The Nervous System Overview

Oligodendrocytes

Wrap axons in myelin sheath, have many branches, found in the CNS

Schwann cells

Wrap axons in myelin sheath, one branch, found in PNS

Sagittal Plane

A plane that divides the body into right and left portions (Through corpus collusum)

Midbrain

Region between the hindbrain and the forebrain; it is important for hearing and sight.

Medulla

Regulates mechanisms for controlling reflex actions (ex: heart rate, breathing, blood pressure, etc.)

Dendrites

A neuron's bushy, branching extensions that receive information from other neurons and conduct impulses toward the cell body.

Cerebellum

A large structure of the hindbrain that controls fine motor skills (ex: balance and coordination)

Cranial nerves

12 pairs of nerves that carry messages to and from the brain

Spinal nerves

31 pairs of nerves arising from the spinal cord

Pons

A brain structure that relays information from the cerebellum to the rest of the brain

Basal Ganglia network

A set of connected brain areas involved in motor learning and action selection

Papez Circuit network

A set of connected brain areas that deal with emotion and memory

Central Nervous System

A subdivision of the human nervous system comprising the brain and spinal cord. Transmits & receives messages to & from the PNS

Autonomic Nervous System

A subdivision of the peripheral nervous system. Controls involuntary activity/regulates internal organs and glands.

Hindbrain

An area of the brain that coordinates information coming into and out of the spinal cord (contains cerebellum, medulla, and pons)

These are the three types of glia cells in the brain

Astrocytes, Oligodendrocytes/Schwann cells, and Microglia

Action potential of a neuron firing is initially generated in the ______ _______.

Axon hillock

The Central Nervous System is separated from the circulatory system by a ____ _____ _____.

Blood brain barrier

The central nervous system is comprised of the ______ and _______.

Brain and spinal cord

Axons

Branching extension from the cell body that transmits signals away from the cell body

Glia

Cells in the nervous system that support, nourish, and protect neurons.

Oxygen and nutrients from the blood reach the CNS through the ____ _____ _____.

Cerebral spinal fluid

Axon hillock

Connection between soma and axon that generates the signal to travel down the axon

Ventral side

Downward side of an organism

Ventricles

Fluid-filled spaces in the brain where tissue contains cerebral spinal fluid

The cerebrum is divided into these 4 lobes

Frontal, Parietal, Temporal, and Occipital

Feed-back neurons

Go back into the initial system/circuit (A>B>C>A)

Horizontal Plane

Going straight across from side to side, separating top and bottom half of the brain

Sympathetic Nervous System

Increases the body's use of energy to be productive (ex: fight or flight)

Astrocytes

Interface between circulatory system and nervous system, provide structural support, and can modulate local neuron activity

Feed-forward neurons

Keep going to new and different places (A>B>C)

Cerebrum

Largest area of the brain responsible for all voluntary activities of the body

The peripheral nervous system is compromised of ________.

Nerves

The nervous system is composed of these two types of cells

Neurons and glia

Interneurons

Neurons within the brain and spinal cord that communicate internally (only to local neurons)

Visceral nervous system

Sensory and motor innervation of involuntary structures like heart, internal organs, blood vessels, and glands (the inside)

Parasympathetic Nervous System

Stores and conserves energy, while slowing the activities of muscles and glands (ex: digestion, slowing heart rate, etc.)

The Autonomic Nervous System is divided into the ________ and ________ systems.

Sympathetic and Parasympathetic

Posterior end

The back end (occipital lobe/cerebellum)

Anterior end

The front end (frontal lobe)

Forebrain

The largest and most complicated region of the brain, including the thalamus, hypothalamus, limbic system, and cerebrum

Cerebral Cortex

The outermost layer of the cerebrum, responsible for complex perceptual, behavioral, and cognitive processes

Nucleus

The separated part of the cell containing DNA and RNA

Dorsal side

Upper side of an organism

Coronal Plane

Vertical body plane, divides brain into front and back sections

Soma

a neuron's cell body

Microglia

an essential part of the brain's immune system, containing macrophages that engulf/eat cells, bacteria, and molecules that shouldn't be in the brain

The medulla contains nuclei that regulate ___________.

breathing, heart rate, etc.

Electrical synapses are also called ______ _____ ______

gap junction synapses

Projection neurons

have axons that extend to distant targets and make signals onto other neurons

Inhibitory neurons

make neurons less likely to activate (decrease action potential)

Peripheral Nervous System

network of nerves and neuron axons carrying signals into and out of the central nervous system

Excitatory neurons

neurons that makes postsynaptic neurons more likely to activate (increase action potential)

The orientation of the brain can be described with _____ and _____.

planes and axes

Somatic nervous system

subdivision of the motor division of the peripheral nervous system that controls the voluntary movement of skeletal muscles (interaction with the outside world)

Synapses

the connections between neurons