1. Spinal Cord and Spinal Nerves
Chapter 13
Lab Exercises 17-19

2. Introduction The purpose of this part of the course is to:
Identify & describe anatomical features of spinal cord & spinal nerves
Discuss functions of spinal cord & spinal nerves  homeostasis
Understand spinal reflex arcs
Integration of EPSP + IPSP
Sensory and motor tracts

3. Functions of the Spinal Cord
Processes reflexes
Integrates nerve impulses
Conducts sensory impulses to the brain and motor impulses to effectors

4. Protection of the Spinal Cord
The spinal cord is protected by:
Bone
Meninges
CSF

5. Meninges The meninges are composed of three layers Dura mater
Arachnoid mater
Pia mater
Denticulate
ligaments 3 2 1

6. Meninges Epidural space Subdural space Subarachnoid space3
Epidural space
Subdural space
Subarachnoid space
A spinal tap can be done to withdraw CSF for diagnostics 2 1

7. Anatomy

8. Fig. 13.1 Gross Anatomy of Spinal Cord

9. (b) Posterior view of cervical region of spinal cord
SUPERIOR
Fourth ventricle
Cerebellum of brain (cut)
Glossopharyngeal (IX)
and vagus (X) nerves
Occipital bone (cut)
Accessory (XI) nerve
Posterior median sulcus
Gracile fasciculus
Vertebral artery
Cuneate fasciculus
Denticulate ligament
Posterior (dorsal) rootlets
of spinal nerve
Dura mater and arachnoid mater (cut)
INFERIOR
(b) Posterior view of cervical region of spinal cord

10. View
Transverse plane
Dura mater and arachnoid mater
POSTERIOR
Spinal cord
Pia mater
Spinous process of vertebra
Epidural space
Subarachnoid space
Superior articular facet of vertebra
Posterior (dorsal) root of spinal nerve
Posterior (dorsal) ramus of spinal nerve
Denticulate ligament
Anterior (ventral) root of spinal nerve
Spinal nerve
Anterior (ventral) ramus of spinal nerve
Transverse foramen
Body of vertebra
Vertebral artery in transverse foramen
ANTERIOR
Figure 13.1 (b) Transverse section of the spinal cord within a cervical vertebra

11. External Anatomy of the Spinal Cord
Begins… Ends… Landmarks

12. Fig. 13.2 External Anatomy of Spinal Cord
Posterior view of entire spinal cord and portions of spinal nerves
CERVICAL PLEXUS (C1–C5):
Lesser occipital nerve
Great auricular
Ansa cervicalis
Transverse cervical nerve
Supraclavicular nerve
Phrenic nerve
BRACHIAL PLEXUS (C5–T1):
Musculocutaneous nerve
Axillary nerve
Median nerve
Radial nerve
Ulnar nerve
Intercostal (thoracic) nerves
Subcostal nerve (intercostal nerve 12)
LUMBAR PLEXUS (L1–L4):
Iliohypogastric nerve
Ilioinguinal nerve
Genitofemoral nerve
Lateral femoral cutaneous nerve
Femoral nerve
Obturator nerve
SACRAL PLEXUS (L4–S4):
Superior gluteal nerve
Inferior gluteal nerve
Sciatic nerve:
Common fibular nerve
Tibial nerve
Posterior cutaneous nerve of thigh
Pudendal nerve
Medulla oblongata
Atlas (first cervical vertebra)
CERVICAL NERVES (8 pairs)
Cervical enlargement
First thoracic vertebra
THORACIC NERVES (12 pairs)
Lumbar enlargement
First lumbar vertebra
Conus medullaris
LUMBAR NERVES (5 pairs)
Cauda equina
Ilium of hip bone
Sacrum
SACRAL NERVES (5 pairs)
COCCYGEAL NERVES (1 pair)
Filum terminale C1 C2 C3 C4 C5 C6 C7 C8 T1 T2 T3 T4 T5 T6 T7 T8 T9
T10
T11
T12 L1 L2 L3 L4 L5 S1 S2 S3 S4 S5

13. External Anatomy of the Spinal Cord

14. Internal Anatomy of the Spinal Cord
Gray matter White matter Landmarks

15. Fig. 13.3 Internal Anatomy of Spinal Cord

16. Fig. 13.3 Internal Anatomy of Spinal Cord

17. Internal Anatomy of the Spinal Cord

18. Sensory and Motor Processing

19. Spinal Cord Segments Table 13.1 Cervical (Segment C6) Thoracic
(Segment T5)
Lumbar
(Segment L4)
Sacral
(Segment S3)