Neurological High-Yield Biomedical Sciences Flashcards

Biomedical Sciences

What is the role of the notochord during neural tube development?

The notochord is a ventral structure that secretes Shh, inhibiting Wnt signaling to establish the dorsal-ventral axis.

What is the embryological origin of the central nervous system (CNS)?

The CNS originates from neuroepithelia in the neural tube.

What do neural crest cells develop into?

Neural crest cells differentiate into Schwann cells, melanocytes, enterochromaffin cells, and various other cell types.

What are the primary vesicles formed by week 4 of embryonic development?

Forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon).

What are the secondary vesicles that arise from the primary vesicles during embryonic development?

Telencephalon and diencephalon (from the forebrain), mesencephalon, metencephalon and myelencephalon (from the hindbrain).

What adult structures derive from the telencephalon?

The adult structures from the telencephalon are the cerebral hemispheres and lateral ventricles.

How is gray matter defined in the CNS?

Gray matter is primarily made up of neuronal cell bodies.

What are the two types of neurons based on their signaling direction?

Motor neurons (signal from CNS) and sensory neurons (signal to CNS).

What initiates the action potential in a neuron?

An action potential is initiated when the threshold is reached at the axon hillock.

What is Wallerian degeneration?

Wallerian degeneration is the process that begins at the point of axonal injury and spreads distally.

Describe chromatolysis. What does it indicate?

Chromatolysis is a reaction in neuronal cells to axonal injury, resulting in cellular swelling and displacement of the nucleus.

What are astrocytes?

Astrocytes are the most common glial cell type, providing structural support, repair after trauma, and maintaining the blood-brain barrier.

What is the function of oligodendrocytes?

Oligodendrocytes myelinate neurons in the CNS and can myelinate multiple axons.

What cells contribute to the blood-brain barrier?

The blood-brain barrier is formed by tight junctions between endothelial cells, a basement membrane, and astrocytic foot processes.

What is the difference between the CNS and PNS?

The CNS is comprised of the brain and spinal cord, while the PNS includes all other nerves and ganglia.

What is myelinated by Schwann cells?

Schwann cells myelinate the axons of neurons in the peripheral nervous system.

What is Guillain-Barré syndrome?

Guillain-Barré syndrome is an autoimmune condition affecting Schwann cells, leading to demyelination of peripheral nerves.

What is the embryological origin of microglia?

Microglia are derived from mesoderm, originating from monocytes.

What role do ependymal cells play in cerebrospinal fluid (CSF) production?

Ependymal cells line the ventricles and produce CSF.

Function of the hypoglossal nerve (CN XII)?

The hypoglossal nerve controls tongue movement for chewing, swallowing, and speech.

Which cranial nerves provide sensory innervation to the tongue?

CN V (lingual nerve) for general sensation; CN VII (chorda tympani) for taste from anterior 2/3; CN IX for taste and sensation from posterior 1/3.

What are the motor functions of the vagus nerve (CN X)?

The vagus nerve elevates the posterior tongue during swallowing.

How do sensory neurons transmit signals to the CNS?

Sensory neurons send signals to the CNS via synapses with afferent neurons in the spinal cord.

What are the two main types of sensory receptors?

Slowly adapting receptors (e.g., Ruffini corpuscles) provide continuous response to stimuli, whereas rapidly adapting receptors (e.g., Pacinian corpuscles) respond to changes.

What is the role of the node of Ranvier?

The node of Ranvier facilitates saltatory conduction by separating segments of the myelin sheath, concentrating Na+ channels.

Define the term 'sensory neuron fiber type.'

Sensory neuron fiber types classify neurons based on their response to stimuli (e.g., rapidly adapting or slowly adapting).

What is the role of astrocytes in the central nervous system?

Astrocytes provide structural support, regulate ion balance, and maintain the blood-brain barrier.

What happens during injury to a neuron?

Injury can cause Wallerian degeneration and chromatolysis, reflecting attempts to repair the damaged axon.

What is the main function of the thalamus?

The thalamus serves as the major relay station for all ascending sensory information, except olfaction.

What is the function of the limbic system?

The limbic system connects neural structures involved in emotion, memory, olfaction, and autonomic functions.

What are the components of the cerebellum?

The cerebellum includes the midline vermis for truncal coordination, intermediate vermis for limb coordination, and lateral vermis for voluntary motor planning.

What anatomical structure does the midbrain contain?

The midbrain contains the cerebral aqueduct and the red nuclei regulating involuntary motor signals.

What is the role of neurotransmitter synaptic transmission?

Neurotransmitter synaptic transmission is crucial for communication between neurons, relaying signals across synapses.

What factors influence the action potential conduction speed?

Conduction speed is influenced by myelination and the diameter of the neuron.

How does dopamine influence motor control?

Dopamine activates the direct pathway to facilitate movement and inhibits the indirect pathway to prevent inhibition of movement.

What is the structure of a neuron?

A neuron consists of a cell body, dendrites for input, and an axon for output to transmit signals.

What is the function of blood-brain barrier?

The blood-brain barrier protects the brain by preventing most water-soluble substances from entering.

What is the significance of the arachnoid granulations?

Arachnoid granulations reabsorb cerebrospinal fluid back into the blood via the dural venous sinuses.

What are the primary symptoms of cerebrovascular accident (CVA)?

Symptoms include sudden numbness, confusion, trouble speaking, and loss of balance.

What impacts does stroke have on the brain?

Stroke can lead to disruption in blood flow, ischemia, and subsequent neuronal death.

What is the relationship between the autonomic nervous system and neurotransmitters?

The autonomic nervous system utilizes neurotransmitters such as acetylcholine and norepinephrine to communicate between nerve cells.

What is Amyotrophic lateral sclerosis (ALS)?

ALS is a neurodegenerative disease characterized by the degeneration of both upper and lower motor neurons.

Define neuroplasticity. How does it relate to learning?

Neuroplasticity is the brain's ability to reorganize itself by forming new neural connections, crucial for learning and recovery after injury.

What are the consequences of axonal injury?

Axonal injury can result in cell death, loss of function, and possibly Wallerian degeneration.

What characterizes Parkinson's disease?

Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra, causing motor deficits.

How can pain be classified based on nerve involvement?

Pain can be classified based on nerve fiber types: A-delta (sharp pain) and C fibers (dull, throbbing pain).

What are the diagnostic tools for assessing cerebrovascular diseases?

Non-contrast CT and diffusion-weighted MRI are key tools for diagnosing cerebrovascular accidents.

What composes cerebrospinal fluid (CSF)?

CSF is composed of water, electrolytes, glucose, and various proteins.

What is the primary function of cranial nerves?

Cranial nerves are responsible for transmitting sensory and motor information to and from the brain.

What influences blood pressure in relation to cerebral perfusion?

Cerebral perfusion pressure is determined by the mean arterial pressure (MAP) minus intracranial pressure.

What is the principal neurotransmitter of the sympathetic nervous system?

Norepinephrine is the principal neurotransmitter of the sympathetic nervous system.

Describe the structure of the blood-brain barrier. What is its main function?

The blood-brain barrier consists of endothelial cells with tight junctions, a basement membrane, and astrocyte foot processes, protecting the brain from harmful substances.

What are the long-term effects of chronic alcohol use on the nervous system?

Chronic alcohol use can lead to neurodegeneration, cognitive deficits, and symptoms such as Wernicke-Korsakoff syndrome.

What are the common causes of meningitis in adults versus children?

In adults, common causes are S. pneumoniae and N. meningitidis; in children, S. pneumoniae and enteroviruses are more prevalent.

How does multiple sclerosis (MS) affect the central nervous system?

MS is characterized by autoimmune damage to myelin sheaths in the CNS, which leads to neurological deficits and relapses.

What symptoms may indicate damage to the peripheral nervous system?

Symptoms may include weakness, sensory loss, and diminished reflexes corresponding to affected nerve roots.

What is the significance of the Circle of Willis?

The Circle of Willis is critical for providing a collateral blood supply to the brain, protecting against ischemia.

What are the clinical features of a cerebrospinal fluid leak?

Clinical features may include headache, clear fluid drainage from the nose or ears, and symptoms of meningitis.

What is the role of cranial nerves in sensory perception?

Cranial nerves transmit sensory information (taste, smell, sight, hearing) from various organs to the brain.

What is considered a worse headache in the context of a subarachnoid hemorrhage?

The worst headache of a patient's life is often associated with a sudden subarachnoid hemorrhage.

How do structural abnormalities contribute to central nervous system pathologies?

Structural abnormalities, like tumors or malformations, can impede normal function, resulting in neurological deficits or compromised blood flow.

What are the primary functions of the spinal cord?

The spinal cord processes sensory input, coordinates motor output, and facilitates reflex actions.