2017 Group Project 6

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2017 Student Projects 
Student Projects: 1 Cerebral Cortex | 2 Kidney | 3 Heart | 4 Eye | 5 Lung | 6 Cerebellum
Student Page - here is the sample page I demonstrated with in the first labs.I remind all students that you have your own Group Forum on Moodle for your discussions, it is only accessible by members of your group.
Editing Links: Editing Basics | Images | Tables | Referencing | Journal Searches | Copyright | Font Colours | Virtual Slide Permalink | My Preferences | One Page Wiki Card | Printing | Movies | Language Translation | Student Movies | Using OpenOffice | Internet Browsers | Moodle | Navigation/Contribution | Term Link | Short URLs | 2018 Test Student

Cerebellum

Introduction

The cerebellum is a large portion of the brain that functions in coordination, balance and control, and its development occurs both prenatally and postnatally. The cerebellum underlies the occipital and temporal lobes of the cerebral cortex and constitutes to about 10% of the brains weight however contains around 50% of the neurons. This page will highlight the anatomy of the cerebellum, its developmental process, current research on the structure, animal models and abnormalities associated with it. The anatomy will discuss the distinguishable lobes and zones of the cerebellum. The anatomy of the cerebellum cannot be completely discussed without explaining the vasculature of the structure and hence this page will provide a brief overview of it. The development of the cerebellum discusses the neural development and where the cerebellum forms on the neural tube. The development will highlight how the circuitry of the post-natal cerebellum came to be from neurons. Hence purkinje cells, granule cells, deep nuclei cells, glia cells and cerebellar nuclei will be highlighted to discuss the developmental process. A developmental timeline of the formation of the cerebellum is also included on this page. The cerebellum is a topic of continuous research and past findings would not have been done without the use of animal models, hence key historical discoveries, current research and animal models will be discussed. The cerebellum is still being research and at the end of the page there are future questions listed on future investigations that could be performed. The abnormalities that could happen if the cerebellum were to be affected is also highlighted. Terms that may be difficult to understand have also been defined.

The following video provides a brief overview on the development of the cerebellum which will be heavily discussed on the page:

Basic Anatomy of the Cerebellum

The cerebellum has 3 distinguishable lobes; flocculonodular lobe, anterior lobe and the posterior lobe. The anterior and posterior lobe can be further divided in a midline cerebellar vermis and lateral cerebellar hemispheres (Figure 1) [1]. In a superior cerebellar view, the cerebellum contains a vermis that runs through the middle of the organ and 2 intermediate zones located laterally from the vermis (Figure 2).

Anatomical-Lobes-of-the-Cerebellum.jpg

Figure 1: Anatomical lobes observed in the cerebellum; anterior lobe, posterior lobe and flocculonodular lobe, which is divided by two fissures – the primary fissure and posterolateral fissure [2]

Cerebellum anatomical subdivisions.png

Figure 2: Superior view of the 3 cerebellar zones. The middle is the vermis. Either side of the vermis is the intermediate zone. Lateral to the intermediate zone is the lateral hemispheres. There is no difference in gross structure between the lateral hemispheres and intermediate zones. [3]


Figure 3: Diagram of the main arteries of the cerebellum [2]

Vasculature

The cerebellum contains 3 bilateral paired arteries which supplies this organ with oxygenated blood. These arteries all originate from the vertebrobasilar system; Superior Cerebellar Artery (SCA), Anterior Inferior Cerebellar Artery (AICA) and the Posterior inferior cerebellar artery (PICA). The SCA and AICA are branches of the basilar artery, which wraps around the anterior aspect of the pons before reaching the cerebellum. The PICA arises from the left and right vertebral artery, which form the basilar artery [4]. The PICA and AICA combine to supply the inferior half of the cerebellum, while the SCA supplies the majority of the superior half. The PICA and SCA combine to supply the vermis[5]. Blood is then drained by superior and inferior cerebellar veins into the superior petrosal and then straight dural venous sinuses. (Figure 3) [6]

Ectoderm

There are 3 germ layers present in the early embryo; ectoderm (most distal layer), mesoderm (middle layer) and endoderm (most proximal layer). The ectoderm differentiates into the nervous system, forming the spine, peripheral nerves, cerebrum and cerebellum. It also differentiates to form tooth enamel, epidermis, and the linings of the mouth, anus, sweat glands and nostrils[7].

Microanatomy

Cortical Layers

Figure 4: (A). Cell types and where they are found in the cerebellar cortical layers. (B) Shows how the different layers of the cerebellum can be easily determined. P - the Purkinje layer; G - the granular layer; M - the molecular layer; W - the white matter. [8]

There are 3 major cortical layers of the cerebellum: the molecular layer, the purkinje cell layer, and the granule cell layer. The molecular layer contains basket cells, stellate cells and the purkinje cell and Golgi cell d

  1. <pubmed> 9735944</pubmed>
  2. 2.0 2.1 Venturini, S. (2017, October 21). The Cerebellum. Retrieved October 23, 2017, from http://teachmeanatomy.info/neuro/structures/cerebellum/
  3. File:CerebellumDiv.png. (2016, December 15). Wikimedia Commons, the free media repository. Retrieved 12:48, October 24, 2017 from https://commons.wikimedia.org/w/index.php?title=File:CerebellumDiv.png&oldid=226277429.
  4. The Blood Supply of the Brain and Spinal Cord. (2001). In D. Purves, G. Augustine, & D. Fitzpatrick (Eds.), Neuroscience (2nd ed.). Sunderland, MA: Sinauer Associates.
  5. <pubmed> 2535662</pubmed>
  6. <pubmed> 27766499</pubmed>
  7. <pubmed> 14550785</pubmed>
  8. <pubmed>3527225</pubmed>