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.