Psychobiology part 2 unit 5 Flashcards

1
Q

Question: What does the word “cerebellum” mean, and how does its neuron count compare to the cerebral cortex?

A

Answer: The cerebellum means “little brain,” but it contains 50 billion neurons—more than twice the 22 billion neurons in the cerebral cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Question: What key functions does the cerebellum manage?

A

Answer: The cerebellum manages balance, posture, muscle tone, and the coordination of movement, all unconsciously.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does the cerebellum help with muscle tone?

A

Answer: Muscle tone refers to the tension in a muscle at rest, and the cerebellum adjusts it to maintain posture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What sensory and motor inputs does the cerebellum integrate to produce movement?

A

Answer: The cerebellum combines visual, auditory, vestibular, somatosensory, and motor commands from the brain to create smooth, coordinated actions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Question: What symptoms can occur if the cerebellum is damaged?

A

Answer: Damage can cause jerky, uncoordinated movements, difficulty with rhythmic actions (like clapping), trouble speaking or writing, and struggles with fine motor skills.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why is the cerebellum important in sobriety tests like the finger-to-nose test?

A

Answer: Alcohol impairs cerebellar function, making it difficult to perform tasks requiring precise coordination, like touching the nose with a finger.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Question: How is the cerebellum connected to the brainstem?

A

Answer: The cerebellum is attached to the brainstem by three cerebellar peduncles:

Superior peduncle connects to the midbrain.
Middle peduncle connects to the pons.
Inferior peduncle connects to the medulla.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Question: What are the main structural divisions of the cerebellum?

A

Answer: The cerebellum has two hemispheres joined by a central region called the vermis. The surface is folded into structures called folia, which maximize surface area.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Question: How is the cerebellum divided into lobes?

A

Picture a pizza with three slices. The cerebellum has three “lobes” divided by grooves called fissures:

Anterior lobe: The small slice at the front, responsible for basic motor tasks.
Posterior lobe: The larger slice at the back, involved in coordination of fine movements.
Flocculonodular lobe: A tiny slice underneath, critical for balance and eye movements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Question: What are the main layers of the cerebellum, and what are their functions?

A

Answer:

Outer grey matter (cerebellar cortex): Processes incoming information.
Inner white matter: Contains axons forming a branching pattern called the arbor vitae (“tree of life”).
Deep cerebellar nuclei: Output center sending signals to other brain regions. responsible for producing the
messages sent from the cerebellum to other areas of
the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Question: What are the three layers of the cerebellar cortex (cerrebelum), and what do they contain?

A

Molecular layer (outer): Contains the branches (dendrites) of specialized neurons called Purkinje cells and axons called parallel fibers, where many connections happen.
Purkinje layer (middle): A single row of Purkinje cells, which act like master regulators. They collect all the input and send processed information to the deep nuclei.
Granular layer (inner): The entry point for signals coming into the cerebellum, where cells process input and pass it upward.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the three layers of the cerebellar cortex, and what do they do?

A

Granular (Inner) Layer:

Role: Collects information from other parts of the brain and body.
Analogy: Like a mailroom, receiving and sending signals upward.
Purkinje (Middle) Layer:

Role: Processes information and sends instructions out of the cerebellum.
Analogy: Like a control center, making decisions about movement.
Molecular (Outer) Layer:

Role: Connects granule cells and Purkinje cells for communication.
Analogy: Like a network of phone wires, facilitating communication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Question: What is the role of Purkinje cells in the cerebellum?

A

Answer:

Purkinje cells are the only neurons that send output from the cerebellar cortex.
They project to the deep cerebellar nuclei and control cerebellar output using inhibitory signals via GABA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Question: What are the two main types of afferent fibers in the cerebellum?

A

Answer:

Mossy fibers: Terminate in the granular layer and communicate with granule cells.
Climbing fibers: Directly synapse with Purkinje cells and sometimes project to deep nuclei.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Question: What is the “arbor vitae,” and what does it contain?

A

Answer: The “arbor vitae” is the branching pattern of white matter in the cerebellum. It contains:

Axons of Purkinje cells projecting to the deep nuclei.
Afferent axons like mossy and climbing fibers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Question: What are the deep cerebellar nuclei, and what is their function?

A

Answer:

The nuclei include the dentate, emboliform, globose, and fastigial nuclei.
They are the primary output center, sending signals to influence movement.

These nuclei are like the cerebellum’s “output stations”, sending signals from the cerebellum to other parts of the brain and spinal cord to influence movement.

17
Q

What are the deep cerebellar nuclei, and what do they do?

A

Deep Cerebellar Nuclei: Dentate, Emboliform, Globose, Fastigial.
Location: Inside the white matter of the cerebellum.
Function:
Serve as the output stations of the cerebellum.
Receive inhibitory input from Purkinje cells via the neurotransmitter GABA.
Send refined motor instructions to other brain regions and the spinal cord to adjust and coordinate movements.
Analogy:
The deep cerebellar nuclei are like dispatch centers, processing instructions from the cerebellum and sending messages to motor areas to fine-tune movement.

18
Q

Question: What are afferent and efferent pathways in the cerebellum?

A

Afferent pathways bring sensory, somatosensory, and motor information into the cerebellum.
Efferent pathways send signals from the cerebellum to influence motor commands.

19
Q

What are afferent fibers, and how do they work in the cerebellum?

A

Afferent fibers bring incoming information to the cerebellum via the cerebellar peduncles.
Two types:
Mossy Fibers:
Carry general sensory and motor information.
Terminate in the granular layer and send signals indirectly to Purkinje cells.
Climbing Fibers:
Carry specific error-correcting signals.
Synapse directly with Purkinje cells.
Analogy:
Mossy fibers are like general delivery services, and climbing fibers are priority couriers focusing on specific details.

20
Q

What are efferent fibers, and how do they work in the cerebellum?

A

Efferent fibers send outgoing instructions from the cerebellum via the deep cerebellar nuclei.
Where the signals go:
Spinal cord: Adjusts muscle movements directly.
Brain: Modifies planned movements for better precision.
Analogy:
The cerebellum acts like a movement coach, refining actions and sending perfect instructions to ensure smooth performance.

21
Q

Question: What symptoms occur with damage to the flocculonodular lobe or vermis?

A

Disturbances in posture and balance.
Inability to stand or sit without falling over, even if limb coordination is preserved when lying down.

Analogy: Imagine a chair missing its central support. It collapses when you try to sit on it.

22
Q

Question: What deficits can occur due to damage to the anterior lobe of the cerebellum?

A

This can cause rigidity in your limbs, making them feel stiff and hard to move.
Analogy: Think of a rusty hinge—it still moves but with difficulty and resistance.

23
Q

Why does cerebellar damage affect the same side of the body (ipsilateral)?

A

The cerebellum communicates directly with the spinal cord on the same side of the body.
In some cases, it sends signals to the opposite side of the brain, but those signals cross back to the original side.

Analogy: Imagine sending a package through two couriers who meet and hand it off. Even if the couriers switch sides, the package still arrives back on its original route.

24
Q

What happens in unilateral damage to the neocerebellum?

A

Damage to one side of the neocerebellum affects the same side of the body (ipsilateral).
Causes uncoordinated movements (e.g., jerky motions while raising the hand).
Leads to an unsteady gait (difficulty walking steadily).

25
Q

What happens in bilateral damage to the neocerebellum?

A

Dysarthria: Slow, broken speech, with words split into syllables.
Cerebellar Ataxia: Staggering, unsteady movements affecting both arms and legs.
Common causes: alcohol intoxication or multiple sclerosis.

26
Q

What movement and eye coordination problems occur with neocerebellum damage?

A

Timing of Movements:

Disrupts rapid, pre-planned actions (e.g., throwing a ball).
Muscles fail to activate in the correct order or at the right time.
Eye Movement Problems:

Nystagmus: Rhythmic, uncontrollable eye movements.
Symptoms worsen when looking towards the damaged side.

27
Q

How does cerebellar damage affect rapid movements?

A

Speech becomes slow and broken, like separating syllables (“hel-lo”).
Both arms might move awkwardly, and walking becomes a staggering, wide-based motion (cerebellar ataxia).

Analogy: Think of someone trying to walk across ice—they spread their feet wide to avoid falling but still wobble unsteadily.

28
Q

How does cerebellar damage affect eye movements?

A

Damage can cause nystagmus, where the eyes involuntarily flick back and forth, especially when looking to one side.

Analogy: Imagine a camera with a shaky tripod—it struggles to stay steady, especially when panning to one side.