Lab Exam #2 Review questions Flashcards
In which region of the brain is the midbrain?
mesencephalon
What is the function of the midbrain?
voluntary movement of the head and body
What are the surface features on the anterolateral surface of the midbrain?
crus cerebri-
mamillary body-
cerebral peduncles- relays long motor tracts to the contralateral side of the body
What are the surface features on the posterolateral surface of the midbrain?
Corpora quadrigemina- reflex centers involving vision and hearing
superior colliculus- serve as reflex centers for movements of the eyes, head, & neck in response to visual/other stimuli
inferior colliculus- serve as reflex centers for movements of the head & trunk in response to auditory stimuli
Identify at least 3 internal features found within the midbrain.
- substantia niagra- reward and movement
- red nucleus- motor coordination
- cerebral aqueduct- contains cerebrospinal fluid (CSF), and connects the third ventricle in the diencephalon to the fourth ventricle
What happens if the midbrain is lesioned?
loss of consciousness
What tracts are associated with the structures of the midbrain?
corticospinal and corticobulbar tracts
In which region of the brain is the pons?
metencephalon
What is the function of the pons?
process motor information from the cerebral cortex to the cerebellum
What are 2 internal features of the pons?
- pneumotaxic center- control the intensity of breathing
- apneustic centers- inhibits impulses on inspiration
What happens if the pons is lesioned?
vegetative state
Name the structures of the cerebellum.
- cerebellar peduncles (superior, middle, and inferior)
- cerebellar cortex
- arbor vitae
What does the cerebellum do?
controls the maintenance of equilibrium, posture, and muscle tone coordinates movement
How is the cerebellum connected to the brainstem?
The 3 cerebellar peduncles:
superior peduncle (midbrain)
middle peduncle (pons)
inferior peduncle (medulla)
Name the ventricles of the brain and give their respective locations (developmental regions) and connections to one another.
2 lateral ventricles (cerebral hemispheres)
3rd ventricle (diencephalon)
4th ventricle (hindbrain)
Give the names of the three segments of the brainstem. In which REGION of the brain are each of these segments located?
Midbrain, Pons, Medulla
Mesencephalon, Metencephalon, Mylencephalon
Of the following, which is associated with the pons? Midbrain? Medulla Oblongata?
cerebral peduncles (crus cerebri)
nucleus gracilis and cuneatus
paralysis
blindness
deafness
vegetative functions
respiratory functions
neurodegenerative disease
- Midbrain:
cerebral peduncles
blindness
deafness - Pons:
respiratory functions
vegetative functions - Medulla:
paralysis
Nucleus gracilis & cuneatus
What is the function of the medulla?
cardiovascular control
breathing, head movements, and swallowing
Identify at least 2 surface features found on the medulla.
Fasciculus cuneatus
Fasciculus gracilis
Identify at least 3 internal features found within the medulla.
Nuclei
Nucleus. Gracilis
Nucleus Cuneatus
What is the difference between the cerebral peduncles and the cerebellar peduncles other than where they are located?
Identify the external features of the cerebellum
What happens in a cerebellar lesion? What are the symptoms?
Loss of postural control
Ataxia
Nystagmus
Dysarthria
Tremors
Nystagmus + dysarthria + intentional tremor =
CHARCOT’S TRIAD
What are the pathways that we learned that involve the cerebellum?
Anterior Spinocerebellar Tract
Posterior Spinocerebellar Tract
Spinal nerves (Typical):
T1-T12 thoracic (single nerves)
Spinal nerves (Atypical):
Plexuses (mixed nerves)
What happens if there is a lesion to the pyramids?
paralysis of the upper motor neuron
_____ of decussation happens in the medulla on the contralateral side. The other 10% decussate at the level of _____.
90%, level of synapse on the lower motor neurons within the spinal cord
Large bulges on the anterior surface of the medulla, containing descending motor tracts (corticospinal and corticobulbar)
pyramids
What are the functions of the cerebellum?
- coordination of muscular activity and regulate posture & balance
- functions at a subconscious level & it does not directly stimulate skeletal muscles
What is the reticular formation? Where is it located?
Composed of loosely clustered neurons made of white matter and governs the arousal of the brain as a whole.
Extends through the central core of the medulla oblongata, pons, and midbrain
reticular formation
integrates sensory & cortical information
modulates pain information
Where are the cell bodies of motor neurons located?
lateral horns
Where are the cell bodies of sensory neurons located?
dorsal root ganglia
Describe the organization of the white matter of the cord.
Divided into 3 white columns, or funiculi:
dorsal (posterior)
lateral
ventral (anterior)
*each funiculus contains several fiber tracts, and each tract is made up of axons with similar destinations and functions
Where are the cell bodies of the upper and lower motor neurons located?
upper motor neurons: primary motor cortex
lower motor neurons: anterior horn of the cord
the point-for-point correspondence of an area of the body to a specific point on the central nervous system
Somatotopy
a map of sensory space in the postcentral gyrus
Homunulus