Intro To Psychology - Neuro Anatomy Chapter 3

Front 1

What are the basic parts of a neuron?

Back 1

SOMA: cell body which contains the nucleus

DENDRITE: branch-like tendrils which receive the information from other cells and relays the information to the soma

AXON: segmented, long fiber that transmits info away from the cell body toward other neurons or to muscles or glands.

Myelin sheath: is the fatty tissue of the axon which helps to speed up neural impulses and prevents "shorting out" of electrical impulses

Node of Ranvier: these are the "breaks" or gaps in the axon. The electrical charge actually jumps from segment to segment.

Front 2

Please briefly describe the electrochemical process that occurs between neurons.

Back 2

1) An electrical charge travel through the neuron: when a signal is received by dendrites it is passed to the soma in the form of an electrical signal.

2) If the signal is strong enough, it travels to the axon and then to the terminal button.

3) At the terminal button there is then a release of neurotransmitters across the synapses (the space between the cells)

Resting potential: this is the state of the interior of the neuron during which it contains a greater number of negative ions than does the outside of the cell.

Action potential: this is the change in electrical charge that occurs in a neuron when a nerve impulse is transmitted. The number of positive ions exceeds the number of negative ions and the segment becomes temporarily charged.

note: action potential operates in an "all or nothing" matter. Neurons can provide more energy to neurons down the line by firing more rapidly NOT more strongly.

Front 3

What is the terminal button?

Back 3

The end of the axon which secretes neurotransmitters.

Front 4

What are neurotransmitters?

Back 4

Chemical messengers that relay signals across the synapses between neurons. Neurotransmitters travel across the synaptic space between the TERMINAL BUTTON of one neuron and the DENDRITES of other neurons, where they bind to the dendrites of other neurons. Different terminal buttons release different neurotransmitters. Dendrites will admit neurotransmitters only if they are the right shape to fit on the receptor sites, sort of a lock - and - key mechanism.

Front 5

What is the synapse?

Back 5

The point at which neurons interconnect.

Front 6

What is the synaptic cleft?

Back 6

Is the space in between.

Front 7

What is the presynaptic neuron?

Back 7

Synaptic vesicles, neurotransmitters

Front 8

What is the postsynaptic neuron?

Back 8

Receptor sites

Front 9

Lock and Key mechanism

Back 9

neurotransmitters have a lock-and-key mechanism when they interact with the receptor site. If enough neurotransmitters bind to the receptor site then the signal fires off. (The neuron either fires or it doesn't, there is no middle ground).

*scientists believe that if the neurotransmitters do not bind then they are "sucked back" into the neuron, this is called "RE-UPTAKE".

Front 10

What is Synaptic Pruning?

Back 10

we are efficient creatures and we don't want to retain more neurons than we actually need

Front 11

With regards to types of drugs, what is an AGONIST and what is an ANTAGONIST?

Back 11

Agonist: A drug that mimics the actions of neurotransmitters
Example: in someone who smokes, nicotine mimics acetylcholine. Acetylcholine is a neurotransmitter that functions in both the PNS and CNS and can have both calming and excitatory effects. (can slow the heart and cause jitters)

Antagonist: a drug that blocks the actions of neurotransmitters
Example: SSRI drugs INHIBIT seratonin uptake
Seratonin is a neurotransmitter than is typically associated with the "feeling good" and is found within the GI tract and CNS. SSRI drugs inhibit uptake of seratonin in hopes that the seratonin levels remain high in the body because they cannot be "sucked back up"

Front 12

What is CNS

Back 12

CNS stands for Central Nervous System which is comprised of the neurons which make up the brain and spinal cord.

Front 13

What is PNS

Back 13

PNS stands for Peripheral Nervous System which is collection of neurons that link the CNS (Central Nervous System) to our skin, muscles and glands.

Front 14

What is ANS?

Back 14

Autonomic Nervous System is actually a division of the PNS. It controls INTERNAL activities such as heart rate, breathing, digestion, and other functions which are out of our conscious control

Front 15

Please describe the cerebral hemispheres (left and right)

Back 15

The left and right hemispheres are connected by the corpus callosum.

The LEFT hemisphere is associated with VERBAL processing, language, speech, reading and writing

The RIGHT hemisphere is associated with NON-VERBAL processing, spacial/musical/visual recognition

Front 16

What parts of the brain are considered the "Old Brain"?

Back 16

The Old Brain are the innermost structures of the brain, the parts nearest the spinal cord.

The old brain regulates basic survival functions such as breathing, moving, resting and feeding.

We shared this same brain with our ancestors, thus the name "old brain".

Front 17

What is the "outer brain"?

Back 17

The outer brain, aka the CEREBRAL CORTEX, is comprised of the layers further brain layers (from the Old Brain) which provide more advanced functions such as better memory, more complex social interactions and the ability to experience emotions.

Front 18

What is the brain stem?

Medulla, pons, reticular formation

(part of the HINDBRAIN)

Back 18

The BRAIN STEM is the innermost and oldest region of the brain. It's function is to control the most basic life functions such as breathing, attention and motor responses.

The brain stem begins where the spinal cord enters the skill and forms the MEDULLA. The MEDULLA is the area of the brain stem that controls breathing and heart rate.

The egg-like or spherical shape above the MEDULLA is the PONS. The PONS helps control movements of the body and play a vital role in balance and walking.

Running through both the MEDULLA and the PONS is a network of neurons called the RETICULAR FORMATION. The reticular formation serves as a filter for stimuli which are traveling to the brain from the spinal cord. It relays information to appropriate areas in the brain and plays an important role in walking, eating, sexual activity and sleeping.

Front 19

What is the cerebellum?

(part of the HINDBRAIN)

Back 19

Literally "little brain", the CEREBELLUM consists of 2 ovals located behind the brain stem. It relates to the coordination of voluntary movement such as motor movements and balance.


Additionally, it contributes to our emotional responses and helps up distinguish between different sounds and textures and is involved in learning.

People who have sustained damage to their cerebellum have difficulty walking, maintaining their balance and keeping their hands steady.

Note of interest: People who have imbibed and are drunk have difficulty walking and balancing as alcohol influences the cerebellum.

Front 20

What is "the limbic system"?

(aka the FOREBRAIN)

Back 20

The LIMBIC SYSTEM is the brain area located between the brain stem and the 2 cerebral hemisphere. It governs emotion and memory.

It includes: the amygdala, hypothalamus and hippocampus.

Front 21

What is the amygdala?

(part of limbic system/ FOREBRAIN)

Back 21

The AMYGDALA is primarily responsible for regulating our perceptions of and reactions to aggression and fear.

It consists of two "almond shaped" clusters. (amygdala comes from the latin word for almonds).

In addition to helping us experience fear, the amygdala stimulates the brain to remember the details of the fearful situation so that we can learn from it.

Front 22

What is the hypothalamus?

(part of limbic system)

Back 22

The HYPOTHALAMUS is located under the thalamus and it links the nervous system to the endocrine system via the pituitary gland.

The HYPOTHALAMUS interacts with many other areas of the brain and is involved in regulating body temperature, hunger, thirst, sex, etc. It creates the feelings of pleasure associated with fulfilling these needs. (a reward center).

Front 23

What is the hippocampus?

(part of limbic system)

Back 23

The HIPPOCAMPUS consists of two horn-like extensions which curve away from the amygdala.

It is critical for storing LONG-TERM MEMORY.

If the hippocampus is damaged, a person cannot build new memories. He/she can access old memories but cannot remember present experiences as they simply fade away.

Front 24

What is the cerebral cortex?

Back 24

The CEREBRAL CORTEX is the outer bark like layer of our brain that allows us to use language, acquire complex skills, create tools and live in social groups.

In humans, the CEREBRAL CORTEX is very wrinkled and folded thus possesses a much greater surface area thereby allowing increased capacities in learning, memory and thinking. The folds are also known as corticalization.

Front 25

What are glial cells?

Back 25

GLAIL CELLS are the cells that support the neurons. Glia cells surround and link to the neurons:

1) protect neurons
2) provide neurons with nutrients
3) absorb unused neurotransmitters

Front 26

Overview of the cerebral cortex.

Back 26

The CEREBRAL CORTEX is divided into TWO HEMISPHERES.

Each hemisphere is divided into FOUR LOBES, each separated by fissures.

Front 27

Where is the frontal lobe and what is it responsible for?

(cerebral cortex)

Back 27

Location: The FRONTAL LOBE is the area of the cerebral cortex which resides at the forehead area.

Function: thinking, planning, memory and judgement.

Front 28

Where is the parietal lobe and what is it responsible for?

Please mention BROCA's AREA.

(cerebral cortex)

Back 28

Location: the PARIETAL LOBE is behind the frontal lobe, from the middle toward the back of the skull.

Function: processing information regarding touch

Broca's Area is located in the LEFT parietal lobe and is associated with speech production

Front 29

Where is the occipital lobe and what is it responsible for?

(cerebral cortex)

Back 29

Location: the OCCIPITAL LOBE is located at the back of the skull

Function: the OCCIPITAL LOBE is responsible for processing visual information

Front 30

Where is the temporal lobe and what is it responsible for?

(cerebral cortex)

Also, please mention Wernicke's Area

Back 30

Location: the TEMPORAL LOBE is located in the area between the ears

Function: the TEMPORAL LOBE is primarily responsible for hearing and language

WERNICKE'S AREA is behind Broca's Area, near the Sylvian Fissures. It is involved in the writing and comprehension of language.

Front 31

What is contralateral control?


Who are Gustav Fritsch and Eduard Hitzig?

Back 31

German ohysicists Fritsch and Hitzig applied electrical stimulation to different areas of a dog's cortex and discovered that stimulating the R side of the brain produced movement in the LEFT side of the body and stimulating the L side of the brain produced movement in the RIGHT side of the body.

This provided insight into how the brain is structured, called CONTRALATERAL CONTROL. In most cases, the L hemisphere receives sensations from and controls the R side of the body while the R hemisphere receives sensations from and controls the L side of the body.

Front 32

What is the MOTOR CORTEX?

Back 32

Fritsch and Hitzsig also discovered the MOTOR CORTEX. It is an area of the cortex that controls and executes movements of the body by sending signals to the cerebellum and spinal cord.

Front 33

What is the somatosensory cortex?

Back 33

Running parallel to the motor cortex toward the back of the frontal lobe is the SOMATOSENSORY CORTEX which receives information from the skin's sensory receptors and the movements of different body parts.

Front 34

What is the visual cortex?

Back 34

Located in the occipital lobe that processes visual information.

Front 35

What is the auditory cortex?

Back 35

Located in the temporal lobe that processes hearing and language.

Front 36

What is neuroplasticity?

Back 36

NEUROPLASTICITY refers to the brain's ability to change its structure and function in response to experience or even damage. Neuroplasticity allows us to learn and remember new things as well as adjust to new experiences.

Our brains tend to be more "plastic" when we are young but we can also observe evidence of neuroplasticity in adults - ex/ a musician probably has a larger auditory cortex when compared to the general population.

Plasticity is also apparent when there is damage to either the brain or parts of the body. Ex/ if a person loses a finger, the area of the sensory cortex responsible for the missing finger will begin to receive input from the other fingers and the other remaining fingers will become more sensitive.

Front 37

What is neurogenesis?

Back 37

NEUROGENESIS is the forming of new neurons. It is thought that new neurons are formed deep in the brain and somehow migrate to other areas of the brain where they are needed and form new connections with existing neurons. Scientists are hopeful that they might be able to help rebuild damaged areas of the brain by creating a drug that stimulates neurogenesis.

Front 38

What is brain lateralization and what happens when the corpus callosum is severed?

Back 38

Brain lateralization is the idea that the left and right hemisphere of the brain are specialized to perform different functions.

The region that connects the left and right hemispheres is called the corpus callosum.

Ex: visual and verbal processing in split brain patient
An individual identified as WJ underwent a surgery in which his corpus callosum was severed in order to stop severe seizure activity.

Front 39

Who was Phineas Gage and what is his significance?

Back 39

Phineas Gage was a railroad worker during 1800's who had an iron rod driven into his cheek out through the top of his skull by an explosion. He sustained major damage to his frontal lobe but survived.

Supposedly, the once amiable and gentle man became irritable, rude and dishonest. His case study provided some early evidence that the frontal lobe is involved with emotion and morality. He lived another 12 years after his accident and always had the railroad pike with him.

Front 40

Please distinguish between the following:

Sensory neuron (aka afferent neuron)

Motor neuron (aka efferent neuron)

interneuron

Back 40

An AFFERENT NEURON (aka sensory neuron) carried information from the sensory receptors.

An EFFERENT NEURON (aka motor neuron) carries information to muscles and glands.

An INTERNEURON, which is the most commen neuron, is located within the CNS and is responsible for communicating among the neurons - meaning that interneurons allow the brain to combine multiple sources of information to create a coherent picture.

Front 41

What is a reflex?

Back 41

A reflex in an involuntary, nearly instantaneous movement in response to a stimulus. Reflexes are triggered when sensory information is powerful enough to reach a given threshold and the interneurons in the spinal cord act to send a message back to through the motor neurons without relaying the information to the brain.

sensory info-->interneuron in spinal cord-->motor neuron
*bypasses the brain

Front 42

What is the peripheral nervous system (PNS)?

Back 42

The peripheral nervous system (PNS) represents the "front line" of the body while the central nervous system (CNS) can be likened to the command center of the body.

The peripheral nervous system (PNS) links the central nervous system (CNS) to the body's receptors, muscles and glands.

The PNS can be divided into 2 subsystems:

autonomic nervous system (ANS)which controls internal functions
somatic nervous system (SNS) which controls external functions

Front 43

What is the ANS?

Back 43

ANS is the autonomic nervous system and is a subdivision of the PNS. It governs the internal activities (many of which are out of our conscious control) of the body such:

heart rate
breathing
digestion
salivation
perspiration
urination
sexual arousal

Front 44

What is the SNS?

Back 44

The SNS is the somatic nervous system and it the division of the PNS that controls external aspects of the body such as:

skeletal muscles
skin
sense organs

*it consists primarily of motor nerves which send signals to the brain for muscle contraction

Front 45

The autonomic nervous system can itself be divided into 2 systems - what are they?

Back 45

The ANS can be divided into the sympathetic and parasympathetic systems.

The sympathetic system of the ANS is involved in preparing the body for behaviors related to stress. It activates organs and glands in the endocrine system. Examples are:

dilates pupils
accelerates heart beat
inhibits digestion
stimulates glucose release
stimulates secretion of epinephrine and norepinephrine

The parasympathetic nervous division of the ANS calms the body and allows the body to recover from the activities triggered by the sympathetic nervous system. Examples are:

contracts pupils
slows heartbeat
stimulates digestion

The 2 divisions of the ANS work together to balance the body - homeostasis. An example in everyday life is the following:

When one is nervous for an exam one tends not to be hungry (sympathetic nervous division of ANS). Once the exam is finished usually one's hunger returns strongly (parasympathetic nervous division of ANS).

Front 46

What are epinephrine and norepinephrine?

Back 46

Epinephrine and norepinephrine are both hormones which are released during stressful situations by the adrenal glands (ANS, sympathetic division)

Front 47

Please give a brief overview of the endocrine system.

What are glands and hormones?

Back 47

The ANS, sympathetic and parasympathetic divisions, interact with the endocrine system. The endocrine system is a collection of organs which possess glands that secretes hormones.

A gland is a group of cells whose function is to secrete hormones.

Hormones are chemicals that move throughout the body to help regulate emotions and behaviors.

Glands of the endocrine system include:

Hypothalamus, controls pituitary gland
Pituitary gland, secretes many different hormones "master gland"
thyroid, affects metabolism
parathyroid, regulates calcium levels
adrenal gland, triggers fight or flight
pancreas, regulates sugar level
testes/ovaries, secrete sex hormones

Front 48

What is the pituitary gland?

Back 48

The pituitary gland is located near the center of the brain.

It is responsible for controlling growth. It also secretes hormones that regulate our response to pain as well as hormones that signal the ovaries and testes to make sex hormones. It controls ovulation and the menstrual cycle.

It is often referred to as the "master gland" because it has an important influence on other glands.

Front 49

What is the role of the pancreas within the endocrine system?

Back 49

Although the pancreas is often associated with the digestive system and enzymes, it plays a role within the endocrine system as well. The pancreas releases hormones such as glucagon to help keep the body fueled with energy.

Front 50

What is the pineal gland?

Back 50

The pineal gland is located in the middle of the brain and secretes the hormone melatonin that helps regulate the wake-sleep cycle.

Front 51

What are the adrenal glands?

Back 51

The adrenal glands sit atop the kidneys and are an excellent example of how the endocrine and nervous systems are linked.

In addition to secreting hormones that regulate salt and water balance in the body, metabolism and the immune system adrenal glands also secrete epinephrine (aka ADRENALINE) and norepinephrine when we are stressed or threatened.

Remember, the ANS can be divided into sympathetic and parasympathetic systems. It is the endocrine system that mobilizes the body onto action.