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
connect the pons with the corresponding side of the cerebellum
middle cerebellar peduncles
Lateral to the pyramids lies an elongated elevation called the
olive
The olive function is
control of movement
The roots of the brachial plexus are
ventral rami
carry all motor and sensory axons of a single spinal segment
spinal nerves
In the cervical region, spinal nerves are found above the corresponding vertebrae except_____.
the eighth spinal nerve
spinal nerves below the 8th spinal nerve lie
below the corresponding vertebrae
Spinal levels:
Cervical: C1-C8
Thoracic: T1-T12
Lumbar: L1-L5
Sacral/Coccygeal: S1-S6
horn processes sensory information
dorsal horn
horn processes autonomic information.
lateral horn
horn processes motor information
ventral horn
Blood is supplied to the spinal cord by three spinal arteries :
Anterior
Medial
Posterior
a reflex center in the corpora quadrigemina that relays visual information
superior colliculi
a reflex center in the corpora quadrigemina that relays auditory information
inferior colliculi
The medial geniculate is responsible for:
auditory
The lateral geniculate is responsible for:
vision
Spinothalamic lesion causes:
loss of pain and temperature sensation
Inferior peduncle function and lesion:
function: proprioceptive info from the body to the cerebellum
lesion causes: Ataxia
Red nucleus function and lesion:
function: facilitate LMNs that elicit ext of wrist and fingers
lesion causes: mild weakness to the wrist and fingers extensors, obscured by ataxia
What are the 3 parts of the brainstem?
midbrain
pons
medulla oblongata
What are the 3 parts of the diencephalon?
thalamus
hypothalamus
epithalamus
What is the function of the thalamus?
Consciousness
What happens if the thalamus is lesioned?
stroke (weakness of one side of the body)
What is the function of the hypothalamus?
homeostasis
What is the function of the red nucleus?
motor control
What happens if the substania nigra is lesioned?
Parkinson’s (tremors and shuffling gait)
The midbrain is divided into
tectum (dorsal) and tegmentum (ventral)
Controls the intensity of breathing
Apneustic center
Provides inhibitory impulses on inspiration
Pneumotaxic center
nucleus gracilis and cuneatus is located in which part of the midbrain?
Medulla
nucleus fasciculus and fasciculus is located in which part of the midbrain?
Medulla
Control the rate and depth of respiratory movements of the diaphragm & other respiratory
Respiratory Rhythmicity Center
Cerebellum
3 lobes
2 hemispheres
What are the 2 hemispheres of the cerebellum?
VERMIS
FOLIA
What are the 3 lobes of the cerebellum?
ANTERIOR
POSTERIOR
FLOCCULONODULAR
What are the 4 nuclei (gray matter) of the cerebellum?
Fastigial
Globose
Emboliform
Dentate
What are the white matter structures of the cerebellum?
superior peduncle
middle peduncle
inferior peduncle
Gray Matter Structures of the spinal cord:
Dorsal Root Ganglion
Dorsal Horn
Ventral Horn
White Matter Structures of the spinal cord:
Dorsal Root
Ventral Root
Spinal Nerve
Dorsal Ramus
Ventral Ramus
Dorsal Columns
Lateral Corticospinal Tract
Lateral Spinothalamic Tract
Spinocerebellar Tracts
Rubrospinal Tract
Anterior Corticospinal Tract
Anterior Spinothalamic Tract
What are the 5 terminal branches?
Musculocutaneous Nerve
Median Nerve
Ulnar Nerve
Axillary Nerve
Radial Nerve
What are the typical nerves?
Thoracic nerves (intercostal) T2-T12
What vertebrae does the brachial plexus consist of?
C5-T1
Atypical nerves are
plexuses
What are the plexuses?
Cervical plexus C1-C4
Brachial plexus C5-T1
Lumbar plexus L1-L4
Sacral plexus L4-S4
What is the tail of the spinal cord called?
cauda equinia
What vertebrae do the musculocutaneous nerve innervate?
C5-C7
biceps brachi
brachialis
coracobrachialis
What vertebrae do the axillary nerve innervate?
C5 & C6
Deltoid
Teres Minor
What vertebrae do the median nerve innervate?
C5-T1
Extensors
What vertebrae do the radial nerve innervate?
C5-T1
What vertebrae do the ulnar nerve innervate?
C8 & T1
What nerve causes wrist drop?
radial nerve
What 2 nerves can have “Claw”
ulnar and median
What nerve causes loss of elbow flexion?
musculocutaneous nerve
What nerve causes loss of shoulder abduction?
axillary nerve
What happens when the dorsal column is lesioned?
Multiple Sclerosis
loss of proprioception in the hands/fingers
Astereognosis
What happens when the spinothalamic tract is lesioned?
Syringomyelia
loss of pain/temp awareness
charcots joints
What happens when the spinocerebellar tract is lesioned?
Friedreich’s Ataxia
tremors
ataxia
unsteady gait
What happens when the cerebellum is lesioned?
Cerebellar Syndrome
loss of balance/posture control
ataxia
tremors
dysarthria
nystagmus
BLOOD FLOW OF CEREBELLUM:
Vertebral artery
basilar artery
Posterior cerebral artery
Superior cerebellum artery & anterior inferior cerebellum artery
Posterior inferior cerebellum artery
