Biological Bases of Behavior Exam 1 FAU

Neurons

receive information and transport it to other cells

What are the two types of cells that make up the nervous system?

Neurons and gila

Membrane (Plasma Membrane)

surface of the cell, a structure that separates the inside of the cell from the outside environment

Who was the researcher responsible for proving that cells in the nervous system remain separate? Whose method did he use to prove this?

Cajal, He used Golgi's method of staining

Sensory Neurons

specialized on one end to be highly sensitive to a particular type of stimulation (touch, light, sound)

Where is the sensory cells soma?

little stalk off main trunk

Soma (cell body)

contains nucleus, ribosomes and mitochondria

• most of metabolism’s work

What is an axon?

thin fiber of constant diameter, neurons information sender

_____ receive information from neighboring neurons, while _____ send information to other neurons.

Dendrites, Axons

Dendrites

branching fibers from a neuron that receive information from other neurons

What are dendrite spines?

Short outgrowths on dendrites that increase surface area allowing more information to be received

Axon hillock

Where action potentials originate

Myelin sheath

the insulating material covering axons

______ bring information to a structure while _______ axons bring information away

Afferent, efferent

What are interneurons/Intrinsic neurons?

Neurons that act as a bridge between sensory and motor neurons, axons and neurons are all confined within a given structure

Proteins

provide building materials for the cell and facilitate chemical reactions

Ribosomes

sites within a cell that synthesize new protein molecules

Endoplasmic Recticulum

a network of thin tubes that transport newly synthesized proteins to other locations.

Glia

type of cell in the nervous system that, in contrast to neurons, does not conduct impulses over long distances

Microgila

Major actors in our immune systems that help remove viruses, fungi, and other waste from our brain

Radial Gila

assist neurons during embryonic development

Oligodendrocytes

Provide axons with the nutrients needed for functioning as well as build myelin sheaths, located in the brain and spinal cord

Astrocytes

Star-shaped gila cells that help to synchronize axon activity

Schwann cells

Provide axons with the nutrients needed for functioning as well as build myelin sheaths, located in the periphery of the body

What is the blood-brain barrier?

A mechanism in the brain that works to block most chemicals from entering. It's needed because neurons in the brain typically do not regenerate so our bodies must try to keep as many potentially harmful chemicals out as possible

Which chemicals cross the blood–brain barrier passively?

Small, uncharged molecules such as oxygen, carbon dioxide, and water cross the blood–brain barrier passively. So do chemicals that dissolve in the fats of the membrane.

Why is the blood brain barrier needed?

It's needed because neurons in the brain typically do not regenerate so our bodies must try to keep as many potentially harmful chemicals out as possible, if harmful things enter, the brain will get infected and can lead to death

Blood brain barrier disadvantage

keeps out most nutrients, poses a difficulty for treating brain cancers, because nearly all the drugs used for chemotherapy fail to cross the blood–brain barrier.

Active Transport

a protein-mediated process that expends energy to pump chemicals from the blood into the brain

• glucose

• insulin

• amino acids

• purines

• choline

• vitamins/iron

Selective Permeability

ability of some chemicals to pass more freely than others through a membrane

What is the difference between passive and active transport?

Passive transport happens naturally, while active transport requires energy

What is the primary source of energy for neurons and why is it the primary source?

Glucose is the primary source of energy because it is the only nutrient that can cross the blood-brain barrier in large quantities

What is the purpose of Vitamin B12, or Thiamine?

It's necessary for your body to be able to use glucose. When thiamine is deficient for long periods of time, the neurons end up dying. (Krosakoff's syndrome: severe memory impariment)

Action potential

is the electrical message that is transmitted down the axon of a neuron

Polarization

the difference in electrical charge inside and outside the cell

Resting Potential

condition of a neuron’s membrane when it has not been stimulated or inhibited

Th resting potential of a cell is _____ mV and the common threshold of excitation is _____ mV

-70, -65

Which is more abundant inside the cell, sodium or potassium? Which is more abundant outside of the cell?

Potassium is more abundant inside the cell while sodium is more abundant outside

Electrical Gradient

difference in electrical charge between the inside and outside of the cell

• slightly negative

How does the electrical gradient affect sodium and potassium ions? Hows does the concentration gradient effect them?

The electrical gradient pushes sodium and potassium into the cell while the concentration gradient pushes sodium in and potassium out

What is the difference between depolarization and hyperpolarization?

Depolarization is when the cell is becoming less polarized, less neg more pos. Hyperpolarization is when it is becoming more polarized

What are the two types of refractory periods and what do they do?

Relative refractory period: another action potential can be produced if a stronger stimulus occurs

Absolute refractory period: another action potential cannot be produced at all

What does the all-or-none law state?

No matter how strong the stimulus that caused the action potential is, the amplitude and velocity will be the same for a given neuron

What is the difference between how myelinated and unmyelinated axons produce action potentials?

Myelinated axons sue salatory conduction to reproduce the action potential at the nodes of Renvier. Unmyelinated axons use passive conduction to reproduce the action potential at each segment of the axon

Do all neurons have axons?

Local neurons lack axons. They stay close together and exchange information without an axon

Who discovered synapses and how did they make this discovery? What were the 3 major observations this person made?

Sherrington discovered that neurons have synapses by studying the reflexes of a dog.

1. reflexes are slower than conduction along and axon

2. temporal and spatial summation

3. As one set of muscles becomes excited, another set relaxes

What is the difference between the presynaptic membrane and the postsynaptic membrane?

The presynaptic membrane sends information to another neuron, while the postsynaptic membrane receives information from other neurons

______ summation refers to the combined effect of quickly repeated stimulation at a single synapse, while _______ summation refers to the combined effect of several nearly simultaneous stimulations at several synapses onto one neuron

Temporal, spatial

Graded potentials differ from action potentials because?

Graded potentials can be hyperpolarizations depending on the stimulus. they also don not follow the all-or-none law because their amplitude is reliant on the strength of the stimulus. These potentials also lack refractory periods. Action potentials are only depolarizations, they follow the all-or-none law, and they have a relative and absolute refractory period

The temporary hyperpolarization of a membrane is called ______, which occurs when _______ gates open.

Inhibitory Postsynaptic potential (IPSP), Potassium

The temporary depolarization of a membrane is called ______, which occurs when _____ gates are open

Excitatory Postsynaptic potential (EPSP), sodium

What are antagonistic muscles?

Those that work opposite of one another to have a certain outcome

ex: when a dog flexes one leg, it must extend all three of its other legs to prevent it from falling over

Who proved that nerves shared information by releasing chemicals and how did they prove this?

Loewi by observing frog hearts. He stimulated the nerves of a frog heart and found that they had different responses. He found that if he stimulated an excitatory nerve the heart would beat faster and produce a fluid. When he transferred that fluid into another frog heart that was neutral, he saw that the new heart began beating faster as well. This is how he showed that communication between neurons was mainly chemical.

What are neurotransmitters?

Chemicals that are released by neurons that send messages to other neurons

The process of neurotransmission:

1. An action potential travels down the axon to the presynaptic terminals

2. The action potential causes calcium channels to open, allowing calcium ions to enter the presynaptic terminal

3. The calcium ions work to bring the vesicles containing the neurotransmitters down to the edge of the presynaptic terminal.

4. Once the vesicles are at the edge of the terminal, exocytosis allows the

neurotransmitters to be released from the vesicles into the synapse.

5. The neurotransmitters bind to their respective receptors on the postsynaptic terminal.

6. Once the postsynaptic terminal receives the message the neurotransmitter detaches and goes back into the synapse.

7. At this point three things can happen: reuptake, diffusion, or inactivation.

What is Nitric oxide and what is its function?

A gaseous type of neurotransmitter that is poisonous in large amounts and very difficult to create in a lab, but out bodies naturally produce it. It helps more blood low to areas that are highly active by dilating the blood vessels near that area allowing more blood to get to it

______ are tiny packets located in the presynaptic membrane that hold neurotransmitters

Vesicles

What is MAO and what is its purpose?

MAO stands fro monamine oxidase and it's an enzyme that breaks down excess levels of neurotransmitters into inactive chemicals

Channels that are controlled by neurotransmitters are called

Ligand-gated channels

What is the difference between ionotropic and metabotropic effects?

Ionotropic effects are those that happen quickly and are very short lasting. Metabotropic happen slowly and are long lasting

What is the first messanger and the second messanger?

The first messenger for a metabotropic effect is the neurotransmitter binding to the receptor. The second messenger for a metabotropic effect is the G-Protein bringing energy to other parts of the cell to create more reactions.

Nicotinic or __________ receptors are _____ on neurons responsible for releasing dopamine

Acetylcholine, abundant

LSD resembles the neurotransmitter called

serotonin

Opiates bind to the same receptors as ______. These receptors are located on the ______

endorphins, brain

Difference between reuptake, inactivation, and diffusion

Reuptake is the process by which neurotransmitters are taken back up through

transporters and brought back into the presynaptic terminal to be used again in the future. Inactivation is the process by which an enzyme enters the synapse and breaks the neurotransmitters down into inactive parts so that they just end up diffusing away. Diffusion is when the neurotransmitters in the synapse simply leave and go to other parts

of the cell.

Two types of negative feedback

Autoreceptors are a type of negative feedback receptor located on the presynaptic

terminal. These receptors detect how many neurotransmitters are sent to the postsynaptic and stop when it has sent enough. Postsynaptic neurons are a type of negative feedback receptor located on the postsynaptic terminal. These receptors keep track of how many neurotransmitters the presynaptic is sending and sends a message back to it telling it to stop sending them. children eating candy)

What are cannabinoids and how do they work?

The active chemicals in marijuana that bind to the receptors on the presynaptic neuron. They bind to the presynaptic and tell it to stop sending neurotransmitters because it already got the message

A _________ is when the membrane of one neuron directly connects with the membrane of another neuron. This is a case in which ______ transmission can occur

Gap junction, electrical

Anterior

toward the front end

Inferior

below another part

Superior

above another part

Contralateral

on the opposite side of the body

Ventral

toward the stomach, away from the dorsal

Ipsilateral

on the same side of the body

Distal

located more distant from the point of origin or attachment

Lateral

toward the side

Coronal plane

a plane that shows brain structures as seen from the front

Horizontal plane

a plane that shows brain structures as seen from above

Dorsal

toward the back, top of brain

Sagittal plane

a plane that shows brain structures as seen from the side

Posterior

towards the rear

Proximal

located close to the point of origin or attachment

Medial

toward the midline

What is the difference between the central nervous system (CNS) and the perIpheral nervous system (PNS)?

The central nervous system (CNS) is composed of the spinal cord, the brain, and the retinas. The peripheral nervous system (PNS) is composed of everything other than the CNS.

Differentiate between gray matter and white matter

Gray matter is composed of the cell bodies and dendrites while white matter is composed of myelinated axons

The peripheral nervous system is composed of two subsystems. What are these systems and what are they responsible for? Do either of these subsystems have subsystems of their own? If so, what are they?

The two subsystems that are part of the peripheral nervous system are the somatic and autonomic nervous system. The somatic nervous system is composed of axons that convey messages from sense organs to the CNS then from the CNS to the muscles. The autonomic nervous system

controls organs such as the heart and intestines. The autonomic nervous system is split into two systems called the sympathetic and

parasympathetic nervous systems. The sympathetic nervous system gets our bodies ready for rigorous activity by increasing

heart rate, blood pressure, respiration, etc. (fight or flight) The parasympathetic nervous system returns you back to a resting state. (rest and digest) It basically brings down the rates that the sympathetic nervous system brought up.

What are the three main structures that make up the midbrain?

Pons, medulla, and cerebellum know what they do

Each cranial nerve originates in a _____ that integrates the ______ information, regulates the _____ output, or both

nucleus, sensory, motor

The midbrain is composed of what four main structures?

Tectum, superior and inferir collilulus, tegmemtun, and substantia nigra. know the functions

State how the thalamus, hypothalamus, and hippocampus work.

Thalamus: acts as a relay station for sensory information. Most sensory information, except olfactory information, is send through the thalamus before it is sent to any other structure.

Hypothalamus: sends messages to the pituitary gland to alter the release of hormones Hippocampus: important for storing memory, particularly new events

The ______ are four fluid-filled cavities within the brains central canal containing cerebrospinal fluid

Ventricles (the choroid plexus is the structure that produces CSF)

What are the two bundles of axons that join the two hemispheres of the brain called?

Corpus collosum and anterior commissure

What are the four lobes of the brain?

frontal, parietal, temporal, occipital

Nerve

a set of axons in the periphery, either from the CNS to a muscle or gland or from a sensory organ to the CNS

Mitochondrion

powerhouse of the cell, performs metabolic activities

Colum

a set of cells perpendicular to the surface of the cortex, with similar properties

Gyrus

a protuberance on the surface of the brain

Fissure

a long, deep sulcus

Ganglion

cluster of neuron cell bodies in the PNS

Lamina

a row or layer of cell bodies separated from other cell bodies by a layer of axons and dendrites