Brain Stem Flashcards
What are the 3 components of the brain stem
- Medulla oblongata
- Pons
- Midbrain
What is the medulla oblongata known as and what does it do
Known as the vital brain
Control involuntary actions of breathing, HR, BP, coughing, swallowing, vomiting, hiccupping, and sneezing
True or False the spinal cord is a continuation of the medulla oblongata
True
Name the 2 types of tracts of the white matter of the medulla oblongata
ascending (sensory) and descending (motor) tracts
What are the pyramids of the medulla oblongata and why are the important
Bulges of white matter on the anterior of the medulla oblongata .
It is where the largest motor tracts pass from the cerebrum to the spinal cord
Define decussation of the pyramids
axons of the pyramids cross to opposite sides
What are the 7 medullary nuclei mention in the notes
- Cardiovascular center
- Cochlear nuclei
- The deglutition center
- The gustatory nucleus
- Vestibular nuclei
- Vomiting center
- Medullary rhythmicity center
What does the Cardiovascular center control
regulates blood vessel diameter and the rate and force of the heart
What does the Cochlear nuclei control
receives auditory input from the cochlea
What does the gustatory center control
receives input from the taste buds
What does the deglutition center control
promotes swallowing of a food bolus
What does the vestibular center control
equilibrium pathway from the vestibular apparatus of the inner ear
What does the vomiting center control
area postrema, causes vomiting
What does the medullary rhythmicity area control
basic rhythm of breathing
-divided in 2 clusters of neurons, the inspiration area and expiratory area
What are the Olives
- oval shaped swellings lateral to each pyramid
- relays joint and muscle position impulses from the cerebral cortex, the red nucleus of the midbrain, and spinal cord to the cerebellum
Where are the Pons located
anteriorly superior to medulla, and inferior to the midbrain
What is the overall function of the pons
Acts as a bridge between one part of the brain to another
Name the 2 bundles of axons located in the Pons
Lateral = connect the L and R side of the cerebellum
Vertical= consist of ascending (sensory) and descending (motor) tracts
True or false certain pontine nuclei relay signals for voluntary movement from the cerebral cortex to the cerebellum
True
Name the 2 nuclei in the pons that help control breathing and identify their fxn
Areas coordinate transition between inhalation and exhalation by regulating medullary rhythmicity centers
- Apneustic area= prolongs inhalataion by sending stimulatory impluses to the inspiration area
- The pnuemotaxic region =turns off inspiratory area before they become too full
What is the midbrain also known as and what is it generalized function
- Mesencephalon
- Connects Pons to Diencephalon
Describe the cerebral peduncles
area of the midbrain that conduct motor impulses from the cerebral cortex to the spine and conducts sensory impulses from the medulla to the thalamus
What is the tectum
posterior area of the midbrain that contain the corpora quadrigemina (superior and inferior calliculli)
What is the fxn of the superior callliculi
Reflex center for visual reflexes
- pupillary reflex
- accommodation reflex=adjusting lens
- involuntary turning of the head when an object is in the corner of your eye
Explain the fxn of the inferior callliculi
Part of auditory pathway
Responsible for STARTLE reflex=turning of your head to an unexpected noise
What is the substantia nigra
- Darkly pigmented nuclei that release dopamine, that helps control subconscious muscle activities
- loss of this is associated w/ parkinsons dz
What are the red nuclei
-coordinate muscular movement (primarily large muscles of the shoulders and arms)
–controls swing arms while walking and crowling of babies
-axons from the cerebellum and cerebral cortex synapse with the red nuclei
Describe the reticular formation
an extensive region of gray and white matter in the brain stem , comprised of ascending and descending neurons
- main fxn is to regulate muscle tone
- contains reticular activating system
What is the fxn of the reticular activating system
sensory axons that help maintain consciousness and participate in awakening from sleep
