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