Skip to 0 minutes and 14 secondsProbably you’ve heard someone say: this is your brain on anger, this is your brain on love, or this is your brain choosing the next president. Without a doubt, brain and neurosciences are now
Skip to 0 minutes and 26 secondssexy subjects: they are mentioned in newspapers Or in tv shows, and they are even portrayed in art. In this course, too, we will discuss neuroscientific topics and we’ll talk about the brain, explore its relationship with the body and examine how it can be effected by the food we eat. But before going further in our journey we
Skip to 0 minutes and 50 secondsneed the consider the brain’s characteristics: what makes it a special organ? How does it work? In humans, the brain is the third largest organ behind the skin and the liver, and it's responsible for functions such as m emory emotion language and motor control. It is also responsible for other functions, that
Skip to 1 minute and 13 secondswe might regard as more ‘automatic’: regulation of wakefulness of temperature or of feeding behavior This large number of functions is made possible by the complex architecture of the brain, and by the special characteristics of its most famous cell, the neuron. Neurons can have different shapes and are present both in the brain and outside of itbut
Skip to 1 minute and 38 secondsthey all share some characteristics: they are excitable by electricity and can receive, process and transmit signals. These signal can pass from cell to cell in correspondence of specific structures, the synapses. In an hypothetical ‘standard’ neuron ynapses are densely packed along the dendritesa tree-like structure of the cell that forms one end of the neuron. Going towards the other end we can find a cell body, or ‘soma’ that contains most of the necessary biochemical machinery and the cell nucleus. The last part of our prototypical neuron is the axon a thin projection that acts just an electrical cable and transmits electrical pulses.
Skip to 2 minutes and 32 secondsJust like cables, axons can have an insulating layer – unlike cables, it is not made of rubber, but rather of myelin. Myelin is a fatty substance and it’s whitish in colour – that’s why portions of the brain, where bundles of axons connect different areas, are not grey like we would imagine, but white. The so called ‘grey matter’ is mostly located in the external area of the brain, the cortex, where the cell bodies are more densely packed, and in nuclei buried inside the white matter. The brain is not made only of grey and white
Skip to 3 minutes and 13 secondsmatter: about 10% of his volume is constituted of a clear liquid, the so called cerebrospinal fluidthat cushions the brain and helps maintaining a stable chemical environment. keeping a stable environment – in other words, homeostasis, is crucial for the functioning of the brain. This task is not assigned to neurons, but to other cells. About half of the brain cell compose the so called glia. Glial cells surround neurons, supply nutrients to them, help in fighting infection and removing unwanted substances The brain is a crucial organ, protected by multiple structures. One of them, the blood brain barrier, blocks the entry of unwanted molecules and helps in maintaining homeostasis. It separates the brain from blood circulation and it’s highly selective, permitting the
Skip to 4 minutes and 14 secondstransit only of specific categories of molecules: water, some gases and molecules soluble in fat. The blood brain barrier has also mechanisms to transport molecules needed by the brain, such as glucose, and to block the entry of potentially dangerous molecules. This structure is one of the reasons why the brain is not directly affected by most substances we ingest, even if is only one part of the complete picture.
Introduction to the brain
What are the basic characteristics of the brain? What is a neuron?
In this video, we start discussing the brain and its basic characteristics - its macroanatomy, such as the subdivision in grey and white matter, the cerebrospinal fluid and the blood-brain barrier.
This description will continue in the next two steps of this activity - by the time you will reach your first quiz, we will have covered some basic aspects that will help you understand better some notions discussed in the rest of the course.