Collo 2: lymph/nerves of thoracic part

Question 1

Afferents of Autonomic NS

Answer 1

• are not classified as either sympathetic or parasympathetic
• conduct sensory impulses (usually pain) from viscera, glands, blood vessels to CNS
• usually accompany sympathetic efferents
• travel up to sympathetic ganglia (sympathetic trunk) → via ramus communicans albus → spinal nerve → dorsal root of spinal nerve
• sensory neurons are in spinal ganglia of dorsal roots of C8 – L3 spinal nerves

Question 2

Fibers leave ganglion through

Answer 2

1. ramus communicans griseus
   - contains postganglionic fibres of ganglia paravertebralia
   - joins with n. spinalis, then in content of ventral and dorsal branches of n. spinalis
   - reach the skin (for supplying vessels, sweat glands and m. arrector pili) and also
   skeletal muscles (to maintain trophic and tone)
   - it means that all ventral and dorsal spinal branches receive also sympathetic fibres
2. ramus interganglionalis
   - contain preganglionic fibres what from C8 - L2 ganglia ascend to the cervical ganglia
   or descend to the lower lumbar, sacral and coccygeal ganglia to synapse there
3. ramus vascularis
   - contains postganglionic fibers form the plexus around blood vessels and supply
   them
4. ramus visceralis
   - run as nn. splanchnici to form the plexus around inner organs and supply them
   - contains post- or preganglionic fibers
   - postganglionic fibers supply viscera in the neck and thorax
   - preganglionic fibres via nn. splanchnici reach prevertebral ganglia to synapse in
   them and supply viscera in the abdomen

Question 3

How are the spinal nerves situated?

Answer 3

• Lower C and upper T segments: at level one above
• Middle T segments 2 above vertebrae level
• T10-12: at T8-9 vertebrae
• L at the level T10-11 vertebrae
• S and Co: T12 and L1 vertebrae
–> Radix sensoria/motoria (or dorsal and ventral) -> spinal nerve ->
* ramus ventralis (lateral, anterior trunk/limbs): nervi intercostales, plexus cervicalis/brachialis/lumbosacralis
*ramus dorsalis (skin and muscles of the back and posteriorly neck)
* ramus communicans albus: communicates with the sympathetic trunk; GVE, and GVA fibres; present C8-L2
* ramus meningeus
–> they leave the vertebral canal below their corresponding vertebrae though!

Cauda equina = L, S, Co travel longer distance to reach the foramen  form common band

Question 4

Parasympathetic NS central - cranial part

Answer 4

CN10: nucleus dorsalis nervi vagi

• -> pregg fibers: N. vagus -> target organs
• -> postgg fibers short: heart, lung, gall bladder, liver, stomach, kidneys, pancreas, spleen, small and large intestines till colon descendes

Branches in thoracic part:

• Rr. Cardiac thoracici
• Rr. Bronchiales –> plexus pulmonalis
• Plexus oesophageus –> truncus vagalis anterior et posterior

Branches in abdominal part:

• Truncus vagalis anterior –> rr. Gastrici anteriores, rr. Hepatici
• Truncus vagalis posterior –> rr. Gastrici posteriors, rr. Renales, rr. Coeliaci via plexus coeliacus –> almost all internal organs of abdominal cavity large intestine till 1/3 of colon transversum, upper 2/3 of ureters, PLUS testis et epididymis and ovarium

–> The side branches of the thoracic part:
1) rami cardiaci thoracici join to rr. cardiaci cervicales inferiores to form plexus cardiacus;
2) rami bronchiales join with branches of truncus sympathicus to form pulmonary plexus – plexus pulmonalis which supplies the mucous membrane, the glands and the smooth muscles of the bronchi
as well as the lungs and pleura visceralis s. pulmonalis;
3) plexus oesophageus supplies the mucous membrane, the glands and the smooth muscles of the
oesophagus.

• Nuclei parasympathici sacrales: S2-4
 pregg fibers -> in content of motor roots; the 2nd, 3rd, and 4th sacral spinal nerves and ventral rami of them -> transmit somatic plexus – plexus sacralis
 pregg parasympathetic fibers = nn. Splanchnici pelvini –> synapse in terminal / intramural ganglia of target organs
 postgg fibers short: innervate distal large intestines and bladder (contraction of SMC since makes you pee easier), genitalia

• Sacral part: large intestine end, rectum, urinary bladder, genitalia
  • PS nucleus in spinal cord S2-4

Question 5

Parasympathetic NS: peripheral part - ganglia and fibers

Answer 5

• supply thoracic, abdominal, pelvic cavities
• terminal – near the outer surface of a target organ
• intramural – within the target organ

1. Plexus cardiacs
2. Plexus pulmonalis
3. Plexus oesophageus
4. Plexus coealiacus
5. Plexus aorticus abdominal
6. Plexus mesenteries superior
7. Plexus mesentericus inferior
8. Plexus intermesentericus
9. Plexus Hypogastricus superior
10. Plexus hypogastricus inferior

• -> pregg parasympathetic fibers
• -> postgg sympathetic fibers

Question 6

1. Plexus cardiacus

Answer 6

• at the basis cordis
  o Postgg sympathetic fibers: n. cardiacus cervicalis superior, medius, inferior, rr. Cardiac thoracici

o Pregg parasympathetic fibers of CNX: rr. Cardiac cervicales superiors / inferiores, rr. Cardiaci thoracici

• Divides into:
  o superficial – beneath arcus aortae in front of a. pulmonalis sin. (formed by Psy rr. Cardiac cervicales inferiores sin and Sy. N. cardiacus cervicalis superior sin)
  o deep part – behind arcus aortae in front of bifurcatio trachea
  –> continues along the coronary arteries, its branches are located also between epicardium and myocardium
• plexus cardiacus spreads along the coronary arteries as plexus coronarius dexter et sinister to supply all parts and layers of the heart

Question 7

2. Plexus pulmonalis

Answer 7

o Continuity of plexus cardiacus
o Innervates bronchial tree and visceral pleura
o Divides into anterior and posterior parts
- Postgg sympathetic fibers – rr. Pulmonales; relaxation of SMC and vasoconstriction of pulmonal vessels
- Pregg parasympathetic fibers of CN10 – rr. Bronchiales – stimulate secretion from the bronchial glands, contraction of the bronchial SMC and vasodilation of the pulmonal vessel

Question 8

3. Plexus oesophageus

Answer 8

o Innervate lower oesaphageal SMC glands, and BV
o Postgg sympathetic fibers – rr. Oesophageales (thoracic ganglia)
o Pregg parasympathetic fibers of CN10 – rr. Oesophageales

Question 9

4. Plexus coealiacus

Answer 9

in front of aorta abdominal T12-L2
o Contains sympathetic prevertebral gg; coeliaca and aorticorenalis
o Receives pregg sympathetic fibers from truncus sympathicus – n. splanchnicus major, minur, imus and lumbales –> synapse in gg to postgg fibers
o Transmits pregg parasympathetic fibers from n. vagus – rr.coeliaci from truncus vagalis posterior
- Secondary plexuses divided into:
o Single: plexus hepaticus, splenicus, gastrici, pancreaticus
o Paired: renalis, suprarenalis, uretericus, testicularis/ovaricus

Question 10

5. Plexus aorticus abdominal

Answer 10

• lies in front of aorta abdominalis between the L2 and L4 vertebras.
  o Sides and in front of aorta b. plexus mesentericus superior et inferior
  o Receives fibers from celiac plexus
  o Superior and inferior mesenteric plexuses arise plus hypogastric plexus

From plexus coeliacus et abdominalis are derived plexus renalis, uretericus, testicularis/ovaricus, iliac et femoral

Question 11

6. Plexus mesenteries superior

Answer 11

– surrounds a. mesenterica superior
o Continuation of the two above mentioned
o Ganglion mesentericum superius (prevert. Symp.) synapse with pregg symp. Fibers from plexus coeliacus/ truncus sympatheticus
o Transmits pregg parasymp. Fibers from n. vagus
o Secondary plexuses; small intestine, caecum, ascending colon and transverse colon

Question 12

7. Plexus mesentericus inferior

Answer 12

– surrounds a. mesenterica inferior
o From the plexus aorticus abdominalis
–> receives sympathetic and parasympathetic fibres like plexus mesentericus superior
o Prevertebral symp. Ganglion mesentericum inferius –> synapse with plexus intermesentericus and nn.splanchnici lumbales
o NO FIBERS OF N.VAGUS
o Paras. Pregg – nn. Splanchnici pelvini
o Secondary plexuses – the descending colon, sigmoid colon, upper part of the rectum

Question 13

8. Plexus intermesentericus

Answer 13

– part of aorticus abdominalis ; b. a. mesenterica superior & inferior

Question 14

9. Plexus Hypogastricus superior

Answer 14

– anterior to bifurcation of aorta
o In front of L5 and promontorium b. a. iliaca communis
o Is continuation of the plexus aorticus abdominal and nn. splanchnic lumbalis , plexus intermesentericus
o NO SECONDARY
o 2 lateral portions; n. hypogastricus and forms next plexus

Question 15

10. Plexus hypogastricus inferior s. pelvicus

Answer 15

– on the sides of rectum
o Paired; continuation of superior in form of n. hypogastricus
o Receives postgg symp. Fibers from the symp. Trunk – nn. Splanchinici sacrales
o Receives pregg paras. Fibers from nuclei paras. Sacrales – nn. Splanchnici pelvini
o Secondary plexuses: rectalis medius & inferior, uterovaginalis, prostaticus, deferentialis, vesicalis, cavernous nerves of clitoris and penis

parasympathetic fibres (from nuclei parasympathici sacrales) via blood vessels ascend to supply colon descendens, colon sigmoideum and upper third of the rectum

Question 16

Sympathetic NS - central part

Answer 16

1. Thoracolumbar nucleus = nucleus intermediolateralis – sympathetic nucleus in spinal cord (segments C8-L2)

Question 17

Sympathetic NS - peripheral part

Answer 17

1. Gg. paravertebralia
2. gg. prevertebralia
3. Thoracic ganglia
4. Lumbar ganglia
5. Sacral ganglia

Question 18

1. Gg. paravertebralia

Answer 18

– forms sympathetic trunk , joined by rami interganglionares
–> receives fibers from nucleus intermediolateralis
–> general visceral efferent fibers run through (=GVE all ventral/dorsal rami)
• Ramus communicans albus; myelinated, from the nerve to ganglion C8-L2
–> radix ventralis, nervus spinalis, ramus commnicans albus, g paravertebralium, truncus sympathicus

–> Postgg fibers leave paravertebral ganglion through:

1. ramus communicans griseus –> joins nervus spinalis; run in content of ramus ventralis et dorsali of spinal nerve –> skin & skeletal muscles
   • non-myelinated
2. ramus interganglionaris
   • b. ganglia; ascend to the cervical gg or descend to the lower lumbar, sacral and coccygeal gg to synapse there
3. ramus visceralis
   • nn. Splanchnici that forms plexus around viscera: post- and preganglionic fibres
   * postgg supply viscera in the neck and thorax
   * pregg reach prevertebral gg to synapse
4. ramus vascularis
   • contains post gg fibres: runs to plexus around BV and supply them

Question 19

2. gg. prevertebralia

Answer 19

– lie in front of aorta abdominalis
–> forms autonomic plexus of abdominal cavity
• Ganglion coeliacum – paired (could fuse to form single), half-moon; surrounds truncus coeliacus;
• ganglion mesentericum superius – lies to the right of a. mesenterica superior origin place
• ganglion aorticorenale – paired, lies at the upper part of a. renalis beginning
• ganglion mesentericum inferious – below a. mesenterica inferior origin place

Question 20

3. Thoracic ganglia

Answer 20

lie on caput costae, covered by fascia endothoracica and pleura mediastinalis

• Rr. Vasculares: plexus aorticus thoracicus
• -> supply aorta, vasa intercostalia, v.azygos, v.hemiazygos
• Rr. Viscerales
  1. Rr. Cardiac thoracici –> plexus cardiacus
• with n. cardiacus cervicalis superior, medius et inferior together with rr. cardiaci cervicales superiores et inferiores of the X cranial nerve form plexus cardiacus
  x plexus cardiacus spreads along the coronary arteries as plexus coronarius dexter et sinister to supply all parts and layers of the heart

2. Rr. Tracheales
3. Rr. Pulmonales –> plexus pulmonalis
4. Rr. Oesophagelas –> plexus oesophagus to ductus thoracic as plexus thoracicus
5. N. Spalchnicus major – T5-9 /minor – T10-11 / imus T12 ganglions and form plexus renalis
    contain preganglionic fibers –> pass through diaphragm –> reach prevertebral gg and switch to postganglionic fibers
    via peripheral autonomic plexuses supply abdominal viscera -> take part in formation of plexus coeliacus

Question 21

4. Lumbar ganglia

Answer 21

in front of lumbar vertebrae => covered by aorta in left and v. cava inferior on the right

• Rr. Vasculares : plexus aorticus abdominalis
• Rr. Viscerals : nn. Splanchinici lumbales – for plexus coeliac and plexus hypogastricus superior

Question 22

5. Sacral ganglia

Answer 22

lie on sacrum; joined by coccygeal ganglion

• Rr. Vasculares: plexus to pelvic BV
• Rr. Viscerales: nn. Splanchinici sacrales – to autonomic plexus of pelvic cavity : plexus hypogastricus inferior

Question 23

Lymph

Answer 23

originates as blood plasma that leaks from the capillaries of the circulatory system, becoming interstitial fluid

• > plasma is forced out of capillaries and forced back due to hydrostatic pressure = filtration and absorption
• > most of the fluid is returned to the venous capillaries; the excess 10% is collected by the lymphoid system

> part of circulatory and immune system
from tissue to subclavian veins
primary (thymus, bone marrow) and secondary (spleen, tonsils, lymph nodes) lymphoid tissue
accompany always vessels

• valvula semilunares

There are two groups of vessels:
1. deep vessels drain lymph from the organs and muscles
a. they lie along the deep blood vessels – arteries and veins
2. superficial vessels lie below the skin, above fascias and start from the capillaries in the skin;
they accompany the superficial veins.

Question 24

Main lymph vessels

Answer 24

1. Ductus lympahticus dexter (1/4 of the body)
   o 1-2 cm long
   o Near the neck; goes along medial border of m. scalenus anterior
   o Terminates at angulus venosus juguli dexter or v.subclavia, is formed behind art. sterniclavicularis dexter by 3 trunks:
   –> truncus jugularis dexter – drains the right half of the head and neck
   –> truncus subclavius dexter – drains the right upper limb
   –> truncus bronchomediastinalis dexter – drains the right part of the chest’s cavity
2. Ductus thoracicus (3/4 of the body)
   - 30-40cm long
   - Originates in the abdominal cavity at the level T10-L3 confluence of truncus lumbalis dx et sin
   > divided into 3 parts: abdominal, thoracic, cervical
   - At the place of junction is an enlargement – cisterna chyli – dilated sac that receives tributary truncus intestinalis
   –> Passes through hiatus aorticus diaphragm
   –> Ascends in mediastinum posterius et superius between aorta thoracica (to its left) and vena azygos (to its right), anteriorly oesophagus
   –> crosses to the left at T4-T6
   –> superiorly through thoracic inlet to the left
   –> posteriorly a. subclavia sin and continues in the neck
   –> at the root of the neck arches forward and to the left behind carotic sheath
   –> crosses over the dome of pleura and a. subclavia sin to drain into angulus venosus juguli sinister
   –> tributaries:
   o Truncus bronchomediastinalis sinister – left part of chest cavity
   • Parasternal, paravertebral, superior phren
   • Anterior, posterior mediastinal, bronchopulmonal, inferior/superior tracheobronchial
   ** Inferior and superior tracheobronchial nodes
   o Truncus jugularis sinister – left half of the head/neck
   o Truncus subclavius sinister – left upper limb

Question 25

Lymph drainage

Answer 25

1. from rectum:
   - From upper part –> inferior mesenteric nodes -> preaortic nodes -> truncus intestinalis -> ductus thoracicus
   - Middle part: internal iliac –> common iliac –> lateral aortic –> truncus lumbalis –> ductus thoracicus
   - Lower part: superficial inguinal –> deep inguinal –> external iliac –> the same as above –> same for corpus uteri, vagina, female external genitals, male external genitals
2. From lower ureter, urinary bladder, urethra
   - Paravesical nodes: inguinal -> external/internal iliac -> same as above
3. Prostate, ductus deferens, vesicular seminalis : same as above but sometimes through sacral nodes as well
4. Fundus uteri, tuba uterine; same only with internal iliac though

Question 26

Lymph nodes of thoracic cavity :

Answer 26

Parietal nodes:

1. Nodi lymphdoidei parasternales (2 – 20) – along the margin of sternum on the pathway of a.
et v. thoracica interna
a. afferents
i. the anterior wall of thoracic cavity
ii. pleura, pericardium
iii. the medial part of glandula mammae
iv. superior diaphragmatic nodes
b. efferents
i. truncus subclavius

2. Nodi lymphdoidei intercostales posteriores(1 – 7) – near the vertebral column in intercostal
   spaces
   a. afferents – posterior wall of the thoracic cavity
   b. efferents – ductus thoracicus

3. Nodi lymphdoidei phrenicus superior (1 – 20) – they lie on diaphragm to the left from v. cava
inferior around pericardium
a. afferents
i. diaphragma
ii. pleura
iii. pericardium
b. efferents
i. parasternal nodes and bronchopulmonal nodes

Visceral:

1. Nodi lymphdoidei mediastinales posteriores (1 – 15) – in mediastinum posterius along
   oesophageus and aorta
   a. afferents
   i. organs of mediastinum posterius

b. efferents
i. tracheobronchial nodes or directly to ductus thoracicus

2. Nodi lymphdoidei bronchipulmonales(4 – 25) – in hilum pulmonis around bronchus principalis
division
a. afferents
i. pulmo, bronchi
ii. superior diaphragmatic nodes

b. efferents
i. next two groups

3. Nodi lymphdoidei tracheobronchiales inferiores (1 – 14) – on each side below bifurcatio tracheae

4. Nodi lymphdoidei tracheobronchiales superiores (3 – 30) – on each side above bifurcatio
tracheae
a. afferents
i. trachea
ii. heart
iii. thymus
iv. bronchopulmonal nodes
b. efferents
i. truncus bronchomediastinalis

Question 27

Oesophagus lymph nodes

Answer 27

• superior third: deep cervical lymph nodes
• middle third: posterior mediastinal nodes
• lower third: left gastric and celiac nodes

Question 28

Abdominal cavity lymph nodes

Answer 28

Parietal nodes
1. Nodi lymphdoidei epigastrici inferior (1 – 2) – along corresponding blood vessels

afferents
- anterior abdominal wall
- parietal peritoneum
efferents
- into the lower direction external iliac nodes
- into the upper direction – parasternal nodes

2. Nodi lymphdoidei phrenicus inferior (1 – 2) lie on the lower surface of the diaphragm

afferents

• diaphragm
• parietal peritoneum
• posterior parts of the liver

efferents

• coeliac nodes
• lumbar nodes

3. Nodi lymphdoidei lumbalis (10 – 40) – lie behind peritoneum along aorta et v. cava inferior.
They could be arranged into 2 groups:
a. preaortic nodes – lie around origins of truncus coeliacus, a. mesenterica superior et a.
mesenterica inferior
afferents
- coeliac nodes
- superior mesenteric nodes
- inferior mesenteric nodes
- ileocolic nodes
- precolic nodes
- retrocolic nodes
- right colic nodes
- mesocolic nodes

b. paraaortic nodes – lie along the lateral side of the aorta

afferents

• ren
• glandula suprarenalis
• testis
• ovarium
• tuba uterina
• fundus uteri
• parietal abdominal nodes
• parietal and visceral nodes of the pelvic cavity
• nodes of the lower limbs

efferents form 2 chains:

• truncus lumbalis dexter et sinister
• both fuse together to form ductus thoracicus

Visceral nodes:

To visceral nodes belong coeliac, superior mesenteric, inferior mesenteric and lumbar nodes.

1. Coeliac nodes surround truncus coeliacus and receive lymph from following groups (afferents):

a. left gastric nodes (7 – 38)
- lie along curvatura minor, drain the stomach and oesophagus

b. right gastric nodes (1 – 3)
- inconstant

c. pyloric nodes (1 – 16)
- drain pylorus, caput pancreatis, pars superior duodeni

d. right gastroomental nodes (1 – 45)
- lie along curvatura major

e. left gastroomental nodes (3 – 17)
- lie along curvatura major
- drain corpus gastrici

f. pancreatic nodes (2 – 28)
- lie along margo superior pancreatis
- drain corpus et cauda pancreatis

g. splenic nodes (3 – 6)
- in hilum splenis
- drain splen, fundus gastici

h. hepatic nodes (1 – 10)
- in porta hepatis and lig. Hepatoduodenale
- drain the liver and cystic nodes

i. cystic nodes (1 – 2)
- along collum vesicae biliaris
- efferents from the celiac nodes are directed to the lumbar nodes

2. Superior mesenteric nodes (60 – 400)
 drain lymph (afferents) from
- the lower part of duodenum
- jejunum
- ileum
- caecum
- colon ascendens
- colon transversum

> > nodes lie in mesenteries along corresponding artery and its branches; they are divided into 3 groups:

peripheral mesenteric nodes
- lie between the mesenteric margin of jejunum et ileum and arches of the blood vessels

middle mesenteric nodes
- surround course of a. mesenterica superior and its branches

central mesenteric nodes
- surround commencement of a. mesenterica superior.

Efferents of those three groups run to lumbar nodes.
Among the superior mesenteric nodes there could be distributed some other groups of lymph nodes. They drain lymph from the corresponding organs and their efferents run to central mesenteric nodes or directly to lumbar nodes:
- ileocolic nodes
- precolic nodes
- retrocolic nodes

i. those three groups surround caecum et appendix
vermiformis
- right colic nodes
i. along the corresponding artery
- mesocolic nodes
i. in mesocolon transversum along the corresponding artery

3. Inferior mesenteric nodes (1 – 2) – surround corresponding artery

Afferents
- left colic nodes
- sigmoid nodes
- upper part of the rectum
Efferents
- lumbar nodes

Question 29

Lymphoid organs

Answer 29

• Splen s. Lien
• Thymus
• lymphatic tissues associated with alimentary tract and bronchi:
  o noduli lymphoidei solitarii
  o noduli lymphoidei agregati
  o noduli lymphoidei appendicis vermiformis
• tonsillae
• nodi lymphoidei

Question 30

Lymph nodes of the pelvic cavity

Answer 30

The lymph nodes of the pelvic cavity are divided into visceral and parietal nodes.

Visceral nodes (about 10) surround corresponding organs:

1. paravesical nodes
2. parauterine nodes
3. paravaginal nodes
4. pararectal nodes

a. afferents
- from corresponding organs
b. efferents
- parietal nodes

Parietal nodes are related to similar arteries:

1. Nodi lymphoidei iliaci interni (4 – 8)
2. Nodi lymphoidei iliaci communes (2 – 10)
3. Nodi lymphoidei iliaci externi (2 – 10) lie close to anulus femoralis
4. Nodi lymphoidei sacrales (2 – 3) – on os sacrum, they receive afferents also from rectum
   a. afferents: walls of the pelvic cavity
   b. efferents: lumbar nodes.

Question 31

Nervi intercostales

Answer 31

• ventral rami of thoracic spinal nerves; mixed nerves
  > intercostal nerves by sensory fibres supply the skin of the anterior and lateral parts of the trunk, the costal part of the parietal pleura, fascia endothoracica, fascia endoabdominalis, parietal peritoneum; the skin over the mammary gland.
• run below the corresponding intercostal vein and artery
• The 12th intercostals nerve is nervus subcostalis.

Branches of intercostal nerves:
• ramus collateralis – runs parallel to the main nerve on the upper border of the rib below
• ramus cutaneus lateralis – innervates the skin on the side of the thoracic wall by dividing into anterior and posterior branches; gives rami mammarii laterales to mammary gland;
• ramus cutaneus anterior – is the terminal portion of the intercostal nerves and innervates the skin near
the midline of chest by dividing into medial and lateral branches; gives rr. mammarii mediales to mammary gland;
• rami musculares – innervates the muscles of the intercostal spaces;
• pleural branches – sensory branches that go to the parietal pleura;
• peritoneal branches – are similar to the pleural sensory branches but arise from the lower intercostal nerves because the lower intercostal spaces are more related to the peritoneum that to parietal pleura.

Question 32

THORACIC NERVES

Answer 32

• There are 12 pairs of thoracic spinal nerves. They are mixed and contain GSA, GSE, GVA, GVE fibers.

After leaving vertebral canal each thoracic spinal nerve ramifies into 4 branches:

• ramus ventralis s. anterior
• ramus dorsalis s. posterior
• ramus communicans albus
• ramus meningeus

Ramus dorsalis s. posterior usually is smaller than ventral ramus, contains sensory (afferent) and motor (efferent) fibres, supply skin and muscles of the back and posterior region of the neck

Ramus ventralis s. anterior is intercostal nerve – nervus intercostalis