Exam 1

Question 1

What is the structure of a neuron, know all structures and functions:
Cell body or Soma

Answer 1

The largest part of a neuron, which contains the cell’s nucleus, cytoplasm, and structures that produce proteins, convert nutrients into energy, and eliminate waste materials.

Question 2

What is the structure of a neuron, know all structures and functions:
Dendrites

Answer 2

Extensions that branch out from the neuron cell body and receive information from other neurons. Neuron’s can have multiple making them multipolar, two making them bipolar or one making them unipolar.

Question 3

What is the structure of a neuron, know all structures and functions:
Axon

Answer 3

An extension (like a tail) from a neuron’s cell body that carries information to other locations.

Question 4

What is the structure of a neuron, know all structures and functions:
Axon terminals

Answer 4

A swelling on the branches at the end of a neuron (end part of the axon) that contains neurotransmitters; also called an end bulb. Can releases neurotransmitters from vesicles.

Question 5

What is the structure of a neuron, know all structures and functions:
Axon hillock

Answer 5

the cone-shaped region of a neuron’s cell body where the axon begins.

Question 6

What is a Sensory neuron ? Know the types and their roles:

Answer 6

A neuron that carries information from the body and from the outside world into the central nervous system (the brain and spinal cord). Specialized to recieve information from the outside world. Mostly unipolar and can by bipolar.

Question 7

What is a Motor Neuron ? Know the types and their roles:

Answer 7

A neuron that carries commands to the muscles and organs. Transmit commands from the Central nervous system (CNS) directly to muscles and glands. Mostly multipolar.

Question 8

What are the different types of neurons? Know the types and their roles: Interneurons

Answer 8

A neuron that has a short axon or no axon at all and connects one neuron to another in the same part of the Central nervous system (CNS). Act as a bridges between the sensory and motor systems. Mostly multipolar and the most numerous neuron.

Question 9

Polarization

Answer 9

There is a difference in electrical charge between the inside and outside of the neuron. A difference in electrical charge between two points, such as the poles of a battery or between the inside and outside of a neuron.

Question 10

What Resting Potential? What is the full process.

Answer 10

The difference in charge between the inside and outside of the membrane of a neuron at rest. Usually sits at -70 millivolts (mV).

Question 11

What is and Action Potential? What is the full process.

Answer 11

An all-or-none electrical signal of a neuronal membrane that contains an abrupt voltage depolarization and return to resting potential; allows the neuron to communicate over long distances. Caused by a stimuli. (e. g., a spider on ur leg). If threshold (-60 mV) is reached, an action potential will be triggered.

An abrupt depolarization of the membrane that allows the neuron to communicate over long distances.

Question 12

What is a Graded Potential? What is the full process.

Answer 12

A voltage change in a neuron that varies with the strength of the stimulus that initiated it. Smaller than an action potential because it doesn’t meet the threshold (-60mV).

Question 13

What is the ionic nature of neurons and the role of ions like sodium, potassium, calcium, etc.

Answer 13

The charges in neurons come from ions, atoms that have lost or gained one or more electrons. Sodium ions (Na+) and Potassium ions (K+) are positively charged Chloride ions (Cl-) are negative along with amino acids that makeup the organic anions (A-). The inside of the neuron has more negative ions meanwhile the outside are more positive, making the resting potential negative. Na+ is usually outside of the neurons and K+ is found inside. They are moved in and out through the Sodium-potassium pump.
Calcium ions are related to chemical synapses.

Question 14

What is the Alll-or-none law?

Answer 14

The principle that an action potential occurs at full strength or it does not occur at all. It has to pass -60 mV which is the threshold.

Question 15

What is the difference between absolute versus relative refractory period?

Answer 15

Absolute refractory period: A brief period following the peak of the action potential when the sodium ion channels are inactivated and the neuron cannot be fired again.

Relative refractory period: The period during which a neuron can be fired again following an action potential but only by an above-threshold stimulus.

Question 16

What is myelination? Know structure and function.

Answer 16

when two types of glial cells produce myelin, a fatty tissue that wraps around the axon (like a jelly roll) to insulate it from the surrounding fluid and from other neurons. Myelin is produced in the brain and spinal cord by glial cells called oligodendrocytes (CNS) and in the rest of the nervous system by Schwann cells (PNS).
1. it reduces and electrical effect of the membrane (capacitance)
2. the breaks in myelination makes the signals regenertate an action potential at every node of Ranvier
3. myelinated neurons use as much less energy because there is less work for sodium-potassium pump to do.

Question 17

How does myelination impact conduction speed.

Answer 17

It increases conduction speed since the overall effect of myelination is the equivalent of increasing the axon diameter 100 times.

Question 18

Understand Saltatory conduction and nodes of Ranvier.

Answer 18

The gaps in the myelin sheath (aka nodes of Ranvier) where the membrane is exposed, there are plenty of sodium channels, the grade potential triggers an action potential. Action potentials thus appear to jump from node to node in a form of transmission called saltatory conduction.

Question 19

What are synapses. Know their function and their structure.

Answer 19

The connection between two neurons. The neurons are not in direct physical contact at the synapse but are separate from a small gap called the synaptic cleft. Their structure is the swollen end of the terminals. They connect through the dendrites or cell body of the postsynaptic neuron.
Presynaptic neurons transmit the signal
Post synaptic neurons receive the signal

Question 20

Chemical synapses

Answer 20

Neurotransmitters are stored in the terminals in membrane enclosed bubbles called vesicles.

Question 21

What is the number of typical synaptic connections between neurons

Answer 21

A typical neuron recives input from approximately 1,000 other neurons. Because each neuron has numerous terminals, this amounts to as many as 10,000 synaptic connections.

Question 22

Understand conversion of graded potentials into action potentials.

Answer 22

On the postsynpatic neuron, the neurotransmitters docks with specialized protein receptors that match the molecular shape of the transmitter molecules like a key and lock. Activation of these receptors opens the ion channels, allowing ions to flow across the membrane. Opening the channels is what sets off the graded potential that initiates the action potential.

Question 23

What is Dale’s principle. Why is it a debated/debunked theory?

Answer 23

The theory that a neuron is able to release only one neurotransmitter. It is debunked because we know that many neurons ply their postsynaptic partners with more than one chemical messenger.

Question 24

What is the order of events that can lead to the relase of neurotransmitters.

Answer 24

An action potential arrives at the presynaptic terminal, causing depolarization of the membrane which opens voltage-gated calcium channels, allowing calcium ions to influx, triggering the fusion of synaptic vesicles with the presynaptic membrane, and finally, the release of neurotransmitters into the synaptic cleft

Question 25

EPSPs versus IPSPs

Answer 25

Excitatory Postsynaptic Potential (EPSP): A partial depolarization of the dendrites and cell body, which makes the neuron more likely to fire. Opens Na+ channels. Inhibitory Postsynaptic Potential (IPSP): A hyperpolarization of the dendrites and cell body, which makes a neuron less likely to fire. Opens K+ and/or Cl- channels. They are graded potentials that accumulate in a short time and combine inputs from different locations on dendrites and cell body.

Question 26

Spatial summation

Answer 26

Combines potentials occuring simutaneously at different locations on the dendrites and cell body.

Question 27

Temporal summation

Answer 27

Combines potentials arriving a short time apart, from either the same or seperate inputs.

Question 28

Axoaxonic synapses

Answer 28

Modulate the amount of transmitters released from the axon terminals.

Question 29

What is grey matter

Answer 29

a tissue primarily composed of neuron cell bodies (somas) and is located in the outer layer of the brain, forming the cerebral cortex , as well as deeper structures. lays a crucial role in functions like memory, emotions, movements, and consiousness.

Question 30

What is white matter

Answer 30

A type of tissue in the brain that consist of nervous fibers (axons) covered in a protective sheath (myelin) which gives the white matter its color. It's located in the inner layer of the brain.

Question 31

what is the difference between grey and white matter.

Answer 31

Gray matter is made up of neuron cell bodies and dendrites, while white matter is made up of axons covered in myelin.

Question 32

Know anatomical location terms.

Answer 32

1. Coronal: divides the brain vertically from side to side. (ear to ear) 2. Sagittal: dividdes the brain vertically in an anterior-posterior direction. (between the eyes) 3. Horizontal: divides the brain horizontally between the top and bottom.

Question 33

Frontal lobe Know where it is and it's function.

Answer 33

Is the area anterior to (in front of) the central sucus and superior to (above) the lateral fissure. Contain's *Broca's area* which involves speech and language production; *Motor cortex* which involves body movement; and the *prefrontal cortex* which is involved in planning, impluse control, decision making and is where lobotomy's would be conducted.

Question 34

Parietal lobe. Know where it is and it's function.

Answer 34

Is located superior to the lateral fissure and between the central sulcus and occupational lobe. Involves body sentations, attention, perception, spatial localization, and association areas. It contains the somatosensory cortex and visual association areas.

Question 35

Temporal lobe. Know where it is and it's function.

Answer 35

The part of each cerebral hemisphere ventral to the lateral fissure (bottom part of the brain); it contains the *auditory cortex* (which receives sound info from the ears), visual and auditory association areas, *Wernicke’s area* (intrepts language input arriving from nearby auditory and visual areas), and structures involved in learning and memory.

Question 36

Occipital lobe. Know where it is and it's function.

Answer 36

The most posterior part of each cerebral hemisphere and the location of the visual cortex.

Question 37

What is Homunculus

Answer 37

Latin for "little man" A distorted representation of the body in the brain that shows how different parts of the brain control different parts of the body

Question 38

What is the Corpus Callosum

Answer 38

The largest of the groups of neurons connecting the two cerebral hemispheres.

Question 39

What is the function of the Cerebellum and Basal Ganglia?

Answer 39

1. Cerebellum: A structure in the hindbrain that contributes the order of muscular contractions and their precise timing to intended movements and helps maintain posture and balance. It is also necessary for learning motor skills and contributes to nonmotor learning and cognitive activities. 2. Basal Ganglia: structure surrounding thalamus, that focuses on regulation of voluntary movements, motor learning and procedural memory, control of movement initiation/termination, and reward processing & motivation.

Question 40

What is the function of The Limbic System?

Answer 40

1. Amygdala: involves regulating basic drives and emotions 2. Hippocampus: focuses on encoding certain memories. 3. Hypothalamus: A subcortical structure in the forebrain just below the thalamus that plays a major role in controlling emotion and motivated behaviors, such as eating, drinking, and sexual activity. 4. Pituitary glands: regulates production and release of hormones.

Question 41

What is th brainstem composed of?

Answer 41

1. Medulla: the lower part of the hindbrain (under the pons; its nuclei are involved with control of essential life processes, vital reflexes, such as cardiovascular activity and respiration (heart & lungs). 2. Pons: A part of the brain stem that contains centers related to sleep and arousal. "bridge" in latin. 3. Midbrain: Located under the thalamus, contains structures that have secondary roles in vision, hearing, and movement (species-typical movement patterns, eyes, ears, tail) --->the middle part of the brain, consisting of the tectum (roof) on the dorsal side and the tegmentum on the ventral side. 4. Thalamus: A forebrain structure lying just below the lateral ventricles, which receives information from all sensory systems except olfaction (smell) and relays it to the respective cortical projection areas. It has additional roles in movement, memory, and consciousness. Focused on routing and regulating.

Question 42

Where and what is the function of the Spinal Cord?

Answer 42

A part of the central nervous system; the spinal nerves, which communicate with the body below the head, enter and leave the spinal cord.

Question 43

The main regions of the brain. Consider what damage to these regions would result in.

Answer 43

Stokes: caused by a loss of blood flow to the brain. (aka cerebrovasular accident). most are ischemic (caused by artery blockage) and hemorrhagic strokes (caused by an artery rupture). neurons are depreived of oxygen, and glucose. most damage is due to excitotoxicty (dying neuron relase excess glutamate which overstimulates the surrounding neurons) and edema (accumlation of fluid that causes pressure on the brain, swelling). Tramatic brain injury (TBI): caused by an external mechanical force, suc as a blow to the head, sudden acceleration or deceleration, or penetration. Even trauma that does not produce concussion can result in brain changes typically seen in Alzheimer’s patients.

Question 44

Somatic nervous system

Answer 44

Includes motor neurons that operate the skeletal muscles -that is, the ones that move your body-and the sensory neurons that bring information into the central nervous system (CNS) from the body and the outside world.

Question 45

Automatic nervous system

Answer 45

Controls smooth muscle (stomach, blood vessels, etc.), the glands, and the heart and other organs.

Question 46

Know the order of the stages of development for the nervous system

Answer 46

Four distinct stages 1. **Cell proliferation:** the cells that will become neurons divide and multiple at the rate of 250,000 new cells every minute. This occurs in the ventricular zone (area surrounding the hollow tube that will become the ventricles and central canal) 2. **Migration:** Newly formed neuron move from the ventricular zone to their final location; most of them move perpendicularly from the ventricular surface using specialized radial glial cells. 3. **Circuit formation:** the axons of developing neurons grow toward their target cells and form functional connections. to find their way, axons form growth cones at their tip, which samples the enviroment for directional cues. 4. **Circuit pruning:** involves the elimination of excess neurons and synapses. neurons die if they are unsucessful in finding a place on a target cell, are crowded off by a more active neuron, or arrive late. the nervous system refines its organization and continues to correct errors by eliminating large numbers of excessive synapses.

Question 47

Staining techniques

Answer 47

Highly detailed, often monochrome or two-tone, used for visualizing individual neurons, cell bodies, or axons. Has 3 different types: 1. Golgi stain: highlights individual neurons 2. Myelin stain: emphasizes white matter (dark blue), stains the fatty insulation on axons, thus identifying neural pathways 3. Nissl stain: emphasizes cell bodies (darker). staining method that stains cell bodies.

Question 48

what is Autoradiography

Answer 48

A technique for identifying brain structures involved in an activity; it involves injecting a radioactive substance (such as 2-DG) that will be absorbed most by the more active neurons, which then will show up on an X-ray image. Dark patches or heatmap-like visualization of receptor activity, often used in neurotransmitter research. It reveals which neurons are active.

Question 49

what is Immunocytochemistry

Answer 49

Brightly fluorescent-stained structures due to tagged antibodies binding to specific proteins. Uses antibodies to show neural components. A procedure for labeling cellular components such as receptors, neurotransmitters, or enzymes by using a dye attached to an antibody designed to attach the component.

Question 50

What is EEG, stereotaxic atlas

Answer 50

A measure of brain activity recorded from two electrodes on the scalp over the area of interest and connected to an electronic amplifier; this detects the combined electrical activity of all the neurons between the two electrodes. Waveform patterns or brain activity maps showing electrical activity overtime.

Question 51

What is an MRI

Answer 51

An imaging technique that involves measuring the radio-frequency waves emitted by hydrogen atoms when they are subjected to a strong magnetic field. Because different structures have different concentrations of hydrogen atoms, the waves can be used to form a detailed image of the brain.

Question 52

Difference is lesions vs aspiration vs ablation

Answer 52

**Lesioning:** damages neural tissue with heat, electrical current, neurotoxins, or by serving connections. Lesions occur naturally as a result of trauma, disease, or developmental error. **Ablation:** removal of brain tissue.

Question 53

What is a DTI

Answer 53

(Diffusion Tensor Imaging): Vivid, colorful fiber tract images showing white matter pathways. A variant of MRI that measures movement of water molecules to image brain pathways and quantify their quality.

Question 54

what is a PET

Answer 54

Color-coded activity map showing metabolic or neurotransmitter activity (often warm colors like red, orange, yellow). It involves injecting a radioactive substance into the bloodstream, which is taken up by parts of the brain according to how active they are; the scanner makes an image that is color coded to show the relative amounts of activity.

Question 55

What is a CT

Answer 55

A black-and-white, X-ray-like slices of the brain showing dense structures (bone, hemorrhage) clearly. An imaging technique that produces a series of X-rays taken from different angles; these are combined by a computer into a three-dimensional image of the brain or another part of the body.

Question 56

fMRI

Answer 56

A brain-imaging procedure that measures brain activation by detecting increases in blood flow and oxygen usage in active neural structures. High-resolution grayscale or color images showing localized brain activation over time.