Central Nervous System Flashcards
1
Q
CNS is composed of the ____ ___ and _____.
A
spinal cord and brain
- the CNS is the motor command center for planning, originating, and carrying out the transmission of messages received by PNS and organs.
2
Q
CNS is enclosed within the ____ _____ and ______ _____
A
vertebral column; cranial structure
3
Q
the most important sructure in the body for speech, language and hearing
A
BRAIN
- the brain is much more related than the spinal cord and his housed and protected in the cranial cavity of the skull
4
Q
Key structures of the brainstem
A
- Midbrain
- Pons
- Medulla
5
Q
Connects the spinal cord with the brain via the diencephalon;
serves as bridge between the cerebellum and all other CNS structures (incl. spinal cord, thalamus, basal ganglia, cerebrum).
The oldest part of the brain
Many cranial nerves originate from here
A
BRAINSTEM
6
Q
Narrow structure that lis superior to the ponsand inferior to diencephalon
A
MIDBRAIN aka mesencephalon
7
Q
part of midbrain that connects the brainstem and the cerebellum
A
SUPERIOR PEDUNCLES
8
Q
FUNCTIONS OF MIDBRAIN
A
- controls many motor and sensory functions
- postural reflexes
- visual reflexes
- eye movements
- coordination of vestibular-generated eye and head movements
- contains cranial nerve nuclei for trochlear (IV) and oculomotor (III) nerves
9
Q
Roundish, bulging structure that bridges the two halves of the cerebellum
- located inferior to the midbrain
- aka metencephalon
A
PONS
10
Q
The _____ and _______ serve as a connection point between the cerebellum and various cerebral structures the inferior and middle peduncles
A
PONS; MIDBRAIN
11
Q
Part of brainstem that transmits information relative to movement from the cerebral hemispheres to the cerebellum
A
PONS
- The pons contains many descending motor fibers and is involved with hearing and balance
- it also houses nuclei for the trigeminal V and facial VII nerves that are important for speech production
12
Q
- aka myelencephalon
- inferior to midbrain and pons
- uppermost portion of the spinal cord
- contains all fibers that originate in cerebellum and cerebrum and move downward to form the spinal cord
A
MEDULLA
13
Q
Functins of the Medulla
A
- includes several centers that control vital, automatic bodily functions, such as breathing, digestion, heart rate, and blood pressure
- facilitates many reflexes such as sneezing, coughing, blinking, vomiting
- very important for speech production because it contains descending fibers that transmit motor information to several cranial nerve nuclei
14
Q
Nerve fibers contained in medulla that carry commands from the motor center of brain to various muscles
A
PYRAMIDAL TRACTS
- controls many movements and supply some of the muscles that are involved in speech.
- at the level of the medulla, many of these tracts crossover from left and right sides of the brain. Thus, the right side of the body is primarily controlled by the left side of the brain and vice versa
15
Q
the part of the CNS that responds to incoming information by affecting the state of a person’s alertness and consciousness
A
RETICULAR ACTIVATING SYSTEM (RAS)
- RAS is a structure within the midbrain, brainstem, and upper portion of spinal cord
- It integrates motor impulses flowing out of the brain and sensory impulses flowing into it
16
Q
Primary roles of RAS
A
- plays a role in execution of motor activity - sends diffuse impulses to various regions of the cortex
- and alerts cortex to incoming impulses
- primary mechanism of attention and consciousness
- arouses the cortex
- important in controlling sleep-wake cycles
- critical role in maintaining states of consciousness (sleep, drowsiness, alertness, and excitement)
17
Q
Structure that lies above the midbrain and between the brainstem and the cerebral hemispheres
A
DIENCEPHALON
18
Q
Structures of the Diencephalon
A
- Thalamus
- Hypothalamus
- Third Ventricle
19
Q
Largest structure of diencephalon that is considered a primary sensory relay and integration center
- critical for maintenance of consciousness and alertness
- also receives motor impulses from cerebellum and basal ganglia and relays information to motor areas of cerebral cortex
- it regulates sensory information that flows into the brain and relays sensory impulses to various portions of cerebral cortex
A
THALAMUS
20
Q
Structure of diencephalon that helps integrate actions of ANS
- controls emotions
- lies inferior to thalamus
A
HYPOTHALAMUS
21
Q
Tall, narrow space found in diencephalon filled with CSF
A
THIRD VENTRICLE
22
Q
structures deep within the brain, near the thalamus and lateral ventricles
- primarily composed of gray matter
- receives input primarily from the frontal lobe and relay information back to the higher centers of the brain via the thalamus
- part of the extrapyramidal system
A
BASAL GANGLIA
23
Q
The ______________ ________ that helps regulate and modify cortically initiated motor movements, including speech
A
EXTRAPYRAMIDAL SYSTEM
24
Q
An important part of the extra pyramidal system in which Dopamine is produced and projected to the corpus striatum
A
SUBSTANTIA NIGRA
- functionally related to basal ganglia but not a part of it
25
Neurotransmitter generated in the substantia nigra
-lack of this neurotransmitter creates motor disorders such as Parkinsonism
DOPAMINE
26
Signs of lesions in basal ganglia
* unusual body postures
* dysarthria
* changes in body tone
* involuntary and uncontrolled movements (dyskinesias) that interfere with person's voluntary attempts to walk, speak, or do many other activities
27
Referred to as the "little brain"
- consists of two hemispheres connected separated by the vermis
- located below the cerebrum and behind the brainstem
CEREBELLUM
28
Large neurons found in the cerebellum, that release gamma-aminobutyric acid (GABA)
-the only output cells of the cerebellum
PURKINJE CELLS
29
an inhibitory neurotransmitter released by Purkinje cells crucial in the regulation and coordination of motor movements
GAMMA-AMINOBUTYRIC ACID (GABA)
30
Role and function of cerebellum
* regulates :
* equilibrium (balance)
* body posture
* coordinated fine motor movements
* very important to speech production because these movements are necessary for speech
31
A neurological disorder resulting from damage to the cerebellum
ATAXIA
* found in some people with cerebral palsy & cerebellar damage
* shows :
* abnormal gait
* disturbed balance
* speech disorder called : *Ataxic Dysarthria*
* creates other communication disorders
32
biggest most important CNS structure for language, speech, and hearing
- complex structure of intricate neural connections with 10-15 billion neurons
- weighs about 3 lbs.
CEREBRUM/CEREBRAL CORTEX
33
Lobes of Cerebrum
* FRONTAL
* PARIETAL
* OCCIPITAL
* TEMPORAL
named based on cranial bones they are in contact with.
34
Gray matter or cells are inside the cerebrum
T/F
False
Gray matter is on the top of the cerebrum but inside the spinal cord and brainstem
35
Ridge on the cortex
GYRUS
36
A shallow valley on the cortex
SULCUS
-there are many sulci on the surface of the brain
37
Deeper valleys of the brain
FISSURES
- boundaries between the broad divisions of the cerebrum
- there are fewer fissures than sulci
38
Fissures of the brain
* **_Longitudinal_** - runs along teh middle of the brain from front to back
* divides the cerebrum into left and right hemispheres
* deep and extends down to corpus callosum
* **_Central Sulcus (Fissure of Rolando)_** - runs laterally, downward and forward
* divides the anterior from posterior half of brain
* **_Sylvian Fissure (lateral cerebral fissure)_** - starts at inferior portion fo the frontal lobe at base of brain and moves laterally and upward
* Areas of brain surrounding Sylvian fissure are critical in speech, language and hearing
39
Lobe critical to deliberate formation of plans an intentions that dictate a person's conscious behavior
FRONTAL LOBE
40
People who have difficulty carrying out consciously organized activity may have damage to the \_\_\_\_\_\_lobe
FRONTAL
41
FRONTAL LOBE AREAS CRITICAL TO SPEECH PRODUCTION
* Primary motor cortex
* Supplementary Motor Cortex
* Broca's area
42
Area of frontal lobe that controls voluntary movements of skeletal muscle on opposite side of body (contralateral motor control)
PRIMARY MOTOR CORTEX (MOTOR STRIP)
- located on the precentral gyrus anterior to centeral sulcus
- all muscles including those for speech production are connected here
- specific regions that are stimulated correspond with motor responses of that area (e.g. movement of hand)
- large area represents the larynx, jaw, tongue and lips = importance in cortical control of speech-related structures
- controls muscle movements through neural pathway called pyramidal system
43
Part of frontal lobe believed to be involved with motor planning of speech
-plays secondary role in regulating muscle movements
SUPPLEMENTARY MOTOR CORTEX
44
Part of frontal lobe known as the "speech center" and motor speech area
-controls motor movements involved in speech production
BROCA'S AREA
- located on left inferior frontal gyrus
- damage/lesions to this area cause motor speech problems
45
The primary somatic sensory area
- integrates contralateral somatic sensations like pressure, pain, temperature and touch
- integrates information with other areas, predominantly with vision
PARIETAL LOBE
46
Gyrus that integrates and controls somatic sensory impulses
-lies just behind the central sulcus
POST CENTRAL GYRUS
aka sensory cortex or sensory strip
47
2 areas of parietal lobe important for speech and language
* supramarginal gyrus
* angular gyrus
48
Damage to this gyrus can cause conduction aphasia and agraphia (a writing disorder)
SUPRAMARGINAL GYRUS
-lies superior to lateral fissure in the inferior portion of the parietal lobe; posterior
49
Damage to this gyrus can cause writing, reading, and naming difficulties and, in some cases, transcortical sensory aphasia
ANGULAR GYRUS
50
Lobe primarily concerns with receiving and processing visual information
OCCIPITAL LOBE
51
Lobe that lies inferior to frontal and parietal lobes and in front of the occipital lobe
- Contains two general areas critical to adequate hearing and speech
a. Primary Auditory Cortex
b. Auditory association area
- Also contains Wernicke's area
TEMPORAL LOBE
52
Part of temporal lobe that receives sound stimuli from acoustic nerve CN VIII
PRIMARY AUDITORY CORTEX
53
Area in temporal lobe that receives sound stimuli from primary auditory cortex, then synthesizes it so that it can be recognized as whole units
AUDITORY ASSOCIATION AREA
- Dominant Hemisphere (left in most people) - analyzes speech sounds so that the person recognizes words and sentences
- Nondominant Hemisphere (right hemisphere, for most people) - analyzes nonverbal sound stimuli such as environmental noises, music and prosody (e.g. stress rate, rate, melody)
54
Important area within left temporal lobe that is critical to comprehension of spoken and written language
-Connected to Broca's area through the arcuate fasciculus
WERNICKE'S AREA
55
Lesions in his area of the temporal lobe produces fluent but meaningless speech and significant language comprehension problems
WERNICKE'S AREA
56
Part of temporal lobe responsible for recalling information and storing long-term memories.
HIPPOCAMPUS
- Lesions to this area can result in anterograde amnesia (inability to create new memories) or retrograde amnesia ( inability to remember memories prior to lesion)
57
the direct motor activation pathway that is responsible for facilitating voluntary muscle movement (including speech)
[responsible for carrying the impulses that control voluntary fine movements]
PYRAMIDAL SYSTEM
58
The nerve fiber tract of the pyramidal system comes from the _____ \_\_\_\_\_ to the spinal cord and brainstem to supply the muscles of the head, neck, and limbs
CEREBRAL CORTEX
- Voluntary movements needed to produce speech are initiated in the primary motor cortex.
59
Parts of pyramidal system
* Corticobulbar - Critical to speech production
* controls all voluntary movements of speech muscles (except respiratory muscles)
* terminates in the brainstem
* Corticospinal tracts - terminate in the spinal cord
- Both are further subdivided into :
Lower Motor Neurons
* efferent nerves that result in muscular movement; part of the PNS
Upper Motor Neurons
* efferent nerves within CNS; incude pathway sof both pyramidal and extrapyramidal systems
60
transmits impulses that control the postural support needed by fine motor movements
-helps maintain posture and tone and regulate the movement that results from lower motor neuron activity
EXTRAPYRAMIDAL SYSTEM
- "extra" refers to the motor tracts that are not part of the pyramidal system
- composed ot differenct subcortical nuclei incudeing red nucleus, substantia, nigra, subthalamus, basal ganglia, and pathways that connect these structures together
- indirect activation system that interacts with various motor systems in the nervous system
61
Damage to this system creates motor disturbances that fall under "involuntary movement disorders"
-patients may show unusual movement patterns of variuos muscles (including facial muscles) and bizarre postures
EXTRAPYRAMIDAL SYSTEM
62
Bundle of fibers that connect Broca's area with Wernicke's area
ARCUATE FASCICULUS
- important for verbal memory, language acquisition, meaningful language production, and repetition.
- Damage to this structure can cause conduction aphasia
63
Type of aphasia that can be caused by damage to arcuate fasciculus in which there are little to no receptive and expressive langauge deficits but individual is unable to repeat language presented auditorily
CONDUCTION APHASIA
64
Fibers that connect areas within the same hemisphere & maintains communication between the structures in a hemisphere
ASSOCIATION FIBERS
65
Fibers that connect between the cortex and subcortical structures like the cerebellum, basal ganglia, brainstem and spinal cord
PROJECTION FIBERS
66
Fibers that are interhemispheric connectors that connect corresponding areas of the two hemispheres
COMMISURAL FIBERS
- Most Important is Corpus Callosum
67
Corpus Callosum
thick broad band of myelinated fibers that connect the two hemispheres at their base
68
Signs of damage to corpus callosum
- damage disconnects the two hemispoheres resulting in *dysconnection syndromes*, characterized by problems in naming, reading, movement and other functions
69
Cerebral Ventricles
System of cavities deep within the brain filled with CSF
Four Cerebral Ventricles
* Two lateral ventricles (largest )- one in each hemisphere
* Third ventricle - behind lateral ventricles at top of brainstem
* Fourth Ventricle- between cerebellum and pons and continuous with teh central canal of the spinal cord below and cerebral aqueduct
70
Produces CSF
choroid plexus
71
Connects the fourth and third ventricles
CEREBRAL AQUEDUCT
72
Four branches aortic arch divides into
2 carotid
2 subclavian
73
Arteries that branch out from aortic arch and supply the upper extremities
SUBCLAVIAN ARTERIES
74
Arteries that branch out from the two subclavian arteries
Vertebral Arteries
- enters the skull and branches out to supply the spinal cord and many organs of body
75
As vertebral arteries move up to lower level of pons, they join to form the _____ \_\_\_\_\_
BASILAR ARTERY
76
As basilar artery moves toward upper portion of pons, it divides into two _______ \_\_\_\_ \_\_\_\_
POSTERIOR CEREBRAL ARTERIES
- they supply the lateral and lower portions of the temporal lobes adn lateral and middle portions of occipital lobes
77
Carotid artery that supplies blood to muscles of the mouth, nose, forehead and face
EXTERNAL CAROTID ARTERIES
78
Carotid artery that is major supplier of blood to the brain
INTERNAL CAROTID ARTERY
- Has 2 key branches:
* Middle Cerebral Artery
* Anterior Cerebral Artery
79
Biggest branch of internal carotid artery branch that supplies the entire lateral surface of cortex, including major regions of frontal lobe
MIDDLE CEREBRAL ARTERY
- Supplies blood to major areas involved with motor and sensory functions and language, speech and hearing functions.
80
Damage to middle cerebral artery may result in:
* strokes - causing aphasia, reading and writing deficits
* contralateral hemiplegia
* impaired sense of pain, temperature, touch and position
81
Carotid Artery that supplies the middle portion of the parietal and frontal lobes, corpus callosum, and basal ganglia
ANTERIOR CEREBRAL ARTERY
82
Damage to anterior cerebral artery can cause
* cognitive deficits
* impaired judgement, concentration, reasoning
* paralysis of feet and legs
83
Connections between arteries formed at base of brain where the two carotid and vertebral arteries join
- provides a common blood supply to various cerebral branches
CIRCLE OF WILLIS
84
If artery is blocked above Circle of Willis, brain damage (will/will not) occur because brain has no alternate source of blood
will
85
If artery is blocked below the circle of Willis, brain damage may be minimal because alternate channgels of blodo flow may be maintained or compensate for the lack of blood flow
T/F
TRUE
