BioPsychology: Exam 1 (Revised)

sensory neuron

Information, in the form of light, sound, odors, tastes, or contact with objects, is gathered from the environment by specialized cells of the PNS

interneuron

Between sensory neurons and motor neurons are this, neurons that lie entirely within the CNS.

Local: form circuits with nearby neurons and analyze small pieces of information.

Relay: connect circuits of local interneurons in one region of the brain with those in other regions.

soma

Cell body. Contains the nucleus and much of the machinery involved in the life processes of the cell.

dendrite

Neurons communicate with one another, and this receives the messages.

synapse

A small space between the terminal buttons of the sending cell and a portion of the somatic or dendritic membrane of the receiving cell.

axon

A long, thin tube. The outer surface of the axon carries information from the cell body to the terminal buttons. The basic message the axon carries is called an action potential, involving both an electrical and a chemical component.

neurotransmitter

Chemical messengers that either excites or inhibits the receiving cell and helps determine whether an action potential occurs in the receiving cell's axon.

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

mRNA

A macromolecule that delivers genetic information concerning the synthesis of a protein from a portion of a chromosome to a ribosome.

oligodendrocyte

The principle functions of them are to provide support to axons and to produce the myelin sheath, which insulates most axons from one another in the CNS

Scwann cell

In the central nervous system, the oligodendrocytes support axons and produce myelin. In the peripheral nervous system, the these cells perform the same functions. They also help digest dead and dying axons. They then arrange themselves in tube-like structures to help guide the regrowth of axons.

hyperpolarization

When the inside of an axon become more negative (from resting potential) relative to the outside. Less likely to send an electrical signal. {-70mV to -90mV}

electrostatic pressure

The attractive force between atomic particles charged with opposite signs or the repulsive force between atomic particles charged with the same sign.

presynaptic membrane

the membrane of a terminal button that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released

autoreceptor

Located on the presynaptic membrane and regulate synthesis and release of neurotransmitters

sulci

shallow grooves found on the surface of the human cortex

frontal lobe

Planning and movement occurs in

periaqueductal gray matter

What area of the brainstem is involved in pain reactivity

Sodium Ions

What types of ions are more concentrated outside the axon membrane

Neuroaxis

an imaginary line that runs the length of the spinal cord to the front of the brain

central nervous system

Consists of the brain and spinal cord.

peripheral nervous system

Consists of the nerves and most of the sensory organs.

motor neuron

Motor behavior such as contracting muscles are controlled by this

terminal buttons

At the end of branches are little knobs called this. When an action potential traveling down the axon reaches them, they secrete a chemical called a neurotransmitter.

membrane

Defines the boundary of the neuron. It consists of a double layer of lipid (fatlike) molecules.

microtubules

A long strand of bundles of protein filaments arranged around a hallow core; part of the cytoskeleton and involved in transporting substances from place to place within the cell.

cytoplasm

The viscous, semiliquid contained in the interior of a cell.

nucleus

An identifiable group of neural cell bodies in the central nervous system, or a structure in the central region of a cell, containing the nucleolus and chromosomes.

ribosome

Cytoplasmic organelles at which proteins are synthesized.

chromosome

Consists of long strands of DNA. They function like cookbooks and contain the recipes for making proteins.

mitochondria

Found in the cytoplasm, this uses nutrients such as glucose to provide the cell with energy to perform its functions. Produces ATP, which can be used throughout the cell as an energy source.

glia

The supporting cells of the nervous system.

astrocyte

Means "star cell". A glial cell that provides support for neurons of the central nervous system, provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid.

phagocytosis

The process by which cells engulf and digest other cells or debris caused by cellular degeneration.

node of Ranvier

A naked portion of a myelinated axon between adjacent oligodendroglia or Schwann cells. They provide a small boost to the action potential pulse to keep the signal going down the length of an axon.

microglia

The smallest of the glial cells. They serve as phagocytes and protect the brain from invading microorganisms.

blood-brain barrier

A semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain's capillaries.

membrane potential

Any difference in charge across the membrane is called this. The term potential refers to a stored-up source of energy, in this case, electrical energy.

resting potential

When the neuron is at rest and not involved in communicating with other neurons, the membrane potential remains at approximately -70 mV

depolarization

Reduction (toward 0) of the membrane potential of a cell from its normal resting potential; membrane potential becomes more positive. More likely to send and electrical signal.

threshold of excitation

Each neuron has a set point for depolarization to trigger the main electrical event in an axon - the action potential.

action potential

A burst of rapid depolarization followed by hyperpolarization. The brief electrical impulse that provides the basis for conduction of information along an axon.

diffusion

The process whereby molecules distribute themselves evenly throughout the medium in which they are dissolved is called this. Movement of molecules from regions of high concentration to regions of low concentration.

electrolyte

When some substances are dissolved in water, they split into two particles, each with an opposing electrical charge. Usually a soluble base, acid, or salt.

ion

The charged particles made from electrolytes are called this. Cations have a positive charge and anions have a negative charge.

intracellular fluid

The fluid inside cells.

extracellular fluid

All fluids outside cells; Calcium ions are found at the highest concentration

sodium-potassium fluid

4 important ions in these fluids. Organic anions (A-) chloride ions (Cl-), sodium ions (Na+), and potassium ions (K+). Organic ions are found only in the intracellular fluid and cannot leave the cell. K+ is found mostly in the intracellular, which Na+ and Cl- are found mostly in the extracellular.

The fluid that surrounds our cells is similar to seawater, which is predominately a solution of salt, NaCl.

ion channel

A pore in a cell membrane through which certain ions can pass.

voltage-dependent ion channel

an ion channel that opens or closes according to the value of the membrane potential

all-or-none law

principle that the action potential in a neuron does not vary in strength; the neuron either fires at full strength or it does not fire at all

rate law

The principle that variations in the intensity of the stimulus or other information being transmitted in an axon are represented by variations in the rate at which the axon fires.

saltatory conduction

Conduction of action potentials by myelinated axons. The action potential appears to jump from one node of Ranvier to the next.

This is advantageous because it requires less energy for the requires Na+ to go in and out.

postsynaptic potential

brief depolarizations or hyperpolarizations that increase or decrease the rate of firing of the axon of the postsynaptic neuron.

Alterations in the membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse.

binding site

Neurotransmitters exert their effects on cells by attaching to a particular region of a receptor molecule called the binding site. A molecule of the chemical fits into the binding site the way a key fits into a lock: The shape of the binding site and the shape of the molecule of the neurotransmitter are complementary.

ligand

a chemical that binds with the binding site of a receptor.

dendrite spine

a small bud on the surface of a dendrite, with which a terminal button of another neuron forms a synapse

postsynaptic membrane

the cell membrane opposite the terminal button in a synapse; the membrane of the cell that receives the message

synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell; Junction between terminal button and neuron

synaptic vesicle

a small, spherical structure that contains molecules of neurotransmitter

exocytosis

the process in which neurotransmitters are secreted

postsynaptic receptor

receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter

neurotransmitter-dependent ion channel

ion channel that opens up when a molecule of a neurotransmitter binds w/ a postsynaptic receptor

ionotropic receptor

receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of a neurotransmitter attaches to the binding site

G protein

a protein coupled to a metabotropic receptor; conveys messages to other molecules when a ligand binds with and activates the receptor

second messenger

a molecule that is generated when a specific substance attaches to a receptor on the outside of a cell membrane, which produces a change in cellular function

acts as a signal molecule in the cytoplasm

excitatory postsynaptic potential (EPSP)

a slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential

inhibitory postsynaptic potential (IPSP)

temporary hyperpolarization of a membrane

neural integration

spinal neurons receive input from multiple sources, integrate it, and execute appropriate output (e.g., bladder control)

reuptake

The primary killer of neurotransmitters

enzymatic deactivation

Destruction of a neurotransmitter by enzyme after its release

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

released at the ends of nerve cells

Acetylcholinesterase

the enzyme that breaks down acetylcholine in the synaptic cleft

presynaptic inhibition

The action of a presynaptic terminal button in an axoaxonic synapse; reduces the amount of neurotransmitter released by the postsynaptic terminal button.

presynaptic facilitation

Action of an axoaxonic synapse at a synaptic terminal that increases the neurotransmitter released by presynaptic membrane

cerebrospinal fluid

Fluid in the space between the meninges that acts as a shock absorber that protects the central nervous system.

anterior

front of the body

posterior

back of body

dorsal

In a human being the anatomical direction from the spine to the stomach

ventral

Toward the belly

lateral

Away from the midline of the body

medial

Toward the middle of the body

ipsilateral

on the same side of the body

contralateral

on the opposite side of the body

cross section

a diagram that shows what the inside of something looks like

frontal section

a slice through the brain parallel to the forehead

horizontal section

a slice through the brain parallel to the ground

sagittal section

a slice through the brain parallel to the neuraxis and perpendicular to the ground

midsagittal plane

divides the body into equal right and left sides

meninges

three protective membranes that surround the brain and spinal cord

dura mater, arachnoid mater, pia mater

dura mater

thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord

arachnoid membrane

middle layer of the three membranes that surround the brain and spinal cord

pia mater

the delicate innermost membrane enveloping the brain and spinal cord.

subarachnoid space

a space in the meninges beneath the arachnoid membrane and above the pia mater that contains the cerebrospinal fluid

ventricle

cavities within the brain that produce and store cerebrospinal fluid

help keep the brain buoyant and cushioned

lateral ventricle

a complex C-shaped lateral portion of the ventricular system located in the center of the telencephalon

third ventricle

The midline ventricle that conducts cerebrospinal fluid from the lateral ventricles to the fourth ventricle.

cerebral aqueduct

connects the third and fourth ventricles

fourth ventricle

the ventricle located between the cerebellum and the dorsal pons, in the center of the metencephalon