1 / 46

Human Anatomy

Human Anatomy. Peripheral Nervous System PNS Part I. 2 Components of PNS. 12 pr. of cranial nerves 31 pr. of spinal nerves So….what is a nerve?. Structure of a Nerve. Structure of a Nerve. Connective tissue organized similar to muscle Epineurium – surrounds the entire nerve.

lonato
Télécharger la présentation

Human Anatomy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Human Anatomy Peripheral Nervous System PNS Part I

  2. 2 Components of PNS • 12 pr. of cranial nerves • 31 pr. of spinal nerves So….what is a nerve?

  3. Structure of a Nerve

  4. Structure of a Nerve • Connective tissue organized similar to muscle • Epineurium – surrounds the entire nerve

  5. Structure of a Nerve 2. perineurium– surrounds a fascicle fascicle Fascicle – a bundle of axons perineurium

  6. Structure of a Nerve Fascicle Perineurium

  7. Structure of a Nerve 3. Endoneurium – surrounds each axon

  8. Types of Nerves • Sensory – all axons in all fascicles going from periphery to spinal cord • Motor – all axons in all fascicles going from spinal cord to skeletal muscle (or other organs) • Mixed – axons within the nerve going in different directions BUT not within the same fascicles. • All axons within a single fascicle are going in only one direction

  9. Structure of a Nerve Axons

  10. Cranial Nerves (12)

  11. Cranial Nerves • Found on inferior surface of brain

  12. Cranial Nerves • Some are sensory n. • Periphery (skin or other organs) to brain • Some are motor n. • Brain to periphery (muscle or another organ) • Some are mixed n. • Both directions • All 12 pr. can be used to test various areas of the brain For instance….

  13. The Optic Nerve A patient comes in with a vision problem

  14. Study Hint for the Cranial Nerves • Make a table with 6 columns • The headings for the 6 columns (L to R) should be: • Number • Name • S, M, or B (B = mixed) • Function • Test • Special features

  15. I Olfactory • Sensory • Olfaction • Bulb

  16. I Olfactory

  17. I Olfactory Olfactory bulb Cribriform plate

  18. Location of Olfactory Bulb Cribriform plates

  19. II Optic • Sensory • Vision • Comprised of axons from rods and cones of retina

  20. II Optic

  21. Extrinsic Eye Muscle • Six muscles that attach to eyeball and are responsible for moving (gazing) the eye within the orbit.

  22. Extrinsic Eye Muscles • Names: • Superior rectus • Inferior rectus • Lateral rectus • Medial rectus • Superior oblique • Inferior oblique

  23. III, IV and VI • Cranial n. III, IV and VI innervate the 6 extrinsic eye muscles • All 3 nerves are pure motor nerves • III – oculomotor • IV – trochlear • VI -- abducens

  24. Extrinsic Eye Muscles • Which nerve innervates which muscle(s)? • LR6SO4 • Superior rectus III • Inferior rectus III • Lateral rectus VI • Medial rectus III • Superior oblique IV • Inferior oblique III

  25. V Trigeminal • Three divisions (branches) of V: V1, V2 and V3

  26. V Trigeminal • V1 – ophthalmic branch, purely sensory

  27. V Trigeminal • V2 – maxillary branch, purely sensory

  28. V Trigeminal • V3 – mandibular branch, both motor and sensory – a mixed nerve branch • Therefore, because V3 is a mixed nerve, the trigeminal nerve has to be considered a mixed cranial nerve.

  29. V3 Trigeminal • Motor to muscles of mastication (chewing) sensory

  30. Tic Douloureux • Sudden discharge of V2 and V3 • Causes intense pain to areas innervated by V2 and V3 • Trigeminal neuralgia • 1/25,000 and usually 40 yo and older

  31. VII Facial

  32. VII Facial • Mixed • Motor to facial muscles (5 branches) • Sensory from taste buds – anterior 2/3 of the tongue • Exits through stylomastoid foramen • Bell’s Palsey -- dysfunction of VII because of viral inflammation • Results in facial muscle paralysis on one side • Usually “cures itself” within weeks or a few months

  33. VII Facial

  34. VIII Vestibulocochlear • Semicircular canals – balance abd equilibrium • Cochlea – hearing

  35. VIII Vestibulocochlear • Sensory • Hearing and balance • Cochlea and semicircular canals

  36. IX Glossopharyngeal

  37. IX Glossopharyngeal • Mixed • Motor to: • Swallowing muscles of pharynx • Parotid salivary gland (saliva producing) • Sensory from: • Taste from posterior 1/3 of tongue • Lining of pharynx • Soft palate

  38. X Vagus • Longest cranial n. in human body • Innervates head, neck, thorax and abdomen

  39. X Vagus • Mixed • Motor to: • Pharyngeal and laryngeal muscles • Organs in thorax and abdomen • Lungs and heart • Liver, stomach, intestines

  40. X Vagus

  41. X Vagus • Mixed • Sensory from: • Pharynx • External auditory canal • Organs of thorax and abdomen

  42. X Vagus Vagotomy – to inhibit gastric acid secretion

  43. XI Accessory

  44. XI Accessory • Motor • Motor to: • Sternocleidomastoid • Trapezius • Pharyngeal and laryngeal muscles

  45. XII Hypoglossal • Motor to muscles of the tongue • Tongue points to side of lesion

More Related