Models of the Human Mind and Divisions of the Nervous System

Comparative Neuroanatomy between humans and other animal findings

• size of brain is not proportional to animal’s intelligence

• the more neurons within brain = greater number of synaptic connections = greater complexity of functions the brain can support

• brains support functional specialisation = animals with particular types of skills have relatively larger brain areas dedicated to those skills

The Allen Brain Institute

A project that created detailed maps/atlases using data from mouse and human brains, from brain areas down to neurons and genes.

The Human Brain Project

An EU initiative focused on simulating neurons for brain-inspired computing = in silico neuroscience. Aims to reduce the need for animal experiments, study diseases in unprecedented in silico experiments and improve validation of data and experiments with computational validation

Central Nervous System (CNS)

brain + spinal cord = central processing unit of the nervous system

Peripheral Nervous System (PNS)

The network of nerves extending from the CNS throughout the body, sends messages from CNS to control muscle movement and receives sensory info to transmit to CNS. Includes somatic and autonomic systems

Somatic Nervous System

receives sensory info from sensory organs (input) and controls movement of skeletal muscle (output)

Efferent nerve fibers

send signals from the brain to muscles.

Afferent nerve fibers

send signals from peripheral sensory areas to the brain.

Autonomic Nervous System (ANS)

connects the central system to non-voluntary muscles and glands, mediating non-voluntary functions. Includes smooth muscle, cardiac muscle and glands. Consists of parasympathetic and sympathetic = regulate bodily functions through opposing influences. Also includes and enteric nervous system

Parasympathetic Nervous System

restoration and digestion during calm times - driven by increased acetylcholine. When activated signals from preganglionic neurons in brainstem and sacral part of spinal cord are sent to ganglia. Signal is passed to postganglionic neurons uses acetylcholine to regulate activity of target tissues

Sympathetic Nervous System

prepares body for activity during times of stress/excitement; = 'fight or flight'. driven by increased noradrenaline and adrenaline. when activated preganglionic neurons in thoracic lumbar spinal cords send signals to PNS and some send signals to chain of ganglia down spinal column. Postganglionic neurons transmit signal to target tissues. 3rd group of preganglionic neurons travels directly to adrenal gland to stimulate production of hormones like adrenaline that mediates stress response thruout body

Enteric Nervous System (ENS)

has own reflexes and senses that can act independently of brain (only part of PNS that acts autonomously). Plays major role in emotions and stress. Helps digestion

ganglia

clusters of neuronal cells bodies in peripheral nervous system near the organs or glands being controlled.