Exam 2 Flashcards
Is the grey matter of the brain found on the inside or outside?
Outside
Is the white matter of the brain found on the inside or outside?
Inside
Grey brain matter is made of…
Cell bodies
White brain matter is made of…
Myelinated cell axons
Where is the basal nuclei found?
The middle of the brain
Along with the basal nuclei, ventricles are also in the middle of the brain. What do they house?
Cerebrospinal fluid
Define sulci in the brain.
Sulci are spaces created by folds of the brain
What is the function of brain meninges?
They encase the brain stem
Define gyri in the brain.
Gyri are the hills of the brain
Name the 6 functions of the meninges.
- Cover & protect the Central NS
- Creates spaces between meninge layers
- Protects blood vessels
- Encloses venous sinuses that drain CSF
- Contains CSF
- Forms skull partitions
Name the three types of meninges.
Dura
Arachnoid
Pia
What are the functions of the first meninge of the brain?
Dura mater provides structure and protects the brain
What are the functions of the second meninge of the brain?
Arachnoid mater houses the blood vessels and veins
What are the functions of the third meninge layer?
Pia mater adheres to the brain, like gyri and sulci
Name the 2 spaces created by the meninges.
Subdural & Subarachnoid
What two meninges create the subdural space?
Dura and arachnoid
What two meninges create the subarachnoid layer?
Subarachnoid and the sheath of pia mater
Name the 5 functions of cerebrospinal fluid (CSF).
- Forms cushion that gives brain constant volume
- Gives buoyancy to CNS structures
- Reduces brain weight by 97% via floating
- Protects CNS from trauma
- Nourishes brain and carries chemical signals
How many ventricles are there and what are they?
The four ventricles are spaces where cerebrospinal fluid builds up
Where is cerebrospinal fluid created?
In the C-shaped First & Second ventricles
Name the important parts and lobes of the brain discussed in lecture.
Central sulcus
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Cerebellum
Where is the frontal lobe located and what two important things are found there?
Frontal lobe is found in the anterior division of the central sulcus
- Primary Motor Cortex
- Working Memory
Why is working memory important?
Involved with remembering, manipulating, and expressing info, and cognitive control (i.e. the ability to switch between tasks)
What is the parietal lobe involved in?
Perception
- “Mind’s eye”
- Imagination
- Balance
What is the occipital lobe involved in?
Visual perception
What is the temporal lobe involved in?
Involved in forming/recalling memories, naming, and complex perception (i.e. faces)
What is the cerebellum involved in?
involved in movement control and error correction
Define hemispatial neglect.
Condition where parietal lobe damage causes inability to attend to things on one side of the body (i.e. dog eating from one side of bowl)
What are the important features of hemispatial neglect?
Vision is okay but patient just cannot pay attention to affected side
Difficult to diagnose but recognizable by others
Define prosopagnosia.
Condition characterized by the inability to recognize faces
What are the 3 divisions of the nervous system?
Central
Peripheral
Autonomic (visceromotor)
What is found in each division of the nervous system?
Central - brain & spinal cord
Peripheral - sensory neurons and motor neuron axons
Autonomic - everything motor-related except skeletal muscle
Name the 4 divisions of the central nervous system.
Forebrain (anything above brainstem)
Brainstem
Cerebellum
Spinal Cord
What is found in the forebrain?
Cerebral hemispheres
Limbic system
Thalamus
Basal nuclei
What is the forebrain involved in?
Higher processes
- Working Memory
- Attention
- Motor planning
- Sensory integration (getting environmental signals and forming motor response)
What is the limbic system involved in?
Emotional processing
What is the function of the thalamus?
Relay center for all sensory info entering brain
What are the 3 parts of the brainstem?
Pons
Medulla
Brainstem
What does the medulla do?
Supports breathing & heart rate changes
What does the brainstem do?
Holds axons for movements and nuclei vital to motor control
What is the cerebellum involved?
Motor coordination
Error correction
Integrating sensory information with motor system
What is the difference between the spinal cord and the brain regarding white and grey matter?
Brain grey matter is outside & white matter is inside
Spinal grey matter is inside & white matter is outside
What are the two types of horns in the spinal cord?
Ventral
Dorsal
What is the difference between ventral and dorsal horns?
Sensory neurons enter dorsal horn
Motor neurons exit ventral horn
areas of the frontal lobe
What parts of the brain are important for specific behaviors?
Primary motor cortex
Wernicke’s Area
Broca’s Area
How is the PMC important for specific behaviors?
Vital for movement, movement planning, & motor learning
How is Wernicke’s Area important for specific behaviors?
Involved in understanding speech
Describe what happens if there is damage to Wernicke’s Area
Difficulty coherently expressing thoughts
- “word soup”
- Ability to speak but it makes no sense
Describe what happens if there is damage to Broca’s Area
Stuttering although person is able to have coherent thoughts
What is the main difference between damage to Wernicke’s & Broca’s area?
Wernicke - ability to speak, no coherent thoughts
Broca’s - inability to speak. has coherent thoughts
Name the PCML system’s role
Posterior Medial Lemniscal System tells brain about body’s position
Name the 3 types of sensation the PCML system is responsible for.
Proprioception
Discriminative Touch
Vibration
Describe how the PCML system ascends the spinal cord.
Sensory info enters dorsal horn, travels up through posterior column of spinal cord to end up in brain
Do axons travel contralaterally or ipsilaterally in the PCML system?
Ipsilaterally
Relate the PCML system to the lower extremities (LEs)
The signal synapses the gracile fasciculus then gracile nucleus, crosses the body, synapses the thalamus, and ends in medial S1
Relate the PCML system to the upper extremities (UEs)
The signal synapses the cuneate fasciculus then cuneate nucleus, then crosses the body, synapses the thalamus, and ends in lateral S1
complex path the signal takes
Describe the signal travel in the PCML pathway
Signal enters through sensory neuron
Signal crosses the body and synapses nuclei
Signal turns into medial lemniscus
Signal is sent to thalamus and finally ends in somatosensory cortex
What is the main difference between PCML signals from the UEs and LEs?
UEs travel laterally
LEs travel medially
Name the role of the AL system
Anterolateral system is vital in nociception and protecting the body
Name the 2 reflexes in the AL system
Spinal Flexor Withdrawal Reflex
Spinal Crossed Extensor Reflex
What does the spinal flexor withdrawal reflex do?
Body will withdraw from painful stimulus
What does the spinal crossed extensor reflex do?
Helps opposing limb support pained limb
- eg. if left leg hurts, the right leg will support
What is important to remember about the pain reflexes?
Extension of the non-affected limn
Flexion of affected limb
Name the 4 differences of the AL and PCML systems
- Sensory functions
- Crossing levels
- Innervating nerves
- Receptive fields
Name the sensory functions of the AL and PCML systems
AL - crude touch, thermal sensation, nociception
PCML - discriminative touch, kinethesia, propriception
Name the crossing levels of the AL and PCML systems
AL - crosses at spinal cord
PCML - crosses at medulla
Name the innervated nerves of the AL and PCML systems
AL - Type III & IV (smaller, slower, & unmyelinated
PCML - 1A & 1B (bigger & myelinated)
Name the receptive fields of the AL and PCML systems
AL - larger receptive field
PCML - smaller receptive field
Name the 5 cutaneous mechanoreceptors
- Ruffini endings
- Pacinian corpuscles
- Hair follicles
- Meisner’s corpuscules
- Merkel cell
What is the role of the cutaneous mechanoreceptors?
Supports ability to receive sensations
How are mechanoreceptors divided?
Slow-adapting receptors
Rapid-adapting receptors
Define slow-adapting receptors
Fire at a higher rate and sustained activation throughout pressure
What mechanoreceptors fall under slow-adapting receptors?
Merkel cells
Ruffini ending
Hair follicles
Define rapid-adapting receptors
Fire when pressure occurs and release; quick activation
What mechanoreceptors fall under rapid-adapting receptors?
Meisner’s corpuscules
Pacinian corpuscules
Hair follicles
Why are dermatomes important to sensation?
Dermatomes detect where pain occurs or where damage occurs in the body
Define referred pain
The disconnect between body part that experiences sensation and where you think sensation is occurring
- Nerve activation is so intense that pain bleeds into adjoining nerves
What are the 4 results of damage in the AL system lecture?
- Sensitization
- Increase in receptive field
- Hyperalgesia
- Allodynia
Define hyperalgesia
Pain amplification
Define allodynia
Pain from non-harmful stimuli
What is central sensitization?
Increased pain response causes signal to bleed into surrounding nerves
What is the difference between pain and suffering?
Pain - initial response to painful stimuli
Suffering - prolong activation of reticular nucleus; sustained pain
Why is pain experienced?
Because of the thalamus & somatosensory cortex
Name the 4 treatments of pain
- Thalamic lesioning
- DBS Stimulation
- Chronic stimulation with implanted electrodes
- Drugs
What does the autonomic nervous system innervate?
Smooth & cardiac muscles
Glands
Name the two divisions of the ANS and their functions
Sympathetic - fight or flight
Parasympathetic - rest and digest
Relate dual innervation to the ANS
Sympathetic & Parasympathetic innervate the same organs but cause different effects
What are the differences between the Parasympathetic and Sympathetic ganglia?
Parasympathetic ganglia are closer to organ
Sympathetic ganglia are closer to spinal cord
Name the 4 differences between the parasympathetic and sympathetic NS fibers
- Origin
- Fiber length
- Ganglia location
- Complexity
Describe the fibers in the Parasympathetic NS
Originate from craniosacral region
Longer and extend to organ with relay point
Ganglia is closer to target organ
Simple
Describe the fibers in the Sympathetic NS
Originate from thoracilumbar regions
Shorter in length
Ganglia is closer to spinal cord
More complex
Name the four parts that control the ANS
Hypothalamus - has final say in activation
Brainstem - controls HR, vasoconstriction, effects on GI
Spinal cord - controls urination & defecation
Limbic system - controls emotion, expression, & influences hypothalamus in emotional expression
What is the anatomy of the cerebellum?
Anterior lobe
Primary fissure
Posterior lobe
Horizontal fissure
Vermis
Name the functions of the cerebellum
Plays a role in balance, coordination, & error correction
Associated with vestibular system
The cerebellum receives information from what?
Spinal cord, muscles, brain, and brain stem
Describe how the cerebellum sends information
It sends out info, relays from the brain stem, and ends in the motor cortex and spinal cord
How is the Purkinje cell and deep cerebellar nuclei involved in cerebellar transmission?
Purjinke cell receives action potentials and sends it to the deep cerebellar nuclei
When activated, inhibitory signal is sent to deep cerebellar nuclei (which inhibits accidental movement)
What are the cerebellar separations?
Intermediate zone
Lateral zone
Vermis
Name the three cerebellar modules
Vestibulocerebellar
Spinocerebellar
Pontocerebellar
Describe the relationship of the vestibulocerebellar module and its function
The vestibulocerebellar module is involved in posture and balance
Describe the relationship of the spinocerebellar module and its function
The spinocerebellar module is involved in control of axial muscles and limbs
Describe the relationship of the pontocerebellar module and its function
The pontocerebellar module is involved in planning & control of precise dexterous movements of arm and hand, control of agonist/antagonist activation patter, and timing and duration of contraction
What are the 2 clinical exams to test for cerebellar damage?
Finger to Nose test
Rapid Alternative Movements
What are the signs of ataxia?
Difficulty walking and hitting target
Increased muscle tone
Nystagmus
Babinski reflex
Name the anatomy of the basal nuclei
Dorsal striatum
Substansia Nigra
Subthalamic nucleus
Globus pallidus
Describe the location of the dorsal striatum in relation to the thalamus
Caudate is separated into head, body, tail, and wraps around thalamus
Putamen is lateral to thalamus
Describe the location of the globus pallidus
Medial to putamen
Name the 5 functions of the basal nuclei
- Role in cognition & emotion
- Regulates intensity of movements
- Inhibits inappropriate actions
- Habits
- Skill learning
Describe the motor loop process
Motor cortex provides exhibitory input to striatum
Striatum provides inhibitory input to globus pallidus
Globus pallidus provides inhibitory input to thalamus
Thalamus provides excitatory input back to motor cortex
Describe the motor loop process during a success
Large influx of dopamine and excitation of striatum
- Inhibition of globus and less inhibition of thalamus causes excited cortical area leading to reinforcement
Success = higher motor cortex activity = reinforcement
Describe the motor loop process during a failure
Dopamine to striatum will drop, which shuts down striatum. This allows globus to inhibit thalamus, leading to less active motor cortex
Describe Parkinson’s disease
A hypokinetic disease of rapid degeneration of dopamine cells
What are the motor symptoms of Parkinson’s
Tremors
Rigidity
Akinesia
Postural instability
(TRAP)
What are the cognitive symptoms of Parkinson’s
Difficulty learning skills
Memory impairment
Decision-making problems
Describe Huntington’s disease
A hyperkinetic disease that is a loss of striatum neurons due to genetic mutation
What are the motor symptoms of Huntington’s
Choreiform movements
Balismus
Stumbling
Clumsiness
(Crazy Bears Stumble Clumsily)
What are the cognitive symptoms of Huntington’s
Memory lapses
Difficult concentrating
What causes Tourette’s
Hyperactivity of dopamine neurons
Dopamine is produced and released by which structure?
Substantia nigra
What makes up the striatum?
Caudate & Putamen
