Neural Communication and Brain Function Overview

Neurons are the basic building blocks of the nervous system, analogous to wiring in a car.
Sensory neurons gather information from sensory receptors, transmitting it to the brain and spinal cord.
Motor neurons send commands from the brain/spinal cord to muscles and glands.
Interneurons process information internally within the brain and spinal cord.

Neurons transmit information as electrical impulses known as action potentials.
This process is initiated by signals from sensory receptors or neighboring neurons.
Resting potential: A neuron at rest is polarized, with a negative charge inside compared to the outside.
Upon firing, sodium ions rush into the neuron, leading to depolarization and subsequently triggering an action potential.
The action potential travels down the axon's length to the axon terminals.

At the axon's end, the action potential causes the release of neurotransmitters, which are chemical messengers.
These molecules cross the synaptic gap to bind with receptor sites on the receiving neuron's dendrites.
Reuptake: After signaling, the excess neurotransmitters are reabsorbed by the sending neuron.
- Example: Acetylcholine (ACh) influences muscle contraction and memory.
Neurotransmitter activity can be affected by drugs (agonists mimic neurotransmitters, antagonists block them).

Comprises the brain and spinal cord; processes information and directs responses.

Connects CNS to the body's muscles and organs, subdivided into:
- Somatic nervous system (voluntary muscle movements)
- Autonomic nervous system (controls involuntary actions such as digestion; further divided into sympathetic and parasympathetic systems).

Comprises glands that release hormones into the bloodstream, influencing various body functions.
The pituitary gland is the master gland, regulating other glands and bodily functions.

The brain's lower structures regulate basic life functions; higher structures process complex decisions and emotions.
The limbic system plays a crucial role in emotions and drives, comprising structures like the amygdala (aggression and fear) and hippocampus (memory).

Cerebral cortex: The brain's outer layer where higher-level thinking occurs, divided into lobes:
- Frontal lobes: Involved in planning and decision-making.
- Parietal lobes: Sensory input processing.
- Occipital lobes: Visual processing.
- Temporal lobes: Auditory processing and memory.

Split-brain research shows that each hemisphere has specialized functions.
The left hemisphere is typically involved in language and logic, whereas the right hemisphere excels in creativity and spatial abilities.

The brain's capacity to change and adapt, particularly after injury or during development.
This plasticity allows for the recovery of functions, especially in younger individuals.
Experimentations have shown that engaging in therapies can stimulate reorganization of neuronal pathways.