Biological Bases of Bx: The Nervous System Flashcards
Functions of the prefrontal lobe
Executive functions, including organizational ability, decision making, problem solving
Prefrontal association cortex
Control & regulation of cognition and planning. Damage associated with decreased initiative, deficient self awareness, & concrete thinking
Corpus callosum
Nerve fibers connecting 2 hemispheres of the brain
Frontal Lobe contains
Prefrontal cortex, brocas area
Iconic memory
memory of visual stimuli; temporary visual impression after the stimulus is removed
Apperceptive agnosia
Inability to recognize familiar objects by sight, especially in low light, but may still identify object by touch
2 Main Divisions of the Nervous System
Central Nervous System (CNS): Brain & Spinal Cord
Peripheral Nervous System (PNS): Nerves that go to & from CNS (cranial nerves, spinal nerves, peripheral ganglia)
2 Main Subdivisions of the Peripheral Nervous System
(PNS)
Hint: Nerves connected to all bodily functions, both voluntary & automatic
Somatic Nervous System (voluntary movement)
Autonomic Nervous System (automatic bodily fxs)
Somatic Nervous System
Sends & receives sensory msgs controlling voluntary motor movement of the skeletal muscles
2 subdivisions of the Autonomic Nervous System
Hint: Body automatically resp to stress and then calms down
Sympathetic Nervous System (body’s mobilizing system)
Parasympathetic Nervous System (body’s energy conserving system)
Autonomic Nervous System (ANS): what does it control & primary function
Controls automatic bodily functions of the muscles & glands, like heart rate, breathing, digestion, etc
Function: maintain homeostasis within body
Sympathetic Nervous System (SNS)
Hint: Sympathetic to stress, so body mobilizes to respond
Body’s mobilizing/fight or flight system, takes over in times of stress
Releases hormones to inc resp, HR, BP; decr digestion & elimination
Parasympathetic Nervous System (PNS)
Hint: Biofeedback helps to access PNS; stress response is PARAlyzed
Body’s energy conserving system, dominant during relaxation
Slows HR, resp, BP, etc
2 Main Divisions of the Central Nervous System (CNS)
Brain
Spinal Cord
____ neurons, also known as ____ neurons, carry info into the CNS, while ___ neurons, also known as ____ neurons, carry info away from CNS to the muscles & glands
Sensory; Afferent (Hint: senses AFFect the brain)
Motor; Efferent (Hint: info has to motor to muscles in order to EFFect movement)
4 Regions of the Spinal Cord from top to bottom
- Cervical (C1-C7)
- Thoracic (T1-T12)
- Lumbar (L1-L5)
- Sacral (S1)
How does spinal cord damage impact body functioning?
Muscles served by section of the spinal cord below the damage do not function normally
____ results from severing of spinal cord between __ and __ , leading to paralysis in all 4 limbs
Quadriplegia; C1 and C5
_____, or paralysis of the legs, & partial paralysis in the arms results from severing of spinal cord between __ or __
Paraplegia, C6 or C7
___ results for severing the spinal cord from T1 on down
Paraplegia
Paresis
Muscle weakness resulting from incomplete severing of the spinal cord
True or False: A man with paralysis may still be able to achieve an erection
True,as reflexes (like arousal & ejaculation) can remain intact with spinal cord damage.
3 Major Divisions of the Brain
Cerebrum, Cerebellum, Brain Stem
2 Layers of the Cerebrum
Hint: Like an orange
Cerebral Cortex
Subcortical Areas
Fx of Cerebrum
Complex thought, perception, action
How is the cerebral cortex divided?
Left & Right Hemisphere
Each Hemisphere divided by 4 lobes (frontal, parietal, temporal, occipital
How are the left & right hemispheres of the brain connected?
Band of nerve fibers, called corpus callosum
*Left hem controls right side of body, right hem controls left side of body
Central sulcus
The groove, or sulci, that separates the frontal & parietal lobes
Lateral sulcus
The groove, or sulci, that separates the temporal lobe from the frontal & parietal lobes
What does Left Hemisphere control
Hint: 2 Ls; EPPP success anchored here
LANGUAGE: reading, writing, speaking, naming, motor control
LOGIC: rational, analytical, logical, abstract thinking
Impact of damage to the left hemisphere
Speech disorders (aphasia), other lang probs (agraphia, anomia), motor disorder (apraxia), difficulties w/right side of body
What does Right Hemisphere control?
Perception Visual spatial reasoning (even body image) Creativity (art, music) Intuition Emotion (comprehension & expression)
Aphasia
Inability to understand or produce language
Agnosia
Inability to recognize objects or perceive stimuli
Agraphia
Inability to write
Alexia
Problems w/reading
Anomia
Inability to name objects
Acalculia
problems doing math/calculation
Proprioception
Ability to locate one’s body parts in space
Impact of damage to the right hemisphere?
Visual perceptual disturbances
Prosopagnosia
Agnosia for musical sounds
Affective abnormalities (indiff, euphoria, hysteria, depr, mania, disinhibition, impulsivity, sexual bx)
Prosopagnosia
Inability to recognize familiar faces
approx. how much of the pop is left hem dominant?
97%
3 Divisions of the Frontal Lobes
- Prefrontal Cortex
- Premotor Area
- Motor Area
Fxs of the Prefrontal Cortex
Hint: Makes us who we are, separates humans from other animals
Personality, Emotionality, Inhibition, Planning, Abstract thinking, Judgment, Executive cognitive skills
Function of Premotor Area
Planning Movement
Fx of Motor Area
Instigate voluntary muscle movement
Impact of Damage to Frontal Lobes
Loss of mvmt/paralysis, changes in personality/temperament, emotional lability, perseveration, inattention, poor problem solving, Broca’s aphasia
Usually result of TBI, stroke, Tumor
Broca’s Aphasia
Inability to express language
Fx of Parietal Lobes
Primary sensory areas (pain, heat, proprioception)
Enable integration sensations of touch to create 3 dimensional experience of objects (shape, size, wt, texture)
Key Role of Right Parietal Lobe
Directing Attention
Visual & spatial skills
Key Role of Left Parietal Lobe
Overlearned motor routines
Linguistic skills- reading, writing, naming objects
Impact of damage to the parietal lobes
Anomia, agraphia, alexia, acalculia, difficulty drawing objects, difficulty distinguishing rt from lt, lack of awareness of body parts, probs w/hand eye coordination
Most often caused by stroke
4 Primary Sxs of Gerstmann’s Syndrome
Lesions of the Left Parietal Lobe Agraphia Acalculia Rt-Lft Disorientation Finger Agnosia (unable to recognize own fingers as part of body)
Temporal lobes contain the ___ _____ ____
*Hint: temporal lobes located around the temples, area of the EARS
Primary Auditory Cortex
Temporal lobes are also connected to the ___ ____, so they are involved in ___ and ____
- Hint: This system contains amygdala & hippocampus
- Hint: Temporal lobes implicated in temper
Limbic System
Fxs of the Temporal Lobe
Hearing
Emotions & Memory (due to connection to Limbic system)
Verbal Memory & Language comprehension (Left Temporal- Wernicke’s area)
Wernicke’s Area
Located in left temporal lobe, involved in verbal memory and language comprehension
Broca’s Area
Located in Left Frontal Lobe- controls muscles that produce speech
Key Role of Left Temporal Lobe
*Hint: Left is for Language
Verbal Memory & Language Comprehension
Key Role of Right Temporal Lobe
Visual Memory
Impact of Damage to the Temporal Lobes
Aggressive bx, change in sexual bx, interference w/memory, prosopagnosia, problems understanding speech (Wernicke’s aphasia)
Most often caused by TBI, stroke, encephalitis
Wernicke’s aphasia
Problems understanding speech
Occipital Lobes contain the ___ ___ cortex, which are involved in ___, ___, and _____
*Hint: OCcipital involved in OCular functioning
Primary Visual
Sight, Reading & Visual Images
Fx of the Occipital Lobes
Sight
Reading
Visual Images
Impact of Damage to the Occipital Lobes
Uncommon, usually result of tumor or stroke
Difficulty recognizing drawn objects/recognizing colors
Hallucinations or illusions
Word blindness (can’t recognize)
Problems w/reading or writing
3 Main Subcortical Brain Areas
Corpus Callosum
Limbic System
Basal Ganglia
Fx of Corpus Callosum
Right Hem controls Left side of body (body & sensation)
Left Hem controls Right side of body
Corp call serves as bridge between the 2 hemispheres
Split Brain Patients
Corpus callosum severed to reduce epileptic seizures
Opposite side of brain still controls sensory input from opp side of body, but now no communication between hemispheres
Classic “heart” study w/split brain patients
Word HEART flashed such that “HE” is seen in Left Visual Field (so processed by Right side of the brain) and “ART” seen by Right Visual Field (so processed by Left side of the brain). Patients unable to verbalize the whole word due to no language in right hem, they were only able to verbalize “ART” because it was processed by lang center of the brain in the left hemisphere
Key Roles of Limbic System
*Hint: What do you need to survive?
Primitive brain, SURVIVAL Influences autonomic nervous system & endocrine system Emotions Basic Drives (sex, hunger) Learning Olfaction Memory
5 Key Limbic System Structures
Thalamus Hypothalamus Hippocampus Amygdala Septum
Fx of Thalamus
Sensory relay center, input from all senses, except smell, projects info to appropriate cortical areas
Critical to perception of pain
Abnormalities linked to schiz due to misperception of sensory input
5 Fs of the Hypothalamus
Fever Feeding Fighting Falling asleep Fucking
Fx of the Hypothalamus
Connection to endocrine system & autonomic nervous system
Major role is homeostasis, incl temp, hunger, thirst, sex, hormone secretion, aggression, sleep-wake cycle
The ____ contains a group of cells, the ___ ___, which are considered the body’s circadian clock b/c regulates sleep wake cycle
Hypothalamus; Suprachiasmic Nucleus (SCN)
Influence of hypothalamus on pituitary gland
Hypothal secretes hormones (thryotropin releasing hormone & corticotropin releasing hormone) that stimulates pituitary gland to secrete its own hormones (growth hormone, thyroid stimulating, adrenocorticotropic), which then activate other glands (thyroid, pancreas)
Fx of Hippocampus
*Hint: If you saw a HIPPO on CAMPUS, you would REMEMBER him
Consolidation of conscious memories, stores new information and events as lasting memories
Short term memory –> long term memory
fx of Amygdala
Hint: A is for Aggression
Attaches emotions to sensory input, strong connection to fear/startle, aggression, emotional memory
Determines level of threat
Involved in memory of fear (PTSD)
The ____ has been linked to PTSD due to involvement in memory of fear
Amygdala
Kluver Bucy Syndrome
Complete removal of the amygdala results in placidity, apathy, hyerphagia, hypersexuality, agnosias
Fx of Septum
*Septum allows you to Simmer down
Moderates or decreases aggression; damage leads to Septal Rage Syndrome
Fx of Basal Ganglia
Hint: He is Gangly in his Movement, which he tries to INHIBIT
Regulate movement & establish posture
Sends info to the premotor & primary motor cortex
INHIBIT movement so we can be still and maintain posture
5 Nuclei of the Basal Ganglia
Caudate Nucleus Putamen Substantia Nigra Globus Pallidus Subthalamic nucleus
2 Main Problems assoc with dysfunction of Basal Ganglia
Extraneous unwanted muscle movements (Huntingtons)
Difficulty w/intended movement (Parkinsons)
Huntington’s Disease
Result of degeneration of Caudate Nucleus & Putamen
produces thrusting movements of face & limbs
Parkinson’s Disease
Result of slow & steady loss of dopaminergic neurons in the substantia nigra, leading to tremor, rigidity, bradykinesia (slowed mvmt)
2 psychiatric disorders where Basal Ganglia are implicated
Tourette Syndrome
OCD
Cerebellum: Location & Function
*Hint: BELLUM is for Balance
2nd largest struc in the brain, base of brain, behind brain stem
Responsible for smooth movement & coordinating motor activity
Maintain BALANCE & Equilibrium
Ataxia
Sx of cerebellar disease, lack of coordination of voluntary mvmts in the absence of weakness or sensory loss
Symptoms of Cerebellar Damage
incorrect timing of muscle activation, disequilibrium, vertigo, inability to grab objects, probs coordinating fine movements
Fx of the Brain Stem
Most primitive part of the brain, extension of the spinal cord
12 cranial nerves begin in brain stem
3 Major Brain Stem Areas
Pons
Medulla
Reticular Formulation
Pons & Medulla
Pons- Upper portion of brain stem
Medulla- Bottom of brain stem
Involved in sleep, respiration, movement, & cardio activity
Damage to the medulla or pons can lead to failure of bodily fxs and ___
death
Reticular Formation
Interconnected nuclei in the brain stem
Awareness, attention, sleep
Reticular Activating System
Projects from brain stem to thalamus, involved in sleep wake cycle
Filter for incoming sensory info
Mediates alertness
What are neurons?
Cells of the brain & spinal cord, communicate w/one another and to muscles, glands, organs by releasing tiny amounts of neurotransmitters
3 parts of Neurons
Dendrites
Cell Body/Soma
Axon
Dendrites
Receive info by capturing neurotrans released into the synaptic cleft
Neuron may have thousands of dendrites
Soma/Cell body
Integrates info from dendrites
Contains nucleus, which regulates all cell activity & controls hereditary charac (DNA)
Axon
Tube extending from soma that transmits info
Neurons communicate to one another through ___ ___, which is an electrochemical impulse
Action Potential
What happens to chemicals inside/outside of neuron during action potential?
At Rest: Excess of sodium outside cell body, Excess Potassium inside
During Action potential: Potassium rushes out, Sodium rushes into cell and through axons, triggering release of neurotrans by the terminal buttons
Those neurotrans cross synaptic cleft to bind to receptor sites of next neurons & reuptake occurs
All or None Principle of Neuronal Firing
A neuron will either by sufficiently stimulated to fire to its fullest extent, or it won’t fire at all
Absolute Refractory Period
Period of time after firing that a neuron absolutely cannot fire, followed by a relative refractory period where only very intense stimulation triggers firing
Provides time for neuron to return to resting state with excess potassium inside and sodium outside
2 categories of Neurotransmitters
Classical & Peptide
Agonist
Any Substance that enhances the effect of a neurotransmitter
Antagonist
any substance that inhibits the neurotrans effect
2 classifications of Neurotransmitters (Impact on Action Potential)
Excitatory- increase likelihood of action potential
Inhibitory- decrease likelihood of action potential
Classical Neurotransmitters
Hint: Classical CASA
Catecholamines (dopamine, norepinephrine)
Acetylcholine
Serotonin
Amino Acids
Fx of Acetylcholine (Ach)
Most common neurotransmitter
Voluntary Movement
Memory & Cognition
The neurotransmitter ____ is prevalent in the hippocampus, which explains its involvement in Alzheimer’s Disease
Acetylcholine
2 Principle Catecholamines
Hint: CATs, NOt DOgs
Norepinephrine
Dopamine
Synthesized from dietary tyrosine & phenylanine
Dopamine Hypothesis of Schizophrenia
Proposes that schiz is result of excess dopamine, thus antipsychotics have been dopamine antagonists
However, newer antipsychotics do not primarily work on dopamine so hypothesis has been questioned
Role of dopamine in Parkinson’s Disease
Degeneration of neurons in substantia nigra results in decrease in available dopamine to basal ganglia. So L-Dopa or levodopa (a precursor to dop) treats parkinsons
Norepinephrine
Significantly involved in mood
Also implicated in pain, sleep
Catecholamine Hypothesis of Affective Disorders
Hint: Cat lady gets more cats to feel better
Too little catecholamines, esp Norepinephrine- low mood
Too much- Mania
Serotonin (5-HT)
Significantly involved in mood disorders
Produced by dietary mod of tryptophan
Aggression, sex, sleep onset, pain percep, possibly schiz
Permissive Hypothesis of Serotonin Functioning
proposes 2 steps in the development of mood disorders
- Deficiency in serotonin
- Levels of norepinephrine determine whether mania (too much) or depression (too little)
3 Main Amino Acids
GABA
Glycine
Glutamate
Major Inhibitory Neurotransmitters of the CNS
Hint: 2 Amino Acids makes things AMicable & calm
GABA
Glycine
Insufficient levels of GABA have been linked to ___ and ___
Anxiety; Epilepsy
Benzodiazapines are ___ ___, where they increase levels of __ to reduce overarousal
*Remember AMino acids make things amicable and calm
GABA agonists; GABA
Glutamate
Mediator of fast, excitatory synaptic transmission
Peptide Neurotransmitters are long chains of ___ ___, and there are dozens of them.
amino acids
2 Endogenous opioids
Peptide neurotrans,
Enkephalins
Endorphins
Help to regulate stress & pain
Substance P
*Hint: P regulate Pain
A peptide neurotransmitter involved in pain regulation
