Ch. 12 The CNS Flashcards
The central nervous system develops from ____.
neural tube
The anterior end of the neural tube expands and constrictions mark 3 primary brain vesicles. What are they?
Prosencephalon- Forebrain
Mesencephalon- Midbrain
Rhombencephalon- Hindbrain
During week 5 of embryonic development, the primary vesicles give rise to secondary vesicles called what?
Forebrain- Telencephalon and Dienchephalon
Midbrain is unchanged
Hindbrain- Metencephalon and Myencephalon
Secondary vesicle, telencephalon, forms what major structures of the brain.
Cerebrum
Secondary vesicle, Diencephalon, forms what major structures of the brain.
- Thalamus
- Hypothalamus
- Epithalamus
Secondary vesicle, Mesencephalon, forms what major structures of the brain.
Midbrain
Secondary vesicle, Metencephalon, forms what major structures of the brain.
- Pons
2. Cerebellum
Secondary vesicle, Myencephalon, forms what major structures of the brain.
Medulla Oblongata
These are 4 hollow chambers filled with cerebrospinal fluid and lined by ependymal cells, continuous tubes.
Ventricles
These are C shaped chambers in each cerebral hemisphere separated by the septum pellucidum.
Lateral Ventricle
This ventricle is in the diencephalon, connected to the lateral ventricles by the interventricular foramen.
Third Ventricle
This ventricle is dorsal to the pons, open to the subarachnoid space by the lateral and medial apertures, connected to the third ventricle by the cerebral aqueduct.
Fourth Ventricle
This is the largest and most superior part of the brain divided into right and left hemispheres.
Cerebral Hemispheres.
Another name for the many ridges of the brain.
Gyri
Another name for the grooves of the brain.
Sulci
Deep groves of the brain are called? They separate regions of the brain.
Fissures
What are the 2 fissures of the brain called?
- Longitudinal Fissure
2. Transverse Cerebral Fissure
The longitudinal fissure separates what region?
Separates Hemisphers
The transverse fissure separates what regions of the brain?
The cerebrum from the cerebellum
Hemispheres are divided into 5 lobes by what?
Sulci
What are the 5 lobes of the brain?
- Frontal
- Parietal
- Temporal
- Occipital
- Insula (internal)
What does the central sulcus divide?
Frontal and parietal lobes
What does the Parieto-Occipital sulcus divide?
Parietal from occipital lobe
What does the lateral sulcus divide?
Temporal from frontal and parietal
Where can you find the insula?
Under the lateral sulcus
Each hemisphere has superficial cortex of gray matter and internal white matter with islands of gray matter called what?
Basal Nuclei
This has billions of neurons arranged in 6 layers.
Cerebral Cortex
52 cortical areas described by thickness and structure of cortex are called? Roughly matches major functions of the cortex.
Brodmann Areas
What is the cerebral cortex and what are it’s are the 3 functional areas?
The outermost layer of the brain. Grey matter arranged in 6 layers.
- Motor
- Sensory
- Association
Each hemisphere of the cerebral cortex controls____ side of the body.
Contralateral (opposite)
The hemispheres of the cerebral cortex are not equal in function.
Lateralization
Which part of the brain hold the motor areas of the cerebral cortex?
Posterior parts of the frontal lobe
What are the 4 motor areas of the cerebral cortex?
- Primary Motor Cortex
- Premotor Cortex
- Broca’s Area
- Frontal Eye Field
This motor area contains the precentral gyrus, and the pyramidal cells control voluntary movements and send axons to spinal cord in pyramidal tracts.
Primary Motor Cortex
This motor area controls learned motor skills and planning motor behaviors.
Premotor cortex
This is the motor speech area and controls muscles for speech.
Broca’s Area
This motor area controls voluntary eye movement.
Frontal Eye Field
What are the sensory areas of the cerebral cortex? Where are they found?
- Olfactory cortex- uncus
- Gustatory cortex- insula
- Visceral sensory cortex- insula
- Vestibular cortex- insula
This is a sensory area receives emotional inputs from olfactory centers and limbic system.
Olfactory Cortex
This is a primitive part of the cerebrum containing olfactory centers and limbic system (control of emotions)
Rhinencephalon
This sensory area receives taste sensation inputs.
Gustatory Cortex
This sensory area receives input perception from internal organs sensation.
Visceral Sensory Cortex
This sensory area receives input on balance.
Vestibular Cortex
This association area of the cortex is in charge of personality, cognition, judgement, reasoning and planning.
Anterior association area
This association area of the cortex is in charge of recognition, all senses and attention to location of body and objects in space.
Posterior Association area
This association area of the cortex controls emotions.
Limbic association area
Connecting fibers for communication between parts of the cerebral cortex and also with rest of the CNS.
Cerebral White Matter
This connecting fiber of the cerebral white matter connects the right and left hemispheres.
Commissures
This is a broad band of nerve fibers joining the 2 hemispheres of the brain. It is the largest commissure and superior to lateral ventricles.
Corpus Callosum
This is a type of connecting fiber that connects different parts (gyrus to gyrus) of the same hemisphere.
Association Fibers
This is a type of connecting fiber that connects lower brain centers and spinal cord to cortex.
Projection Fibers
This is a compact band of projection fibers passing between thalamus and basal nuclei.
Internal Capsule
These are fibers fanning out from the internal capsule to connect cortex. They carry information from muscles and skin to the brain and carry motor commands from the brain to the body.
Corona Radiata
This is also called the subcortical nuclei. It is involved in the stopping, starting and monitoring of movements. It is functionally associated with the subthalamic nuclei and the substantia nigra.
Basal Nuclei
The basal nuclei is composed of which 3 parts.
- caudate nucleus
- putamen
- globulis pallidus.
All three parts of the basal nuclei together form what?
Corpus stratium
What are 2 diseases that affect the basal nuclei?
- Huntingtons -stopping movement
2. Parkinsons- starting movement
This portion of the brain is on top of the brain stem and is composed of the thalamus, hypothalamus and the epithalimus.
Diencephalon
This is an egg shaped nuclei in the lateral walls of the third ventricle. All information is sorted and edited here.
Thalamus
What is the main purpose of the thalamus?
All sensory inputs are sorted and edited and then certain information is sent to the cerebrum. Some information can bypass the thalamus and go straight to the cerebrum but still has to pass through it.
This is a portion of the diencephalon below the thamalus. It is smaller and in the inferolateral walls of the third ventricle. It is the main visceral and homeostatic control center. Endocrine system control.
Hypothalamus
What are the 2 main structures of the hypothalamus?
- Mammillary bodies
2. Infundibulum
These are found on the inferior surface of the hypothalamus and are the olfactory relay nuclei.
Mammillary bodies
This connects the pituitary gland to the hypothalamus and is found between the optic chiasm and the mammillary bodies.
Infundibulum
This structure includes the pineal body and the roof of the third ventricle. it produces meletonin to regulate sleep-wake cycle.
Epithalamus
This controls rigidly programmed, automatic behaviors. It is where most cranial nerves enter and exit.
Brainstem
The brainstem is composed of what 3 structures?
- Midbrain
- Pons
- Medulla Oblongata
This structure of the brainstem is found between the diencephalon and the pons.
Midbrain
This aspect of the midbrain is dominated by the cerebral peduncles (“little feet”)
Ventral Aspect
This aspect of the midbrain is made up of superior cerebral peduncles which connect midbrain to cerebellum.
Dorsal Aspect
This part of the midbrain separates the cerebral peduncles from the tectum or roof of the midbrain.
Cerebral Aqueduct
This portion of the midbrain is 4 dome shaped bumps on the dorsal surface including the superior and inferior colluculi.
Corpora Quadrigemina
This is the dopamine producing neurons of the midbrain connected to basal nuclei.
Substantia Nigra
This part of the midbrain relays neurons that affect limb flexion and is a useful tool in triage assessment of unconscious individuals.
Red nucleus
This structure of the brainstem is found between the midbrain and the medulla oblongata “bridge”. It is a conduction pathway going from upper portions of the brain to lower portions and vice versa.
Pons
This structure of the pons is the relay center between the motor cortex and the cerebellum.
Pontine nuclei
This structure of the pons connects the pons and the cerebellum.
Middle cerebral peduncles
This structure of the brainstem is between the pons and the spinal cord.
Medulla Oblongata
This aspect of the medulla oblongata are pyramids that crossover fibers from right to left.
Ventral aspect
This occurs at the ventral aspect of the medulla oblongata and is the crossover of fibers from left to right and vice versa at the medulla-spinal cord junction.
Decussatoin of the pyramids
This part of the medulla oblongata connects the medulla and the cerebellum.
Inferior Cerebral Peduncles
This part of the medulla oblongata relays information on stretch of muscles.
Inferior Olivary Nuclei
This part of the medulla oblongata relays auditory information.
Cochlear Nuclei
This part of the medulla oblongata relays balance informaiton.
Vestibular Nuclei
This center of the medulla oblongata control the force and rate of heart contrations and regulates blood pressure.
Cardiovascular Center
This center of the medulla oblongata controls rate, depth, and rhythm of breathing.
Respiratory Center
The medulla oblongata is the regulation center for what actions?
Vomiting Hiccuping Swallowing Coughing Sneezing
This is the second largest part of the brain. It controls timing and patterning of skeletal muscles for smooth coordinated movements. It helps with coordination of movement and keeping us balanced.
Cerebellum
The cerebellum hemispheres are connected by medial ____
Vermis
The cerebellum is divided into what 3 lobes? And what are their main functions?
Anterior- influence motor activities of the trunk and girdle muscles.
Posterior- influence distal parts of the limbs and skilled movements involved in planning movement.
Flocculonodular- adjusts posture to maintain balance
The inner gray matter of the cerebellum is called what? Grey matter version of the arbor vitae in white matter.
Folia
These are large neurons that synapse with dentate nuclei in the cerebellum. They are in between the outer grey matter and the internal white matter.
Purkinje cells
This is distinctive branched tree like white matter tracts within the cerebellum.
Arbor vitae
This lobe of the cerebellum adjusts posture to maintain balance.
Flocculonodular lobe
These connect the cerebellum to the brain stem and are ipsilateral fibers. They allow communication between the cerebellum and other parts of the CNS.
Cerebellum peduncles
This encircles the upper brain stem and is a complex system of nerves and networks in the brain that control basic emotions and drives.
Limbic system
This part of the limbic system recognizes danger and fear.
Amygdaloid
This part of the limbic system controls emotional expressions and resolving mental conflicts. It’s why you smile when happy or frown when upset.
Cingulate gyrus
This part of the limbic system is the center of emotion.
Hippocampus
Is a diffuse network of nerve pathways in the brain stem connecting the spinal cord, cerebellum, and cerebrum and controls arousal of the brain. Can be inhibited by sleep centers.
Reticular formation
This records general electrical activity in different areas of the brain.
Electroencephalogram (EEG)
These are patterns of neuronal activity in the cortex.
Brain waves
What are the 4 types of brain waves?
Alpha
Beta
Theta
Delta
This brain wave indicates a calm relaxed state of wakefulness.
Alpha wave
This brain wave indicates concentrations to one particular thing.
Beta wave
This type of wave is common in children but not adults. Will see if an adult is intensely frustrated.
Theta waves
This type of brain wave indicates deep sleep or brain damage (in awake adults)
Delta waves
What is the clinical continuum of consciousness?
Alertness—> drowsiness/lethargy—> stupor—> coms
Sleep cycle is controlled by the______.
Hypothalamus
What are the 2 types of sleep?
Non rapid eye movement (NREM)
Rapid eye movement (REM)
REM sleep occurs after stage ___ NREM sleep which is the dreaming stage.
4
Nightmares originate in which 2 stages of NREM?
3&4
Which is the shortest REM period?
The longest?
First period
Last period
Why is REM sleep important?
For normal cognitive function
This is loss of language ability due to damage of the brain.
Aphasia
Functions linked to speech. Lesions leading to loss of speech but understanding is spared.
Brocas area
Important for language development. Lesions lead to the inability to understand language but speaking is unaffected.
Wernickes area
This is working memory and is limited in capacity. An example is remembering a phone number you just looked up.
Short term memory.
This is permanent storage with unlimited capacity.
Long term memory
The transfer of information from short term to long term memory depends on what 4 things?
- Emotional state
- Rehearsal
- Association
- Automatic memory
What are the two categories of memory? Which is easy to forget?
Declarative- facts- easy to forget
Nondeclarative- experiences- hard to forget
A occurs during learning and is a persistent strengthening of synapses based on recent activity. The number and size of presynaptic terminals may increase and more neurotransmitter is released.
Long term potentiation (LTP)
These are 3 membranous envelopes that surround the brain and spinal cord. They protect blood vessels and enclose venous sinuses.
Meninges
What are the 3 meningeal membranes in order from superficial to deep?
Dura mater
Arachnoid mater
Pia mater
This is meningeal later that is a thick two layered fibrous connective tissue and is most superficial.
Dura mater
These are the 2 layers of dura mater? One is the inner surface of the dura mater called? One is the external covering of CNS?
Periosteal layer
Meningeal layer
The meningeal layer of the dura mater contains what two structures?
Dural sinuses- collect venous blood
Dural septa- partitions dividing cranial cavity.
What are the 3 partitions of the dural septa? What do they separate?
Falx Cerebri- cerebral hemispheres
Falx Cerebelli- midline partitions over cerebellum- vermis
Tentorium cerebelli- cerebellum from cerebrum
Weblike extensions of arachnoid span this space containing cerebrospinal fluid
Subarachnoid space
These protrude through the dura into the superior Sagittarius sinus to allow the absorption of CSF into the blood.
Arachnoid villi
This is a delicate connective tissue that adheres to be outer layers of the brain and spinal cord.
Pia mater
This fluid helps protect the CNS from trauma, helps to nourish it and carries chemical signals from one part of the brain to another.
Cerebrospinal fluid
Cerebrospinal fluid is made by what? And is made up of what type of cells?
Choroid plexus in the roof of each ventricle.
Ependymal cells
This is a protective mechanism to maintain stable brain environment. It is made up of astrocytes.
Blood brain barrier
Blood is separated from the brain by what 3 aspects?
- Endothelium of capillaries
- Thick basal lamina
- Astrocytes wrapping capillaries
The blood brain barrier is a selective barrier only allowing what to pass through?
- Glucose
- Essential amino acids
- Some electrolytes
This is a progressive form of dementia that usually effects the cortex first. Memory is first lost and as it worsens it becomes lethal.
Alzheimer’s disease
This is a loss of dopamine neurons in the SN.
Parkinson’s disease
This is degeneration if the basal nuclei.
Huntington’s chorea
What are the 2 plates of the spinal cord?
Roof (alar) plate
Floor plate
This plate of the spinal cord is made of interneurons.
Roof (alar) plate
This plate of the spinal cord has motor neurons and interneurons.
Floor plate
What is the function of the two plates of the spinal cord?
Releases chemical signals to generate different types of spinal neurons.
The spinal cord extends from ____ to ____.
Medulla to L1-2 vertebra
The spinal cord terminates as the _____?
Conus medularris
This connects the conus medullaris to the coccyx.
Filum terminale
There are ____ pairs of spinal nerves that attach to the cord by dorsal and central roots.
31
This part of the spinal cord control limb muscles.
Cervical and lumbar enlargements.
This is the lumbar and sacral nerves at the inferior end of the spinal cord
Cauda equina
Central roots of the spinal cord have motor neuron _____.
Axons
Dorsal roots of the spinal cord have axons from ____ sensory neurons.
Peripheral
This is the fusion of ventral and dorsal roots.
Spinal nerve
These are cell bodies of sensory neurons in the spinal cord.
Dorsal root ganglia
What are the 4 gray matter zones of the spinal cord?
- Somatic sensory
- Somatic motor
- Visceral sensory
- Visceral motor
These are major pathways between the brain and the periphery and are divided into 3 funiculi each of which contains several tracts of axons.
White matter tracts
Most spinal tracts cross from one side to the other… this is known as?
Decussate
This is a sensory/nerve pathway that goes upward from the spinal cord toward the brain carrying sensory information from the body to the brain.
Ascending pathways
This ascending pathway is sensory to pain and temperature.
Lateral spinothalamic
This ascending pathway is sensory to crude touch and pressure and is under the ventral horns.
Anterior spinothalamic
This ascending pathway is sensory to discrimative touch, pressure and body sense. This would be the ability to determine if 2 places are being touched at the same times and can test for spinal cord injry.
Fasciculus cuneatus and faciculus gracilis
What are the two ascending pathways in the cerebellum?
- Posterior spinocerebellum
2. Anterior spinocerebellum
This is a sensory/nerve pathway that goes down the spinal cord and allows the brain to control movement of the body below the head.
Descending Pathways
This descending pathway are pyramidal cells of motor cortex and neurons of subcutical nuclei (brain).
Upper Motor Neurons
This descending pathway is ventral horn motor neurons located in either the anterior grey column, anterior nerve roots (spinal lower motor neurons) or the cranial nerve nuclei of the brainstem and cranial nerves with motor function (spinal cord)
Lower Motor Neurons
This is a direct descending pathway that connects upper motor neuron (pyramidal cells) with lower motor neurons (motor neurons and interneurons).
Corticospinal (pyramidal)
This is a descending pathway that the head moves in response to visual stimuli.
Tectospinal
This is a descending pathway that maintains balance.
Vestibulospinal
This is a descending pathway that controls flexor muscles (red nucleus).
Rubrospinal
This is a descending pathway that visceral muscle controls (reticular formation).
Reticulospinal
This is a type of paralysis where damage to ventral root or horn causes complete relaxation of muscle.
Flaccid paralysis
This is a type of paralysis where there is damage to the upper motor neurons causing complete contraction.
Spastic paralysis
This is a type of paralysis where there is transection between T1-L1 and effects the lower limbs.
Paraplegia
This is a type of paralysis where all limbs area effected.
Quadriplegia
This is where the polio virus destroys the ventral horn motor neurons.
Poliomyelitis
This is a progressive destruction of upper and lower motor neurons, also known as Lou Gehrig’s Disease.
Amyotrophic Lateral Sclerosis (ALS)