Cerebellum: Gross anatomy

Question 1

Where is the cerebellum located in the brain?

Answer 1

The cerebellum is situated in the posterior cranial fossa, below the tentorium cerebelli, and lies posterior to the fourth ventricle, the pons, and the medulla oblongata.

Question 2

What is the largest part of the hindbrain?

Answer 2

The cerebellum.

Question 3

What are the highly convoluted folds of the cerebellum called?

Answer 3

Folia.

Question 4

What are the main functions of the cerebellum?

Answer 4

Controls posture and voluntary movements.
Influences smooth contraction of voluntary muscles.
Coordinates muscle actions and relaxation of antagonistic muscles.

Question 5

What is the shape of the cerebellum, and how is it structured?

Answer 5

The cerebellum is ovoid in shape, with a constricted median part. It consists of two cerebellar hemispheres joined by a narrow median vermis.

Question 6

What is the role of the vermis in the cerebellum?

Answer 6

The vermis connects the two cerebellar hemispheres and contributes to body posture and coordination.

Question 7

What are the three main lobes of the cerebellum?

Answer 7

Anterior lobe
Posterior lobe
Flocculonodular lobe

Question 8

What does the primary fissure of the cerebellum separate?

Answer 8

The primary fissure separates the anterior and posterior lobes.

Question 9

What does the posterolateral fissure of the cerebellum separate?

Answer 9

The posterolateral fissure separates the posterior lobe from the flocculonodular lobe.

Question 10

What is the significance of the horizontal fissure in the cerebellum?

Answer 10

The horizontal fissure is a deep fissure along the margin of the cerebellum, separating the superior and inferior surfaces. It has no morphological or functional significance.

Question 11

What are the three main components of the cerebellum’s gross anatomy?

Answer 11

Outer gray matter (cerebellar cortex)
Inner white matter
Deep nuclei

Question 12

What is the distinctive tree-like appearance of cerebellar white matter called?

Answer 12

Arbor vitae.

Question 13

Name the four deep cerebellar nuclei.

Answer 13

Dentate
Globose
Emboliform
Fastigial

Question 14

What is the function of the deep cerebellar nuclei?

Answer 14

They act as the main output centers for the cerebellum, processing information from the cerebellar cortex and sending it to other parts of the brain.

Question 15

What are the three cerebellar peduncles, and what do they connect?

Answer 15

• Superior cerebellar peduncle: Connects cerebellum to midbrain.
• Middle cerebellar peduncle: Connects cerebellum to pons.
• Inferior cerebellar peduncle: Connects cerebellum to medulla.

Question 16

What is the primary role of the superior cerebellar peduncle?

Answer 16

• Contains mostly efferent fibers to the thalamus and red nucleus.
• Afferent fibers from the ventral spinothalamic tract.
• Conveys sensation and proprioception.

Question 17

What is the function of the middle cerebellar peduncle?

Answer 17

Largest peduncle.
Transmits motor information from the cerebral cortex and pons to the cerebellum via the corticopontocerebellar pathway.

Question 18

What is the function of the inferior cerebellar peduncle?

Answer 18

Carries efferent and afferent fibers.
Integrates proprioceptive sensory information and motor functions like balance through the dorsal spinocerebellar tract.

Question 19

What are the three zones of the cerebellum?

Answer 19

Vermis: Located in the midline.
Intermediate zone: Adjacent to the vermis.
Lateral hemispheres: Lateral to the intermediate zone.

Question 20

What are the functional divisions of the cerebellum and their roles?

Answer 20

• Cerebrocerebellum (Lateral Zone)
• Spinocerebellum (Vermis & Intermediate Zone)
• Vestibulocerebellum (Flocculonodular Lobe)

Question 21

What are the functions of the Cerebrocerebellum?

Answer 21

• Planning movements and motor learning.
• Inputs from cerebral cortex and pontine nuclei; outputs to thalamus and red nucleus.
• Coordinates muscle activation.

Question 22

What are the functions of the spinocerebellum?

Answer 22

Regulates body movements with error correction.
Receives proprioceptive input.

Question 23

What are the functions of the Vestibulocerebellum (Flocculonodular Lobe)?

Answer 23

Controls balance and ocular reflexes.
Inputs from the vestibular system; outputs to vestibular nuclei.

Question 24

What are the major fissures of the cerebellum?

Answer 24

• Primary fissure: Separates anterior and posterior lobes.
• Posterolateral fissure: Separates posterior and flocculonodular lobes.
• Horizontal fissure: Divides superior and inferior surfaces (no functional significance).

Question 25

What is the "arbor vitae" of the cerebellum?

Answer 25

The tree-like pattern of white matter in the cerebellum.

Question 26

What are the functions of the dentate nucleus?

Answer 26

- Involved in planning, initiation, and control of voluntary movements, especially fine motor tasks. - Coordinates output to the motor and premotor areas of the cerebral cortex via the thalamus. - Functional Division Association: Linked with the cerebrocerebellum (lateral zone).

Question 27

What are the functions of the Globose and Emboliform Nuclei (Interposed Nuclei)?

Answer 27

- Control of proximal limb movements. - Modulate movement through connections to the red nucleus (rubrospinal tract). - Assist in error correction during ongoing movements. - Functional Division Association: Linked with the spinocerebellum (vermis and intermediate zones).

Question 28

Describe the functions of the Fastigial Nucleus

Answer 28

- Involved in balance, posture, and eye movement control. - Regulates axial and proximal musculature by influencing the vestibulospinal and reticulospinal tracts. - Plays a key role in controlling gaze stabilization and equilibrium. - Functional Division Association: Linked with the vestibulocerebellum (flocculonodular lobe) and parts of the spinocerebellum.

Question 29

What are common signs of cerebellar disease?

Answer 29

- Hypotonia: Reduced muscle tone. - Altered gait: Wide-based, lurching, staggering gait. - Ataxia: Disturbance in voluntary movements, intentional tremor, and past-pointing. - Dysdiadochokinesia: Difficulty performing rapid alternating movements. - Dysarthria: Speech difficulties. - Nystagmus: Involuntary eye movements.