WARM UP 3/17

1. What is a Schwann cell?

2. What are interneurons?

3. What are the 2 divisions of the autonomic?

4. What are the 3 meninges in order?

5. What is the sympathetic system?

6. Name 3 things that the sympathetic does?

NOTES CH 10: 3/17

SPINAL CORD

FUNCTION

1. Brings messages to and from the brain

2. Reflex center

STRUCTURE• Approx. 17” long• From brain base

to 1st lumbar vertebrae

• Size of thumb                                      

• Center looks like an “H”

- gray matter – cell bodies

- white matter – myelinated axon

(more white mater on top – all axons from body go through there)

TRACTS = bundles of nerves

1. ASCENDING TRACTS – carry impulses up the sp cord (afferent neurons)

2. DESCENDING TRACTS – carry impulses down the sp cord (efferent neurons)

A pair of SPINAL NERVES exit from each segment of the sp cord

31 pairs total:

8 prs – cervical nerves

12 prs – thoracic

5 prs – lumbar

5 prs – sacral

1 coccygeal

EXTRA CREDIT OPP.

There are 31 pairs of spinal nerves……

If you can memorize all 31 in 2 minutes, then you get an ec slip….BUT

If you don’t get them all, then you have to lose 5 participation points from your grade.

WHO WANTS TO PLAY?????????????

SPINAL CORD NERVE NAMES

C1, C2, C3, C4, C5, C6, C7, C8

T1, T2, T3….. T12

1L, 2L …5L

1S, 2S …. 5 S

coccygeal

PARALYSIS – if sp cord cut or crushed, loss of senses and motor of area below it

PARAPLEGIC – legs paralyzed

QUADRAPLEGIC – arms and legs paralyzed

LABELING

1. Dura mater

2. Subdural space

3. Arachnoid

4. Pia mater

5. Skin

6. Periosteum

7. Bone

8. Dura mater

9. Arachnoid

10. Pia mater

11. Spinal cord

12. Dorsal root

13. Ventral root

** Central canal

14. Dura mater

15. Arachnoid

16. Pia mater

17. Spinal nerves

18. vertebrae (bone)

On labeling sheet

HOW A MESSAGE TRAVELS THROUGH THE BODY

1. Stimulus detected by receptors2. Impulse travels through afferent neurons

to spinal cord (* see steps through a neuron)

3. Ascending tract up spinal cord to brain4. Brain interprets message5. MESSAGE CAN STOP HERE OR

CAUSE A REACTION

6. Brain sends response

7. Descending tract down spinal cord from the brain

8. Impulse travels through efferent neurons to muscle or gland

9. Body response