Unit 1_Spinal Cord and Brainstem Structures Flashcards
What important names are associated with what is termed the “five vesicle” brain?
Myelencephalon = Medulla
Metencephalon = Pons and Cerebellum
Mesencephalon = Midbrain
Diencephalon = Thalamus, Hypothalamus, Subthalamus (subthalamic n.), Epithalamus
Telencephalon = Cerebrum and most of Basal Ganglia
What vesicle gives rise to the Medulla?
Myelencephalon
What vesicle gives rise to the Pons and Cerebellum?
Metencephalon
What vesicle gives rise to the Midbrain?
Mesencephalon
What vesicle gives rise to the Thalamus, Hypothalamus, Subthalamus (subthalamic n.), Epithalamus?
Diencephalon
What vesicle gives rise to the Cerebrum and most of Basal Ganglia?
Telencephalon
At what point in the embryo/fetus does the ventricle system begin to take shape?
50 days
At what point in the embryo/fetus does the facial features begin to take shape?
100 days
At what point in the embryo/fetus does the typical lateral ventricle appear?
5-6 months
At what point in the embryo/fetus does the lateral ventricle shape appear?
9 months
At what point in the embryo/fetus do internal structures/C-shape gives rise to insular cortex where the brain is folded in?
8 months
The developing CNS is susceptible to damage into when?
Into early adolescence
What is the process by which congenital malformations are produced in an embryo or fetus?
Terateogenesis
Which structures make up the brainstem from caudal to rostral?
- Medulla
- Pons
- Midbrain
What sits dorsal to the fourth ventricle?
Cerebellum
What information do the Cuneate tubercle and the Gracile tubercle on the dorsal surface of the brainstem carry?
Sensory information
What information do the pyramids on the ventral surface of the brainstem carry?
Motor information
What forms at the level of the foramen magnum where the the spinal cord is rostrally continuous with the first level of the brainstem? This area is structurally similar to the spinal cord especially at its caudal end.
Medulla Oblongata
In the medulla and throughout the brainstem, what is often organized into structures called nuclei?
Gray matter
What represents the cell bodies of a functionally related group of neurons and associated structures (e.g., cranial nerve nuclei)?
A nuclei
What continue to course through the medulla transmitting ascending and descending information?
White matter (axon) tracts
What continues into the medulla and at the rostral end of the medulla it widens and opens up to form the fourth ventricle?
The central canal
What two components can the medulla be divided into?
A closed caudal medulla and an open rostral medulla
What component of the medulla is more caudal?
Closed medulla
What component of the medulla is more rostral?
Open medulla
What is found on the ventral surface of the medulla and is continuous with the ventral median fissure of the spinal cord?
Ventral Median Fissure
What is interrupted by the DECUSSATION OF THE PYRAMIDS at the spinomedullary junction?
Ventral Median Fissure
In addition to the Ventral Median Fissure, what also continues into the medulla from the spinal cord?
The VENTROLATERAL SULCUS
What lies between the ventral median fissure and the ventrolateral sulcus on each side and is a prominent swelling?
Pyramids
What composes the pyramids that are made up of bundles of nerve (axons) fibers which originate in the motor and sensory cerebral cortices and descend to innervate neurons in the brainstem and spinal cord?
CORTICOSPINAL/CORTICOBULBAR TRACTS
What connect two or more regions of the CNS; Usually named by where they start and where they finish?
CORTICOSPINAL/CORTICOBULBAR TRACTS
What three cranial nerves exit the brainstem at the junction of the pons and medulla on the ventral surface?
- ABDUCENS (VI)
- FACIAL (VII)
- VESTIBULOCOCHLEAR (VIII)
What nerve emerges from the ventral medulla posterior to the pyramid in the ventrolateral sulcus?
The HYPOGLOSSAL nerve (XII)
What also continues up into the medulla on the dorsal surface from the spinal cord?
DORSAL MEDIAN SULCUS
DORSAL LATERAL SULCUS
DORSAL INTERMEDIATE SULCUS
What continues into the lower (caudal) half of the medulla and widen in the upper (rostral) medulla to form the CUNEATE TUBERCLE and the GRACILE TUBERCLE?
The FASCICULUS CUNEATUS and the FASCICULUS GRACILIS
What are the CUNEATE TUBERCLE and the GRACILE TUBERCLE produced by which are involved in light touch and proprioception?
The underlying CUNEATE AND GRACILE NUCLEI
What is found in the lateral area between the ventrolateral and the dorsolateral sulci?
Olive
What is a large olive shaped swelling on the ventrolateral surface produced by the underlying INFERIOR OLIVARY NUCLEUS? This nucleus has a major role in motor learning.
Olive
What three cranial nerves exit the medulla dorsal to the olive and can be seen from either the ventral or lateral view of the brainstem?
- GLOSSOPHARYNGEAL (IX)
- VAGUS (X)
- CRANIAL ROOT OF THE ACCESSORY NERVE (XI)
What medulla feature located in a closed medulla helps shape receptive fields and send sensory information to thalamus?
Cuneate
What medulla feature located in a closed medulla helps shape receptive fields and send sensory information to thalamus?
Gracile
What medulla feature scattered throughout open and closed sections handles cardiovascular regulation and pain modulation?
Reticular
What medulla feature located in a open medulla handles motor learning?
Inferior Olivary
Which part of the neuron is reponsible for receiving signals from other neurons or tissues?
Dendrites
Which specific system of branch of the broad nervous system controls vital functions for homeostasis?
Autonomic Nervous System
Which of the following glial cells is responsible for providing neurons with myelin in the Central Nervous System?
Oligiodendrocytes
White matter in the central nervous system is made up of what structures?
Axons
What best describes ganglia?
Collection of cell bodies in the peripheral nervous system
What is the middle component of the brainstem? The boundaries on the ventral surface are obvious. On the dorsal surface, the rostral boundary is the inferior (caudal) margin of the inferior colliculus, and the caudal boundary is difficult to demarcate. It lies anterior (ventral) to the cerebellum, rostral to the medulla oblongata and caudal to the midbrain. The superior half of the fourth ventricle lies dorsal and separates it from the cerebellum.
Pons
What is the anterior surface of the pons and the surface shows many transverse fibers that converge on each side to form the middle cerebellar peduncles?
Convex
What is the shallow groove in the midline of the ventral pons? The basilar artery sits in this groove.
BASILAR GROOVE
What large nerve exits the brainstem from the ventrolateral surface of the pons?
The TRIGEMINAL nerve (V)
What is a shallow cavity overlying the pons and medulla with these structures forming the floor of the ventricle? It extends from the central canal of the spinal cord to the cerebral aqueduct of the midbrain.
4th Ventricle
On the dorsal surface of the pons, what structure connects the pons with the cerebellum?
Cerebellar Peduncles
On the dorsal surface of the pons, what structure do we have to cut in order to see the 4th ventricle?
Cerebellum/Cerebellar Peduncles
Where on the pons are the pontine nuclei and longitudinal and transverse fibers found?
The ventral portion of the pons
What is a major relay station in the pons, connecting the cerebral cortex with the cerebellum on the opposite side?
The ventral portion of the pons
What do the longitudinal fibers in the ventral portion of the pons consist of which originated in the motor cortex and are descending to cells in the brainstem and spinal cord? This will continue through the medulla in the pyramids (made of white matter).
Axons from the CORTICOSPINAL/CORTICOBULBAR TRACT
What do the transverse fibers in the ventral portion of the pons consist of that cross the midline and form the opposite middle cerebellar peduncle (PONTOCEREBELLAR FIBERS)?
Axons from the pontine nuclei
What is the dorsal portion of the pons structurally similar to with the continuation of several tracts and the presence of cranial nerve nuclei?
The medulla
What structure in the medulla contains the CORTICOSPINAL tract?
Pyramids
Where are the corticobulbar tracts traveling to from the ventral pons?
Cranial nerves
When a patient has bulbar signs and symptoms, including cranial nerve impairments, mostly relating to speech and swallowing difficulties, visual changes, motor and sensation on the face, what is it due to?
Cranial nerve involvement or corticobulbar tract involvement
What is the most rostral portion of the brainstem connecting the pons and cerebellum with the cerebral cortex?
The midbrain
What is transversed by the cerebral aqueduct containing cerebrospinal fluid?
The midbrain
What extends from the pons to the mammillary bodies of the diencephalon on the ventral surface and from the inferior border of the inferior colliculi to the thalamus and pineal body on the dorsal surface?
The midbrain
On the dorsal surface, what is the most rostral portion of the midbrain?
The colliculi
On the ventral aspect of the midbrain, what is a deep depression in the midline called, bounded by the CRUS CEREBRI OR base of CEREBRAL PEDUNCLES?
INTERPEDUNCULAR FOSSA
What paired nerves emerge from the midbrain just lateral to the interpeduncular fossa?
OCULOMOTOR NERVES (III)
On the dorsal aspect of the midbrain, what are the four round bumps known as?
COLLICULI
On the dorsal aspect of the midbrain, what are important centers in the visual system for reflexive eye control and control of head posture?
SUPERIOR COLLICULI
On the dorsal aspect of the midbrain, what are important for the auditory system?
INFERIOR COLLICULI
On the dorsal aspect of the midbrain, what are the only cranial nerves that emerge from the dorsal aspect of the brainstem and they emerge just inferior to the inferior colliculi?
TROCHLEAR nerves (IV)
In cross section, the midbrain can be seen to consist of what two separate parts?
TECTUM
TEGMENTUM
In cross section, what part of the midbrain can be seen to consist as the roof that lies dorsal to the cerebral aqueduct and consists mainly of the paired colliculi?
TECTUM
In cross section, what part of the midbrain is ventral to the aqueduct and it contains the ascending and descending tracts (including corticobulbar/corticospinal), nuclei of cranial nerves, and other nuclei?
TEGMENTUM
What area of the midbrain is important to individuals with Parkinson’s Disease and is the dopamine (with melanin) producing center?
Substania Niagra
In the midbrain, what surrounds the cerebral aqueduct and is a place where neural pathways are involved with pain?
Periaqueductal Gray
What area in the midbrain is the red nucleus located?
Rostral