Chapter 12 Flashcards
(143 cards)
1
Q
Central Nervous System (CNS)
A
Brain and Spinal Cord
2
Q
Cephalization
A
More developed brain
Neurons
3
Q
Embryonic Developement
A
Brain and Spinal Cord start as neural tube
4
Q
Neural Tube: 3 Primary Vesicles at Anterior End
A
Forebrain
Midbrain
Hindbrain
5
Q
Neural Tube: Posterior End
A
Spinal Cord
6
Q
Brain vs. Membranous Skull
A
Brain develops faster
- Folds
- Forebrain moved towards brain stem
- Cerebral hemispheres envelope midbrain
7
Q
Creases and Folds Purpose in Brain
A
Caused by developing fast
-Increases surface area
8
Q
Regions of Brain
A
Cerebral hemispheres
Diencephalon
Brain Stem
Cerebellum
9
Q
Spinal Cord
A
Central cavity surrounded by gray matter
External white matter
10
Q
Brain
A
Higher amounts of gray matter in brain
Two parts
-Cerebral hemispheres
-Cerebellum
11
Q
Cortex
A
The outer gray matter of the cerebral hemispheres and cerebellum
-Disappears in brain stem- scatters
12
Q
Ventricles of Brain
A
Filled with cerebrospinal fluid
Lined by ependymal cells
Connected to one another and to central canal of spinal cord
13
Q
Lateral Ventricles
A
Third ventricle via interventricular foramen
14
Q
Third Ventricle
A
Fourth ventricle via cerebral aqueduct
15
Q
Third and Fourth Ventricles
A
Paired, C-shaped lateral ventricles in cerebral hemispheres
16
Q
Septum
A
Separating lateral ventricles of brain (Look at Diagram)
17
Q
Gyrus (Gyri)
A
Ridge, mountain like
18
Q
Sulcus (Sulci)
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Valley
19
Q
Fissure (Fissures)
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Deep Groove
20
Q
Longitudinal Fissure
A
Location
-Right sagittal
Function/Purpose
-Makes right and left
21
Q
Transverse Cerebral Fissure
A
Location -Cerebrum -Cerebellum Function/Purpose -Makes top and bottom
22
Q
Cerebral Hemispheres (5 Lobes)
A
Frontal Parietal Temporal Occipital Insula
23
Q
Central Sulcus
A
Separates frontal lobe and parietal lobe
24
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Parieto-Occipital Sulcus
A
Separates occipital and parietal lobes
25
Lateral Sulcus
Outlines temporal lobes
26
3 Layers of Cerebral Hemispheres
Cerebral Cortex
White Matter
Basal Nuclei
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Cerebral Cortex
Gray matter superficially
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White Matter
Internal
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Basal Nuclei
Deep within the white matter
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Cerebral Cortex
Thin- superficial layer
| 40% mass of brain
31
Cerebral Cortex (Site of Conscious Mind)
```
Awareness
Sensory Perception
Voluntary Motor Initiation (versus reflex)
Communication
Memory Storage
Understanding
```
32
Cerebral Cortex (Functional Areas)
Motor Area
Sensory Area
Association Area
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Motor Area
Control voluntary movement
34
Sensory Area
Conscious awareness of sensation
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Association Areas
Integrate diverse information
36
Motor Areas of Cerebral Cotrex
Frontal Lobe
Primary Motor Cortex in Precentral Gyrus
Premotor Cortex anterior to Precentral Gyrus
37
Frontal Lobe
Control of voluntary movement
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Primary Motor Cortex
Long axons
-Corticospinal Tracts of spinal cord
-Allows conscious control of precise/skilled movements
Motor Homunculi
-upside-down caricatures
-Contralateral motor innervation of body regions
39
Premotor Cortex
Plans movement
Controls repetitious/patterned motor skills
Coordinates simultaneous or sequential actions
Controls voluntary actions that depend of sensory feedback
40
Broca's Area
Present in one hemisphere
-Left
Motor Speech area that directs muscles of speech production
Active in planning speech and voluntary motor activities
41
Primary Somatosensory Cortex
In postcentral gyri of parietal lobe
- Proprioceptors
- Spatial Discrimination
- Somatosensory Homunculus
42
Visual Areas
Visual Association Area
- Surrounds primary visual cortex
- Uses part experiences to interpret visual stimuli
- Complex processes involves entire posterior half of cerebral hemispheres
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Auditory Areas (2 Parts)
Primary Auditory Cortex
| Auditory Association Area
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Primary Auditory Cortex
Superior margin of temporal lobes
| Interprets information from inner ear as pitch, loudness, and location
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Auditory Association Area
Located posterior to primary auditory cortex
| Stores memories of sounds and permits perception of sound stimulus
46
Vestibular Cortex
Responsible for conscious awareness of balance (position of head in space)
47
Olfactory Cortex
Smell
- Medial aspect of temporal lobes
- Olfactory bulbs and tracts
- Part of limbic system
- Region of conscious awareness of odors
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Gustatory Cortex
Deep to temporal lobe
| Involved in perception of taste
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Visceral Sensory Area
```
Posterior to gustatory cortex
Conscious perception of visceral sensations
Examples
-Upset stomach
-Full bladder
```
50
Multimodal Association Areas (3 Parts)
Anterior Association Area
Posterior Association Area
Limbic Association Area
51
Anterior Association Area (Prefrontal Cortex)
Involves
-Intellect
-Cognition
-Recall
-Personality
Contains working memory needed for abstract ideas, judgement, reasoning, persistence, and planning
Development depends on feedback from social environment
52
Posterior Association Area
Large Region:
-Temporal
-Parietal
-Occipital
Recognizes patterns and faces and localizing us in space
Involved in understanding written and spoken language (Wernicke's Area)
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Limbic Association Area
Part of Limbic System
Involves Hippocampus
Provides emotional impact, helps establish memories
54
Lateralization of Cortical Function
Hemispheres almost identical
| Cerebral Dominance- dominate for language
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Lateralization
Right and Left
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Left Hemisphere
Language
Math
Logic
57
Right Hemisphere
```
Visual-spatial skills
Intuition
Emotion
Artistic Skills
Musical Skills
```
58
Hemisphere Communication
Instantly due to fiber tracts
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Cerebral White Matter
Myelinated fibers and tracts
Communication between cerebral areas, and between cortex and lower CNS
-same
-between
60
Diencephalon (3 Paired Structures)
Thalamus
Hypothalamus
Epithalamus
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Thalamus
80% of diencephalon
Bilateral nuclei connected by interthalamic adhesion
-Contains several nuclei, named for location
-Nuclei project and receive fibers from cerebral cortex
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Thalamus Function
Gateway to cerebral cortex
Sorts, edits, and relays ascending input
Mediates sensation, motor activities, cortical arousal, learning, and memory
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Hypothalamic Function
```
Controls Autonomic Nervous System
Physical responses to emotions
Regulates
-Body temperature
-Hunger
-Thirst
-Wake-Sleep
-Endocrine System
```
64
Epithalamus
Most dorsal portion of diencephalon
| Pineal Gland
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Pineal Gland
Extends from posterior border and secretes melatonin
66
Melatonin
Helps regulates sleep-wake cycle
67
Brain Stem (3 Parts)
Midbrain
Pons
Medulla Oblongata
68
Brain Stem
Similar structure to spinal cord but contains nuclei embedded in white matter
Controls automatic behaviors necessary for survival
Nuclei associated with 10 or the 12 pairs of cranial nerves
69
Pons
4th ventricle separates pons and cerebellum
Fiber of pons:
-Connect higher brain centers and spinal cord
-Relay impulses between motor cortex and cerebellum
Origin of cranial nerves V (trigeminal), VI (abducens), VII (facial)
Nuclei help maintain normal rhythm of breathing
70
Medulla Oblongata (Medulla)
Joins spinal cord at foramen magnum
Contains choroid plexus of fourth ventricle
Two ventral longitudinal ridges formed by pyramidal tracts
Cranial nerves are associated with medulla
Several nuclei relay sensory information
71
Decussation of Pyramids
Crossover of corticospinal tracts
72
Inferior Olivary Nuclei
Relay sensory information from muscles and joints to cerebellum
73
Vestibular System
(Pons and Medulla)
| Mediate responses that maintain equilibrium
74
Medulla Oblongata Functions
Autonomic reflex center
-Functions overlap with hypothalamus
Cardiovascular Center
Respiratory Center
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Cardiovascular Center
Cardiac center adjusts force and rate of heart contraction
| Vasomotor center adjusts blood vessel diameter for blood pressure regulation
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Respiratory Center
Generate respiratory rhythm
| Control rate and depth of breathing
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Cerebellum
11% of brain mass
Dorsal to pons and medulla
Input from cortex, brain stem and sensory receptors
Allows smooth, coordinated movements
78
Cerebellum Function
Receives impulses from cerebral cortex
-initiate voluntary muscle contraction
Role in thinking, language, and emotion
79
Functional Brain Systems
Networks of neurons that work together but span wide areas of brain
- Limbic System
- Reticular Formation
80
Limbic System
Structures on medial aspects of cerebral hemispheres and diencephalon
Located in Middle Brain
81
Limbic System Function
```
Emotional or affective brain
-Recognition
-Expression
Emotional Responses to odors
-Example skunks smell bad
Most output relayed via hypothalamus
```
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Limbic System: Emotion and Cognition
Limbic systems interacts with prefrontal lobes
- React emotionally to things we consciously understand to be happening
- Consciously aware of emotional richness in our lives
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Hippocampus
Plays a role in memory
84
Brain Wave Patterns and EEG
EEG= Electroencephalogram
Records electrical activity that accompanies brain function
Measures electrical potential differences between various cortical areas
85
Brain Waves
Patterns of neuronal electrical activity
Generated by synaptic activity in cortex
Each person's brain waves are unique
Can be grouped into four classes based on frequency measured as Hertz (Hz)
86
Types of Brain Waves
Alpha
Beta
Theta
Delta
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Alpha
8-13 Hz
| Regular and rhythmic, low-amplitude, synchronous waves indicating an "idling" brain
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Beta
14-30 Hz
| Rhythmic, less regular waves occurring when mentally alert
89
Theta
4-7 Hz
| More irregular, common in children and uncommon in awake adults
90
Delta
4 Hz or less
| High-amplitude waves of deep sleep, indicate brain damage in awake adult
91
Brain Waves: State of the Brain
Change with age, sensory stimuli, brain disease, and chemical state of brain
EEGs used to diagnose and localize brain lesions
92
Epilepsy
Loss of consciousness, fall stiffly, and have uncontrollable jerking
Intelligence or lack there of
Incidence
93
Aura
Sensory Hallucination may precede seizure
94
Absence Seizures
Petit Mal
| Mild seizures; few seconds
95
Tonic-Clonic Seizures
Grand Mal
| Most severe: few minutes
96
Control of Epilepsy
Vagus Nerve stimulation or deep brain
-Simulators that affect certain areas of brain to prevent seizures
Anti-convulsive drugs
97
Consciousness
```
Perception of sensation
Movement
Loss of consciousness signal that brain function impaired
-Fainting/Syncopy
-Coma
```
98
Sleep and Sleep Wake Cycles
Non-Rapid Eye Movement (NREM) Sleep
| Rapid Eye movement (REM) Sleep
99
Narcolepsy
Abrupt lapse into sleep from awake state
| Often have cataplexy
100
Insommnia
Chronic inability to obtain amount/quality of sleep needed
101
Sleep Apnea
Temporary cessation of breathing during sleep
| Causes hypoxia
102
Memory
Storage and retrieval of information
103
Two Stages of Memory Storing
Short Term- not needed for life
| Long Term- limitless capacity
104
Factors Affecting Transfer from Short Term to Long Term Memory
Emotional State- Alert Motivated
Rehearsal
Association
Automatic Memory
105
Protection of Brain
Bone
Membrane
Watery Cushion
Blood Brain Barrier
106
Meninges
Cover and protect CNS
Protect blood vessels and enclose venous sinuses
Contain cerebrospinal fluid (CSF)
Form partitions in skull
107
3 Layers of Meninges
Dura Mater
Arachnoid Mater
Pia Mater
108
Meningitis
Inflammation of meninges
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Arachnoid Mater
Middle layer with weblike extensions
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Subarachnoid Space
Contains CSF and largest blood vessels of brain
111
Cerebrospinal Fluid (CSF)
Watery solution form from blood plasma
-Less protein and different ion concentrations than plasma
Constant volume
112
Functions of Cerebrospinal Fluid
Buoyancy
Protects
Nourishes
113
Choroid Plexuses
Hang from roof of each ventricle: produce CSF at constant rate: keep in motion
Normal Volume: 150 mL, replaced every 8 hours
114
Hydrocephalus
Obstruction blocks CSF circulation or drainage
Unfused skull bones of newborn allow enlargement of head
Brain damage in adult due to rigid adult skull
Treated by draining with ventricular shunt to abdominal cavity
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Blood Brain Barrier
Helps maintain stable environment for brain
| Separates neurons from some blood borne substances
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Composition of Blood Brain Barrier
Contrinous endothelium of capillary walls
| Thick basal lamina around cappilaries
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Function of Blood Brain Barrier
Selective Barrier
- Allows nutrients to move by facilitated diffusion
- Denies metabolic wastes, proteins, toxins, most drugs, small nonessential amino acids, and K+
- Allows any fat-soluble substances to pass, including alcohol, nicotine, and anesthetics
118
Homeostatic Imbalances of the Brain
Traumatic Brain Injuries
OR
Cerebrovascular Accidents (CVA's or Strokes)
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Concussion
Temporary
120
Contusion
Permanent damage
121
Subdural or Subarachnoid Hemorrhage
Could result in death
122
Cerebral Edema
Swelling of brain associated with traumatic head injury
123
Ischemia
Tissue deprived of blood supply: brain tissue dies
Example
-Blockage of cerebral artery by blood clot
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Hemiplegia
One side
125
Transient Ischemic Attacks (TIA)
Temporary episodes of reversible cerebral ischemia
126
Tissue Plasminogen Activator (TPA)
Only approved for treatment of strokes
127
Parkinson's Disease
Degeneration of dopamine-releasing neurons of substantia nigra
Basal nuclei deprived of dopamine become over-active; tremors at rest
Unknown Cause
Treated with L-Dopa: Deep brain stimulation
128
Huntington's Disease
Fatal hereditary disorder
-wild jerky flapping movements
Treated with drugs that block dopamine effects
129
Spinal Cord Location
Begins at Foramen Magnum
| Ends Lumbar 2 Vertebrae
130
Spinal Cord Function
Provides 2-way communication to and from brain
| Contains Spinal Reflex Centers
131
Spinal Cord Protection
Bone, meninges, and CSF
Epidural Space- Cushioning
CSF in subarachnoid space
Dural and arachnoid membranes extend to sacrum
132
Spinal Nerves
31 Pairs
Cervical and lumbosacral enlargements
-Nerves serving upper and lower limbs emerge here
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White Matter
Myelinated and nonmyelinated nerve fibers allow communication between:
-Parts of spinal cord
-Spinal cord to brain
Each spinal tract composed of axons with similar destinations
134
3 Directions of White Matter
Ascending
Descending
Transverse
135
White Matter Divided into 3 Columns on Each Side
Dorsal
Lateral
Ventral
136
Ascending Pathways 3 Neurons
First
Second
Third
Transmit somatosensory information to sensory cortex via thalamus or terminate in the cerebellum
137
First Neuron
- Conducts impulses from cutaneous receptors and proprioceptors
- Branches diffusely as enters spinal cord or medulla
- Synapses with second order neuron
138
Second Neuron
- Interneuron
- Cell body in dorsal horn of spinal cord
- Axons extend to thalamus or cerebellum
139
Third Neuron
- Interneuron
- Cell body in thalamus
- Axon extends to somatosensory cortex
140
Spinal Cord Trauma
Functional Losses
- Paresthesias- Sensory Loss
- Paralysis- Loss of Motor Function
141
Flaccid Paralysis
Severe damage to ventral root or ventral horn cells
| -End result
142
Paraplegia
Transection between Thoracic 1 and Lumbar 1
143
Quadriplegia
Transection in Cervical Region
