Basic Neuro for S&H Exam 1

University of Iowa

language

a system of symbols that is used to communicate meaning

natural language

any language that occurs naturally in a human community

semanticity

usage of symbols

structure dependency

ordering of symbols influences meaning

creativity

combination of a finite symbols into an infinite number of meanings

displacement

refer to objects in another time or place

communication

a process by which information is exchanged through a common system of symbols

speech

human vocal communication using language

necessary for communication

conditions that must be present for an effect

things that are necessary for communication

intent, message, output, input, comprehension

sufficient for communication

set of conditions that will guarantee an effect

neuroscience

the study of the nervous system

central nervous system (CNS)

brain, brainstem, spinal cord

peripheral nervous system (PNS)

includes spinal nerves, cranial nerves, sensory and motor connections

plane

a flat or relatively smooth surface

section

a cut that divides the body in a specific way

axial

separating the upper and lower parts; transverse

coronal

separating into front and back parts

sagittal

separating into left and right parts

anterior

in front of

posterior

behind

superior

above

inferior

below

rostral

towards the nose

caudal

towards the tail

dorsal

towards the back

ventral

towards the front

medial

towards the middle

lateral

towards the side

ispilateral

same side

contralateral

different side

meninges

3 membranes that surround the brain and spinal cord

dura mater

membrane closest to skull; “hard mother”

arachnoid

middle membrane; “spider’s web”

pia mater

membrane closest to brain; “soft mother”

cerebrospinal fluid

cushions the brain from sudden movements of the head and delivers nutrients/hormones/chemicals and removes waste

gray matter

cell bodies of neurons

white matter

myelinated axons

cerebral cortex

outer layer of cells in the brain; made up of 6 layers of cells organized by function

gyrus/gyri

hills/bumps between folds

sulcus/sulci

valleys/folds

fissure

large sulci

lobes of the cerebral cortex

frontal, parietal, temporal, occipital, insula

brodmann’s areas

48 regions of the cerebral cortex with different cellular morphology and organization

brainstem

begins where the spinal cord enters the skull and extends up; responsible for most unconscious behavior (breathing, vomiting)

diencephalon

thalamus and hypothalamus

thalamus

integrates sensory and motor information; the gateway through which all sensory information must pass before going on to the cortex

hypothalamus

controls hormone production by interacting with the pituitary gland (feeding, sleeping, temperature regulation, sexual behavior, emotional behavior)

cerebellum

important for fine motor control, gait, balance, and motor learning

basal ganglia

group of subcortical nuclei; helps to control voluntary movement and higher cortical functions

hippocampus

in temporal lobe; learning and memory

tracts

bundle of axons within the CNS; carries neural signals between different parts of the CNS

nerves

bundle of axons in the PNS; carries neural signals between the CNS and structures in the body

commissural tract

between hemispheres

association tract

within hemispheres

projection tracts

connect cortex with other parts of the nervous system

corpus callosum

commissural tract that transfers information between cerebral hemispheres; process sensory, motor, and high-level cognitive signals

short association fibers

connect adjacent gyri in the same hemisphere

long association fibers

connect more distant parts of the same cerebral hemisphere

afferent

arrive (ex. PNS into CNS)

efferent

exit (ex. CNS to PNS)

corticospinal tract

signal originates in cortex and crosses in caudal medulla

corticobulbar tract

signal originates in cortex and most have bilateral projections

lower motor neurons

synapse on muscle fibers

amytrophic lateral sclerosis

progressive degeneration of upper and lower motor neurons that causes weakness

synapse

connection between neurons

axodendritic synapse

axon to dendrites (majority)

axosomatic synapse

axon to soma

axoaxonic synapse

axon to axon

neuromuscular junction

synapse from lower motor neuron to muscle

interstitial space

confined space between neural cells and vasculature; connects vascular system and neural networks

interstitial (extracellular) fluid

water solvent containing ions, proteins, peptides, enzymes, and extracellular vesicles; direct medium for supply of nutrients, removal of waste, and intercellular communication

phospholipid bilayer

hydrophilic head and hydrophobic tails that make up the cell membrane

selective permeability

only some stuff can get in and out; small uncharged molecules can get in, large polar molecules cannot

glial cells

support cells

microglia

remove dying cells through phagocytosis and can help in immune response to infections

macroglia

two types: astrocytes, oligodendrocytes/schwann cells

astrocytes

structural support for neurons, regular supply of nutrients/energy to neurons, assist with neurotransmitter regulation and synaptic plasticity (surround synapses)

oligodendrocytes

create myelin in the CNS

schwann cells

create myelin in the PNS

myelin

fat that speeds up neural signal transmission

multiple sclerosis

blood brain barrier disruption that causes autoimmunity (demyelination) and inflammation

ion

atom or group of atoms that have an electric charge

concentration gradient

things want to move from an area of high concentration to low concentration

facilitated diffusion

molecules pass through transmembrane proteins within the phospholipid bilayer along concentration or electrochemical gradients; passive and selective

ion channels

transmembrane proteins that form pores in the cell membranes that open under certain conditions to allow ions to pass

leakage ion channels

spontaneously open to allow ions through

voltage-gated ion channels

changes in charges across membrane cause channel to open and allow ions through

mechanically-gated ion channels

are physically pulled open to allow ions through

ligand-gated ion channels

molecule binds to something else to open and allow ions through

pumps

transport ions against their concentration gradients; active transport

sodium-potassium pump

pumps 2 K+ ions into the cell and 3 Na+ ions out of the the cell for every molecule of ATP

electrochemical potential

difference in charge inside and outside the cell

resting membrane potential

difference in charge inside and outside the cell at rest; typically -70 mV

polarized

positive or negative charge

neuron membranes have a relatively ____ charge at rest

negative

action potential

a rapid, temporary change in electrical voltage across a cell membrane that allows neurons and muscle cells to communicate

steps of the action potential

1. something happens

2. leads to depolarization of the cell membrane (voltage gets closer to 0)

3. if threshold is reached (-55 mV) voltage-gated sodium channels open and an action potential will happen

4. in the depolarization phase Na+ floods into the cell through voltage-gated Na+ channels

5. at +40 mV the voltage-gated Na+ channels are closed

6. at the same time, voltage-gated K+ channels are opened and K+ flows out of the cell (repolarization)

7. neuron is briefly hyperpolarized (refractory period)

8. to return back to resting potential, the neuron uses sodium/potassium pumps (3 Na+ out/2 K+ in)

tertrodotoxin

voltage-sensitive sodium channel blocker that impacts motor, sensory, and autonomic functions

postsynaptic potentials

ionic movements in the dendrites cause local changes in membrane potentials