Nervous System Flashcards
Pre-central gyrus controls what function? What is it also known as?
Motor function. Primary motor cortex.
Post-central gyrus relates to what function? What is it also known as?
Sensory function. Primary sensory cortex.
What ‘landmarks’ outline the frontal lobe?
Central gyrus, followed down past lateral fissure.
What are the three main areas of the frontal lobe?
Premotor/planning cortex, Primary motor cortex, and frontal association cortex.
What is the brocas area responsible for, and where can it be found?
Production of speech/language, in the premotor cortex.
What ‘landmarks’ outline the parietal lobe?
Central gyrus, lateral fissure, parieto-occipital sulcus.
What is the supramarginal gyrus responsible for?
reading/writing.
What distinguishes the primary and secondary visual cortex’s?
The secondary visual cortex receives information from the primary visual cortex and is important for depth perception among other roles.
What is the wernicke’s area responsible for and where is it found?
Comprehension of language, below the lateral fissure in the temporal lobe.
What is the primary auditory cortex responsible for and where is it located?
Initial processing of sounds and speech (not comprehension), within the wernicke’s area (temporal lobe, below lateral fissure).
How many nerves are there in the spinal cord?
31
How many cervical nerves are there? how many corresponding vertebrae?
8/7
How many thoracic nerves are there? how many corresponding vertebrae?
12/12
How many lumbar nerves are there? how many corresponding vertebrae?
5/5
How many sacral nerves are there? how many corresponding vertebrae?
5, there are no vertebrae… there is a sacrum
How many coccygeal nerves are there? how many corresponding vertebrae?
1, there are no vertebrae… there is a coccyx
What is the cingulate gyrus and where is it found?
A gyrus where fight/flight responses and logical reasoning from the frontal lobe interconnect and meet.
What is the corpus callosum and where is it found?
A collection of white matter the links the right and left
Where is the hypothalamus located?
Below the corpus callosum, and above the mid brain
Where is the mid brain located?
below the hypothalamus and above the hind brain
Where is the fore brain located?
around the occipital lobe
Where is the hind brain located?
around the cerebellum
Order the following from outside to inside: Sub-dural space, sub-arachnoid space, pia mater, arachnoid mater, dura mater, epidural space
epidural space, dura mater, sub-dura space, arachnoid mater, sub arachnoid space, pia mater
What two pathways create a spinal nerve?
A dorsal and ventral root
What root is responsible for the motor nerves?
Ventral root
What root is responsible for the sensory nerves?
Dorsal root
What lies in the sub-arachnoid space?
Cerebral spinal fluid
What is the function of the filum terminale, and where is it located?
To anchor the spinal nerves
What is the function and location of the cervical enlargement?
To allow for more efficient output of motor nerve communication and input of sensory nerve communication for areas such as the arms
What is the function of the thoracolumbar enlargement and where is it located?
To allow for more efficient output of motor nerve communication and input of sensory nerve communication for areas such as the legs
Where does the spinal cord end?
L1
What sensory function is associated with free ended peripheral nerves? What speed do these nerves propagate action potentials? what root do these nerves enter?
Pain + temperature. 1m/s. dorsal roots.
What sensory function is associated with myelin sheeted peripheral nerves? what speed do these nerves propagate action potentials? what root do these nerves enter?
Pressure + touch. Very fast. Dorsal roots.
Touch and pressure are associated with which corpuscles?
Meisner’s corpuscle and pacinian corpuscle.
How are the broca’s area and wernicke’s area/primary auditory cortex connected?
Arcuate fassiculus
What is a fassiculi?
A grouping of white matter that acts as a connective component
What is the function of the exeners area?
Hand coordination
What is the function of the angular gyrus?
Writing
Define aphasia
Inability to speak
Fluent/sensory aphasia impacts function how? Which region of the brain is impacted in this context? how may this have occurred in a patient?
Patient is able to produce speech/language, but is unable to interpret or understand language. Wernickes area. From a stroke or lesion.
Contrast ischemic and hemorrhagic strokes
Ischemic strokes are caused by a lack of oxygen to a region of the brain due to a blood clot. A hemorrhagic stroke is caused by bleeding/an aneurysm in a blood vessel located in the brain. This can cause pressure increase and lack of oxygen supply.
Non-fluent/motor aphasia impacts function how? Which region of the brain is impacted in this context? how may this have occurred in a patient?
Patient is able to comprehend speech/language, but has impaired motor function in the context of language (cannot produce language verbally). Brocas region. A stroke or lesion in the brocas area.
Define/describe connection aphasia
A lesion or stroke impacting the arcuate fassiculus. This creates a lack of communication effectiveness between the brocas and wernickes regions.
What is the function of the pre-occipital notch and where is it located?
It is located at the bottom of the parieto-occipital sulcus. It’s function is to distinguish between the occipital and parietal lobes.
What are some of the functions of the frontal association cortex?
Intelligence, personality, behavior, mood, cognitive function
What are some of the functions of the temporal association cortex?
Memory, mood, aggression, intelligence
What are some of the functions of the parietal association cortex?
Spatial skills, 3D recognition (shapes, faces, concepts, abstract recognition)
What are some of the functions of the non-dominant (right) hemisphere?
Body language, emotional components of speech, spatial skills, conceptional understanding, artistic/musical skills
What does encapsulation mean?
A unit around a nerve fiber that codes what it is for
Order the following from thickest to thinnest; Lemniscus, Funiculi, Fassiculus
Funiculi, Fassiculus, Lemniscus
What is a dermatome?
A map of skin sensitivity
What is a myotome?
A map of muscle activation
At a spinal segment level, what groupings of white matter are there? What are there functions?
Dorsal funiculi/columns (proprioception), Lateral columns (motor information), ventral columns
At a spinal segment level, what are groups 1+2 for?
Pain + temperature
What is the nucleus proprius?
Proprioception, 3+4
At a spinal segment level, what are groups 8+9 for?
Motor fiber information
Where are the gracile and cuneate fassiculi located?
Dorsal columns
Finger, elbow, shoulder and neck are sections of what area of white matter?
Cuneate fassiculus
What is cenvergence?
Joining of nerve fibers onto a single neuron
What is the name for the route of proprioception
dorsal column, medial lemniscal system
What are the sections of the brain stem?
Medulla, pons, midbrain
Where is a sensory peripheral cell body located?
Dorsal root ganglian
Where does a nerve cross over in proprioception?
Medulla (cuneate+gracile fassiculus)
Where does a 2nd order proprioceptive nerve fibre go?
From the Gracile/cuneate nucleus along the medial lemniscal tracts
What are the internal arcuate fibers?
The point of crossing over/decussation in the touch and pressure pathway
Where does the 2nd order proprioceptive nerve fibre end?
The thalamus
Where does the 3rd order proprioceptive nerve go to and from?
Through the internal capsule into the primary sensory cortex
DCML stands for?
Dorsal column medial lemniscus
What is the route at a segmental level, of the proprioceptive pathway
Dorsal funiculi, gracile/cuneate fassiculi, medial lemniscus, through internal acruate fibers, through mid brain, through thalamus, to primary sensory cortex
What is the route for sensing pain and temperature
Spinothalamic tract
What is the tract of lissauer?
path of pain+temperature nerves in dorsal root ganglian
What is the Ant White commisure?
Region in ventral columns where spinothalamic cross over
What is decussation?
crossing over
In the spinothalamic tract, where does the 1st order neuron end?
Through the tract of lissauer in areas 1 or 2 at spinosegmental level
Where in the spinal cord are the medial lemniscus and spinothalamic tracts close together?
Pons
In the spinothalamic tract, where does the 2nd order neuron end and 3rd order neuron start?
Thalamus
What is brown sequard syndrome?
A dissociative sensory loss
Lesion in right side of brain stem?
All information from left side blocked (left sided associative sensory loss)
Difference between associative and dissociative?
Associative is a lesion in the brain STEM, where both tracts of sensory function are inpaired but on the opposite side of the body. Dissociative is when sensory loss is on different sides
Lesion of right side of spinal cord?
Loss of proprioception/pain and temperature sensation on different sides
What is the corticospinal tract?
Motor tract
What is the function of pyramidal cells?
Motor neurons
What is the route of a motor neuron tract/cotricospinal tract?
Primary motor cortex, through internal capsule, midbrain, pons, lower medulla, to pyramidal decussation, through lateral corticospinal tract, from lateral column to area 8+9 and out ventral root.
Where do pyramidal cells decussate?
Lower medulla
Where does the UMN end and LMN start?
Area 8+9
What is the function of the myotactic reflex?
To sense limb tension and give instructions to LMN
What is the route of the myotactic relfex?
From peripheral, through dorsal root (where cell body is), to both regions 3+4 and 8+9 to innovate LMN
Is the myotactic reflex fast or slow?
Fast
What is the result of a lesion in the corticospinal tract?
Spastic paralysis
How to test for a spastic paralysis?
Pull the arm or hand of patient. Observe reaction. If they pull back quickly and vigorously, they have a spastic paralysis.
What is the result of a lesion in the LMN?
Flaccid paralysis
How to test for a flaccid paralysis?
Hold patients arm up, and let go. If it goes limp, there is a flaccid paralysis
What is the function of the basal ganglia?
Initiation and planning of movement, mood and facial expression
Structures of basal ganglia?
Caudate nucleus, putamen (striatum), globus pellidus, subthalamic nucleus, substantia nigra.
Function and colour of substantia nigra?
95% of brains dopamine, black in colour
Path of neuron in basal ganglia
Planning cortex, to striatum, delivers glutamate, to either internal external globus pallidus or substantia nigra via GABA fibers. GLobus pallidus goes to thalamus with GABA, Glutamate fibre from thalamus to planning coretex to UMN, UMN to LMN
What innovates the striatum? (putamen)
Substantia nigra via dopamine
What are people with Parkinson’s disease deficient in?
Dopamine
Consequence of Parkinson’s disease?
Dependence of glutamate, becomes excitotoxic. Difficult to initiate movement. Inhibitory neuron fires more, hypoexcitability
Treatments for Parkinson’s disease?
Pallidotomy (lesioning globus pallidus), Deep brain stimulation (probe in brain, electrical stimulus, allows brain to reset), Levo-Dopa
What is the purpose of Levo-dopa?
To be metabolized to dopamine
Consequences of Levo-dopa?
Short term, can resemble schizophrenia
Drug for schizophrenia does what?
Reduces dopamine in the brain
Function of cerebellum?
To stop or counter movement
