cervello elabora dati

Can we live without some parts of the brain? Yes, but there are indispensable areas: which are

The human brain is a complex interconnected systembut some areas play a crucial and not replaceable role for survival, while others are not fundamental for life. The fundamental brain areas For our survival they are mainly those involved in the control of automatic vital functions, such as breathingheartbeat and body temperature regulation. These functions mainly depend on encephalic trunkwhich represents a sort of “command center” for the basic activities necessary for life. In addition to the brain trunk, other regions such as thehypothalamus and the limbic system They regulate adaptation to external and internal conditions and contribute to the regulation of essential processes such as the energy balance and the response to stress. Also the cerebral cortexalthough not directly involved in vital functions, plays an important role in maintenance of survival through the control of complex behaviors and the interaction with the environment. While injuries to the brain trunk and the hypothalamus are often fatal Because they compromise vital functions, even the malfunction of the limbic system or the cerebral cortex, although not fatal, can make Difficult to respond to dangerous situationscompromising the ability to survive in a hostile environment.

The role of the brain trunk: the vital functions operating center

The brain trunk, located at the base of the brain, consists of three main structures: the lengthened cordThe bridge and the mid-brain. These areas are responsible for the automatic regulation of functions such as:

  • Breathing: the elongated core contains the respiratory centers that regulate the rhythm of the breath, adapting it to the needs of the body (for example during physical effort).
  • Heartbeat: Always in the elongated marrow there are the centers that control heart rate and blood pressure.
  • Regulation of the reflection of vomiting, cough and swallowing: These apparently trivial functions are essential to avoid suffering or physical damage and are controlled both by the cunning marrow and by the bridge.

Furthermore, bridge and mesencephalous are involved in the modulation and integration of the reflections and of theArousal, The widespread condition of attention that allows us to raise the surveillance suddenly as much as we understand imminent dangers.

Image
The encephalic trunk, with its various parts in evidence: the mesencefalo (Midbrain), the bridge (Pons) and the core marrow (medulla). Credit: Blausen.com Staff (2014). Medical Gallery of Blausen Medical 2014, via Wikimedia Commons.

Without the brain trunk, The body would lose the ability to maintain its fundamental vital functions independently And injuries to this area are almost always fatalbecause they compromise functions like the breathing and the heartbeat. The control of these functions is however the result of a complicated network of neurons on various levels involving the for example spinal cord for the reflection of breathing and heartbeat, and the prossencephal for the processing of metabolic information.

Hypothalamus: the thermostat and the director of the body

Just thehypothalamus It is one of those structures found in prossencephalprecisely in the center of our skull, but with a huge role in controlling survival. Thanks to the hypothalamus, the body can adapt to the variations of the internal and external environment. An injury to this part of the brain would be fatal.

Image
The hypothalamus. Credit: Life Science Databases, via Wikimedia Commons.

Despite being a small structure, it is densely populated by neural nuclei that regulate the following functions:

  • Body temperature: Through signals to the autonomous nervous system, it maintains the body at an ideal temperature for cellular functioning.
  • The water and energy balance: through the arched core and the lateral hypothalamic area, control the thirst, hunger and the sense of satiety, allowing the body to receive and use the resources necessary for life.
  • The hormonal response: stimulates the production of various hormones, such as oxytocin, vasopressin and above all cortisol through the hypothalamic-pituitary-legal axis, essential for face emergency situations.
  • The circadian rhythm: in the part of the hypothalamus called the suprachiasmatic nucleus the Sleep-wake cycle adjustmentin concert with some areas of the brain trunk such as the bridge and the mesencephalon.

The limbic system: emotions and essential reactions

The limbic systemterm coined in 1952 by the American physiologist Paul D. Maclean To indicate a set of crucial structures in emotional responses, attention and memories, at first glance it would not seem so important. Yet, on closer inspection, the emotions they are the closer to the programs written for Avoid dangers and maximize the survival chances. For example:

  • THE’amigdala activate the answers of struggle or escape Faced with a threat, preparing the body to act. It is closely connected to the Prossencephalon and is involved in thelearningin memory and attention in response to emotionally significant stimuli. To a particular structure of the amygdala, the Basolateral complex, input arrive from all sensory systems, and is therefore crucial for escape from a danger.
  • THE’hippocampus It contributes to forming and recovering useful memories to avoid future dangers. The injury to the hippocampus or nearby areas that connect it to the neocortex they produce serious memory deficits.

These emotional and mnemonic functions are fundamental to ensure that our behavior is adaptive and protection oriented. The injury of these parts of the brain, unlike the deeper ones seen before, does not involve instant death, but a drastic decrease in the possibilities of survival.

The cerebral cortex: decisions and planning

The cerebral cortex, if taken in an isolated way, does not compromise the basic vital functionsjust as the famous case of Phineas Gagethe worker pierced by a metal bar in the Orbitofrontal region, who procured him a massive export of cerebral matter of the cortex, but not death.

Image
Computerized reconstruction of the brain damage of Phineas Gage. Credits: Van Horn JD, Ireimia A, Torgerson cm, Chambers Mc, Kikinis R, et al., Via Wikimedia Commons.

There cerebral cortex It allows you to process complex strategies for survival. For example:

  • Frontal lobe: Plan actions and risk currency.
  • Parietal lobe: coordinates movement and interaction with the environment.
  • Occipital and temporal lobe: Elaborate visual and auditory information, allowing to identify dangers or opportunities.

Tendentially, with cortical injuries the individual continues to survivebut it would not be able to adapt to complex situations or to develop strategies to avoid risks. In the most serious cases, as in the case of injuries to the motor cortex or some area of ​​the sensory bark, The ability of movement and perception would be compromisedwith everything that follows.