The spinal cord contains ascending and descending tracts that transmit signals between the brain and body. Ascending tracts carry sensory information from the body to the brain, including touch, proprioception, and pain. Descending tracts convey motor and postural signals from the brain to the spinal cord and body, such as the corticospinal tract controlling movement. Within the spinal cord, sensory and motor neurons form reflex arcs that coordinate simple reflexive responses without involving the brain.

1. Spinal Cord and Reflexes
Fundamentals of Human Biology II
SCB 204

2. Overview

3. Meninges

4. Spinal Nerve Function

5. Spinal Cord Cross-Section

6. The total number of paired spinal nerves is
a. 12
b. 26
c. 31
d. 48

7. Dissected Ventral Surface

8. Ascending and Descending Tracts

9. Ascending Tracts
Fascicular - touch, somesthesis
Spinocerebellar - Proprioception
Spinothalamic - pressure, pain, crude
touch

10. Descending Tracts
Corticospinal - somatic motor function
Vestibulospinal - equilibrium
Tectospinal - reflex postural movements
in response to visual and auditory
stimuli
Rubrospinal - reduced function in
humans. thought to control some gross
action of flexors and extensors (walking)

11. Why is there no cerebellospinal
pathway?
A. the cerebellum does not have a
motor function.
B. it’s included with the cerebrospinal
pathway
C. it’s included with the tectospinal
pathway
D. both B and C

12. Which part of the brain is involved
with somatic motor function?
A. precentral gyrus
B. thalamus
C. cerebellum
D. all of these

13. Sensory Pathways

14. Somatic Reflex Arc

15. Ipsilateral andContralateral Reflexes

16. Types of Reflexes

17. Motor Integration

18. Sensory Endings
Mechanoreceptors -
Thermoreceptors -
Photoreceptors -
Chemoreceptors -
Nociceptors -

19. Cutaneous Endings

20. Cutaneous Endings

21. Dermatomes

22. If a reflex involves your big toe, what
is its pathway?
A. brachial plexus and cervical cord
B. thoracic plexus and thoracic cord
C. lumbar plexus and lumbar cord
D. sacral plexus and sacral cord

23. Spinal Nerve Structure