Patient with a missing cerebellum
- Dashboard
- Patient with a missing cerebellum
Most Recent Score Report
| Questions Correct | Questions Answered | Time Spent | Status | Attempt Date | |
|---|---|---|---|---|---|
| -- | -- | -- | -- | -- |
Previous Score Reports
| Questions Correct | Questions Answered | Time Spent | Status | Attempt Date | |
|---|---|---|---|---|---|
| -- | -- | -- | -- | -- |
Patient with a missing cerebellum
Array
(
[passage] => WP_Post Object
(
[ID] => 558495
[post_author] => 12815
[post_date] => 2024-12-25 13:32:44
[post_date_gmt] => 2024-12-25 18:32:44
[post_content] => Practice Passage (Question 1-5)
*This passage is the property of Khan Academy and has been reformatted into an AAMC-style interface in their entirety by MedLife Mastery. MedLife Mastery does not endorse and is not an affiliate of Khan Academy.
In September of 2014, a 24-year-old woman entered a clinic reporting symptoms of dizziness and nausea. Upon a Computerized Tomography (CT) scan, physicians were fascinated to discover that the patient completely lacked a cerebellum. The empty space in her brain was filled with cerebrospinal fluid, which is important for immune processes and the prevention of shock trauma to the spine. See Figure 1.
Figure 1. The CT scan of the patient. Notice the missing cerebellum on the right side.
The cerebellum is a portion of the hindbrain that is involved in balance, movement, and fine motor control. Recent research suggests that it might also be involved in the fear and pleasure response. The cerebellum contains a significant amount of Purkinje fibers, a specialized neuron hallmarked by its unique dendrite layer. Due to this distinctive structure, Purkinje fibers are able to accommodate more synaptic information than any other type of neuron. Because of this specialization, they exist in greater quantities where speed and efficiency of neural signalling are critical. Purkinje fibers are often connected by gap junctions or desmosomes.
In an effort to explore the potential further effects of a missing cerebellum, scientists performed neurosurgery on male mice to remove the cerebellum. The mice were divided into two groups: a control group that underwent the operation and another that was sham-operated. The mice were then tested for a number of factors, including hormonal levels and sensory awareness. Vision, smell, and taste abilities of the experimental group were not significantly different from the control group. Further, testosterone and ADH levels were no different than average. However, cortisol, the hormone that instigates the fear response, had significantly lower levels in the experimental group.
Source: Thompson, H. (2014). Woman of 24 found to have no cerebellum in her brain. NewScientist Health. Issue 2986.
[post_title] => Patient with a missing cerebellum
[post_excerpt] =>
[post_status] => publish
[comment_status] => closed
[ping_status] => closed
[post_password] =>
[post_name] => patient-with-a-missing-cerebellum
[to_ping] =>
[pinged] =>
[post_modified] => 2024-12-25 13:32:44
[post_modified_gmt] => 2024-12-25 18:32:44
[post_content_filtered] =>
[post_parent] => 0
[guid] => https://medlifemastery.com/?post_type=passage&p=558495
[menu_order] => 0
[post_type] => passage
[post_mime_type] =>
[comment_count] => 0
[filter] => raw
)
[questions] => Array
(
[0] => Array
(
[quiz_unique_key] => 578908434
[question] => What is a viable prediction from the mice study?
[value] => Array
(
[answer] => 4
[description] => Reason for the Correct Answer:
The only difference between the experimental and control group is that the experimental group had lower cortisol levels.
Cortisol is involved in the fear response. In other words, it is involved in the sympathetic nervous system response.
A decrease in sympathetic stimulation would result in a lower heart rate and blood pressure for the experimental group.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. The experimental group will have more relaxed bronchi
)
[1] => Array
(
[each_answer] => B. The control group will have slower digestive processes
)
[2] => Array
(
[each_answer] => C. The control group will have a slower heart rate
)
[3] => Array
(
[each_answer] => D. The experimental group will have decreased blood pressure
)
)
)
[1] => Array
(
[quiz_unique_key] => 3873426850
[question] => What does the patient’s ability to properly walk with minimal difficulty indicate about the brain?
[value] => Array
(
[answer] => 2
[description] => Reason for the Correct Answer:
It is an established fact that the cerebellum is primarily responsible for motor control.
If someone does not have a cerebellum but can still control their movement, it means another part of the brain has taken over the role.
Note that if the cerebellum works with other parts of the brain, then lacking a cerebellum would still result in immobility, as the cerebellum is still required to walk.
This situation is an example of brain plasticity, or the brain’s ability to adapt to different situations.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. The cerebellum is not involved in motor control
)
[1] => Array
(
[each_answer] => B. It is evidence of the brain’s plasticity
)
[2] => Array
(
[each_answer] => C. The cerebellum has other functions not fully understood
)
[3] => Array
(
[each_answer] => D. The cerebellum works with other parts of the brain to regulate movement
)
)
)
[2] => Array
(
[quiz_unique_key] => 83407773
[question] => What are other potential symptoms the patient might experience?
[value] => Array
(
[answer] => 4
[description] => Reason for the Correct Answer:
The cerebrum is responsible for complex reasoning. The patient’s cerebrum is intact (Figure 1).
The hippocampus is involved in recalling information.
The hypothalamus is responsible for maintaining homeostasis.
The cerebellum is not only involved in motor control. It also controls speech. Lacking a cerebellum might result in delayed language development.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. She might incapable of engaging in complex reasoning
)
[1] => Array
(
[each_answer] => B. She might be unable to properly maintain her body temperature
)
[2] => Array
(
[each_answer] => C. She might have difficulty remembering information
)
[3] => Array
(
[each_answer] => D. She might have had delayed language development as a child
)
)
)
[3] => Array
(
[quiz_unique_key] => 2261298308
[question] => What might be an underlying consequence of the patient’s condition?
[value] => Array
(
[answer] => 2
[description] => Reason for the Correct Answer:
The space where the patient’s cerebellum should be is filled with cerebrospinal fluid.
The passage states that cerebrospinal fluid is involved in the immune response and prevention of shock trauma.
As such, the patient would have a decreased risk of disease and a decreased risk of physical cranial trauma.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. She is more susceptible to physical cranial trauma
)
[1] => Array
(
[each_answer] => B. She has a decreased risk of contracting neurological disease
)
[2] => Array
(
[each_answer] => C. She would have decreased cranial pressure inside her skull
)
[3] => Array
(
[each_answer] => D. She would have greater difficulty falling asleep
)
)
)
[4] => Array
(
[quiz_unique_key] => 574431310
[question] => Where else might a large concentration of Purkinje fibers be located?
[value] => Array
(
[answer] => 2
[description] => Reason for the Correct Answer:
Purkinje fibers are able to transmit high amounts of information quickly.
The passage states that Purkinje fibers are often connected by gap junctions.
One of the hallmarks of cardiac muscle is that its connections are made of gap junctions. Further, the heart must be able to quickly respond to environmental change in order to maintain homeostasis, requiring the quick information processing Purkinje fibers provide.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. The biceps
)
[1] => Array
(
[each_answer] => B. The heart
)
[2] => Array
(
[each_answer] => C. The lungs
)
[3] => Array
(
[each_answer] => D. The liver
)
)
)
)
[total_question] => 5
[correct_answers] => Array
(
[558495|1] => D
[558495|2] => B
[558495|3] => D
[558495|4] => B
[558495|5] => B
)
[hide_display_feedback_settings] =>
[hide_solutions] =>
)
