Introduction to Neuroscience Flashcards
What type of neuroscience is the most important for us as clinicians?
Systems neuroscience - functional groups/interactions
What does rostral mean?
Towards the nose
What does caudal mean?
Towards the tail
True or False
The longitudinal axis of the forebrain is perfectly horizontal.
False
The rostral end is tipped superiorly, and the caudal end is tipped inferiorly
What is the first division of the nervous system?
PNS: all nervous system structures not encased in bone/meninges
CNS: spinal cord, brainstem and cerebellar region, and cerebral region
If you want to test a spinal nerve, will you test a dermatome or a peripheral nerve distribution?
You would test a dermatome. A dermatome is an area of skin that sends signals to the brain using a specific spinal nerve.
You want to test the obturator nerve. Would you test a dermatome or a peripheral nerve field?
You would test a peripheral nerve field. A peripheral nerve is outside of the brain and spinal cord and relays information between the brain and the rest of the body.
Where are the most diagnostic regions to test?
Hands and feet are the most diagnostic areas.
You are looking at a cadaver brain. One area appears to be a darker gray, and one area appears to be a lighter gray. What can you determine about these areas?
The darker gray portion is called gray matter. It is darker because it is made up of cell bodies and dendrites that are denser because they hold all the organelles.
The lighter portion is called white matter. It is made up of axons. The axons are covered in myelin which is made up of fat and protein. The fat makes them look white.
What is the function of the gray matter?
Information is integrated and processed in gray matter because it happens in the cell bodies.
What is the function of white matter in the brain?
The white matter is made up of axons, so its function is information transmission. Axons perform efferent transmission from the cell body.
The cerebellum is an outgrowth of…
The pons. It also has some connection to medulla and cerebrum.
The central region is made up of... A) Dermatomes and myotomes B) Spinal cord C) Cerebrum D) Peripheral nerve regions E) Brainstem and cerebellum
B, C, and E
List the three basic functions of the nervous system.
- Information coming in - afferent/sensory
- Processing information - integration by gray matter
- Information going out - efferent/motor (occurs when the gray matter decides to take action)
Which of the three basic functions of the nervous system do reflexes skip?
Reflexes bypass the integration of information. They don’t require the forebrain.
What is the difference between a polysynaptic and a monosynaptic reflex?
Polysynaptic reflexes involve an interneuron. A monosynaptic reflex does not use an interneuron.
Which direction do afferent neurons carry information?
Afferent neurons carry information toward the CNS.
Efferent axons carry information…
away from the CNS.
Describe the pattern of all somatic sensory and visceral sensory neurons.
There is a single axon that goes all the way to the CNS. The cell body is close to but not in the CNS.
What pattern do somatic motor neurons have?
The cell body is in the CNS. The neuron extends all the way to the muscle without synapsing.
Describe the pattern of autonomic - visceromotor neurons.
The pre-synaptic ganglion is inside the CNS. The pre-ganglionic neuron extends from this and synapses with a relay ganglion. From the relay ganglion, the post-ganglionic neuron extends to the organ.
True or False
The adrenal medulla is a ball of post-ganglionic neurons.
True. It turns your blood into a post-ganglionic synapse.
Which nervous system divisions only use one neuron receptor to CNS? A. Somatic sensory B. Visceral sensory C. Somatic motor D. Visceral motor
A, B, and C
Which nervous system divisions use two neurons? A. Somatic sensory B. Visceral sensory C. Somatic motor D. Visceral motor
D
True or False
The horns of the spinal cord are mixed regions of the nervous system.
False.
The horns are complete divisions of the nervous system. The peripheral nerves are mixed, but they split near the spinal cord.
What type of matter is in the middle of the spinal cord?
Gray matter makes up the center of the spinal cord. It is in the shape of an H and surrounded by white matter.
The dorsal horn is…
A. Visceromotor
B. Somatic motor
C. Sensory
C.
The dorsal horn is sensory input/synapses. There are no motor nerves here. Sensory cell bodies are in dorsal root ganglia, but you find interneurons here.
The lateral horn is…
A. Visceromotor
B. Somatic motor
C. Sensory
A. Visceromotor cell bodies
The ventral horn is…
A. Visceromotor
B. Somatic motor
C. Sensory
B. Somatic motor cell bodies
There is no sensory information.
Describe the difference between spinal region symptoms and spinal tract symptoms in an injury.
Damage to the spinal cord gives you spinal region symptoms and spinal tract symptoms. These are different. A spinal region involves integration and processing at that spinal level. If you get an injury at C6, you will get regional signs. You’ll also see that sensory tracts ascending from that region don’t function as well, and motor tracts descending from that level don’t function well either.
Is there more white matter at the top or bottom of the spinal cord?
White matter builds up going up the spinal cord, so there is more at the top.
What does the dorsal horn consist of?
Cell bodies of interneurons and the endings of sensory neurons.
Is the dorsal horn sensory or motor?
Sensory
What does the ventral horn contain?
Somatic motor cell bodies
Is the ventral horn sensory or motor?
Motor
What kind of neurons are in the lateral horn?
Cell bodies of autonomic motor neurons
What are the two main functions of a spinal “region”?
- To convey information between the neurons innervating peripheral structures and the brain
- To process information
A spinal “region”…
Conveys somatosensory information to the brain and also conveys signals from the brain to neurons that directly control movement.
Where are reflexes processed?
They are processed in the spinal “region”
Is the lateral horn…
A. Sensory ganglion
B. Visceromotor ganglion
C. Somatic motor ganglion
B. Visceromotor ganglion
True or False
Spinal white matter ascending tracts carry motor control/coordination from above.
False
Spinal white matter ascending tracts carry sensory information from below.
What do descending white matter tracts carry?
Descending white matter tracts carry motor control/coordination from above.
Which column of white matter is purely sensory tracts?
The dorsal column
Which two columns of white matter are a mixture of sensory and motor?
The lateral and anterior columns
What is contained in the brainstem?
- Contains all sensory pathways coming up
- Contains all motor pathways going down
- Contains the nuclei of cranial nerves 3-12
- Many white matter tracts travel through
- Many tracts beginning or ending at groups of neuron c.b. (nuclei) that control equilibrium, cardiovascular activity, respiration, and other functions.
At what level do 80% of axons enter and exit the cerebellum?
80% of axons entering or exiting cerebellum do so at the level of the pons
What does the cerebellum consist of?
Two large cerebellar hemispheres and a midline vermis
The cerebellum connects to the posterior brainstem by large bundles of fibers called…
Peduncles
- Superior, middle, and inferior peduncles join the midbrain, pons, and medulla with the cerebellum
The cerebellum coordinates movements and has three other functions. What are they?
- Equilibrium
- Subconscious proprioception
- Helps smooth motion and with balance
What four structures make up the cerebrum (diencephalon)?
- Thalamus
- Hypothalamus
- Epithalamus
- Subthalamus
Is the diencephalon part of the…
A. Forebrain
B. Midbrain
C. Hindbrain
A. Forebrain. It is the core of the forebrain.
True or False
The thalamus is the primary motor processing.
False
The thalamus is the primary sensory processing. It sends info where it needs to go.
What motor role does the thalamus play?
It coordinates some motor activity. Motor activity does not begin here. It is more like a relay center.
What types of information does the thalamus relay to the cerebral cortex?
It processes emotional and some memory information. It integrates different types of sensation or regulates consciousness, arousal, and attention.
True or False
The hypothalamus is the primary sensory processing.
False
The hypothalamus is the main visceral info processing center. It is the top of the autonomic control system.
What does the hypothalamus do?
Maintains body temperature, metabolic rate, and chemical composition of tissues and fluids.
How is the posterior pituitary connected to the hypothalamus?
The posterior pituitary is a neural extension of the hypothalamus.
What is the epithalamus made up of?
The epithalamus is mostly the pineal gland.
What does the pineal gland do?
Influences the secretion of other endocrine glands. It secretes melatonin.
Where is the subthalamus located?
Inferolateral to the thalamus. It connects diencephalon to basal ganglia
What is the function of the subthalamus?
Controls some movement.
The thalamus is…
A. Somatic
B. Circadian rhythms
C. Visceral
A. Somatic
The hypothalamus is…
A. Somatic
B. Circadian rhythms
C. Visceral
C. Visceral
The epithalamus is…
A. Somatic
B. Circadian rhythms
C. Visceral
B. Circadian rhythms
The cortex is where…
Rational thought and higher processing occurs
What type of information does the cerebral cortex process?
It processes sensory, motor, and memory information.
Reasoning, language, nonverbal communication, intelligence, and personality occur where?
In the cerebral cortex
What are the three nuclei of the basal ganglia in the cerebral hemispheres?
- Caudate
- Putamen
- Globus pallidus
The lenticular nucleus is made up of what?
Putamen and the globus pallidus
The caudate and the putamen =
Corpus striatum
True or False Subthalamic nucleus (in the diencephalon) and the substantia nigra (in the midbrain) are also parts of the basal ganglia.
True!
What function does the limbic system serve?
Emotional processing and memory
The limbic system is a
A. Structural group
B. Functional group
B. Functional group
Functional group of structures located in the diencephalon and cerebral hemispheres
The limbic system includes…
Parts of the
- hypothalamus
- thalamus
- cerebral cortex
- several deep cerebral nuclei
- and the hippocampus
What is cerebrospinal fluid composed of?
Cerebrospinal fluid (CSF) is modified filtrate of plasma
Describe the flow of CSF
Circulates from cavities inside the brain to surface of the CNS and is absorbed into the venous blood system
Interventricular foramen drains which ventricles?
Fluid can only leave the lateral ventricles through the interventricular foramen
How does CSF flow from the third ventricle to the fourth ventricle?
It flows through the cerebral aqueduct
What releases CSF into the arachnoid layer from the 4th ventricle?
Median aperture and lateral aperture
What function does the central canal serve?
It is very small and extends through the spinal cord. It allows drainage from the 4th ventricle.
True or False
The pair of lateral ventricles are located in the diencephalon.
False!
The pair of lateral ventricles are located in the cerebral hemispheres.
The third ventricle is a midline slit in the diencephalon.
Fluid is collecting posterior to the pons and medulla and anterior to the cerebellum. Which ventricle is it in?
The fourth ventricle.
CSF has... A. More platelets than plasma B. No platelets C. Fewer clotting factors than plasma D. More clotting factors than plasma E. Both B and C F. Both A and D
E. Both B and C
Where is CSF produced and by what?
CSF is produced in the ventricles and secreted by the choroid plexus.
What condition does hydrocephalus describe?
Hydrocephalus is when there is blockage and too much fluid in a ventricle.
How does CSF leave the fourth ventricle?
CSF leaves the fourth ventricle through the lateral foramina and the medial foramen to circulate around the CNS.
The brain is covered by three meninges. What are they?
- Dura mater
- Arachnoid
- Pia mater
A patient’s meninges tears away from the skull. Which meninges is this affecting?
Mainly the dura mater. The dura mater has two layers that are pushed up against the skull. The periosteal layer is closer to the skull than the meningeal layer.
How does the dura mater keep the veins open and collect blood?
The dura mater creates the dural venous sinuses when it creates a gap between the two dura. These keep the veins open and collect blood. It creates negative pressure outside the veins to keep them open since the pressure inside the veins is so low.
