Cranial Nerves and Special Senses PDF

Cranial Nerves and Special Senses Cranial Nerves Chart Name # Mnemoni c Origin Function Example Olfactory I Some Cerebrum Sensory Nose Optic II Say Cerebrum Sensory Eye Oculomotor III Marry Midbrain Motor All eye muscles except those supplied by IV and VI Trochlear IV Money...

Cranial Nerves and Special Senses Cranial Nerves Chart Name # Mnemoni c Origin Function Example Olfactory I Some Cerebrum Sensory Nose Optic II Say Cerebrum Sensory Eye Oculomotor III Marry Midbrain Motor All eye muscles except those supplied by IV and VI Trochlear IV Money Midbrain Motor Superior Oblique Muscle Trigeminal V But Pons Both Sensory: face, sinuses, teeth Motor: muscles of mastication Abducens VI My Pons Motor External Rectus Muscle Facial VII Brother Pons Both Muscles of the face Auditory (Vestibulocochlear) VIII Says Pons Sensory Inner ear Glossopharyngeal IX Big Medulla Both Motor: pharyngeal musculature Sensory: posterior part of tongue, tonsil, pharynx Vagus X Brains Medulla Both Motor: heart, lungs, bronchi, GI tract, external ear Sensory: heart, lungs, bronchi, trachea, larynx, pharynx, GI tract, external ear Spinal Accessory XI Matter Medulla / Brainstem Motor Sternocleidomastoid, trapezius muscles Hypoglossal XII More Medulla Motor Muscles of the tounge Sensory Perception Somatosensory afferents convey information from periphery to central circuits ● Receptor - structure specialized to detect a stimulus ● Transduction - the conversion of one form of energy to another Sensory receptors transmit four kinds of information 1. Modality - type of stimulus or the perception it produces 2. Location - where a stimulus is location a. Receptive field - area within which a sensory neuron to detects stimuli 3. Intensity - strength of stimulus 4. Duration - how long a stimulus lasts a. Sensory adaptation - if a stimulus is prolonged, firing of the neuron gets slower over time and we become less aware of it b. Phasic receptors - adapt quickly c. Tonic receptors - adapt slowly Sensory receptor classification ● Modality ○ Thermoreceptors ○ Photoreceptors ○ Nociceptors ○ Chemoreceptors ○ Mechanoreceptors ● Location ○ Exteroceptors ○ Interoceptors ○ Proprioceptors Receptors of the general senses ● Free nerve endings ● Tactile disc (merkel) ● Hair receptor ● Tactile corpuscle (meissner) ● End bulb (krause) ● Bulbous corpuscle (ruffini) ● Lamellar corpuscle (pacinian) ● Muscle spindle ● Tendon organ Special senses ● Olfaction (sense of smell) steps ○ Odorants bind to receptors ○ Olfactory receptor cells are activated and send electric signals ○ The signals are relayed in glomeruli ○ The signals are transmitted to higher regions of the brain Gustation (taste) ● Taste receptor cells ○ Sweet: Associated with sugars and carbohydrates. ○ Sour: Associated with acidic substances. ○ Salty: Associated with salts and minerals. ○ Bitter: Associated with alkaline substances. Middle and inner ear anatomy Hearing (inner ear and cochlear anatomy) Equilibrium (vestibular system) Vision (light induces changes in photoreceptor electrical activity) Structure of the retina Kitchen sink for equilibrium and movement planning ● S1 ● Posteropariteal cortex ● Temporo-parietal cortex ● Visual cortex ● Cerebellum ● Vestibular cortex ● Brainstem ● Thalamus