DA

Exam Review Notes

Grading and Visible Body Scores

  • Post school quizzes will be graded and scores uploaded to Canvas.

  • Visible Body quiz grades will be ported over; the lowest grade will be dropped.

  • There will be eight quizzes on Visible Body.

Autonomic Nervous System

  • Divisions: Sympathetic and Parasympathetic.

  • Concepts: Preganglionic and Postganglionic neurons.

Preganglionic vs. Postganglionic

  • Preganglionic: Before the collection of cell bodies (ganglion).

  • Sympathetics: Short preganglionic fibers; long postganglionic fibers.

  • Parasympathetics: Long preganglionic fibers; short postganglionic fibers.

Neurotransmitters

  • Three neurotransmitters: Acetylcholine, Epinephrine, and Norepinephrine.

  • Parasympathetics: Use Acetylcholine.

  • Sympathetics: Primarily use Epinephrine and Norepinephrine (fight or flight; adrenaline rush).

Location in the Nervous System

  • Parasympathetics: Cranial and Sacral nerves (bookends).

    • Cranial nerves: 3, 7, 9, and 10.

    • Sacral nerves: S2, S3, S4 (keeps the feces off the floor).

  • Sympathetics: Thoracic spine (entire) and L1-L2 (middle).

Organ Intervention

  • Many organs have both sympathetic and parasympathetic innervation.

  • Example: The heart can speed up (sympathetic) or slow down (parasympathetic).

  • Vagus nerve stimulation:

    • Heart: Slows down (parasympathetic).

    • Intestines: Speeds up (parasympathetic).

Digestive System

  • Parasympathetic activation (specifically vagus nerve) affects:

    • Stomach.

    • Small and Large Intestines.

    • Pancreas.

    • Gallbladder.

    • Liver.

Cranial Nerves

  • Questions on the final exam will pertain to:

    • Function (motor, sensory, or both).

    • How to test each nerve.

Olfactory Nerve

  • Function: Sense of smell.

  • Passes through the cribriform plate of the ethmoid bone.

  • Hardwired into the limbic system via the hypothalamus.

Trigeminal Nerve

  • Testing: Patient blinks when poked in the eye.

Cranial Nerves Affecting Taste

  • Direct impact:

    • Facial Nerve (anterior two-thirds of the tongue).

    • Glossopharyngeal Nerve (posterior one-third of the tongue).

  • Indirect impact:

    • Hypoglossal Nerve (motor only, controls tongue movement).

      • If damaged, impairs taste indirectly as you can't move the tongue to taste.

Facial Nerve (VII)

  • Functions:

    • Facial expression.

    • Tear production.

    • Saliva production.

  • Peripheral Nerve System (PNS).

  • Paired (one on each side).

Facial Nerve Damage

  • Damage to the right facial nerve results in Bell's Palsy (drooping on one side of the face).

  • Bell's Palsy: Affects only the face.

  • Hemiplegia: Affects one side of the body (face, arm, leg) due to a stroke on the contralateral side of the brain.

Eye Movements

  • Six extrinsic eye muscles control eye movements (cardinal fields of gaze).

  • Looking straight up: Oculomotor nerve (superior rectus).

  • Looking straight down: Oculomotor nerve (inferior rectus).

  • Looking down and out: Trochlear nerve (superior oblique muscle).

  • Looking left or right: Eyes move in tandem (lateral and medial).

Spinal Cord

Cross-Section Anatomy

  • Dorsal Root Ganglion: Bump on the posterior side; contains sensory (afferent) fibers.

  • Middle (Gray Matter): Part of the Central Nervous System (CNS); unmyelinated (slower).

    • Posterior, lateral, and anterior gray horns.

  • Outside (White Matter): Myelinated (faster); contains tracts or columns (elevators).

    • Tracts and Columns are the same thing.

Spinal Cerebellar Tract

  • Starts in the spine, goes to the cerebellum.

  • Afferent (sensory) fibers.

  • Carries proprioception (joint position sense, balance).

Spinal Thalamic Tract

  • Starts in the spine, goes to the thalamus.

  • Conducts pain and temperature.

  • Afferent fibers.

  • All sensory pathways go to the thalamus except for olfactory.

Posterior White Columns

  • Conduct vibration.

Sensory Input on Skin

  • Core muscles (Merkel discs): Pressure.

  • Meissner's Corpuscles (Tactile Corpuscles): Light touch.

  • Free Nerve Endings: Pain.

  • Sensory input is picked up and travels via afferent pathways to the spinal cord.

Brain Cortex

  • Central Sulcus: Separates the frontal (anterior) and posterior parts of the brain (coronal/frontal plane).

  • Posterior:

    • Sensory areas (primary sensory area, taste, vision).

  • Anterior:

    • Motor areas (primary motor area, Broca's area).

Broca's Area

  • Involved in the movement of the tongue for speech.

Wernicke's Area

  • Association area.

  • Damage results in the ability to speak, but the speech doesn't make sense (gibberish).

Strokes (CVA)

  • Lack of oxygen to the brain (ischemic event).

  • Caused by blood clots, fat thrombi, hardening, or breaks in blood vessels.

  • CNS nerve cells do not regenerate once dead.

Peripheral Nerve Damage

  • Peripheral nerves (e.g., musculocutaneous, median) can regenerate if perfectly realigned after damage.

  • Neurotmesis: Complete cut of a nerve.

  • PNS can regenerate, CNS cannot.