscles of mastication, tensor tympani muscle)
What three nerves emerge at the ponto-medullary junction?
The Abducens, Facial and Vestibulococchlear.
What is CN VI?
Abducens; innervates the (extrinsic) lateral rectus muscle, movement of the eyeball
The nucleus is located in the pons
What is CN VII?
Facial nerve; sensory-anterior 2/3 of tongue for taste
Motor- muscles of facial expression, tension on bones of middle ear
PNS; salivary and lacrimal glands
What is CN VIII?
Vestibulococchlear; vestibular apparatus (position and movement of head)
What is CN IX?
General taste and sensation
What is CN X?
general sensation, chemo- and baroreception visceral sensation, speech and swallowing
Control of cardiovascular, respiratory and gastrointestinal tracts
What is CN XI?
Accessory nerve; sternomastoid and trapezius muscles, movement of head and shoulders
Special visceral efferent
What is CN XII?
Hypoglossal; Intrinsic and extrinsic muscles of the tongue
Where are the 'pyramids' found and their purpose?
Found in the medulla, it is the re-emergence of the corticospinal tract. This is where pyramidal decussation occurs (90-95% fibres cross).
Which cranial nerves are general somatic efferent?
III, IV, VI, XII
Which cranial nerves are special visceral efferent?
V, VII, IX, X, XI
Which cranial nerves are general visceral efferent?
III, VII, IX, X
Which cranial nerves are general somatic afferent?
V, VII, IX, X
Which areas of the brainstem do the GSA fibres of the trigeminal nerve return to?
Mesencephalic trigeminal nerve
Pontine trigeminal nerve
Spinal trigeminal nerve