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Flashcards in nerves of the thorax Deck (90)
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1

somatic nerves

supply skeletal muscles only
11 pairs of intercostal nerves and 1 pair phrenic nerves

2

somatic sensory nerves

sensation from the skin muscles and bones and parietal pleura of peicardium
much non-cutaneous sensation is proprioceptive - feedback on function in muscles, tendons, and joints

3

autonomic

supply sm, cardiac muscle, exocrine glands (heart muscles, bv, bronchi, bronchila glands, sweat gland)

4

autonomic sensory fibres

carry sensory info from viscera

5

sympathetic nerves

motor to sm and cardiac muscle, exocrine glands and carry pain sensation from viscera

6

chest wall sympathetic innevation

from spinal nerves T1-11

7

thoracic viscera innevation

from spinal nerves T3-T6

8

parasympathetic nerves

motor- sm, cardiac pacemaker sstem, exocrine glands and carry sensory information providing functional feedback (enteroception) from the viscera
only to viscera

9

parasympathetic supply to thoracic viscera

from brainstem in vagus nerves - 10th pair of cranial nerves

10

intercostal nerves

T1-11
segmental nerves - each pair supplies single body segment containing single vertebrae and associated muscles and skin
forms roots from spinal cord
ventral - motor
dorsal - sensory
cell bodies of sensory in ganglion on posteror root just before spinal nerve
cell bodies of motor - in anterior horn in spinal cord
ganglion and junction of roots is in intervertebral foremen
spinal nerve divide into rami
smaller rami is posterior - imnervates posterior muscles and skin
anterior is larger - runs between internal and innermost IC muscles suppluing muscles to midline and branches that innervate skin (2 branches from each nerve - one lateral and 1 anterior)

11

intercostal nerves

nerves from the anterior rami

12

dermatome

area of skin supplied by spinal nerve

13

myotome

muscles supplied by a particular spinal nerve

14

what is the overlap between dermatomes

50%

15

phrenic nerves

from anterior rami of 3 adjoining cervical spinal nerves C3, 4, 5
C4 main contributor

16

effect of damage to motor tracts above C4

disconnects diaphragm
breathing cant occur
asphyxia

17

plexi

areas of shared distribution of several pairs of spinal nerves - cervical plexus is from C2 - 5

18

path of phrenic nerve

down neck on muscles from cervical transverse process
pass through diaphragm, either side of the mediastinum
R - follow path of great veins (R brachiocephalic - SVC - fibrous pericardium covering sinus venous and inferior vena cava
L crosses arch of aorta and then runs across fibrous pericardium overlaying the L ventricle

19

what does each phrenic nerve supply

the muscles on its side of the diaphragm

20

difference between the autonomic and somatic motor nerve

somatic - axons of lower motor neurons extend from spinal cord to their end plates
autonomic - preganglionic in brain and spinal cord, post ganglionic go to target tissue - reduces cell bodies in CNS, but also reduces precision

21

SNS

preganglionic T1 - L2
simple segmntal spinal nerves
to body wall travel with somatic but have ganglia
preganglionic leave the spinal cord - synapse in sympathetic chain
postganglionic then return to the spinal nerves

22

rami communicantes

bundles of nerves joining the sympathetic ganglia to spinal nerves

23

SNS preganglionic fibres ramus communican

wrapped in white coloured myelin sheath - form white ramus communican

24

SNS postganglionic fibres ramus communican

not myelinated - grey

25

sympathetic chain

formed from the ganglia joined by bundles of nerves
extend beyond T1-L2 from mid cervical to pelvis

26

purpose of the sympathetic chain

allow preganglionic fibres to run up/down for one or more segments before synapsing
therefore provide innervation to the whole body

27

Visceral SNS

pass to white rami but don't synapse
instead they synapse closer to the target organ

28

SNS supplies to heart and lungs

reach cardiac and pulmonary plexi and synapse here

29

where do teh thoracic visceral supplies arise from

T3-6

30

where does the sympathetic supply to the heart arise

T2 - 4