Somatic & Visceral Innervation of the Chest Flashcards Preview

Gross Anatomy/Embryology > Somatic & Visceral Innervation of the Chest > Flashcards

Flashcards in Somatic & Visceral Innervation of the Chest Deck (40):
1

dorsal ramus

- branch going toward back side
- has both motor and sensory neurons

2

rami communicans

- allow different spinal nerves to synapse on one another (communication between neurons)
- gray and white

3

dorsal root

- only associated with sensory components

4

ventral root

- only associated with motor components

5

spinal cord segment

- one inch component of spinal cord (i.e. T4 segment of spinal cord)

6

Would damage of one nerve remove all sensory input from the regions it touches?

- no, overlap of dermatomes means that there would still be some sensory input

7

innervation of diaphragm

- two domes of muscle that meet in middle and attach at central tendon (where heart sits)
- skeletal muscle that gets somatic innervation (from phrenic nerves--C3, C4, C5 in domes, from intercostal nerves in lateral portions)
- phrenic nerve

8

ventral rami

- both sensory and motor nerves
- innervates front of chest for dif sensations

9

phrenic nerve

- C3/C4/C5
- goes through superior thoracic aperture, enters into chest in middle mediastinum (medial to parietal pleura) and innervates diaphragm
- sensory nerves return at same level of those of supraclavicular nerve

10

Why do C3, C4, C5 nerves extend all the way down to diaphragm?

- four week embryo --> relative position of heart bulge & respiratory diaphragm in future neck region
- cervical nerves serve diaphragm and heart (in close proximity)
- when diaphragm and heart moved later in development, pulled cervical nerves with them

11

What do neural crest cells become?

- become dorsal root ganglia & autonomic (sympathetic) ganglia

12

What does neural crest tube become?

- becomes cell body of ventral horn (somatic)

13

somatic nervous system

- one neuron effector system --> only one cell from CNS to skeletal muscle

14

autonomic nervous system

- two neuron effector system --> pre-synaptic cell and post-synaptic cell

15

intercostobrachial nerve

- at T2
- goes into arm

16

cutaneous branches of segmental spinal nerves

- some of skin on chest gets innervation coming neck (C3, C4)

17

supraclavicular nerves

- C3, C4
- come off ventral rami
- passes around sternocleidomastoid and descends to innervate skin over superior region of chest and shoulder

18

segmental spinal nerves

- remnant of "metameric segmentation"
- branches into cutaneous branches
- contains mix of motor and sensory nerves (mixed nerve)

19

pericardiophrenic vessels

- pericardiophrenic artery/vein and phrenic nerve travel together through mediastinum

20

internal thoracic artery (left and right)

- branches from subclavian artery
- descends along anterior thoracic wall lateral to sternum
- gives off anterior intercostals (supply intercostal spaces)

21

intercostal nerves

- T1/T2 supply upper limb
- T3-T6 distributed throughout wall of thoracic cavity
- T7-T12 supply parts of thoracic and abdominal cavity walls
- make up afferents of periphery of diaphragm

22

"referred pain"

- pain is felt in dermatomes
- diaphragm innervated by C3-5, so afferents return to those vertebrae
- on dermatome, C3-5 corresponds to neck and upper chest region
- pain felt in diaphragm is often "felt" in neck/chest because mix of sensory info at spinal cord

23

pseudo-unipolar neuron

- sensory neuron of somatic NS
- dendrites on receptor "organ" and axon terminals in spinal cord
- cell bodies always outside CNS ( in dorsal root ganglia)

24

multipolar neuron

- motor neuron
- cell body found in CNS (spinal cord)
- peripheral axon terminals synapse on effector organ
- in somatic NS, one neuron effector system (cell body found in Ventral horn)
- in autonomic NS, two neuron effector system (cell body found in lateral horn --> sympathetic)

25

dorsal root ganglia

- collection of pseudo-unipolar cell bodies
- derivative of neural crest cells

26

sympathetic NS

- spinal cord segments: T1 to L2/3 (thoracolumbar outflow)
- preganglionic (presynaptic) cell bodies found in lateral horn
- many post-synaptic cell bodies found sympathetic trunk in paravertebral ganglia
- presynaptic axons are short (sympathetic truck ganglia), postsynaptic axons are long and go to effector organ

27

splanchnic nerves

- innervate visceral organs (sympathetic NS)
- pre-synaptic and post-synaptic cells synapse in prevertebral ganglia

28

white communicating rami

- preganglionic sympathetic nerve fibers from spinal cord enter ganglia through these communicating rami and synapse with postganglionic sympathetic nerve fibers
- may synapse at level of entry or run up or down sympathetic trunk to a dif level before synapsing

29

gray communicating rami

- postganglionic fibers exit ganglia of sympathetic trunk through these communicating rami and branch to plexuses or organs

30

pulmonary ligament

- some of pleura dips down to innervate belly
- posterior to root of lung

31

parasympathetic NS

- craniosacral outflow
- brainstem (cranial nerves) and sacral nerves
- ganglia close to or within effector organs
- long presynaptic axon, short postsynaptic axon

32

CN III

- pupillary sphincter
- parasympathetic

33

CN VII & IX

- salivary and tear glands
- parasympathetic

34

CN X

- vagus nerve --> leaves head and goes through superior thoracic aperture
- parasympathetic
- heart, lungs, and digestive tract

35

sacral spinal cord segments (S1-S5)

- large intestine, urogenital tract
- parasympathetic

36

formation of esophageal plexus

- vagus nerves (left and right) go behind root of lung and down esophagus, forming plexus
- posterior mediastinum

37

anterior vagus nerve

- branch of vagus nerve
- down esophagus past diaphragm at stomach

38

formation of cardiac plexus

- SNS & PNS --> comes around arch of aorta
- goes backwards to heart, following blood vessels
- pain fibers --> pain from heart because cardiac muscle is hungry for oxygen
forms from these nerves: superior cervical ganglion, middle cervical ganglion, inferior cervical and T1 ganglia, T2 sympathetic ganglion, T3 sympathetic ganglion

39

balancing heart rate in autonomic NS

- brain telling heart to slow down
- withdrawing vagus stimulation causes heart to beat faster

40

cardiac radiating pain (referred pain)

- crisscrossing of signals from heart and other nerves
- T1/T2/T3 --> experience pain in these dermatomes