Chapter 6 - Organization of the Brainstem

What are the primary functions of the brainstem?

basic life functions (cardiac and respiratory), consciousness, sleep, motor and sensory pathways

What are the structures of the brainstem?

midbrain, pons, medulla

Which cranial nerves emerge from the brainstem?

III-XII

Describe the role of the corticospinal tract and the spinothalamic tract.

corticospinal tracts = motor information

spinothalamic tracts = pain, temperature, itch, and crude touch

What is the function of the superior and inferior colliculi in the midbrain?

unconscious registration of visual (superior) and auditory (inferior) information

What vital functions does the pons help regulate?

bridge between cerebellum and cerebrum: breathing and relay signals

cranial nerve VI, VII, VIII emerge here

Where is the location and connection of the medulla?

anterior to the cerebellum, connects to the spinal cord

What cranial nerves emerge from the medulla?

CN X, XI, XII

How are cranial nerves I and II different from the other cranial nerves?

they emerge from the cerebrum

How many pairs of cranial nerves?

12

How many CN have nuclei in the brainstem?

9

What kind of neurons are cranial nerves?

cranial nerves are considered lower motor neurons

Locate the origin of CN in the brainstem

What syndrome results from bilateral destruction of the pons, and how does it affect the patient?

Locked-In syndrome

- not vegetative, but sometimes assumed

-paralysis of all neck down, eye movements for communication

What syndrome results from vascular damage to the inferior cerebellar artery?

Wallenberg syndrome

What is the presentation of Wallenburg syndrome?

- decreased pain/temp sensation face

- dysphagia

- dysarthria

- dysphonia

- vertigo, nausea, vomiting and nystagmus

- cerebellar signs: ataxia, dysmetria, dysdiadochokinesia

- Paralysis or numbness on one side of face with weak or

numb limbs on the other side of body

- Loss of taste on one side of tongue

- Horner's syndrome- constricted pupil and drooping eyelid

Functions of the Midbrain

vision

hearing

motor control

sleep-wake cycles

alertness

temperature regulation

Functions of the pons

sleep

respiration

swallowing

bladder control

hearing, equilibrium

taste

eye movement

facial expressions, sensation

posture

Functions of the medulla

cardiac, respiratory, vomiting, autonomic and involuntary functions (breathing, HR, BP)