L1 - Introduction and Nervous System

Question 1

Dualism

Answer 1

The mind and the brain are distinct.

Descartes’ notion that the mind is subject only to spiritual interactions while the body is subject only to material interactions. Rejected by modern mainstream neuroscientists – who argue that all the workings of the mind can be understood as purely physical processes that occur in the material world, specifically in the brain.

Question 2

Neurons

Answer 2

The basic unit of the nervous system (a.k.a. nerve cell)

There are an estimated 86 billion nerve cells in one’s head. The contact points between neurons are called synapses, of which there are trillions, and extensions of neurons are known as axons – which are incredibly slender but long (up to several feet)

All neurons feature input, integration, conduction, and output zones. There are three main structures of neurons = multipolar, bipolar, unipolar neurons.

We have pre-synaptic and post-synaptic neurons – and many drugs only work on one or the other.

Information transmission/communication occurs at the synapse.

Flow of information is in one direction, along the neuron and the synapse.

There are different functional types of neurons (e.g., motor vs. sensory neurons)

Question 3

Glial Cells

Answer 3

Nonneuronal nervous system support cells, which provide structural, functional and other types of support (e.g., supplying neurons with more energy to enable action potentials, breaking down debris that forms/synaptic spillage). They are particularly important after brain damage. Some work in the CNS, others in the PNS.

Types of Glial Cells Include:
* Astrocyte (star-shaped): ensure that neurons receive nutrients from the blood.
* Microglia (small): keep things cleaned up.
* Oligodendrocyte: fatty myelin for central nervous system (brain and spinal cord) + other functions
* Schwann cell: fatty myelin for peripheral nervous system.

Question 4

Central Nervous System

Answer 4

Composed of the brain and the spinal cord.

The cerebral cortex is part of the CNS - it is the outermost layer of the brain (a thin sheet with folds - gyri/hills and sulci/valleys). It is responsible for a majority of the brain’s computations.

Question 5

Peripheral Nervous System

Answer 5

PNS consists of all the nerves and neurons outside of the brain and spinal cord. More specifically, the cranial nerves, the spinal nerves (which make up the somatic nervous system) and then the autonomic nervous system.

Subdivisions of the ANS:
* Sympathetic
* Parasympathetic
* Enteric