Review: Action Potentials, Synapses, and Cranial Nerves

Flashcards about action potentials, synapses, cranial nerves, and related neurological concepts.

What is the role of the presynaptic neuron?

To transmit signals across the synapse to the postsynaptic neuron.

What are the main components of a neuron?

Dendrites, cell body (soma), axon, and axon terminals (arborizations).

What is the synapse?

The junction between two neurons where signals are transmitted.

What is the myelin sheath?

A fatty insulation layer around the axon that speeds up action potential conduction.

What are Nodes of Ranvier?

Gaps in the myelin sheath where action potentials are regenerated.

What ions are crucial for action potential generation and propagation?

Sodium (Na+) and Potassium (K+).

What happens during depolarization?

Na+ ions move into the cell, making it more likely to fire an action potential.

What is the role of Calcium (Ca2+) in synaptic transmission?

Ca2+ influx triggers synaptic vesicles to release neurotransmitter.

What happens to neurotransmitters after being released?

They bind to receptors on the target cell, causing positive ions to flow in.

What are the main steps of an action potential?

Resting state, Depolarization, Repolarization, Hyperpolarization, and return to Resting state.

What are the main functions of the olfactory nerve (I)?

Sensory (smell).

What are the main functions of the optic nerve (II)?

Sensory (sight).

What are the main functions of the oculomotor nerve (III)?

Motor (4 of 6 eye muscles), Parasympathetic (constriction of pupil, movement of lens).

What are the main functions of the trochlear nerve (IV)?

Motor (1 eye muscle).

What are the main functions of the trigeminal nerve (V)?

Sensory (face, nasal cavity, cheeks, lips, skin of mandible), Motor (muscles of mastication, anterior belly of digastric, mylohyoid).

What are the main functions of the abducens nerve (VI)?

Motor (1 eye muscle).

What are the main functions of the facial nerve (VII)?

Sensory (taste), Motor (facial muscles, posterior belly of digastric), Parasympathetic (salivary glands, glands of nasal cavity).

What are the main functions of the vestibulocochlear nerve (VIII)?

Sensory (hearing and balance).

What are the functions of the glossopharyngeal nerve (IX)?

Sensory (taste, back of mouth, tonsils, middle ear), Motor (1 muscle of pharynx), Parasympathetic (salivary gland, glands of tongue).

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

Sensory (taste, back of mouth, larynx, thoracic and abdominal organs), Motor (muscles of larynx, 1 muscle of tongue), Parasympathetic (thoracic and abdominal organs).

What are the main functions of the accessory nerve (XI)?

Motor (sternocleidomastoid, trapezius).

What are the main functions of the hypoglossal nerve (XII)?

Motor (tongue and throat muscles).

What is Proprioception?

The sense of self-movement, force, and body position, mediated by proprioceptors located within muscles, tendons, and joints.

What is the Refractory period?

The time it takes for an excitable membrane (like a muscle or nerve cell) to recover and be ready for a new stimulus after it has been stimulated.

What are Purkinje cells and where are they located?

Located in the cerebellar cortex, they have massive, intricately branched, flat dendritic trees and are necessary for well-coordinated movement, cognition, and emotion.

What are the primary responsibilities of the sympathetic and parasympathetic divisions?

The sympathetic division is primarily responsible for the "fight or flight" response, while the parasympathetic division promotes "rest and digest" responses.

What are astrocytes?

Star-shaped glial cells with processes that form feet covering surfaces of neurons, blood vessels, and the pia mater, regulating extracellular brain fluid composition, maintaining the blood-brain barrier, and releasing chemicals.