Neurology Flashcards
Canine Brain
Canine Brain
Canine Brain
Which cranial nerves are associated with the oral cavity and pharynx?
Trigeminal nerve (CN V), glossopharyngeal nerve (CN IX), vagus nerve (CN X)
These nerves are connected via the solitary fasciculus (aka solitary tract or tractus solitarius or fasciculus solitarius is a compact fiber bundle that extends longitudinally through the posterolateral region of the medulla oblongata).
Where is the swallowing center located?
In the lateral reticular formation
Upper motor neuron
What muscles in regard to the tongue does the Trigeminal nerve (CN V) innervate?
Mylohyoideus and digastricus muscles
These muscles control the elevation of the base of the tongue.
Which cranial nerve innervates the voluntary muscles of the oral cavity?
Facial nerve (CN VII)
What does the Glossopharyngeal nerve (CN IX) innervate?
The Pharynx
Which structures does the Vagus nerve (CN X) innervate?
Pharynx, Larynx (via recurrent laryngeal nerve), Esophagus
What does the Hypoglossal nerve (Cranial Nerve XII) innervate?
The Tongue
What is the nature of the respiratory center mentioned in regardess to swallowing center?
Inhibitory
What type of swelling is cytotoxic edema?
Intracellular swelling in presence of normal blood-brain barrier
Cytotoxic edema is a type of brain swelling that occurs when cells in the brain take in excessive water, causing them to expand and swell.
What causes cytotoxic edema?
Failure of cell membrane ion pumps leading to excessive entry of sodium and water
Cytotoxic edema is a type of brain swelling that occurs when cells in the brain take in excessive water, causing them to expand and swell.
What conditions are associated with cytotoxic edema?
- Ischemia and hypoxia (contusions, vascular disease, repeated seizures)
- Metabolic disorders
- Intoxication
Cytotoxic edema is a type of brain swelling that occurs when cells in the brain take in excessive water, causing them to expand and swell.
Which cell type is most affected by cytotoxic edema?
Astrocytes
Cytotoxic edema is a type of brain swelling that occurs when cells in the brain take in excessive water, causing them to expand and swell.
What type of brain matter is vasogenic edema largely confined to?
white matter
Vasogenic edema primarily affects the white matter of the brain.
What causes vasogenic edema?
increased vascular permeability
This condition leads to the accumulation of extracellular fluid.
Name the four causes of vasogenic edema.
- Contusion
- Inflammatory disease
- Vascular disease
- Compressive diseases like neoplasia
Each of these conditions can contribute to the development of vasogenic edema.
What does contusion of the spinal cord or brain cause?
Primary mechanical damage to the CNS and initiates a chain of biochemical events
This leads to neuronal and glial cell necrosis and apoptosis (secondary injury) and an inflammatory response.
What is secondary injury in neuronal injury?
Biochemical events following primary injury leading neuronal and glial cell necrosis and apoptosis.
Involves an inflammatory response.
List the changes that occur during secondary injury.
- Intracellular ion increase (Na, Cl, Ca) -> Cytotoxic edema
- Decreased astrocyte uptake of glutamate -> Increased levels of glutamate causing excitotoxicity
These changes lead to cell death.
What is cytotoxic edema?
Swelling of cells due to increased intracellular ions
This is a consequence of secondary injury.
What causes excitotoxicity in neuronal injury?
Increased levels of glutamate due to decreased astrocyte uptake
This results in excitatory cell death.
True or False: Primary injury leads directly to inflammatory response.
False
Primary injury initiates biochemical events that lead to secondary injury and inflammation.
Fill in the blank: The increase of intracellular ions during secondary injury includes _______.
[Na, Cl, Ca]
What is the flow pathway of CSF from the lateral ventricles to the spinal cord?
Lateral ventricles → interventricular foramina → third ventricles → mesencephalic aqueduct → fourth ventricle → subarachnoid space via lateral apertures OR caudally to enter the central canal of the spinal cord
Cerebrospinal fluid (CSF) is primarily produced by the choroid plexus in teh ventricles
Where is CSF located in the central nervous system?
In the subarachnoid space between the arachnoid and the pia mater
What are the main components of CSF?
Ultrafiltrate of plasma
Low protein
Low cellularity
Glucose (lower than peripheral glucose)
Electrolytes
True or False: CSF has a high protein content.
False
low protein
What is the significance of CSF being lower in cellularity compared to peripheral blood?
Indicates a lower immune cell presence in CSF
What is the role of the lateral apertures of the fourth ventricle?
Allows CSF to enter the subarachnoid space
What structure connects the third and fourth ventricles?
Mesencephalic aqueduct
What happens to CSF once it reaches the fourth ventricle?
It can enter the subarachnoid space or the central canal of the spinal cord
Cerebrospinal fluid (CSF) is primarily produced by the choroid plexus in the ventricles.
What are the main functional divisions of the brain?
Forebrain, Brainstem, Cerebellum
These divisions categorize the brain based on functionality.
What is the other name for the Forebrain?
Prosencephalon
The Forebrain is also referred to as the Prosencephalon.
What structures are included in the Telencephalon?
Cerebrum
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Olfactory bulb
The Telencephalon encompasses major regions of the brain.
What is the function of the Corpus callosum?
Interneurons that connect the two hemispheres - coordinate movement
It facilitates communication between the left and right hemispheres of the brain.
What are corticocortical fibers?
Also known as association fibers, are white matter tracts that connect different areas within the same cerebral hemisphere, facilitating communication and integration of information between various cortical regions.
These fibers play a role in integrating information across various brain regions.
What does the Internal capsule connect?
A bundle of nerve fibers, connects the cerebral cortex with the brainstem, spinal cord, and other subcortical structures, acting as a major pathway for both motor and sensory information.
It is a crucial pathway for information traveling to and from the cerebral cortex.
What structures are included in the Diencephalon?
Hypothalamus, Thalamus
The Diencephalon is responsible for relay and control of various autonomic functions.
What is the other name for the Midbrain/ rostral brainstem?
Mesencephalon
The Midbrain is also known as the Mesencephalon and is part of the brainstem.
What is the Rhombencephalon also known as?
Hindbrain
The Rhombencephalon includes structures that are critical for basic life functions.
What is the Metencephalon?
Part of the Rhombencephalon that includes the Pons (ventral brainstem) and Cerebellum
It plays a significant role in motor control and coordination.
What is the Myelencephalon?
Part of the Rhombencephalon that includes the Medulla oblongata (caudal brainstem)
It is responsible for regulating vital functions such as breathing and heart rate.
What connects medulla oblongata to cerebellum?
Inferior peduncle
Vagus nerve % of parasympathetic to body?
75%
Immune/Phagocytic cell of the CNS?
Microglia
Are resident macrophages that act as the first and main form of active immune defense in the brain and spinal cord.
Microglia release what?
Microglial cells release:
* IL-1
* TNF-a
* H2O2
* NO
* Proteinases
The Monro-Kellie doctrine, a fundamental principle in neurophysiology, states that the sum of the volumes of ____ , ____ , and ____ is constant within the rigid skull, meaning an increase in one component necessitates a decrease in the others to maintain a stable intracranial pressure.
- brain tissue
- cerebrospinal fluid (CSF)
- intracranial blood
The Monro-Kellie doctrine, a fundamental principle in neurophysiology, states that the sum of the volumes of brain tissue, cerebrospinal fluid (CSF), and intracranial blood is constant within the rigid skull, meaning an increase in one component necessitates a ____ in the others to maintain a stable intracranial pressure.
Decrease
Which cells make up BBB?
- endothelial cells (tight junctions between cells)
- astrocyte
- a basal lamina
- pericytes
- perivascular microglia
What does the femoral nerve innervate?
- stifle extension (cranial thigh muscles)
- saphenous n. (medial limb sensation)
- hip flexion (rectus femoris)
What signs are noted with injury to the Sciatic nerve innervate?
- Plantigrade (tibial nerve dysfunction)
- Sensation of the paw on the dorsal surface (fibular nerve dysfunction)
however, the limb can support weight if thefemoralnerve is intact because the stifle joint can be extended for weight support.
Patellar reflex test for what major nerve of the hind limb?
Femoral Nerve (L4-L6)
Most reliable reflex
If the patellar tendon reflex is hyporeflexive does it mean UMN or LMN?
LMN
If hyperreflexive = UMN
Withdrawal of the forequater evaluated which vertebral nerves?
C6-T2
* Dorsal Thoracic
* Axillary
* Musculocutaneous
* Median
* Ulnar
* Radial
Flexion Shoulder, Elbow, Carpus, digits
With drawal of the hinWithdrawal of the hindlimbs evaluated which vertebral nerves?dlimbs
L6-S1 - Sciatic n.
- A patient can walk w/ sciatic paralysis but is plantigrade (Tibial n. dysfunction), and paw is misplaced on the dr surface (fibular n. dysfunction)
Can support wt if the Femoral n. is intact (stifle extension)
Cutaneous Trunci
- C8 and T1 → Synapse on LMN of both lateral thoracic n.
- Begins at ilium
Reflex preserved for 1-2 vertebral bodies caudal to the level of the spinal cord lesion - nerves travel cranially before entering the vertebral column
Which cranial nerves exit from cribriform plate and optic foramen.?
I, II
What are the exit points for cranial nerves III and IV?
Orbital fissure
These nerves exit from the midbrain (rostral brainstem).
Which cranial nerve exits through the orbital fissure?
VI
This nerve is associated with the mid and caudal brainstem.
List the exit points for cranial nerve V.
- Ophthalmic → orbital fissure
- Maxillary → round foramen
- Mandibular → oval foramen
This nerve has three branches with different exit points.
Where does cranial nerve VII exit?
Internal acoustic meatus and stylomastoid foramen
This nerve is involved with facial functions.
Which cranial nerve remains within the temporal bone after exiting?
VIII
This nerve exits through the internal acoustic meatus.
What is the exit point for cranial nerves IX, X, and XI?
Tympano-occipital fissure
These nerves exit from the mid and caudal brainstem.
What is the exit point for cranial nerve XII?
Hypoglossal canal
This nerve is involved in tongue movement.
What is the dens or odontoid process, it lies within the vertebral foramen of the atlas and is held by ligaments.
True
What is the function of the transverse ligament?
It prevents dorsal movement into the vertebral canal but allows rotational movement.
Transverse ligament - Yellow
Which bone is the dens connected to by the apical ligament?
The basioccipital bone.
Apical ligament - green
What do the bilateral alar ligaments connect?
They connect the dens to the occipital condyles.
Bilateral alar ligaments - purple
What does the dorsal atlantoaxial ligament join?
It joins the dorsal arch of the atlas and the craniodorsal spine of the axis.
Dorsal atlantoaxial ligament - orange
Based on studies, which ligaments provide the most important stabilization against ventrodorsal shearing?
The alar ligaments.
Bilateral alar ligaments - purple
What is cervical spondylomyelopathy commonly known as?
Cervical Compression
Wobbler syndrome
It is a condition affecting dogs, particularly their cervical spine.
What are the two main forms of cervical spondylomyelopathy (CSM)?
- Osseous-associated CSM (OA-CSM)
- Disc-associated CSM (DA-CSM)
These forms differ based on their underlying causes and the age of the affected dogs.
Which breed type is more commonly affected by osseous-associated CSM (OA-CSM)?
Young giant breeds
OA-CSM is particularly prevalent in large dog breeds during their early development.
Which breed type is more prevalent for disc-associated CSM (DA-CSM)?
Older large breeds
DA-CSM typically affects larger dogs as they age.
Cervical spondylomyelopathy osseous cause?
Cause: Spinal cord compression due to bony structures, particularly the articular processes, surrounding the spinal cord.
Cervical spondylomyelopathy disc associatedcause?
Cause: Spinal cord and nerve root compression due to intervertebral disc protrusion.
Ligament noted during a V-slot approach?
Dorsal longitudinal ligament
Functional Classification of Peripherial Neurons?
Afferent Sensory Somatic
* Somatic
* Visceral
* Proprioceptive
Efferent Motor
* Somatic
* Visceral
Name the Autonomic Plexuses of the Abdominal Region.
- Cellaco mesentric
- Hepatic
- Splenic
- Left gastric
- Phrenic-abdominal
- Adrenal
- Renal
- Cranial mesentric
- Aortic
- Testicular
- Utero-ovarian
- Caudal mesentric
Vagus nerve innervate what organs?
Vagus provide 75% of Parasympathetic
* Heart & Lungs
* Recurrent laryngeal Nerve (larynx, esophagus, trachea)
* Abdominal viscera
Originates from the medulla oblongata (brainstem) and exits the skull through the jugular foramen
Where does the Vagus originates from and exit the skull?
Vagus originates from the medulla oblongata (brainstem) and exits the skull through the jugular foramen
