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DPT 736 Neuroanatomy > Brainstem > Flashcards

Flashcards in Brainstem Deck (20)
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1
Q

Brainstem

A
  • consists of medulla, pons, and midbrain
  • posterior fossa of cranial cavity
  • often referred to as the bulb
  • contains ascending and descending tracts that pass thru it
  • contains tracts that originate in nuclei of brainstem
  • brainstem nuclei send and/or receive fibers from 10-12 cranial nerves (III-XII)
  • also contains reticular formation
2
Q

External Features

A

-look at pictures and be able to label

3
Q

Junctions in Brain

A
  • midbrain-diencephalon junction
  • pontomesencephalic junction
  • pontomedullary junction
  • cervicomedullary junction at level of foramen magnum (pyramidal decussation happens here)
4
Q

Midbrain

A
  • dorsal surface: tectum is roof of midbrain made up of superior and inferior colliculi
  • ventral surface: cerebral peduncles (in between-interpeduncular fossa)
5
Q

Pons

A
  • dorsal surface: 4th ventricle

- dorsolateral surface: superior, middle, and inferior cerebellar peduncles-connect pons to cerebellum (white tracts)

6
Q

Medulla

A
  • ventral surface: pyramids descend from the pontomedullary junction to pyramidal decussation
  • rostral: inferior olivary nuclei-lateral to pyramids
  • caudal medulla: posterior columns-fasciculus gracilis, fasciculus cuneatus; posterior column nuclei-nucleus cuneatus, nucleus gracilis
7
Q

Floor of Fourth Ventricle

A
  • extends from pons to rostral half of medulla
  • ends at obex (entry to spinal cord’s central canal-closed in adults)
  • drains into subarachnoid space at foramina of luschka and foramen of magendie
  • facial colliculi: abducens (VI) and middle fibers of facial nerve (VII)
  • hypoglossal trigone: hypoglossal nucleus (XII)
  • vagal trigone: dorsal nucleus of vagus (X)
8
Q

Reticular Formation

A
  • region in brainstem that is involved in multiple tasks such as regulating the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli
  • essential for governing some of basic functions of higher organisms and one of the phylogenetically oldest portions of the brain
  • motor control
  • pain modulation
  • sleep and consciousness
  • habituation
9
Q

Cranial Nerves Exit Brainstem-Midbrain

A
  • CN III: ventrally from interpeduncular fossa-passes between PCA and superior cerebellar artery
  • CN IV: dorsally
10
Q

Cranial Nerves Exit Brainstem-Pons

A

-CN V: ventrolateral

11
Q

Cranial Nerves Exit Brainstem-Pontomedullar Junction and Rostral Medulla

A
  • CN VI: ventrally at pontomedullary junction

- CN VII, VIII, IX, and X: ventrolaterally (medial to lateral) at pontomedullary junction and rostral medulla

12
Q

Cranial Nerves Exit Brainstem-Cerebellopontine Angle

A

-region where CN VII, VIII, and IX exit brainstem

13
Q

Cranial Nerves Exit Brainstem-CN XI

A

-laterally from upper cervical spinal cord

14
Q

Cranial Nerves Exit Brainstem-Medulla

A

-CN XII ventrally between pyramids and inferior olivary nuclei

15
Q

Sensory and Motor Organization of Cranial Nerves

A
  • have sensor and motor functions
  • motor cranial nuclei are more ventral
  • sensory cranial nuclei are more dorsal
  • three motor columns and three sensory columns of cranial nerve nuclei run through the length of brainstem
  • p 500-502
16
Q

Somatic Motor Nuclei

A
  • CN III, IV, XII nuclei remain adjacent to midline and send fibers out near midline
  • innervates extraoccular and intrinsic tongue muscles
17
Q

Visceral Motor Nuclei

A
  • two columns
  • brachial motor nuclei: functions=muscles of mastication, facial expression, middle ear, pharynx, larynx, SCM, upper trap; trigeminal motor nucleus (CN V), facial nucleus (CN VII), nucleus ambiguous (CN IX, X), spinal accessory nucleus (CN XI)
  • parasympathetic nuclei: parasympathetic innervation of head, and thoracoabdominal viscera above splenic flexure; Edgar-Westphal nucleus (CN III), superior (VII), and inferior (IX) salivatory nuclei, dorsal motor nucleus of vagus (CN X)
18
Q

Visceral Sensory Nucleus

A
  • nucleus solitarius (2 parts)
  • sleep regulation as well as the following
  • rostral nucleus solitarius (gustatory nucleus), taste input from CN VII and IX and X
  • caudal cardio-respiratory nucleus: inputs for regulation of cardiac, respiratory, and GI function from CN IX, and X
19
Q

General Somatosensory Nuclei

A
  • aka trigeminal nuclei
  • mediates touch, pain, temperature, position, and vibration for the face, sinuses and meninges
  • CN V, VII, IX, and X
20
Q

Special Somatic Sensory

A
  • olfaction, vision, hearing, vestibular and taste

- cochlear nuclei and vestibular nuclei from CN VIII