PSYC3200 CNA Exam 1

Neurons

basic units of the NS, have 4 functional zones: input (dendrites), integration (cell body), conduction (single axon/nerve fiber), output (axon terminals)

presynaptic neuron

nerve cell that sends a signal, like chemical or electrical message, across a synapse to another cell

postsynaptic neuron

nerve cell that receives a chemical/electrical signal from a sending cell across a small gap called a synapse (info transmitted from presynaptic to postsynaptic)

Presynaptic membrane

(component of synapse) on the axon terminal of the presynaptic neuron

Postsynaptic membrane

(component of synapse) on the dendrite or cell body of the postsynaptic neuron

Synaptic cleft

(component of synapse) the gap that separates the membranes

synaptic vesicles

small spheres in presynaptic axon terminals that contain a neurotransmitter, a specialized chemical

neurotransmitter

a specialized chemical which is released in response to electrical activity in the axon

neurotransmitter receptors

in the postsynaptic membrane are specialized proteins that react to neurotransmitter molecules

neural plasticity

refers to the continual remodeling of neuronal connections

glial cells

assist neuronal activity by providing raw materials, chemical signals, and structure and also participate in information proccessing

oligodendrocytes

form the myelin sheaths in the brain and spinal cord (wraps wound axons to provide a fatty insulation layer called myelin)

Schwann cells

provide myelin to neurons outside the brain and spinal cord (wraps wound axons to provide a fatty insulation layer called myelin)

Nodes of Ranvier

gaps between sections of myelin where the axon is exposed

Astrocytes

type of glial cell, star shaped cell with many processes that stretch around and between neurons and sometimes blood vessels; secrete chemicals; help form the outer membrane around the brain

microglial cells

type of glial cell, they are tiny, mobile cells that remove debris from injured or dead cells (engulfs & destroys debris)

Central Nervous System

consists of brain and spinal cord

Peripheral Nervous System

includes all other parts of the nervous system outside the brain and spinal cord

Motor nerves

transmit information from the spinal cord and brain to muscles and glands

sensory nerves

convey information from the body to the CNS

somatic nervous system

nerves that interconnect the brain and he major muscles and sensory systems of the body. manages voluntary muscle movements and transmits sensory information to CNS

autonomic nervous system

nerves that connect to the viscera (internal organs), controls involuntary automatic body functions like heart rate, digestion, and breathing

cranial nerves

(nerves of somatic NS) innervate the head, neck, and visceral organs directly from the brain

spinal nerves

(nerves of somatic NS) connect to the spinal cord. there are 31 pairs & each spinal nerve consists of a group of motor fibers that project from the spinal cord and a group of sensory fibers that enter the spinal cord

Cervical

(neck) — 8 segments

thoracic

(trunk) — 12 segments

lumbar

(lower back) — 5 segments

sacral

(pelvic)— 5 segments

coccygeal

(bottom)— 1 segment

dorsal roots

carry afferent sensory axons, while the ventral roots carry efferent motor axons. The spinal nerve emerges from the spinal column through an opening (intervertebral foramen) between adjacent vertebrae.

Sympathetic NS

part of the autonomic NS. it has axons that innervate the sympathetic ganglia— small clusters of neurons outside the CNS. Sympathetic innervation prepares the body for action— the”fight or flight” response”

parasympathetic NS

part of autonomic NS. helps the body relax. parasympathetic neurons extend longer distances from the CNS to the parasympathetic ganglia & their ganglia are usually close to the organ they innervate

afferent

nerve/pathway is afferent if it carries information into a region of interested

efferent

if a nerve or pathway carries information away from a region of interest

gray matter

contains more cell bodies and dendrites, which lack myelin

white matter

consists mostly of axons with white myelin sheaths

gyri

ridged or raised portions

frontal lobe

most anterior region

parietal lobe

lies between the frontal and occipital lobes

occipital lobe

posterior region, visual processing

temporal lobe

lateral region, auditory processing

sylvian fissure

boundary of the temporal lobe

central sulcus

divides the frontal love from the parietal lobe

corpus callosum

bundle of axons that connects the two cerebral hemispheres

postcentral gyrus

strip of cortex behind the central cortex, important for touch

precentral gyrus

in the frontal love, important for motor control

embryonic development

the neural tube develops 3 subdivisions: forebrain, midbrain, and hindbrain. The forebrain develops into the telencephalon and diencephalon. The hind brain develops into the cerebellum, pons and medulla

brainstem

refers to midbrain, pons, annd medulla combined

basal ganglia

important in motor control and consist mainly of the caudate nucleus, putamen and globus pallidus

limbic system

includes structures important for emotion and learning such as amygdala, hippocampus, olfactory bulb, and cingulate gyrus

amygdala

emotional regulation and perception of odor

hippocampus

learning

cingulate gyrus

Above corpus callosum and process emotions and regulates plain and manages cognitive tasks

olfactory bulb

sense of smell

thalamus

cluster of nuclei that relay sensory information

hypothalamus

contains nuclei with many functions; also controls the pituitary

cerebellum

(back of the brain) attached to the brainstem; crucial for motor coordination and control; participates in some types of learning

Pons

(back of brain) contains sensory and motor nuclei; origin of some cranial nerves

medulla

(back of brain) marks transition from brain to spinal cord; drives essential processes such as respiration and heart rate; origin of some cranial nerves

dura mater

the tough, outermost membrane (layer of meninges) that covers and protects the brain and spinal cord

pia mater

innermost layer of meninges, surround the brain and spinal cord

meningitis

an acute infection of the meninges

microelectrode

inserted into a resting cell will shwo that the interior is more negative than the exterior

electrostatic pressure

causes ions to flow towards oppositely charged areas

depolarization

is a decrease in membrane potential— the interior of the cell becomes less negative and closer to zero

myelin

a sheath of insulation around the axon, formed by glial cells which speeds conduction

excitatory postsynaptic potential

a small local depolarizing potential in the postsynaptic membrane that pushes the cell closer to the action potential threshold, increasing the likelihood that the neuron will fire an action potential (Na+ channels open, letting positive ions into the cell)

inhibitory postsynaptic potential

hyperpolarizing potential in the postsynaptic membrane that pushes the cell further away from threshold, decreasing likelihood of the neuron firing an action potential (this results when chloride ions rush into the cell, making the inside more negative)

spatial summation

the summing of all the potentials that reach the axon hillock from locations across the cell body. (if overall depolarization— the sum of EPSPs and ISPS— reaches or exceeds the threshold, an action potential is produced)

temporal summation

the summing of all the potentials that reach the axon hillock based on time of arrival (the closer together in time the potentials arrive, the greater their impact and likelihood of producing an action potential)

Afferent

Afferent nerves carry sensory information towards the central nervous system

Efferent

Efferent nerves carry motor commands away from it