Nervous System Organization

CNS Central Nervous System

Consists of the brain and spinal cord

PNS (peripheral nervous system)

Any neural tissue outside of the brain and spinal cord belongs here

• nerves that connec the CNS to various organs and muscles

• neurons that form distinct clusters, or ganglia

Spinal Cord

Cylindrical bundle of nerve fibers enclosed in spine and connects nearly all parts of the body to the the brain, forms the CNS

Brain

Organ of soft nervous tissue contained in the skull of vertebrates, function- as the coordinat- center of sensation and intellectual and nervous activity, controls all body functions of a human being

Ventral

Toward the abdomen (underside) of the body or the underside of the head in non-human animals (Ventra = abdomen)

Dorsal

Toward the back of the body/top of the head in non-human animals when they hold their head high; ambiguous in humans (dorsa = back)

Medial

Toward the organism’s midline

Lateral

toward the L or R sides of the body; for brain: toward the L or R right sides of the skull

Superior

Toward the top of the head in humans

Inferior

Toward the bottom of the feet in humans, when standing upright, for the brain: toward the neck

Coronal

Cut through human body transversely, at right angles to the body’s long axis

Brain: a plane that is parallel to the face and perpendicular to the midsaggital and horizontal planes

Like a bread loaf

Sagittal

Divides body into right and left sections, running from front to back

Ipsilateral

On the same side (right arm and right leg)

Contralateral

on the opposite side of the midline (right arm and left leg)

Neuron

specialized cell transmitting nerve impulses; a nerve cell

Glial Cell

a non-neuronal cell type that is a prominent component of the NS; includes astrocytes, microglgia, olgiodendrocytes, and Schwann cells

Axon

long and thin neuronal process that remain relatively constant in thickness along its length; main function conducting action potentials over long distances

Dendrite

Parts of a neuron that taper as they extend away from the cell body and often branch repeatedly; tend to be covered with synapses

Brain Lobes

Frontal Lobe, Parietal Lobe, Occipital Lobe, Temporal Lobe, and Insular Lobe

Sulcus

inward fold/groove of the cerebral cortex; valleys of the brain wrinkles

Gyrus/gyri

outward fold/ridge of the cerebral cortex; the hills of the brain, makes the wrinkles

Forebrain

Corpus Callosum, cerebral cortex, and thalamus (includes telencephalon and diencephalon)

Midbrain

region between hind and forebrain

Hindbrain

Medulla, pons, and cerebellum

How do neuroscientists study the brain?

Neuroanatomical Techniques, physiological techniques, opto and chemogenetic techniques

Basic Components of the Nervous System

CNS and PNS

What kind of circuits do neurons form?

Neural Circuits : networks of neurons that process specific information

What is the brain’s functional architecture?

Specialized regions organized into network that collaborate to perform tasks

How can scientist’s reverse engineer the brain?

Measuring the effects of removing the function of a region

How do brains evolve?

Development and complexity of neurons over millions of years, the more distant two species are the more dissimilar their NS’s are likely to be. The brain evolved to increase efficiency and adaptability to environments

which structure is located between the front and parietal lobe in the human brain?

Central sulcus

Why do neuroscientists use the terms superior and inferior to describe the location of structures in human brains?

Because humans mainly walk on two legs, whereas non-human animals or crawling babies are on all fours changing the position of the body

The formation of cortical folds saves space compared to having a smooth cortex. Why is this

important to the organism?

Without cortical folds, the brain would not be able to fit into the skull, it increases surface area allowing for more neurons

Why do you think so few genes are uniquely expressed in brain tissue?

only 1-2% of human genes are brain specific, the brain is more so “focused” on gene regulation and expression patterns

Why do you think Meynert and James used the example of a child seeing a flame to illustrate their

dual reflex arc model?

The child’s experience links 2 subcortical reflex arcs, as the childs w/draws their hand in pain it strengthens association fibers, showing cognitive and emotional memory

rostral (non-human animals)

rostrum= snout/beak

caudal (non-human animals)

caudam = tail