1. The Pons and Cerebellum

2. The Pons
The pons is a section of the brain stem that lies between the midbrain and the medulla oblongata
Visually it looks like an enlarged section of the medulla oblongata
It’s the “butt” of the brain stem
However the actual structure of the pons and its function are quite different

3. The Pons The cerebellum lies dorsal to the pons
The pons links the cerebellum with the midbrain, diencephalon, cerebrum, medulla and spinal cord

4. The Pons The pons serves as the gateway between sections of the brain
It also has several other important functions
These include sensory visceral and somatic organ control, motor visceral and somatic organ control and coordination of signals during sleep
The pons is directly responsible for the stage of sleep called REM sleep

5. Video https://www.youtube.com/watc h?v=mNdRoeVthVM
/sleep-cycle-alarm- clock/id ?mt=8
Interesting App…

6. Components of the Pons
The pons contains four different types of components
1) Sensory and motor nuclei of control nerves
These enervate the jaw, the anterior surface of the face, one of the eye muscles and sense organs of the internal ear

7. Components of the Pons
2) Nuclei involved with the control of respiration
On each side of the pons, the reticular formation continues from the medulla
The section in the pons has control centers that help the section of the medulla that controls respiration

8. Components of the Pons
3) Nuclei and tracts that process and relay information sent to or from the cerebellum
This is the section of the pons that we talked about earlier
It links the pons to the brain stem, cerebrum and spinal cord
This is how it relays information to higher sections of the brain

9. Components of the Pons 4) Ascending, descending and transverse tracts
These are sections of nerves that connect the pons to the cerebellum
These nerves connect the nuclei of the pons to the cerebellar nerves

10. The Cerebellum
The cerebellum is the autonomic processing center of the brain
It is also the site of processing for voluntary movement
This means it coordinates activities such as staying balanced with activities such as running

11. The Cerebellum
The cerebellum is the most identifiable part of the brain due to its highly folded structure
Folia are complex folds that cover the cerebellum surface
These are used to create a higher surface area and allow for a larger number of nerves in the cerebellum

12. The Cerebellum
The cerebellum is divided into two lobes, the anterior and the posterior lobes
These lobes are identified by their position in the cerebellum
The lobes are separated by the primary fissure

13. The Cerebellum
The cerebellum is also divided into two separate hemispheres
These hemispheres are termed the right hemisphere of the cerebellum and the left hemisphere of the cerebellum
They are divided by a ridge called the vermis

14. The Cerebellum
The cerebellum has a large number of specific nerve cells
These Purkinje cells have extensive dendrites that can connect to up to 200,000 synapses
This means that they can coordinate large amounts of information very quickly

15. Jobs of the Cerebellum
The cerebellum coordinates functions of balance and fine muscle control
Generally these jobs work together
A good example would be a person that has to jump to catch a fly ball
They have to be able to use fine motor control to be able to catch the ball and their balance to land safely

16. Jobs of the Cerebellum
To do this the cerebellum must communicate between the spinal cord and the higher levels of the brain to cause somatic, visceral and higher level changes
The information that is sent to the cerebellum is often coordinated or routed through the pons before it makes it to the Purkinje cells

17. Jobs of the Cerebellum
It is possible for someone to damage their cerebellum
A damaged cerebellum happens most often when there is trauma to the back of the head, from blood loss or from interference by drugs
People who are drunk tend to have trouble coordinating their motor control
This is because alcohol blocks messages being sent it the cerebellum

18. Video
h?v=Ny-tbJPsQgU
Yup…

19. Jobs of the Cerebellum
Ataxia is the result when the cerebellum is not functioning correctly
It can be temporary (in the case of alcohol) or permanent (in the case of a stroke)
Ataxia levels can range from having alight abilities to balance and loss of fine motor control
Severe ataxia can cause the inability to balance and use any motor control

20. Video https://www.youtube.com/watc h?v=mrt0Gq0zS4g
Cerebellum Dissection