for the final exam

Question 1

Explain the organization of the nervous system.

Answer 1

It has two major branches: the central nervous system (CNS) and the peripheral nervous system (PNS). While the CNS is mainly involved with the brain and the spinal cord, the PNS can be further divided. It has two branches of its own: the somatic nervous system and the autonomic nervous system While the somatic branch controls the skeletal muscles, such as helping us walk across a room, the autonomic branch is divided into three subdivisions: sympathetic, parasympathetic, and enteric.

Question 2

Explain how the CNS works.

Answer 2

The CNS involves the brainstem (medulla oblongota, midbrain, and pons), cerebrum, and the cerebellum.
-Brainstem: a stalk-like part that joins the brain to the spinal cord.
-Cerebrum: the largest portion of the brain, divided into two hemispheres.
-Cerebellum: between the cerebrum and brainstem; learning and coordinating motor movements.

Question 3

Explain how the peripheral nervous system works.

Answer 3

Parts: Afferent/sensory neurons, Efferent/Secretomotor neurons, Somatic system, Autonomic system.
Functions:
-Autonomic System-responsible for supplying nerves to the cardiac muscle of the heart. The sympathetic and the parasympathetic branches are involved in our fight-or-flight response.

Question 4

Explain the process of action potential (don’t forget to include the correct definition of reuptake)

Answer 4

Action potential is the process in which the membrane potential of a neuron rapidly rises and falls due to the movement of Na+(sodium) and K+(potassium) channels. It has three phases: depolarization, overshoot, and repolarization. These are all-or-none, since if the threshold potential, or the number of ion channels open leads to the system becoming self-sustaining, isn’t reached, no action potentials will occur. Even if there is a larger stimulus, it doesn’t mean that the action potentials would be larger, but rather its frequency would increase. How its fired would depend on excitatory neurotransmitters, or chemical substances, that make postsynaptic neurons more likely to fire action potentials. On the flip side, there are inhibitory neurotransmitters that make the postsynaptic neuron less likely to fire.

Question 5

Explain the process of action potential (part 2)

Answer 5

The communication between the presynaptic neuron and the postsynaptic neuron happens at the junction called a synapse. There, the action potential arrives at the terminal button. Vesicles release their neurotransmitters into the synapse, which then bind to receptors, large protein molecules, that have a specific, unique structure. Once the signal is delivered, the neurotransmitter must be removed from the synaptic cleft so the postsynaptic neuron can ‘reset’ and receive another signal. This can be done through reuptake, or the reabsorption of the neurotransmitter into the presynaptic neuron to be recycled and then released again.

Question 6

Dive deep into how the action potential travels down a neuron.

Answer 6

An action potential is received by the dendrites, or these branch-like projections that conducts the stimulation received from other neural cells into the cell body, or the soma. Basically, small gates open on the neuronal membrane, allowing Na+ ions to move into the cell. These dendrites are always undergoing remodeling throughout one’s life span. Then, the action potential is propagated through its axon, or the projection that extends from the cell body to its ending and transmits the signal until it reaches the terminal button. Once this is depolarized, it releases a neurotransmitter into the synapse. It then binds to its receptors on the postsynaptic neuron of the target cell, causing either stimulation or inhibition depending on the kind of neurotransmitter. The speed of the propagation depends on the axon’s thickness and whether it’s myelinated. Myelin is the white fatty material that wraps around the axon that not only helps insulate it, but also allows rapid transmission along the axon. It’s produced from oligodendrocytes, a type of glial cell.

Question 7

What is glutamate?

Answer 7

It’s the most abundant EXCITATORY neurotransmitter in the brain; binds to many receptors.

Question 8

What is GABA/gamma-aminobutyric acid?

Answer 8

It’s the most abundant INHIBITORY neurotransmitter in the brain; binds to many receptors.

Question 9

What is glycine?

Answer 9

A neurotransmitter that can either be excitatory OR inhibitory depending on the receptors. It can mirror GABA’s actions in the spinal cord and be a co-agonist for NMDA receptors.

Question 10

What is dopamine?

Answer 10

It’s a monoamine neurotransmitter associated with motor control, determining the activity of the basal ganglia and behaviors related to reward and addiction. It has a lot of functions because it keeps our brain at its optimal level. Low levels: Parkinson’s disease.

Question 11

What is serotonin?

Answer 11

It’s a monoamine neurotransmitter associated with mood, digestion, sleep, and psychological disorders. For example, if there are low levels, it can lead to depression. Low levels: depression.

Question 12

What is acetylcholine?

Answer 12

Responsible for our motor movements. Low levels: Alzheimer’s.

Question 13

What are afferent nerves?

Answer 13

Also called sensory neurons, they carry sensory info from the skin and other organs to the CNS. Its cell bodies are located outside of the spinal cord.

Question 14

What are efferent nerves? Where are their cell bodies located?

Answer 14

Also called motor neurons, they convey info from the CNS to the PNS. Its cell bodies are located in the ventral horn of the spinal cord.d

Question 15

What is efficacy? And how is it different from potency?

Answer 15

The extent to which a drug activates a receptor More = more severe side effects. Antagonists don’t have any because they don’t elicit a physiological reaction. Ex: if you take either morphine or aspirin, your pain would go away. This is efficacy. However, 1/2 of morphine OR 2 aspirins is needed for your pain. This is potency.

Question 16

Describe the theory of system consolidation.

Answer 16

The theory describes the transfer of dependence of old memories to the cortex. For example, the information the professor is relaying to a student in a class is being translated by his or her hippocampus. This is so later on, when that student starts to get more familiar with that info, they can start to consolidate the knowledge, with the help of the hippocampus, into the cortex. Since episodic memories rely upon binding together different cortical areas, and the hippocampus can do this quickly, it’s necessary initially to retrieve those episodic memories. But when the cortical areas are linked together directly, meaning that that info is consolidated into the cortex, you wouldn’t need the hippocampus’ help anymore. Therefore, the hippocampus is no longer essential for memory retrieval.

Question 17

Describe the multiple-trace model of consolidation.

Answer 17

Believes that the hippocampus continues to play a role, well beyond consolidation in the cortex. Therefore, the hippocampus is active during retrieval for both new and old episodic memories.

Question 18

What is memory processed by?

Answer 18

The hippocampus, it’s strongly associated with conscious, episodic memory, and spatial memory. damage could ruin these memories, plus previously acquired memories.

Question 19

Describe how we can see different colors/the impact of different waves.

Answer 19

There is electromagnetic radiation all around us. However, humans can only detect a tiny fraction of the available range. Different surfaces reflect different amounts of light, which albedo, the proportion of incident light that a surface reflects, determines how light a surface appears. Intensity is determined by the amplitude, or height. Hue, or color, is determined by the wavelength, or distance between two peaks of a wave. It’s directly related to the frequency, or the number of waves that pass a given point in a given time period, often expressed in hertz, or cycles per second. longer wavelengths=lower frequencies. shorter wavelengths=higher frequencies. f
Red: long wavelength, short frequency.
green: intermediate.
blues/violets: shorter in wavelength.

Question 20

What is transduction?

Answer 20

It’s a process in which a change of stimuli by a special cell to a chemical that our brain can read.

Question 21

Describe the difference between sensation and perception, then describe what the whole sensory system is.

Answer 21

Sensation is concerned with the physical stimulus, while perception is concerned with interpreting those sensations in terms of the stimulus that produced them. All sense, except for the smell, is processed by the thalamus. Then, inputs are sent to cortical regions that process info. Remember: objects and events only indirectly affect our sense organs. These organs register these effects, but not the objects or events themselves.

Question 22

Describe the difference between midget ganglion cells and parasol ganglion cells. Finally, what are konio cells?

Answer 22

Midget ganglion cells have strong lateral inhibition and are particularly sensitive to spatial change. Input is sent to the parvocellular layers and is concerned with signaling color and fine detail; blue-yellow. Parasol cells have weaker lateral inhibition, but strong delayed inhibition. Input is sent to the magnocellular layers and is concerned with signaling movement. Konio cells are between those layers, which is concerned with red-green opponent cells.

Question 23

Describe what goes in our retina.

Answer 23

In our retina are these photoreceptors: rods and cones. Cones = color. Rods = black and white. Blood vessels and a network of interneurons make up the rest of it. Each type of cone has rhodopsin, a visual pigment that can be bleached in light to produce a response. Each receptor can produce a graded receptor potential, a tiny voltage. Since these are small and densely packed, they can produce a fine-grained ‘neural image’. Then, retinal interneurons transmit that image to the retinal ganglion cells, where they would respond to light in a small region of the retina called the cell’s receptive field.

Question 24

Who is patient H.M and what did he prove?

Answer 24

Patient HM was tested for the treatment of epilepsy. He had his entire medial temporal lobe removed on both sides of the brain, resulting in stabilizing the seizures but also an inability to form new conscious memories (anterograde amnesia) but also appeared to lose the ability to retrieve pre-existing memories(retrograde amnesia). This showed that this area is heavily involved in conscious memory formation, particularly the hippocampus(within that area). However, his unconscious memory remained intact. He was able to learn new motor skills. His case proves the theory of systems consolidation, NOT the multiple-trace theory.

Question 25

Explain the cells of the nervous system: dendrites, soma, axon, neurotransmitters, myelin, oligodendrocytes, astrocytes, and microglia.

Answer 25

-Dendrites: a projection that conducts the electrochemical stimulation received from other neural cells to the soma.
-Soma: cell body.
-Axon: a projection that extends from the soma to the terminal endings and transmits the neural signal.
-Neurotransmitters: a chemical released by a neuron and travels down a synapse to bind to receptors on the postsynaptic terminal of another neuron to change the electrical activity of the target cell.
-Myelin: a white fatty material that insulates the neurons and permits the rapid transmission of electrical signals along the axon.
-Oligodendrocyte: type of glail cell that produces myelin.
-Astrocyte: large star-shaped cells that perform a number of functions depending on where they’re located.
-Microglia: very small cells found throughout the brain and are mostly inactive; can be activated if the brain is damaged or infectious organisms are present; also engulf cell debris through a process called phagocytosis.

Question 26

What is the therapeutic index?

Answer 26

The ratio between the toxic dose and the therapeutic dose of a drug; a measure of drug safety. How it’s calculated is the dose of a drug that elicits a lethal response in 50% of a sample (known as lethal dose or LD50) divided by the dose that elicits a desired response in 50% of a sample (known as the effective dose or ED50).

Question 27

Explain the difference between Broca’s area and Wernicke’s area.

Answer 27

Broca’s area helps in producing speech and is located in the frontal lobe. While Wernicke’s area helps in speech processing and understanding language and is located in the temporal lobe.

Question 28

Where are the primary sensory areas located and what are they responsible for?

Answer 28

-Frontal lobe: executing learned, and purposeful behaviors, voluntary movement, expressive language, and higher level functions, like planning and organizing. has the primary motor cortex, which controls all moving parts of the body.
-Parietal lobe: has the primary somatosensory cortex, which is responsible for sensory perception and integration, including taste, hearing, sight, touch, and smell.
-Temporal lobe: processing auditory info, encoding of memory, and emotion.
-Occipital lobe: visual perception, including color, form and motion; contains the primary visual cortex.

Question 29

What is the difference between the somatosensory cortex and the motor cortex?

Answer 29

The somatosensory cortex coordinates the sensory data that comes up from all over the body/ The motor cortex coordinates our bodily movements, in strong relation with the cerebellum. While both are located between the parietal lobes and the frontal lobes, the motor cortex comes before the somatosensory.

Question 30

Explain the connection between serotonin and mood disorders.

Answer 30

Serotonin is an inhibitory neurotransmitter that helps regulate mood, sleep patterns, sexuality, anxiety, appetite, and pain. Abnormal serotonin levels can lead to mood disorders, such as:
-depression: with low serotonin function(and high GABA production), people could be more susceptible to developing it. variability of serotonin function could be due to: individual differences in 5-HT synthesis release, reuptake, or metabolism//differences in pre- or postsynaptic receptors and their responses.
-anxiety: low serotonin function; it may involve the 5-HT I A receptor. both serotonin selective reuptake inhibitors and tricyclics are used.

Question 31

Explain the similarities/differences between barbiturates and benzodiazepines.

Answer 31

Both medications serve to treat anxiety, bind to GABA-A receptors, and increase the duration of chloride channels opening. However, barbiturates can open the chloride channel directly at high doses. However, benzodiazepines don’t directly open the ion channel in the absence of GABA, but are safer.