Module 2 Nervous System Function Flashcards
(128 cards)
1
Q
How Does the Nervous system function
A
- Overview of Brain Function and Structure
- Evolutionary Development of the Nervous System
- The Central Nervous System: Mediating Behavior
- Somatic Nervous System: Transmitting Information
- Autonomic Nervous System: Balancing Internal Functions
- Ten Principles of Nervous-System Function
2
Q
Overview of Brian Function and Structure
-Evolution of Brain Size and Human Behavior (RECALL)
A
- Human brain has optimized its overall size, (size and number of neurons, the number and length of connections, energy consumption)
- Changing these features would compromise the others and neutralize any performance improvements
3
Q
Overview of Brain Function and Structure
-The brain’s primary function is to produce behavior. To do so, is a must:
A
- Receive information about the world
- Integrate information to create a sensory reality
- Produce commands to control the movement of muscles
4
Q
Plastic Patterns of Neural Organization
A
-The brain is PLASTIC
~Neural tissue has the capacity to adapt to the world by changing how its functions are organized
-NEUROPLASTICITY
~The nervous system’s potential for physical or chemical change that enhances its adaptability to environmental change and its ability to compensate for injury
5
Q
Phenotypic Plasticity
A
-An individual’s genotype (genetic makeup) interacts with the environment to elicit a specific phenotype from a large genetic repertoire of possibilities, a phenomenon the results from EPIGENETIC influences
6
Q
Functional Organization of the Nervous System (RECALL)
A
-Brain and spinal cord together make up the CNS, and all the nerve fibers radiating out beyond the brain and spinal cord as well as all the neurons outside the brain and spinal cord from the PNS
7
Q
Functional Organization of the Nervous System
-The CNS and the PNS constitute an interacting, 3-part system
A
-The CNS
~The brain and spinal cord
-The Somatic Nervous System (SNS)
~Spinal and cranial nerves carrying sensory information to the CNS and motor instructions away from the CNS for movement
-The Autonomic Nervous System (ANS)
~Prepares internal organs for “rest and digest” or “fight or flight”
8
Q
Direction of Neural Information Flow is Important
A
- AFFERENT information (Sensory) is sensory information coming into the CNS (Incoming information)
- EFFERENT information (Motor) is information leaving the CNS (outgoing information)
9
Q
Anatomical Divisions of the Nervous System
A
-Nervous system ~Central Nervous System (CNS) *Brain *Spinal ~Peripheral Nervous System (PNS) *Somatic Nervous System (Transmits sensation, produces movement) **Cranial Nerves **Spinal Nerves *Autonomic Nervous System (Balances internal functions) **Sympathetic Division (arousing) **Parasympathetic Division (calming)
10
Q
The Basics
-Finding Your Way Around the Brain
A
-Many names for the nervous-system structures include information about anatomical locations
~With respect to other body parts of the animal
~With respect to their relative locations
~With respect to a viewer’s perspective
11
Q
“Brain-Body Orientation”
illustrates brain structure location from the frame of reference of the face
A
- Structures atop the brain or structure within the brain are Dorsal (TOP)
- Structures toward the brain’s midline are Medial (MIDDLE)
- Structures located toward the sides are Lateral (SIDES)
- Structures located towards the front are Anterior (FRONT)
- Structurers located towards the back Posterior (BACK)
- Structures towards the bottom of the brain or one of its parts are Ventral (BOTTOM OR BELOW)
12
Q
“Anatomical Orientation” illustrates the direction of a cut, or section, trough the brain (Part A) from the perspective of a viewer (Part B)
A
-Coronal Section
~Cut in a vertical plane, from the crown of the head down, yielding a frontal view of the brain’s structures (Cuts top to bottom and evenly cuts both left and right hemispheres)
-Horizontal Section
~The view or the cut falls along the horizon, is usually viewed looking down on the brain from above- a dorsal view (Parallel to the floor cutting from front to back)
-Sagittal Section
~Is cut length way from front to back and viewed from the side. (Imagine the brain split by an arrow- in Latin, SAGITTA.) Here, a cut in the midsagittal plane divides the brain into symmetrical halves, a medial view (Cuts front to back, but is at a 90 degree angle to horizontal cuts the brain exactly in half of separate left and right hemispheres)
13
Q
Surface Features of the Brain
-Cerebral Cortex (RECALL)
A
-Each hemisphere is divided into four lobes
~Frontal (executive function and decision making)
*Mainly hearing, language, and music
~Parietal (sensory integration)
*Direct movements towards or away from objects
~Temporal (auditory, taste, smell, memory)
~Occipital (visual)
14
Q
Surface Features of the Brain
-Cerebral Cortex (RECALL)
A
- The cerebral cortex is a thin sheet of nerve tissue folded many times to fit inside the skull
- Your right first can serve as a guild to the orientation of the brain’s left hemisphere and its lobes
- Bumps in the brain’s folded surface are called GYRI
- Cracks in the brain are called SULCI
15
Q
Surface Features of the Brain
-Meninges: Three layers of protective tissue
A
-Dura Mater
~”hard mother”; tough outer layer of fibrous tissue (lays beneath the skull)
-Arachnoid layer
~”like a spider’s web”, thin sheet of delicate connective tissue (lays above the Subarachnoid space (filled with Cerebral Spinal Fluid (made up of water and salt compositions)))
-Pia mater
~”soft mother”; moderately tough inner layer that clings to the brain’s surface (then the brain)
16
Q
Surface Features of the Brain
-Cerebrum and Cerebellum
A
-Cerebrum
~Major structure of the forebrain, consisting of two virtually identical hemispheres (left and right)
-Cerebellum: “Little Brain”
~Involved in the coordination of motor and possibly other mental processes
*Anything thing that need to be done fast involves the cerebellum (walking and running as well as someone talking)
17
Q
Surface Features of the Brain
-Gyrus, Sulcus, Fissure
A
-Gyrus (gyri)
~A small protrusion or bump formed by the folding of the cerebral cortex
-Sulcus (sulci)
~A groove in brain matter, usually found in the neocortex or cerebellum
-Fissure
~A very deep sulcus
18
Q
Surface Features of the Brain
-Brainstem
A
- Central structures of the brain, including the hindbrain, midbrain, thalamus, and hypothalamus, responsible for most unconscious behavior
- Could survive for the most part with out the cerebrum, but missing on part of the brainstem could kill you
19
Q
Surface Features of the Brain
-Surface blood Vessels
A
-Anterior, middle, and posterior cerebral arteries
-Stroke
~Sudden appearance of neurological symptoms as a result of severe interruption of blood flow
20
Q
Internal Features of the Brain
-Four Ventricles
A
-Cavities in the brain that contain cerebrospinal fluid (CSF)
~Two lateral ventricles (left and right)
~Third ventricle
~Fourth ventricle
21
Q
Internal Features of the Brain
-Cerebrospinal Fluid (CSF)
A
-Sodium chloride and other salts
-Fills the ventricles and circulates around the brain and spinal cord in the subarachnoid space (located between the arachnoid layer and the pia mater)
-Cushions the brain
-Meningitis
~Infection of the meninges and CSF
22
Q
Internal Features of the Brain
-Macro
A
-Gray Matter
~Areas of the nervous system predominately composed of cell bodies and blood vessels
-White Matter
~Areas of the nervous system rich in fat-sheathed neural axons
-Corpus Callosum
~Fiber system connecting the two cerebral hemispheres
23
Q
Internal Features of the Brain
-Microscopic
A
-Neurons ~Carry out the brain's major functions ~Approximately 80 billion -Glial Cells ~Aid and modulate neurons' activates (giving nutrients, getting rid of waste products, managing the environment) ~Approximately 100 billion
24
Q
Internal Features of the Brain
-Nucleus, Nerve, Tract
A
-Nucleus (nuclei)
~A group of cells forming a cluster that can be identified with special stains to form a functional grouping
-Nerve
~Large collection of axons coursing together outside the central nervous system
-Tract
~Large collection of axons coursing together within the central nervous system
25
Evolutionary Development of the Nervous System
-Human brain is a complex mammalian brain, yet it still retains most of the features of other, less complex mammalian brains
-Most behaviors are not the product of a single locus in the brain, but rather of many brain areas and levels
-Our evolutionary history, our developmental history, and our own personal history are integrated at various anatomical and functional levels of the nervous system
~The forebrain grows dramatically in the evolution of the mammalian brain
26
The Central Nervous System
| -Mediating Behavior
-Three Major Components
~Spinal Cord
~Brainstem
~Forebrain
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Spinal Cord
-Controls most body movements
-Can act independently of the brain
-Spinal Reflex
~Automatic movement
~Hard to prevent (brain cannot inhibit)
~Example
*Knee-jerk reflex (patellar tendon)
28
Brainstem
-Begins where the spinal cord enters the skull
-Receives afferent nerves coming from senses and sends efferent nerves out to control movements
-Three regions (Developed as simple animals evolved a brain)
~Hindbrain (forearm)
~Midbrain (wrist)
~Diencephalon (fist)
-Medial view of the brain shows the relation of the brainstem to the cerebral hemisphere
-The shapes and relative sizes of the brainstem's parts can be imagined as analogous as to your fist, wrist, and forearm
-Hindbrain
~Evolutionarily the oldest part of the brain
~Contains
*Cerebellum
*Reticular Formation
*Pons
*Medulla
~Controls various motor functions ranging from breathing to balance to fine movements
~Integrates both voluntary and involuntary body movements
29
The Brainstem
| -Hindbrain
-Cerebellum
~Controls complex movements and cognitive functions
~Size increases with the physical speed and dexterity of a species
~Relatively large cerebellum enable fine, coordinated movements such as flight and landing in birds and prey catching in cats
~Slow-moving animals such as the sloth have smaller cerebellums relative to their brain size
-Reticular Formation
~Reticular activating system
~Netlike mixture of neurons (gray matter) and nerve fibers (white matter)
~Stimulates the forebrain
*Regulation of sleep-wake behavior and behavioral arousal
-Pons ("bridge")
~Connects cerebellum to the rest of the brain
~Controls important movements of the body
-Medulla
~Rostral tip of spinal cord
~Vital functions
*Control of breathing and heart rate
30
The Brainstem
| -Midbrain
```
-Tectum (roof of midbrain)
~Sensory processing (visual and auditory)
~Produces orienting movements (turning head to see source of sound)
~Superior Colliculus
*Receives visual input
~Inferior colliculus
*Received auditory input
-Tegmentum (floor of midbrain)
~eye and limb movements
~Species-specific behavior
~Perception of pain
```
31
The Brainstem
| -Diencephalon
-Integrates sensory and motor information on its way to the cerebral cortex
-The two principal structures include
~The Hypothalamus
~The Thalamus
-Hypothalamus
~Hormone Function
*Through connections with the pituitary gland
~Feeding (eating/drinking)
~Sexual Behavior
~Sleeping
~Temperature Regulation
~Emotional Behavior
-Thalamus
~Gateway for channeling sensory information to the cortex
~Primary role is sensory processing systems (integrates and projected into the appropriate region of the neocortex)
~Motor processing
~Integrative functions
32
Forebrain
-Neocortex (cerebral cortex)
~Regulates various mental activities
-Basal Ganglia
~Control of voluntary movement
-Limbic System
~Regulates emotions and behaviors that create and require memory
-Integrates sensation, emotion, and memory
-Cognitive functions such as thinking, planning, and language
33
Forebrain
| -The Cortex
```
-Neocortex ("new bark")
~6 Layers of gray matter
~Creates and responds to a perceptual world
-Limbic Cortex
~Evolutionarily older
~3 or 4 layers of gray matter
Controlling motivational states
```
34
Forebrain
| -The Neocortical Lobes
```
-Occipital
~Vision
-Parietal
~Tactile functions
-Temporal
~Visual, auditory, and gustatory functions
-Frontal
~Motor and executive functions
```
35
Forebrain
| -Neocortical Layers and Cytoarchitectonic Map
-Neocortical Layers
~Different layers have different cell types
~Density of cells in each layer varies
~Differences in appearance relate to function
-Cytoarchitectonic Map
~Map of neocortex based on the organization, structure, and distribution of the cells
36
Motor and Sensory Cortex
- Afferents connect to layer IV (coming from the thalamus) as well as to layer II and III
- Efferents in layers V and VI connect to the other parts of the cortex and to motor structures of the brain
37
Cytoarchitectonic Map
- Brodmann defined areas by organization and characteristics of the cells
- The simplest sensory perceptions of touch (red), Vision (purple) and hearing (orange)
38
Forebrain
| -The Basal Ganglia
-Collection of nuclei just below the white matter of the neocortex
~3 principal structures: caudate nucleus, putamen and globus pallidus
-Controls voluntary and involuntary movement
-Related disorders
~Parkinson's disease and Tourette's syndrome possibly OCD
-Control and coordination of movement patterns rather than in activating the muscles to move
39
Forebrain
| -The Limbic System
-Group of structures between the neocortex and brainstem
~Principal structures: amygdala, hippocampus, and cingulate cortex
-Regulation of
~Emotional and sexual behavior
~Memory
~Spinal navigation
40
Forebrain
| -The Olfactory System
- Olfactory bulbs
- Pyriform Cortex
- Thalamus
- Neocortex
41
The Somatic Nervous System (SNS) Transmitting Information
-The SNS is monitored and controlled by the CNS
-The cranial nerves by the brain
~12 pairs of Cranial Nerves
*Olfactory (Smell)
*Optic (Vision)
*Oculomotor (Eye movement)
*Trochlear (Eye movement)
*Trigeminal (Masticatory movements and facial sensations)
*Abducens (Eye movement)
*Facial *Facial movement and sensation
*Auditory Vestibular (Hearing and balance
*Glossopharyngeal (Tongue and pharynx movement and sensation
*Vagus (Heart, blood vessels, viscera, movement of larynx and pharynx
*Spinal Accessory (Neck Muscles)
*Hypoglossal (Tongue muscles)
-The spinal nerves by the spinal cord segments
42
Cranial Nerves
- Afferent functions, such as sensory inputs to the brain from the eyes, eras, mouth, and nose
- Efferent functions such as motor control of the facial muscles, tongue, and eyes
- Both functions, such as modulation of both sensation and movement in the face
43
Spinal Nerves
-Dermatome
~Area of the skin supplied with afferent nerve fibers by a single spinal-cord dorsal root
-Spinal-cord segments are interconnected so adjacent segments can operate together to direct complex coordinated movements
44
Spinal Nerves
| -Dorsal and Ventral
-Dorsal
~Fibers are afferent
*They carry information from the body's sensory receptors
-Ventral
~Fibers are efferent
*They carry information from the spinal cord to the muscles
45
The Autonomic Nervous System
-Sympathetic System
~Arouses the body for action
~Example
*Increases heart rate and blood pressure
~Mediates the "fight of flight" response
-Parasympathetic System
~Opposite of sympathetic: prepares the body to "rest and digest"
~Reverses the "fight or flight" responses
46
Ten Basic Principles on How the Nervous System is Organized
| -Principle 1
-The Nervous System Produces Movement Within a Perceptual World the Brain Creates
~Individual realities are rough approximations of what is actually present
~The brain produces a reality that is adaptive for the species to survive
~The behavior that the brain produces is directly related to the world that the brain has created
47
Ten Principles
| -Principle 2
-The details of Nervous-system functioning are constantly changing, an attribute called neuroplasticity
~Experience alter the brain's organization, and neuroplasticity is required for learning and memory functions as well as for survival
~Information is stored in the nervous system only if neural connections change
48
Ten Principles
| -Principle 3
-Many of the brain's circuits are crossed
~Each hemisphere receives sensory stimulation from the opposite (contralateral) side of the body and controls muscles on the contralateral side as well
49
Ten Principles
| -Principle 4
-The Central Nervous System functions on multiple levels
~Simple animals such as worms have a spinal cord, more complex animals such as fish have a brainstem as well, and yet more complex animals have evolved a forebrain
~Each new addition to the CNS has added a new level of behavioral complexity without discarding previous levels of control
50
Ten Principles
| -Principle 5
-The brain is both symmetrical and asymmetrical
~The left and the right hemispheres look like mirror images; they have some dissimilar features
~Language is usually on the left side, and spatial functions are usually on the right
51
Ten Principles
| -Principle 6
-Brain system are organized both hierarchically and in parallel
~CNS comprises multiple levels of function, these levels must be extensively interconnected to integrate their processing and create unified perceptions or movements
~Subsystems of the brain are organized into multiple parallel pathways, yet our conscious experiences are always unified
52
Ten Principles
| -Principle 7
-Sensory and Motor divisions exist throughout the nervous system
~Sensory and motor divisions in the Somatic Nervous System
~Sensory and motor divisions in the Central nervous System
53
Ten Principles
| -Principle 8
-Sensory input to the brain is divided for object recognition and motor control
~Example
*Dorsal and ventral processing streams in the visual system
~Animals with complex brains evolved separate systems for producing movement towards objects and for recognizing them
54
Ten Principles
| -Principle 9
-Functions in the brain are both localized and distributed
~Damage to a small brain region produces only focal symptoms
~Massive brain damage is required to completely remove some functions
~A small injury could impair some aspect of language function, but is would take a widespread injury to completely remove all language abilities
55
Ten Principles
| -Principle 10
-The Nervous System works by juxtaposing excitation and inhibition
~All neurons have spontaneous rate of activity that can be either increased (excitation) or decreased (inhibition)
~Some neurons excite others, whereas other neurons inhibit
56
Adapitations
-Evolved anatomical/functional features that solved long-standing historical problems
57
Neuroplasticity
-The nervous system's potential to physically or chemically modify itself in response to environmental change and to compensate for age-related changes and injury
58
Phenotypic plasticity
-An individual's capacity to develop into a range of phenotypes
59
Somatic Nervous System (SNS)
-Part of the PNS that includes the cranial and spinal nerves to and from the muscles, joints, and skin; which produce movement, transmit incoming sensory input, and inform the CNS about the position and movement of body parts
60
Autonomic Nervous System (ANS)
- Part of the PNS that regulates the functioning of internal organs and glands
- Produces the rest-and-digest response through the parasympathetic nerves and its opposite, the fight-and-flight response, or vigorous activity through the sympathetic nerves
61
Enteric nervous System (ENS)
- Mesh of neurons embedded in the lining of the gut, running from the esophagus through the colon; controls the gut
- The ENS communicates with the CNS via the ANS but mostly operates autonomously
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Afferent (incoming)
- Conducting towards the CNS structure
| - Information is sensory coming into the CNS or one of its parts
63
Efferent (outgoing)
- Conducted away from the CNS structure
| - Information is leaving the CNS or one of its parts
64
Meninges
-Three layers of protective tissue-dura mater, arachnoid, and pia mater- that encase the brain and spinal cord
65
Cerebrospinal Fluid (CSF)
-Clear solution of sodium, chloride, and other ions that is produced in the ventricles inside the brain and circulates around the brain and spinal cord until it is absorbed beneath the arachnoid layer in the subarachnoid space
66
Cerebral Cortex
- Cortex Latin for "bark"; unlike tree bark the cortex is NOT placed randomly all over the brain but demarcate its functional cortical zones
- Heavily folded and layered tissue that is the outer structure of the forebrain; composed of neocortex and allocortex
67
Frontal Lobe
- Part of the cerebral cortex, which preforms the brain's executive functions, such as decision making, and voluntary movement; lies anterior to the central sulcus and beneath the frontal bone of the skull
- Make a fist with the right hand and above the thumbnail indicates where the frontal lobe is
68
Parietal Lobe
-Part of the cerebral cortex that directs movements towards a goal or to preform a task, such as grasping an object; lies posterior to the central sulcus and beneath the parietal bone at the top of the skull
-Make a fist with the right hand and represented by the knuckles, behind the frontal lobe
~Parietal function include directing our movements towards a goal or to preform a task, such as grasping an object
69
Temporal Lobe
- Part of the cerebral cortex that includes hearing, language, musical abilities, facial recognition, and emotional processing; lies below the lateral fissure, beneath the temporal bone at the side of the skull
- Approximately the same place as the thumb on the right hand
70
Occipital Lobe
- Part of the cerebral cortex where visual scene processing begins; the most posterior part of the neocortex, it lies beneath the occipital bone
- Approximately the same place as the wrist on the right hand
71
Gyri (Gyrus)
-Small protrusions or bumps formed by the folding of the cerebral cortex
72
Sulci (Sulcus)
-Groover in brain matter; most are in the neocortex or cerebellum (Little brain)
73
Fissures
-Are really deep sulci that run between the cerebral hemispheres and the lateral fissure along the sides of the brain
74
Stroke
-Sudden appearance of neurological symptoms as a result of severely reduced blood flow in the brain
75
Gray Matter
- Areas of the nervous system composed predominantly of neuronal cell bodies that collect and modify information and capillary blood vessels that support this activity
- Largely composed of cell bodies and capillary blood vessels
- Within the gray matter, neurons collect and modify information before sending it along
76
White matter
- Areas of the nervous system with fat-rich, myelin-sheathed neuronal axons that form the connections between neurons
- Mostly nervous fibers covered y myelin sheaths that have a high fat content
- There fiber produce the white appearance, much as fat droplets in milk make it appear white
- Form longer-distance connections between and among some of the brain's neurons
77
Ventricles
- Cavities in the brain that make and contain CSF
- Two wing-shaped cavities that contain CSF made by a network of blood vessels, called the CHOROID PLEXUS, which line the ventricles to the third and fourth ventricles are connected which CSF lies on the brain's midline and into the CEREBRAL AQUEDUCT
78
Cerebral Aqueduct
-A canal that runs down the length of the spinal cord
79
Cerebral Spinal Fluid
- Suspends the brain, making it naturally buoyant so that it acts like it is 1/30 of its actual mass.
- Also acts as a shock absorber, providing the brain with important protection form mild blows to the head
- Slight changes to its chemical composition can cause dizziness and fainting
- The brain also produces and distributes about 25 mL of CSF an hour, which accounts for about 1/5 of its total volume
80
Corpus Callosum
-Band of white matter containing about 200 million nerve fibers that connect the two cerebral hemispheres to provide a route for direct communication between them
81
Subcortical Region
-Intimate reciprocal connections with cortical areas that process sensory, perceptual, cognitive, and motor functions
82
Planum Temporale
-Responsible for understanding speech, is larger in the left hemisphere
83
Heschl's Gyrus
-Responsible for analyzing music, is larger in the right hemisphere
84
Nuclei (Nucleus)
-A group of neurons forming a cluster that can be identified using special stains
85
Axons
-Run along together, much like the wires that run from a car engine to the dashboard
86
Nerve
-Large collection of axons coursing together OUTSIDE of the CNS
87
Tract
-Large collection of axons coursing together IN the CNS
88
Brainstem
- Central structure of the brain (including the hindbrain, midbrain, thalamus, and hypothalamus) that is responsible for most life sustaining behavior
- Begins where the spinal cord enters the skull and extends upward into the lower areas of the forebrain
- Receives afferent signals coming in from all of the body's senses, and it sends efferent signals out of the spinal cord to control virtually all of the body's movements except the most complex movements of the fingers and toes
89
Hindbrain
- Evolutionary the oldest part of the brain; contains the pons, medulla, reticular formation, and the cerebellum, the structures that coordinate and control most voluntary and involuntary movements
- Controls motor functions ranging from breathing to balance to fine movements, such as those used in dancing
90
Reticular formation
- Midbrain area in which nuclei and fiber pathways are mixed, producing a netlike appearance; associated with sleep-wake behavior and behavioral arousal
- netlike mixture of neurons (gray matter) and nerve fibers (white matter)
91
Pons
-Receives nuclei input from the cerebellum and actually forma bridge from it to the rest of the brain
92
Medulla
-Nuclei regulate such vital functions as breathing and the cardiovascular system
93
Midbrain
-Central part of the brains; contains neural circuits for hearing and seeing as well as for orienting movements
94
Tectum
- Roof (area above the ventricle) of the midbrain; its functions are sensory processing, particularly visual and auditory, and the production of orienting movements-
- The "roof" is dorsal (posterior in upright humans)
- Massive amounts of sensory from the ears and eyes
95
Tegmentum
- Floor (area below the ventricle) of the midbrain; a collection of nuclei with movement-related, species-specific, and pain perception functions
- "Floor" is ventral (anterior in humans
96
Superior Colliculus
-Receives large bundles of fiber that the optic nerve sends
97
Inferior Colliculus
-Receives much of its input from auditory pathways
98
Orienting Movements
-Movement related to sensory inputs, such as turning the head to see the source of a sound
99
Diencephalon
-The between brain, which integrates sensory and motor information on its way to the cerebral cortex
~Breaks down into the hypothalamus and thalamus
100
Hypothalamus
-Diencephalon structure that contains many nuclei associated with temperature regulation, eating, drinking, and sexual behavior
-Composed of 22 small nuclei and the nerve fiber system that pass through it
-It main functions are
~Hormone regulation/ functions (controlled by the pituitary gland)
*Pituitary gland only accounts for 0.3% of the brain's weight
~Feeding
~Sleeping
~Temperature regulation
~Sexual and emotional behavior
~Movement
101
Thalamus
-Diencephalon structure though which information from all sensory systems is organized, integrated, and projecting into the appropriate region of the neocortex
-Is much larger than the hypothalamus
~As are the 20-odd nuclei
-Thalamic function is its role as an organizer and integrator of sensory information traveling to the cerebral cortex from all sensory systems
-Sends larger fiber bundles to the thalamic region called the LATERAL GENICULATE NECLEUS (LGN)
102
Lateral Geniculate Nucleus (LGN)
-Processes some of this information and then sends it to visual region in the occipital lobe in each hemisphere
103
Forebrain
-Evolutionarily the most recent addition to the brain; coordinates advanced cognitive functions such as thinking, planning, and language; contains the allocortex, neocortex, and basal ganglia
104
Cerebral Cortex
-Regulates a host of mental activities ranging from perception to planning to emotions and memory
105
Basal Ganglia
-Control voluntary movement and also have a role in cognitive functioning
106
Allocortex (Other bark)
- Part of the cerebral cortex ("outer bark"), composed of three or four layers; plays a role in controlling motivational and emotional states as well as in certain forms of memory
- To refer to both the three- and four-layered cortex
107
Neocortex ("New Bark")
-Most recent expanded outer layer of the forebrain, composed of about six layers of gray matter. Its name is a misnomer, as it actually isn't newer because it arose at the same time during evolution as other forms of the cortex. It is also called ISOCORTEX because it is almost always six-layered, with a few exceptions
-Six-layered is the tissue visible when we view the brain from the outside
-Primary function is to construct a perceptual world
and respond to that world
-Surface area as large as 2500 square centimeters but as thickness of only 2.3 to 2.8 centimeters
108
Consolidation
-Allocortex function process of short-term memories are solidified into long-term memories
109
Amygdala
-Plays a critical role in anxiety and fear
-Removing the amygdala produces truly startling changes in emotional behavior
~Instead of not doing something based on safety concerns one will ignore all danger warnings with the missing amygdala
110
Limbic System
- A conceptual system controlling affecting and motivated behaviors and certain forms of memory with key anatomy lying between the neocortex and brainstem; includes the cingulate cortex, amygdala, and hippocampus, among other structures
- Some neuroscientist believe that the limbic system should be abandoned because it is obsolete
111
Olfactory System
-Responsible for detecting odors and providing input to other brain areas responsible for our perception of smell
~Located almost entirely in the forebrain structure
-Smell is one of the first senses to have evolved in animals
~It lies near the olfactory receptors in the nasal cavity
112
Vomeronasal Organ (VNO)
-Collection of neurons that detect pheromones; this organ plays a role in reproduction and social behavior in many mammals through its specific function in humans is disputed
-Molecules that carry information between individuals of the same species
~Axons from the neurons project to the accessory olfactory bulb, which connects to the amygdala and in turn the hypothalamus
-Important role in reproduction and sexual behavior in many mammals, but its presence and functionality in humans is controversial
113
Cytoarchitectonic Maps
| -Neocortex
-Map of the neocortex based on the organization, structure, and distribution of the cells
-Unlike most structures, the neocortex is connected to virtually all other parts of the brain
~Known as an Ultimate meddlers; it take part in everything-a fact that not only make it difficult to identify specific neocortical functions but also complicates our study of the rest of the brain
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Top-Down Processing
-The top level of the nervous system, the neocortex is influencing how information is processed in lower regions of the hierarchy (midbrain and hindbrain)
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Basal Ganglia
-Subcortical forebrain nuclei that coordinate voluntary movements of the limbs and body; connected to the thalamus and to the midbrain
-Collection of nuclei that lie in the forebrain just below the white matter of the cortex
-Three part structure
~Caudate Nucleus
~Putamen
~Globus Pallidus
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Parkinson Disease
- Disorder of the motor system correlated with a loss of dopamine from the substantia nigra and characterized by tremors, muscular rigidity, and a reduction in voluntary movements
- People with Parkinson's take short, shuffling steps; display bent posture; and may need a walker to get around
- Some may have continuous hand tremors and sometimes head tremors
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Tourette Syndrome
-Disorder of the motor system, characterized by involuntary vocalizations (sometimes including curse words and grunting sounds) and odd, involuntary movements of the body, especially of the face and head
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Cranial Nervers
- The 12 nerve pairs that control sensory and motor functions of the head, neck, and internal organs
- Can have afferent functions, such as sensory input to the brain from the eyes, ears, mouth, and nose
- Can have efferent functions, such as motor control of the facial muscles, tongue, and eyes
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Vertebrae
-The bones that form the spinal column
-Categorized into five anatomical regional from top to bottom
~Cervical
~Thoracic
~Lumbar
~Sacral
~Coccygeal
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Dermatome
- Body segment corresponding to a segment of the spinal cord
- Sensory nerve to send information from the skin, joints, and muscles to the spinal cord, as well as motor nerve to control, the muscle movement in that particular area
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Law of Bell and Magendie
- Sensory fibers are dorsal and motor fibers are ventral
- Enables neurologists to make accurate inferences about the location of the spinal cord damage or disease on the basis of changes in sensation or movement
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Autonomic Nervous System (ANS)
- The two pathways exert opposing effects. All fibers connect at "stop" formed by ganglia en route from the CNS to target ANS organs.
-Left
~Arousing sympathetic fibers connect to a chain of ganglia near the spinal cord
-Right
~Calming parasympathetic fibers connect to individual ganglia near target organs
-In-charge of
~Heart beating
~Eyes adjusting to light
~Gut
~Liver releasing glucose
~Lungs
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Sympathetic Division
-Part of the autonomic nervous system that arouses the body for action, such as mediating the involuntary fight-or-flight response to alarm by increasing heart rate and blood pressure
-Arouses the body for action
~Stimulating the heart to beat faster and inhibiting digestion when we exert ourselves during exercise or times of stress
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Parasympathetic Division
-Part of the autonomic nervous system that acts in opposition to the sympathetic division-for example, preparing the body to rest and digest by reversing the alarm response or stimulating digestion
-Calms the body down
~By slowing the heartbeat and stimulating digestion to allow us to rest and digest after exertion and during quite times
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Ganglia
-Controls the internal organs, and each acts as a minibrain for specific organs
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Enteric Nervous System (ENS)
-The ENS is formed by a network of neurons embedded in the lining of the gastrointestinal tract. Congregations of neurons from the ganglia that send projection to the ANS and CNS, in part through the vagus nerve (Cranial nerve 10), to control the gut
-Sometimes called the SECOND BRAIN
~Contains wide range of neuron types, the same chemical transmitters, a profusion of ganglia cells, and complex integrated neural circuits
-Estimated 200-500 million neurons roughly equal the number of the spinal cord
-The gut reacts to a range of hormones and other chemicals with exquisite neural responses
-ENS controls
~Bowel motility
~Secretion
~Blood flow
-Located in a sheet of tissue lining the esophagus, stomach, small intestine, and colon
-The ENS sends information directly to the brain-information that affects our mental state-and the brain can modify gut functions
-Behavioral disorders such as
~Stress and anxiety commonly modify gut functions leading to symptoms as nausea and diarrhea
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Microbiome
- About 3.9X 10^13microbiota populate the adult gut, outnumbering the host cells by a factor of 1.3
- Influence nutrient absorption and are a source of neurochemicals that regulate an array of physiological and psychological processes
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Psychobiotics
- Live microorganisms used to treat behavioral disorders
| - Can influence CNS and ENS, leading to changes in behavior
