101_12AI_neuro_8-SNS_

101_12AI_neuro_8-SNS_ - the somatic motor nervous system...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
the somatic motor nervous system controls our skeletal muscles 1) what does this system consist of? 2) what does it enable us to do? 3) how does it work? 1) organization parallel to ANS: afferent : cranial nerves & spinal nerves -- dorsal roots, dorsal horn, spino-cortical efferent : cranial nerves & spinal nerves -- ventral horn, ventral root, cortico-spinal funiculi 2) controls skeletal muscle examples : locomote, grasp, move, withdraw, posture, chew, talk, move eyes, blink 3) analogous behaviors: involuntary "reflexes" voluntary contractions & coordinated relaxations
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1) the cross-sections are slices where a spinal nerve enters/exits 2) each cross-section show horns note: no lateral horns shown here 3) the spinal cord is continuous with the brain & protected by vertebrae 4) note the afferent & efferent pathways what does this system consist of? “vertical” rostral caudal “horizontal” dorsal vs ventral afferent & efferent Takahashi’s Atlas of the Human Body (1994), p.16
Background image of page 2
1) cross-sections look slightly different at each level 2) there are inputs & outputs @ each level, so each section has horns (grey matter) & funiculi (white matter) 3) right-hand panel: note the ascending & descending tracts Netter 2006 Atlas of Human Body Silverthorn 2010 Human Physiology Fig 9-7 Kandel et al 2000 Principles of Neural Science Fig 18-2 seen yesterday due to different #s of afferents & efferents
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
more detailed “parts list” afferents touch receptors in skin mechanoreceptors in muscle & tendons pain (nocio) & temperature receptors in skin afferents to centers driving homeostatic behaviors e.g. osmoreceptors driving thirst center e.g. stretch receptors at pharynx triggering swallowing efferents motoneurons to muscles centers to drive skeletal muscles for respiration & swallowing cortico-spinal projections: from motor cortex to motoneurons higher motor centers in cortex
Background image of page 4
Kandel etal’00 Principles of Neural Science, Fig 22-13 “map” of somatic receptors p176 dermatome here: 1) 27 of 31 body dermatomes #’s = vertebral foramen. 2) 4 not shown are visible from the opposite side of the body 3) facial skin is innervated by 3 branches of the trigeminal nerve (i, ii, and iii). skin innervated by a (paired) dorsal root
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
somato sensory system 1) ascending in spinal cord & brain 2) horizontal @ dorsal horn spinal cord brainstem relay nuclei thalamus dorsal root ganglion 1 o somatosensory cortex receptors in skin, etc receptor in muscle Fig 5-28
Background image of page 6
Fig 5-27 “map” of routes for somatic inputs to brain same as seen yesterday
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
somatosensory receptors in face project to somatosensory cortex too, via brainstem (not via spinal cord) Purves’04 Fig 1.13 recall from yesterday:
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/05/2012 for the course NPB 101 taught by Professor Fuller,charles/goldberg,jack during the Spring '08 term at UC Davis.

Page1 / 31

101_12AI_neuro_8-SNS_ - the somatic motor nervous system...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online