The brain’s complexity can often be difficult to understand because it serves so many important functions.
In this lesson, you’ll get a little help from Nrr, the alien biologist, who will guide you through understanding the structure and functions of the human brain.
This is Nrr. He is a biologist who has come to Earth to study Human Neurobiology.
This is Phil. He is Nrr’s research subject.One night, Nrr and his research assistant Blrr brought Phil onboard their research ship while he was sleeping and implanted a brain-monitoring device. They then released the subject back into his native habitat (his house) without him ever knowing what happened.
Now Nrr and Blrr can monitor Phil’s every thought and emotion and map the parts of his brain that are stimulated in any given situation. They can even see and hear everything that Phil’s ears and eyes can!After three weeks of monitoring Phil’s brain activity, his different body functions, his thoughts and even tracing some of the neural signals sent to and from the brain, all of the data has now been processed by the research ship’s powerful central computer. Now the results are in, and Nrr is not disappointed. In front of him is a diagram of the human brain with a list of biological functions associated with each part. Let’s take a look at that diagram and see what Nrr discovered about the human brain. This diagram shows basically what the human brain looks like if it was cut in half just about in the middle between the right and left sides, so that Nrr can see what the structures in the middle of the brain look like.
We’ll start with the brain stem which is the part of the brain that connects to the spinal cord, Nrr discovered that the brain stem regulated many vital, but basic processes such as regulates heart rate, breathing, blood pressure, swallowing, and digestion.
This wasn’t too big a surprise because these are mostly autonomic functions and the brainstem controls them without Phil having to think about them. It makes sense that these functions are controlled by the part of the brain closest to the spinal cord, because there is no reason for the signal to go any further into the conscious part of Phil’s brain to make a decision.
For the most part, the brainstem can handle the relatively simple processing required to regulate these autonomic functions on its own.
Located just above the brain stem is the hippocampus. The hippocampus is a brain structure which is critical for the formation of new memories and spatial orientation. Nrr’s studies indicated that this part of the brain might be important for memory formation and spatial orientation. However, we know that these are critical roles of the hippocampus because several studies of people with extensive hippocampal damage have shown that they cannot form new long-term memories after the damage and find themselves easily disoriented.
In addition, in Alzheimer’s disease, the hippocampus is one of the first parts of the brain that sustains damage, and memory loss and disorientation are among the first symptoms of the disease .
Above the forward part of the hippocampus is a brain structure called the hypothalamus. The hypothalamus is the part of the brain that tells the body what it needs to do to survive and reproduce. It controls the internal thermostat of the body, hunger, thirst, the Fight or Flight response, the Rest and Digest Response and mating behavior.
About a week ago, Blrr observed a major stimulation of the hypothalamus when Phil came across a bear on a hike, and the Fight or Flight Response was activated by the hypothalamus. After Phil was a safe distance away from the bear, the Fight or Flight Response was shut down and the hypothalamus activated the Rest and Digest Response to allow Phil to recover from his close call with the bear.
A little bit above and behind the hypothalamus is the thalamus, which is the relay station for sensory information to the cerebral cortex. The thalamus receives sensory signals from all of the sensory systems except for the olfactory system. It then processes the signals and sends them along to their associated area of the cerebral cortex where they are integrated with the conscious mind.
The thalamus also controls Phil’s conscious state, or basically if he is asleep or awake and how alert he is.Sleep is basically a state where no sensory signals are sent to the cerebral cortex, and therefore the person is not aware of any of their senses. The sensory organs are still functioning and sending signals to the thalamus, but during sleep, the thalamus doesn’t send the signals to the cerebral cortex.
The olfactory bulbs are the structures in the brain that process signals from the olfactory sensory neurons.
Even though Nrr didn’t know the name of these structures, he had been fairly certain that they were involved in processing the sense of smell because they are located right next to the chemoreceptors in the nasal cavity that humans use to sense odors, and the chemoreceptors send signals directly to the olfactory bulbs, but it was good to get confirmation from the computer analysis anyway.
The cerebellum is located in the back of the skull behind the brainstem and coordinates movement, balance and hand-eye coordination.
The cerebellum does not initiate body movements. Instead, the cerebellum receives sensory inputs about the states of the muscles and the positioning of all the parts of the body as well as visual input. It then fine-tunes the motor outputs to adjust the positions of the body parts to maintain balance and coordinate body movements to achieve the desired action.
So let’s review, the brain stem is the part of the brain that connects to the spinal cord. The brain stem regulates many vital, but basic processes such as heart rate, breathing, blood pressure, swallowing and digestion.Located just above the brain stem is the hippocampus.
The hippocampus is a brain structure which is critical for the formation of new memories and spatial orientation.Above the forward part of the hippocampus is a brain structure called the hypothalamus. The hypothalamus is the part of the brain that tells the body what it needs to do to survive and reproduce It controls the internal thermostat of the body, hunger, thirst, the Fight or Flight response, the Rest and Digest Response and mating behavior.A little bit above and behind the hypothalamus is the thalamus which is the relay station for sensory information to the cerebral cortex.
The thalamus receives sensory signals from all of the sensory systems except for the olfactory system. It then processes the signals and sends them along to their associated area of the cerebral cortex, where they are integrated with the conscious mind.The olfactory bulbs are the structures in the brain that process signals from the olfactory sensory neurons.And finally, the cerebellum is located in the back of the skull behind the brainstem and coordinates movement, balance, and hand-eye coordination.