Several cranial nerve nuclei are found there, as well as the inferior olivary nuclei , which are densely interconnected with the cerebellum and thought to play a role in motor control. The nucleus gracilis and nucleus cuneatus are both found in the medulla; they are important nuclei along a pathway called the dorsal columns-medial lemniscus , which carries sensory information to the brain.
The medulla's position as the lowest part of the brainstem also causes it to also be a conduit for a number of tracts that pass from the spinal cord into the brainstem and from the brainstem into the spinal cord. For example, the corticospinal tract a major descending tract for voluntary movementpasses from the medulla into the spinal cord.
The corticospinal tract and another tract called the corticobulbar tract , which is involved with movement of the head and neck, form triangular bundles of fibers in the medulla that create ridges on the outside of the brainstem. The bundles and associated ridges have been termed the medullary pyramids , and the corticospinal and corticobulbar tracts are often referred to as the pyramidal tracts because of their association with the pyramids. At the junction of the medulla and spinal cord, the corticospinal tract decussates , or crosses over to the other side of the body, before continuing down into the spinal cord.
The location of this decussation is referred to as the pyramidal decussation. Thus, the medulla oblongata's functions are extraordinarily diverse and include those that are essential to life as well as to other important activities like movement.
Due to its role in regulating vital functions, however, you could make the argument that the medulla is perhaps the most important area of the brain. Nolte J. Philadelphia, PA.
Memory is another complex function of the brain. The things we've done, learned, and seen are first processed in the cortex. Then, if we sense that this information is important enough to remember permanently, it's passed inward to other regions of the brain such as the hippocampus and amygdala for long-term storage and retrieval.
As these messages travel through the brain, they too create pathways that serve as the basis of memory. Different parts of the cerebrum move different body parts. The left side of the brain controls the movements of the right side of the body, and the right side of the brain controls the movements of the left side of the body. When you press your car's accelerator with your right foot, for example, it's the left side of your brain that sends the message allowing you to do it.
Basic body functions. A part of the peripheral nervous system called the autonomic nervous system controls many of the body processes we almost never need to think about, like breathing, digestion, sweating, and shivering.
The autonomic nervous system has two parts: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system prepares the body for sudden stress, like if you witness a robbery. When something frightening happens, the sympathetic nervous system makes the heart beat faster so that it sends blood quickly to the different body parts that might need it.
It also causes the adrenal glands at the top of the kidneys to release adrenaline, a hormone that helps give extra power to the muscles for a quick getaway. This process is known as the body's "fight or flight" response. The parasympathetic nervous system does the exact opposite: It prepares the body for rest. It also helps the digestive tract move along so our bodies can efficiently take in nutrients from the food we eat. Sight probably tells us more about the world than any other sense.
Light entering the eye forms an upside-down image on the retina. The retina transforms the light into nerve signals for the brain. The brain then turns the image right-side up and tells us what we are seeing. Every sound we hear is the result of sound waves entering our ears and making our eardrums vibrate. These vibrations then move along the tiny bones of the middle ear and turned into nerve signals. The cortex processes these signals, telling us what we're hearing. The tongue contains small groups of sensory cells called taste buds that react to chemicals in foods.
Classification 4. Cladistics 6: Human Physiology 1. Digestion 2. The Blood System 3. Disease Defences 4. Gas Exchange 5. Homeostasis Higher Level 7: Nucleic Acids 1. DNA Structure 2. Transcription 3. Translation 8: Metabolism 1. Metabolism 2. Cell Respiration 3. Photosynthesis 9: Plant Biology 1. The AVN passes the wave of excitation down the bundle of His towards the apex of the heart. The bundle of His then branches into the Purkinje fibres which carry the wave upwards.
This causes the ventricles to contract. The SAN is connected to two nerves originating from the medulla oblongata in the brain. The accelerator nerve is part of the sympathetic nervous system and increases the rate of impulse release from the SAN. This increases the heart rate.
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