Week 2- Brainstem & ANS

midbrain

What part of the brainstem is the relay system for spinothalamic tract and corticospinal tracts?

CN III and CN IV

Midbrain is the origin of what CNs?

5-8

Pons is the origin of what CNs?

9-12

Medulla is the origin of what CNs?

Controls vital response (HR, BP, respiration), assists in perception of pain, controls consciousness, origin of 10 pairs of cranial nerves

What are the general responsibilities of the brainstem?

midbrain

What part of the brainstem has these functions:

•Most eye movements

•Processing vision and hearing

•Substantia nigra: Dopamine

•Most eye movements

•Processing vision and hearing

•Substantia nigra: Dopamine

What are the functions of the midbrain?

pons

What part of the brainstem controls the sleep wake cycle?

medulla oblongata

What part of the brainstem links the CV and respiratory systems together, manages: coughing, sneezing, swallowing, vomiting, and maintaining balance, and is a crossover point for motor nerves?

medulla oblongata

What part of the brainstem is the cross over pt for motor nerves?

medulla oblongata

What part of the brainstem is the location of the vagal trigone (landmark for neurosurgical procedures)?

reticular formation

What is a complex network of brainstem nuclei and neurons that helps coordinates functions necessary for survival by integrating, coordinating, and influencing the peripheral nervous system and central nervous system?

reticular activating system

What component of the reticular formation contains a network of neurons that project anteriorly to the hypothalamus to mediate behavior and posteriorly to the thalamus for regulation of consciousness and helps to filter out unimportant information?

V, VI, VII, and VIII as well as inferior cerebellar artery

What CNs and artery does the cerebellopontine angle house?

•Speech impediments

•Unilateral hearing loss

•Disequilibrium

•Diziness

•Tremor

What can cerebellopontine angle syndrome cause?

cerebellopontine angle

What brainstem site is between the cerebellum and the pons in the posterior fossa?

olfactory

smell

sensory

What is the name for CN I, its function, and is it sensory motor or mixed?

optic

vision

sensory

What is the name for CN II, its function, and is it sensory motor or mixed?

oculomotor

extrinsic eye muscles

motor

What is the name for CN III, its function, and is it sensory motor or mixed?

trochlear

extrinsic eye muscles

motor

What is the name for CN IV, its function, and is it sensory motor or mixed?

opthalmic

cornea/skin/mucosa

sensory

What is the name for CN V (trigeminal)- V1, its function, and is it sensory motor or mixed?

maxillary

skin/teeth/oral cavity

sensory

What is the name for CN V (trigeminal)- V2, its function, and is it sensory motor or mixed?

mandibular

muscles of mastication/face/teeth

mixed

What is the name for CN V (trigeminal)- V3, its function, and is it sensory motor or mixed?

abducens

eye abduction

motor

What is the name for CN VI, its function, and is it sensory motor or mixed?

facial

muscles of facial expression/taste/glands

mixed

What is the name for CN VII, its function, and is it sensory motor or mixed?

vestibulocochlear

hearing/equilibrium

sensory

What is the name for CN VIII, its function, and is it sensory motor or mixed?

glossopharyngeal

taste/tongue/pharynx

mixed

What is the name for CN IX, its function, and is it sensory motor or mixed?

vagus

pharynx/larynx/thoracic organs

mixed

What is the name for CN X, its function, and is it sensory motor or mixed?

accessory

trapezius/SCM

motor

What is the name for CN XI, its function, and is it sensory motor or mixed?

hypoglossal

tongue muscles

motor

What is the name for CN XII, its function, and is it sensory motor or mixed?

•Insomnia secondary to circadian rhythm disruption

•Difficulty breathing

•Difficulty regulating HR and BP

•Nausea

•Dizziness

•Dysphagia: Difficulty swallowing

•Cranial nerve disorders

What are some common symptoms for brainstem lesions?

movement disorder

What type of disorder occurs secondary to reduced dopamine production in the substantia nigra in the midbrain?

locked-in syndrome

What syndrome can occur in a quadriplegia with whole body sensory loss and bulbar palsy due to brainstem damage?

•Controls autonomic functions such as HR, BP, respirations, digestion, and sexual arousal

•It is regulated by the brainstem and hormones from the hypothalamus

What is the role of the ANS and what is it regulated by?

•Sympathetic: Flight, flight, or freeze

•Parasympathetic: Rest and digest

•Enteric: Functions independently of the others, chiefly responsible for digestive processes

What are the 3 divisions of the ANS and what are their functions?

sympathetic

Symp or parasympathetic:

uses postganglionic norepinephrine

parasympathetic

Symp or parasympathetic:

uses postganglionic acetylcholine

sympathetic NS

What part of the ANS originates in the thoracic spine and lumbar spine (T1-L3) and directs responses in dangerous or stressful situation?

thoracic and lumbar spnie

What is the origin of the sympathetic NS?

•Lateral horns of the spinal cord (also called intermediolateral columns) -> Ventral roots

-> Spinal nerve -> white rami communicates -> paravertebral ganglion

•Results in release of norepinephrine that acts on adrenergic receptors

Trace the pathway of the sympathetic chain.

preganglionic fibers- short

postganglionic fibers- long

What is the fiber lengths of the pre and post ganglionic fibers for the sympathetic chain?

cranial nerves and sacral spine

CN III, VIII, IX, X

Where does the ANS parasympathetic portion originate and what CNs does it include?

acetylcholine

What do postganglionic parasympathetic neurons release?

enteric nervous sytem

What part of the ANS influences the GI tract and is the largest and most complex portion of the PNS?

control the digestive functions of muscle contraction/relaxation, secretion/absorption, and blood flow

What is the function of the ENS?

dysautonomia's

What occurs as a result of disruption in autonomic body processes ---- causing possible POTS (postural orthostatic tachycardia syndrome), Ehler's Danlos, orthostatic hypotension, and MSA (multiple systems atrophy)?

horner's syndrome

What is an oculosympathetic paresis that affects nerves to the face and eyes. Impacts pupil size, eye opening, and sweating?

hyperhidrosis

What presents as excessive sweating primarily of the face, palms, soles, or axilla secondary to increased cholinergic stimulation?