Only $35.99/year

Terms in this set (11)

The medulla oblongata controls many SUBCONCIOUS, REGULATORY AFFAIRS. The messages to regulate these processes originally comes from the hypothalamus. Neurons from the hypothalamus synapse in the medulla oblongata, which sends the information to the body. The medulla oblongata essentially keeps you alive. It contains the decussation of pyramids, or the point where pyramidal/corticospinal motor tracts from the cortex cross over so that fibers from the right hand side of the brain control the left hand side of the body and visa versa. It contains the 4th ventricle and inferior cerebellar peduncles. It blends into the spinal cord at the foramen magnum. The medulla oblongata contains the inferior olivary nucleus, the point where afferent neurons coming up the spinal cord synapse before being taken to the cerebellum. So, the cerebellum is able to compare motor output (pons) with sensory input (medulla oblongata), which is very important for coordination. Information about balance from the vestibule also travels to the medulla oblongata's vestibular nuclear complex (VIII) before being sent to the sensory cortex by the thalamus. It contains a cochlear nucleus, which is related to hearing. When you are knocked unconscious and your cortex doesn't function properly, it is your medulla oblongata that keeps you alive by keeping your heart beating and your breathing regular. It sends motor neurons to the diaphragm to make you breathe diaphragmatically (long, spaced breaths) instead of intercostally when you are unconscious. It maintains your body's homeostasis. It contains motor nuclei including a cardiovascular centre (controls rate and force of heart beat), respiratory centre (controls rate, depth and rhythm of breathing) and a vasomotor centre (controls blood vessel diameter, which impacts on blood pressure). It also contains other cetres which control vomiting, swallowing, sneezing, coughing and hiccupping.
Cerebellar processing: the process by which your cerebellum compares motor output regarding desired movment with sensory input regarding your position and makes adjustments to your movement in order to coordinate it.

1. When you want to move, your premotor cortex sends information to your primary motor cortex about the desired movement .
2. The primary motor cortex motor impulses down through the brain stem to the body part you want to move.
3. Some of the motor information is diverted, however, as some of the motor neurons synapse in the pons and are diverted to the cerebellum.
4. This information tells the cerebellum that you want to move or are currently moving a part of your body.
5. At the same time, some of the sensory information travelling up through the spinal cord on its way to the thalamus (which diverts it to the appropriate area of the brain) is diverted to the cerebellum after some afferent neurons synapse in the olivary nucleus of the medulla oblongata. The result is that the cerebellum is able to compare your desired movement with cutaneous sensation to determine if your current body position is conductive to performance of movement.
6. Before the cerebellum allows you to perform the proposed movement (by allowing all motor information to travel directly to the body), it sends information to the motor cortex and brain stem nuclei to tweak the desired movement so that it is physically possible (that is, if the movement needs tweaking; if it doesn't, the movement is allowed to occur).
7. The motor cortex then tells your body to perform the desired movement.