Psychobiology Flashcards
1
Q
What makes up a neuron?
A
A cell body, an axon, and dendrites
2
Q
What is a synpase?
A
A tiny gap between neurons
3
Q
What is SSRI, and explain it in details?
A
Selective serotonin reuptake inhibitor. It’s linked to antidepressants. Usually, people with low serotonin takes it. After serotonin is released, the sending neuron usually takes it back. But if the neuron is stopped from doing this, more serotonin stays between the neurons, helping them communicate better and improving mood.
4
Q
What is the pineal gland?
A
This part of the brain helps control sleep by producing a hormone called melatonin. It releases more melatonin when it’s dark, making you feel sleepy, and less when it’s light, helping you stay awake.
5
Q
Explain what Dopamine is
A
Dopamine is a hormone associated with pleasure and motivation.
* It is released during enjoyable activities
* The brain releases dopamine to encourage behaviors that are beneficial.
* Behaviors that are harmful or unpleasant do not trigger dopamine release.
6
Q
What is a neuron?
A
A specialized cells that send impulses in the brain.
7
Q
Explain neurotransmitters
A
Neurotransmitters are chemicals that help neurons (nerve cells) communicate with each other. When a neuron sends an electrical signal, it triggers the release of neurotransmitters into a gap called the synapse. These chemicals then bind to receptors on the next neuron to pass along the message.
8
Q
Explain synapse
A
A synapse is the small gap or junction between two neurons where communication occurs. It is the site where one neuron communicates with another or with an effector (such as a muscle or gland).
9
Q
Explain how neurotransmission works
A
Neurotransmitters (e.g., dopamine, serotonin, acetylcholine) travel across the synapse and bind to receptors on neighboring neurons, influencing their activity. This process governs everything from mood and emotions to movement and thought.
10
Q
Explain the function of a synapse
A
A synapse is the small gap or junction between two neurons where communication occurs. It is the site where one neuron communicates with another or with an effector (such as a muscle or gland.
11
Q
What is the black box?
A
Input: Stimuli or information received from the environment (e.g., sensory input).
Processing: Internal mechanisms in the nervous system (the “black box”) that analyze and interpret the input.
Output: Behavioral responses or actions resulting from the processing, such as physical reactions or emotional responses.
Key Point: The black box describes the processing stage between input and output, emphasizing that the internal workings of the nervous system are complex and often hidden.
12
Q
Explain René Descartes believes
A
Descartes introduced the idea that some behaviors, like reflexes, are automatic and do not require conscious thought. He proposed Cartesian Dualism, suggesting the mind and body interact, particularly in the pineal gland.
13
Q
Explain reductionism in psychobiology
A
This approach simplifies complex behaviors by studying their fundamental components. For example, to understand the fear response, researchers focus on the role of the amygdala.
14
Q
What is the occipital lobe and where is it located?
A
Its the visual processing area of the brain and located in the back.
15
Q
Explain the gas-filled tube theory
A
How the mind interacts with the body. He proposed that the mind sends “animal spirits” through hollow tubes (nerves) to trigger movement in the body, like how gas flows through a tube to create motion. This analogy aimed to explain the mechanism of reflexes and voluntary actions, illustrating his belief that the mind and body, while separate entities, could still influence each other.
16
Q
Explain Luigi Galvani’s Discovery
A
He discovered that nerves transmit electrical impulses. He demonstrated this with frog experiments, showing that muscles could contract due to nerve impulses even without brain involvement. The neuron is the key to producing movements
17
Q
What was the outcome of the frog experiement?
A
The movement relies on electrical messages sent by neurons.
18
Q
Explain the Neural Transduction
A
Neural transduction refers to the conversion of external stimuli (such as light, sound, or touch) into electrical impulses (neural signals) that can be interpreted by the brain
19
Q
Describe the two Two types of neurons: motor and sensory.
A
Motor nerves control muscle movement.
Sensory nerves relay information to the brain.
20
Q
Explain the model:
(Brain) —> (Nerve) —> (Muscle)
A
The brain sends a signal to the nerves, which carry it to the muscles. When the signal reaches the muscle, it triggers a contraction, causing movement. This process allows the brain to control voluntary actions like walking or lifting an arm.
21
Q
What is basal ganglia?
A
Think of it as a team of different brain parts that work together to make sure your movements are smooth and well-coordinated.
Key Roles:
Helps initiate and control smooth movements.
Involved in learning habits and motor skills.
Dysfunction in the basal ganglia is linked to movement disorders like Parkinson’s and Huntington’s disease.
22
Q
Explain the somatosensory cortex and what it does
A
Its a part of the brain that processes sensory information from your body. It helps you feel things like touch, pressure, temperature, and pain.
- Located in the parietal lobe of the brain.
- It receives signals from all over your body, allowing you to sense where your body is and what it’s feeling.
It helps you recognize things like the texture of an object or the temperature of a surface.
In short, the somatosensory cortex lets your brain understand what’s happening with your body through touch and other sensations
23
Q
Whats the main function of the cerebellum?
A
The cerebellum is a part of the brain that helps control balance, coordination, and fine movements. It ensures that your movements are smooth and precise.
24
Q
What is myelin sheath, and what is the purpose of it?
A
The myelin sheath is a fatty layer that covers and protects the axons of some nerve cells (neurons).
Purpose:
Insulation: It helps keep electrical signals from leaking out, like how insulation keeps electricity from escaping a wire.
Speed: The myelin sheath makes signals travel faster along the nerve, allowing quick communication between different parts of the body.
Protection: It also protects the axon from damage.
25
Explain the pre frontal cortex
The front of the brain. Its all the complex things happening here.
Its important for thinking, planning, and managing how you behave in different situations.
26
What is cerebral localisation?
Definition: The concept that specific areas of the brain are responsible for different functions.
Key Points:
Different brain parts control various activities (e.g., frontal lobe for decision-making, occipital lobe for vision).
Supported by studies showing that damage to specific areas affects certain abilities.
27
What is the central sulcus?
The central sulcus is a prominent groove in the brain that separates two key areas: the frontal lobe and the parietal lobe.
28
Who's Phineas Gage?
A 19th-century railroad worker famous for a severe brain injury.
Accident: In 1848, an iron rod pierced his skull, damaging his frontal lobe.
Behavioral Changes: After the injury, he became impulsive and socially inappropriate, contrasting with his previous responsible personality.
Significance: His case provided early evidence of the frontal lobe's role in personality and decision-making, linking brain function to behavior.
29
What is the 2 types of cells that makes up the brain?
Neurons:
Function: Main signaling cells that transmit information through electrical and chemical signals.
Role: Responsible for communication within the brain and with the rest of the body, enabling thought, feeling, and movement.
Glial Cells (Glia):
Function: Support and protect neurons.
Role: Maintain the environment around neurons, provide nutrients, remove waste, and form the myelin sheath that insulates axons.
30
Who discovered the synapse?
Charles Scott Sherrington
31
Whos disvored the first neurontransmitter and what was it called?
Henry Dale, acetylcholine
32
Explain the Cerebral Cortex
It's the outer layer of the brain and is.
Functions:
Sensory Processing: It processes sensory information from your senses (like touch, sight, and hearing).
Motor Control: It is responsible for planning and executing voluntary movements.
Cognitive Functions: It plays a key role in thinking, reasoning, memory, and language.
Divisions: The cerebral cortex is divided into four main lobes:
Frontal Lobe: Involved in decision-making and planning.
Parietal Lobe: Processes sensory information.
Temporal Lobe: Responsible for hearing and memory.
Occipital Lobe: Processes visual information.
33
Why is the case with patient HM important?
Background: Underwent surgery to treat epilepsy, resulting in the removal of parts of his medial temporal lobes, including the hippocampus.
Memory Loss: Experienced anterograde amnesia—unable to form new long-term memories but retained short-term memory and existing memories.
Significance:
Highlighted the crucial role of the hippocampus in memory formation.
Helped distinguish between different types of memory (short-term vs. long-term) and their brain regions.
34
Explain anterograde amnesia
Anterograde amnesia is a condition where a person cannot form new memories after an event, while they may still recall memories from before that event
35
What is Purkinje cells?
Purkinje cells are a type of neuron found in the cerebellum, which is located at the back of the brain.
36
What is photonrecepter?
37
What is a receptor?
an organ or cell able to respond to light, heat, or other external stimuli and transmit a signal to a sensory nerve. Converting all of the stimuli into electrical energy to the brain.
38
Explain readiness potential
Readiness Potential: This brain signal indicating preparation to move happens about 300 milliseconds before a person feels aware of their decision to act.
39
What is miningis and where is it located?
Three layers of membranes that cover and protect your brain and spinal cord.
Dura mater: The tough, outer layer.
Arachnoid: The middle layer that looks like a spider web.
Pia mater: The delicate, inner layer that sticks closely to the brain and spinal cord.
40
What is the difference between the frontal lobe and the primary motor cortex (precentral gyrus)?
Frontal Lobe
Broad region at the front of the brain
Responsible for decision-making, problem-solving, personality, behavior regulation, and planning
Involves complex cognitive functions, including emotional control and speech production
Primary Motor Cortex:
A specific area in the back of the frontal lobe (along the precentral gyrus)
Controls precise, voluntary muscle movements
41
What is the role of the Occipital Lobe?
Function: Processes visual information. Located at the back of the brain.
42
Where is the Primary Motor Cortex (Precentral Gyrus) located and what is its function?
Location: On the frontal lobe, just in front of the central sulcus (precentral gyrus).
Function: Controls voluntary muscle movements.
43
What is the function of the Frontal Lobe?
Function: Responsible for planning movements, recent memory, and some aspects of emotions.
44
Where is the Central Sulcus located?
Location: Separates the frontal lobe from the parietal lobe; divides the precentral gyrus (motor cortex) from the postcentral gyrus (somatosensory cortex).
45
What is the function of the Primary Somatosensory Cortex (Postcentral Gyrus)?
Function: Processes body sensations like touch, pain, and temperature. Located in the parietal lobe, just behind the central sulcus.
46
What does the Parietal Lobe control?
Function: Responsible for processing body sensations such as touch, temperature, and pain.
47
Where is the Temporal Lobe and what does it do?
Location: On the sides of the brain, below the frontal and parietal lobes.
Function: Involved in hearing and advanced visual processing.
48
What is the role of the Occipital Lobe?
Function: Processes visual information. Located at the back of the brain.
49
Explain retina
The retina is a layer of photoreceptor cells at the back of your eyeball that converts light into nerve signals.
50
Explain simple and complex cells
Simple Cells:
Found in the brain's visual system.
They respond to straight lines or edges in a specific direction (like a vertical line or a horizontal line).
Complex Cells:
These cells respond to lines or edges that are moving.
For example, they might respond when a vertical line moves from left to right.
51
Explain Unconscious Processes
Definition: Mental activities that occur without our awareness, influencing thoughts, feelings, and behaviors without conscious realization
52
Explain Benjamin Libet's ressearch about brain signals
Key Finding: Libet's experiments in the 1980s showed that brain activity related to decision-making occurs before we are consciously aware of that decision.
Readiness Potential: This brain signal indicating preparation to move happens about 300 milliseconds before a person feels aware of their decision to act.
53
Explain the nervours system
Is divided into 2:
Central nervous system (CNS)
peripheral nervous system (PNS)
54
What is the myelin sheath?
insulates the axon to increase the efficiency of the neural impulse
Without the myelin sheath, the neural impulse would be slower, weaker, and would require more energy.
55
What creates myelin sheath?
Myelin is produced by a type of glia called oligodendrocytes in the brain and spinal cord, and Schwann cells when found elsewhere in the nervous system.
56
Explain axon terminals
also called (presynaptic terminals), which form synapses with the
dendrites of other neurones and other effector organs.
57
Explain excitation vs. inhibition in Neural Communication
Excitation:
When a neuron is excited, it increases the likelihood that the next neuron will fire an electrical signal (action potential).
It’s like giving a "go" signal to the next neuron.
Inhibition:
In contrast, inhibition decreases the likelihood that the next neuron will fire.
It’s like a "stop" signal, preventing the next neuron from activating.
58
Explain the two types of blood vessels
Arteries: These blood vessels carry oxygen-rich blood from the heart to the brain and other parts of the body.
Veins: These blood vessels carry oxygen-depleted blood from the brain back to the heart.
59
Explain the difference between a nerve and neuron
Nerve is a lot of neurons packed together, where neuron is just one.
60
What are The brain and spinal cord protected with?
They are both surrounded by a protective three layer
system called the meninges:
dura mater: The tough, outer layer.
arachnoid: The middle layer that looks like a spider web.
pia mater: The delicate, inner layer that sticks closely to the brain and spinal cord.
Cerebrospinal Fluid (CSF): It fills the space between the layers (in the subarachnoid space) and acts like a shock-absorber, protecting the brain and spinal cord from injury.
Blood-Brain Barrier: The blood vessels in the brain are packed tightly, which prevents harmful substances (like toxins) from entering the brain from the bloodstream.
61
What includes in the PNS's somatic nervous system (SNS)?
Voluntary movements—any actions you decide to do, like walking or talking.
Sensing—it lets you feel sensations like heat, cold, pressure, and pain by sending sensory signals from your skin and muscles back to your brain.
Uses spinal nerves for body muscles and cranial nerves for head/neck muscles.
62
What includes in the PNS's autonomic nervous system (ANS)?
The ANS regulates internal organs, smooth muscles, and hormone glands.
It maintains homeostasis by keeping the body’s internal state balanced (e.g., heart rate, digestion, temperature).
It controls key functions like cardiovascular, respiratory, digestive, hormonal, and thermal regulation.
This process is involuntary and happens without conscious control.
These nerves are different from somatic nerves, as they regulate involuntary processes like heart rate and digestion.
63
Explain Afferent and Efferent Neurons
Afferent Neurons (Sensory Neurons):
These neurons carry sensory information from the body to the brain and spinal cord.
They help the brain process things like touch, temperature, and pain.
- Think of afferent neurons as "incoming" messages to the brain.
Efferent Neurons (Motor Neurons):
These neurons send signals from the brain and spinal cord to muscles, organs, and glands.
They help control movement, like making your muscles contract to lift an arm.
Key Tip to Remember:
Afferent = Arrives at the brain.
Efferent = Exits the brain.
64
Does neuron work alone?
No, each neuron receives signals from many other neurons.
Neurons combine inputs from many other neurons and act based on the balance of these signals. (balance between Excitatory vs. inhibitory)
65
Explain the central nervous system
Includes the brain and spinal cord, responsible for processing and coordinating sensory information and responses.
The brain is the control center, handling sensory input, thoughts, emotions, and voluntary and involuntary actions (like heart rate).
The spinal cord transmits signals between the brain and body and controls reflexes independently of the brain.
66
Explain Peripheral Nervous System (PNS)
It's made up of nerves outside the brain and spinal cord.
It's more exposed to damage compared to the Central Nervous System (CNS) (which includes the brain and spinal cord).
The PNS connects the CNS to the rest of the body.
Its divided in the somatic nervous system and autonomic nervous system
67
Explain what a tract is
In the CNS (inside the brain and spinal cord), the bundles of axons are called tracts. So, the same type of structure is called a "nerve" in the PNS and a "tract" in the CNS.
68
Nerves vs. Tracts
A nerve is a bundle of axons located in the PNS, while a tract is a similar bundle found in the CNS.
Nerves carry sensory and motor signals to and from the brain, but tracts relay signals within the brain and spinal cord.
69
Nuclei vs. Ganglia
Nuclei are clusters of neuron cell bodies within the CNS.
Ganglia are clusters of neuron cell bodies within the PNS.
70
How is the somatic and autonomic nerves are not organised in the same way?
SNS motor neurones simply leave the CNS (e.g. the spinal cord) and
connect directly with a target muscle (e.g. the bicep)
ANS neurones, however, make multiple connections before arriving
at their target (e.g. the heart)
71
Explain the Autonomic nerves two-step pathway
Preganglionic Neuron:
Starts in the Central Nervous System (CNS): The preganglionic neuron begins either in the brain or spinal cord.
Travels to the Peripheral Nervous System (PNS): It sends its signal from the CNS to a ganglion, which is a cluster of neurons in the Autonomic Nervous System (ANS). The ganglion is located in the PNS.
Postganglionic Neuron
Continues the signal to the target organ or gland: The postganglionic neuron starts in the ganglion and travels to the target organ or gland, such as the heart, lungs, or digestive organs.
Unlike somatic nerves, which connect directly to muscles for voluntary control, autonomic nerves require this extra step to regulate organs automatically, without conscious effort
72
Explain the Sympathetic Nervous System
The sympathetic system prepares the body for fight or flight in stressful situations.
Preganglionic neurons leave the spinal cord and connect with a chain of ganglia (clusters of neurons) called the sympathetic chain, which controls organs for rapid responses.
Key point: The sympathetic system activates the body for action during stress by working through a chain of neurons.
73
Explain Parasympathetic Nervous System
The parasympathetic system works to relax the body and promote rest and recovery.
Its neurons connect to target organs more directly, without a chain of ganglia, allowing more independent control of organs.
Key point: The parasympathetic system promotes relaxation and recovery by working directly with organs.
74
How does the sympathetic and parasympathetic systems use different neurotransmitters to control organs?
Sympathetic system: Uses noradrenaline for the "fight or flight" response.
Parasympathetic system: Uses acetylcholine to help the body relax.
These systems have opposite effects but work together to maintain balance.
75
What type of Neurotransmitters is used in the sympathetic and parasympathetic system?
Sympathetic system, the neurotransmitter used is noradrenaline (norepinephrine). It helps get your body ready for action (fight or flight).
Parasympathetic system, the neurotransmitter is acetylcholine, which helps the body relax and recover.
76
Explain the Hypothalamus
The hypothalamus is a structure deep within your brain. It's the main link between your endocrine system and your nervous system. Your hypothalamus keeps your body balanced in a stable state called homeostasis
77
How does the sympathetic activity work in fight or flight mode?
The sympathetic system prepares the body for fight or flight in response to stress.
It increases heart rate, dilates pupils, redirects blood to the muscles, and inhibits digestion to focus energy on dealing with the threat.
It also stimulates the release of adrenaline, which helps the body respond more quickly to danger.
78
What is reference axes?
A set of directional terms (like rostral, caudal, dorsal, ventral, medial, and lateral), It helps describe locations and directions in the brain and nervous system, like a map for understanding where things are
79
Explain the reference axe: Rostral/Anterior
It means toward the front (near the face or front of the body).
80
Explain the reference axe: Caudal/Posterior
It means toward the back (like the back of the head or body).
81
Explain the reference axe: Dorsal/Superior
I means toward the top (for the head or upper side of the body, like the upper back)
82
Explain the reference axe: Ventral/Inferior
It means toward the bottom (underside of the brain or the front of the body like belly).
83
Explain the reference axe: Lateral
It means moving away from the middle, toward the sides.
84
85
Explain the reference axe: Medial
This means toward the middle. It’s moving toward the center of your body or brain (closer to the spine or midline of the brain).
86
What is neuraxis?
The neuraxis is an imaginary central line in the nervous system that helps explain directions (by the help of reference axes) and locations in the brain and spinal cord.
87
Explain Ipsilateral and Contralateral
Ipsilateral:
Refers to structures or actions that are on the same side of the body.
Contralateral:
Refers to structures or actions that are on opposite sides of the body.
88
What's the different Brain Planes
The brain can be viewed and sliced in different planes to study its structure.
89
Transverse Plane (also called Coronal Plane)
A slice that divides the brain into front and back parts.
Example: Imagine slicing the brain like cutting a loaf of bread. The front part is separated from the back.
Use: This view helps us see structures from the front (like looking at a face-on view).
90
Sagittal Plane
A slice that divides the brain into left and right halves.
91
Horizontal Plane
A slice that divides the brain into top and bottom parts.
Example: Imagine slicing through the brain horizontally, separating the upper part from the lower part.
92
What is the different brain divisions
Forebrain (Prosencephalon)
Midbrain (Mesencephalon)
Hindbrain (Rhombencephalon)
93
What is neural tube?
The Central Nervous System (CNS) starts out as a hollow tube during early development in the womb. This tube is called the neural tube.
As the fetus develops, the top end of this neural tube swells and forms three main brain divisions
94
Explain the Forebrain (Prosencephalon)
This will eventually develop into the cerebral hemispheres (which handle thinking, learning, and voluntary actions) and other structures like the thalamus and hypothalamus (which control sensory information and internal body functions).
95
Explain Midbrain (Mesencephalon)
This is responsible for functions like vision, hearing, and motor control.
96
Explain Hindbrain (Rhombencephalon)
This develops into structures like the pons, medulla, and cerebellum, which are important for movement, coordination, and basic life functions like breathing and heart rate.
97
What are the cerebral hemispheres and their significance?
The cerebral hemispheres are the two large, symmetrical halves of the brain that make up the cerebral cortex. They consist of the left and right hemispheres, each divided into four lobes (frontal, parietal, temporal, occipital). Each hemisphere controls the opposite side of the body (contralateral control) and specializes in different functions, such as language (left hemisphere) and creativity (right hemisphere). The hemispheres communicate via the corpus callosum, allowing for integrated sensory and motor functions.
98
What is grey matter and its significance in the cerebral cortex?
Grey matter consists of neuronal cell bodies and represents the primary sites of neural processing, where most synapses occur, allowing neurons to communicate.
99
What is white matter and its function in the brain?
White matter consists of axons covered in myelin, which connect different parts of the brain and facilitate communication between grey matter areas.
100
How thick is the cerebral cortex, and why is its folding important?
The cerebral cortex is approximately 3-5 mm thick, and its extensive folding increases surface area, allowing for more neurons to be packed in, enhancing processing capabilities.
101
What are gyri and sulci, and why are they important in the brain?
Gyri are the raised parts (bumps) on the brain's surface, and sulci are the grooves (dips) between them. These folds make the brain bigger and allow for more neurons to fit in, which helps the brain work better and organize different functions
102
What are fissures, and how do they differ from sulci?
Fissures are deeper grooves than sulci that mark significant separations between major brain regions, helping to define the organization of the cerebral cortex.
103
How do the cerebral hemispheres communicate with each other?
The cerebral hemispheres communicate through white matter pathways, primarily the corpus callosum and anterior commissure, which connect different regions of the brain.
104
What is the function of the corpus callosum?
The corpus callosum is the largest white matter structure that connects the left and right hemispheres, allowing them to share information and coordinate activities.
105
What is contralateral processing in the brain?
Contralateral processing means that each hemisphere of the brain processes sensory information and controls movements on the opposite side of the body (e.g., the left hemisphere controls the right side).
106
Why is communication between the hemispheres important?
Communication is crucial because, without the corpus callosum, each hemisphere would only react to information on its own side, limiting overall brain function and coordination.
107
Give an example of contralateral processing in action.
If an object is seen in the left visual field, the information is processed by the right hemisphere, which then communicates with the left hemisphere to coordinate a response.
108
What are laminae and columns in the cerebral cortex?
Laminae: These are six horizontal layers of neurons stacked on top of each other. Each layer has a different job, processing different types of information (like sensory input).
Columns: These are vertical groups of neurons that run through the layers. Neurons in a column work together to process similar types of information from the same source (like touch from a specific area of the skin).
109
Which laminae are primarily responsible for receiving sensory information?
Laminae I, II, and IV are mainly responsible for receiving sensory information from the body.
110
What functions do laminae III and V serve in the cerebral cortex?
Laminae III and V contain neurons that communicate with other parts of the brain, playing a crucial role in producing movements.
111
What is the significance of communication between columns in the cortex?
Columns can communicate with neighboring columns, integrating information from adjacent areas for more complex processing.
112
What does Brodmann's map represent?
Brodmann's map categorizes the cerebral cortex into numbered areas based on cellular structure and organization, showing correspondence with functionally defined regions.
113
What does the term "cytoarchitecture" refer to in the context of the cortex?
Cytoarchitecture refers to how neurons are arranged in the central nervous system, which is essential for understanding the structure-function relationship in different cortical areas
114
What are the three types of axon fibers in white matter?
Association Fibers: Connect different regions within the same hemisphere.
Commissural Fibers: Connect corresponding areas in the left and right hemispheres (e.g., corpus callosum).
Projection Fibers: Connect the cortex to lower brain regions and the spinal cord.
115
What are the four main lobes of the cerebral cortex and their primary functions?
Frontal Lobe: Involved in higher cognitive functions and motor control.
Parietal Lobe: Processes sensory information related to touch and temperature.
Temporal Lobe: Responsible for auditory processing and language comprehension.
Occipital Lobe: Primarily responsible for visual processing.
116
How are the boundaries between the lobes marked?
The boundaries are marked by prominent sulci (grooves) and fissures (deeper grooves), such as the lateral fissure and central sulcus.
117
What is the great longitudial fissure
the part that divided into a left and right hemisphere
118
What is a somatotopic map in the context of the primary somatosensory cortex?
A somatotopic map is an organization where different areas of the somatosensory cortex correspond to sensations from specific body parts. More sensitive areas, like the hands and face, occupy larger sections of the cortex.
119
How is sound processed in the brain?
Sound detected in the inner ear is converted into neural impulses, which travel to the brainstem. Most of this information then crosses to the contralateral hemisphere before reaching the medial geniculate nucleus (MGN) in the thalamus, and finally to the primary auditory cortex in the temporal lobe.
120
What role does Wernicke’s area play in the temporal lobe?
Wernicke’s area, located just posterior to the primary auditory cortex (usually in the left hemisphere), is responsible for interpreting language information that is sent from nearby auditory and visual areas.
121
What is Wernicke’s aphasia, and how does it affect patients?
Wernicke’s aphasia occurs due to damage to Wernicke’s area. Patients produce fluent, grammatically correct speech, but it is often nonsensical and lacks meaning. They also struggle to comprehend spoken language and may experience word deafness, where they can't correctly recognize words.
122
What is the significance of Broca’s area, and where is it located?
Broca’s area, found in the left frontal lobe, is crucial for generating speech. Damage to this area leads to Broca’s aphasia, characterized by difficulties in speech production while comprehension may remain relatively intact.
123
How does the primary motor cortex demonstrate contralateral control?
The primary motor cortex controls movements on the opposite side of the body; for example, the left hemisphere controls movements on the right side of the body.
124
What are the main divisions of the frontal lobe and their functions?
Prefrontal Cortex: Involved in decision-making, planning, problem-solving, and social behavior.
Primary Motor Cortex: Controls voluntary movements with contralateral control, located in the precentral gyrus.
Premotor Cortex: Plans and organizes movements before execution.
Supplementary Motor Area (SMA): Coordinates complex movement sequences, located on the medial surface of the frontal lobe
125
What is grey matter, and what does it consist of?
Grey matter consists of neuronal cell bodies and represents sites of neural processing in the cerebral cortex.
126
What is the role of white matter in the cerebral cortex?
White matter, made up of axons extending inward, carries neural messages connecting different parts of the brain.
127
How thick is the cerebral cortex, and what is significant about its structure?
The cortex is approximately 3-5 mm thick, but extensive folding increases its area, allowing more neurons to be packed in.
128
What are gyri and sulci, and how do they contribute to the cerebral cortex?
Gyri are the raised portions (bulges), while sulci are the grooves (valleys) between them. These folds increase the processing capacity of the brain.
129
What is the role of white matter pathways in the brain?
White matter pathways, such as the corpus callosum and anterior commissure, connect the left and right hemispheres, allowing for communication and integration of sensory and motor functions.
130
How do the hemispheres communicate with each other?
Communication occurs through structures like the corpus callosum, which is the largest white matter pathway connecting the two hemispheres, facilitating the sharing of information.anterior commissure, hippocampal commissure
131
What is meant by "contralateral functions" in the brain?
Contralateral functions refer to the principle that each hemisphere of the brain processes information from and controls the opposite side of the body (e.g., the left hemisphere processes information from the right side).
132
How is the grey matter in the cortex organized?
Grey matter in the cortex is organized into layers called laminae, with each layer having distinct types of neurons that serve different functions.
133
What are the six layers (laminae) of the grey matter, and what are their characteristics?
Laminae I, II and IV receive sensory information detected
from around the body
*
Laminae III and V contain neurones that communicate with
other parts of the brain, and play an important role in
communicating messages for producing movements
*
Lamina VI also contains neurones that send messages to
other parts of the brain (e g thalamus, other areas of the
cerebral cortex)
134
What is the significance of columnar organization in grey matter?
Grey matter is organized into vertical columns, allowing groups of neurons to work together to process similar types of information and communicate efficiently.
135
What was Brodmann's contribution to understanding the organization of the cortex?
Brodmann created a numbered cytoarchitectural map of the cerebral cortex based on cellular structure, which is still referenced in research to understand functional regions of the cortex.
136
What is white matter, and how is it organized in the brain?
White matter consists of myelinated axons that connect different parts of the brain and the spinal cord. It is organized into three main types of fibers:
Association Fibers: Connect different regions within the same hemisphere.
Commissural Fibers: Connect corresponding areas in the left and right hemispheres (e.g., the corpus callosum).
Projection Fibers: Connect the cortex to lower brain areas and the spinal cord, transmitting signals to and from the cortex.
137
How are the boundaries between the lobes of the cerebral cortex defined? names
Boundaries between the lobes are marked by prominent sulci (grooves) and fissures (deeper grooves) that separate them, such as the lateral fissure and the central sulcus.
138
Where is the primary visual cortex (V1) located within the occipital lobe?
The primary visual cortex (V1) is located at the posterior part of the occipital lobe and is the first area to receive and process visual input from the retina.
139
How does visual information travel to the occipital lobe?
Light from visual stimuli is detected by the retina, converted into electrical signals, and sent through the optic nerves. At the optic chiasm, some fibers cross over, and visual information is relayed to the lateral geniculate nucleus (LGN) in the thalamus before reaching the primary visual cortex (V1)
140
What is the primary somatosensory cortex, and where is it located?
The primary somatosensory cortex is located in the postcentral gyrus of the parietal lobe and is responsible for processing sensory information from the body, such as touch and proprioception.
141
How is the primary somatosensory cortex organized?
The primary somatosensory cortex has a somatotopic organization, meaning different parts correspond to sensations from specific body parts. Areas with higher sensitivity, like the hands and face, occupy larger sections of the cortex.
142
What is apraxia, and how is it related to the parietal lobe?
Apraxia is a neurological condition that affects the ability to perform voluntary movements. Damage to the parietal lobe can lead to limb apraxia, where individuals struggle to execute planned movements correctly, even if they have the physical ability to do so.
143
What are the types of apraxia associated with parietal lobe damage?
Limb Apraxia: Difficulty in executing movements or using tools properly.
Constructional Apraxia: Difficulty with spatial tasks, such as assembling objects or drawing shapes.
144
What role does Wernicke’s area play in the temporal lobe?
Wernicke’s area, located in the left temporal lobe, is crucial for understanding spoken and written language. Damage to this area can result in Wernicke’s aphasia, where patients produce fluent but nonsensical speech.
145
How is auditory information transmitted to the brain?
Sound detected in the inner ear is converted into neural impulses that travel to the brainstem, and then it travels through the medial geniculate nucleus (in the thalamus). After most information crosses to the contralateral cerebral hemisphere before reaching the primary auditory cortex.
146
How does the temporal lobe contribute to language comprehension?
The temporal lobe is essential for understanding spoken language. In most individuals, the left temporal lobe is dominant for language processing.
147
What is the function of Wernicke’s area?
Wernicke’s area, located just posterior to the primary auditory cortex (typically in the left hemisphere), is responsible for interpreting language information received from nearby auditory and visual areas.
148
What are the comprehension difficulties associated with Wernicke’s aphasia?
Patients with Wernicke’s aphasia have a reduced ability to comprehend speech and writing. In severe cases, they may experience word deafness, where they struggle to recognize words.
149
What role does Broca’s area play in speech?
Broca’s area, located in the left frontal lobe, is important for generating speech.
150
What is the location and role of the primary motor cortex?
The primary motor cortex is located in the precentral gyrus of the frontal lobe. It controls voluntary movements by sending signals to muscles on the opposite side of the body (contralateral control).
151
What is the function of the premotor cortex?
The premotor cortex is involved in planning and organizing movements before they are executed, helping prepare the primary motor cortex for action.
152
What is a lobotomy, and why was it performed?
A lobotomy is a surgical procedure that involves severing connections in the frontal lobe, particularly in the prefrontal cortex. It was historically performed to treat severe mental disorders, such as schizophrenia and depression, by reducing symptoms.
153
What are primary areas in the cerebral cortex responsible for?
Primary areas are responsible for receiving and sending basic sensory and motor information. They occupy relatively small areas of the cortex.
154
Name the three main primary sensory cortices and their functions.
Primary Visual Cortex (V1): Processes visual information from the eyes.
Primary Somatosensory Cortex: Processes sensory input related to touch and proprioception.
Primary Auditory Cortex: Processes auditory information
