This presentation entails the Examination of plexuses. Plexus are a branching network of nerves, vessels or lymphatic vessels within the body.

1. Cuttington University
Suakoko, Bong County
Herbert & Marion Donovan College of Health
Sciences
Department of Physician Assistant
Health Assessment & Diagnosis
(PHA 304)
Examination of Plexuses
Submitted To: Dr. Prince Patrick Myers,
Course Lecturer
Submitted By: Platon S. Plakar, Jr.
ID#: 219353
Date: May 20, 2023

2. Introduction and Definition
In neuroanatomy, a plexus (from the Latin
term “braid”) is a branching network of vessels
or nerves. The vessels may be blood vessels
(veins, capillaries) or lymphatic vessels. The
nerves are typically axons outside the central
nervous system. There are several plexuses in
the body, including:

3. Different types of plexus
Spinal plexuses
Cervical plexus - serves the head, neck and shoulders
Brachial plexus - serves the chest, shoulders, arms and hands
Lumbosacral plexus
Lumbar plexus - serves the back, abdomen, groin, thighs, knees, and
calves
Subsartorial plexus - below the sartorius muscle of thigh
Sacral plexus - serves the pelvis, buttocks, genitals, thighs, calves,
and feet
Pudendal plexus
Coccygeal plexus - serves a small region over the coccyx
Autonomic plexuses
Celiac plexus (solar plexus) - serves internal organs
Auerbach's plexus (myenteric plexus) - serves the gastrointestinal tract
Meissner's plexus (submucosal plexus) - serves the gastrointestinal tract
Pharyngeal plexus of vagus nerve - serves the palate and pharynx
Cardiac plexus - serves the heart

4. Different types of plexus cont…
Celiac plexus The cervical plexus is a complex neurologic
structure located within the head and neck. The large portion of
the cervical plexus is the communication between the anterior
divisions of C1 through C4 nerves.
Renal plexus The renal plexus is formed by filaments from the
celiac ganglia and plexus, aorticorenal ganglia, lower thoracic
splanchnic nerves and first lumbar splanchnic nerve and aortic
plexus.
Venous plexus a venous plexus is a normal congregation
anywhere in the body of multiple veins.
Choroid plexus The choroid plexus, or plica choroidea, is
a plexus of cells that arises from the tela choroidea in each of
the ventricles of the brain. Regions of the choroid plexus
produce and secrete most of the cerebrospinal fluid (CSF) of
the central nervous system. The choroid plexus consists of
modified ependymal cells surrounding a core

5. Anatomy and Physiology of Plexus
Spinal Plexus Spinal Level Nerves (superior to inferior)
Cervical Plexus C1 – C5
· Lesser occipital, Greater auricular
· Transverse cervical, Ansa
cervicalis, Supraclavicular, Phrenic
Brachial Plexus C5 – T1
· Musculocutaneous, Axillary,
Radial, Median, Ulnar
Lumbar Plexus L1 – L4
· Iliohypogastric, Ilioinguinal
· Genitofemoral, Lateral femoral
cutaneous, Femoral, Obturator
Sacral Plexus L4, L5, S1 – S4
· Superior gluteal, Inferior gluteal
· Posterior cutaneous, Tibial
· Fibular (peroneal), Pudendal
Coccygeal Plexus S4, S5, Co
helps contribute to Pudendal
· Anococcygeal
The following table shows the nerves that arise from each spinal plexus as well
as the spinal level each plexus arises from.

6. Anatomy and Physiology of Plexus
Plexus, diagram and structure

7. Anatomy and Physiology of Plexus
Cardiac Plexus, diagram & structure
The cardiac plexus is a plexus of nerves
situated at the base of the heart that
innervates the heart. It’s located near
the aortic arch and the carina of
the trachea.
Structure
The cardiac plexus is divided into a
superficial part, which lies in the concavity
of the aortic arch, and a deep part, between
the aortic arch and the trachea. The two
parts are, however, closely connected.
The sympathetic component of the cardiac
plexus comes from cardiac nerves, which
originate from the sympathetic trunk.
The parasympathetic component of the
cardiac plexus originates from the cardiac

8. Anatomy and Physiology of Plexus
Celiac Plexus, diagram & structure
The celiac plexus, also known as the solar
plexus because of its radiating nerve fibers, is
a complex network of nerves located in
the abdomen, near where the celiac
trunk, superior mesenteric artery, and renal
arteries branch from the abdominal aorta. It is
behind the stomach and the omental bursa, and
in front of the crura of the diaphragm, on the
level of the first lumbar vertebra.
The plexus is formed in part by the greater and
lesser splanchnic nerves of both sides, and
fibers from the anterior and posterior vagal
trunks.
The celiac plexus proper consists of the celiac
ganglia with a network of interconnecting
fibers. The aorticorenal ganglia are often
considered to be part of the celiac ganglia, and
thus, part of the plexus.

9. Diseases/Disorders of plexus
•Carpal tunnel syndrome affects the wrist (the median
nerve)
•Cubital tunnel syndrome affects the forearm (the
ulnar nerve)
•Brachial plexus disorder affects the arms and hands
•Lumbosacral plexus disorder affects the posterior
thigh, most of the lower leg and foot and part of the
pelvis
•Transverse myelitis (inflammation) affects the areas
below the point of the spine where the inflammation
occurs
•Spinal muscular atrophy causes weakness and
wasting of arm and leg muscles

10. Examination of plexus
Examining a patient with plexus injury may appear as a daunting task and this is
made worse by being watched and questioned at the same time. Whilst there are over
50 named muscles to be tested, it is not practical (and there is not enough time in
FRCS exam) to allow you to examine every single muscle in the upper limb.
Inspection
Best to start with the patient standing with both arms and torso exposed.
Look at the face for Horner's syndrome
Look for surgical scars
Comment on muscle wasting – shoulder girdle, arm, forearm or hand
Comment on the resting posture of the limb
Motor testing
Requires knowledge of the Medical Research Council (MRC) grading
0 – No Contraction
1 – Flicker
2 – Active motion (gravity eliminated)
3 – Active motion (against gravity only)
4 – Actve motion (against resistance)
5 – Normal power
If a muscle is weak, repeat testing in the horizontal plane in order to eliminate
gravity eg abducting the shoulder to test elbow flexion/extension power.

11. Examination of plexus cont..
Muscle testing is an active process involving
Look (for contraction and movement of the limb)
Feel (for contracted muscle/tendon)
Move (to test resistance)
Standing from the back
Trapezius (spinal accessory - XI, C3,4)
Can you shrug your shoulders
Rhomboids (dorsal scapular nerve – C4,5)
Push your shoulder blades together
Serratus anterior (long thoracic nerve - C5,6,7)
The classic test is wall-press test.
In BPI, the patient may be unable to lift the arm.
The arm should be supported by the examiner with one hand and the
patient asked to push forward as if trying to open a door. At the same
time the examiner should hold the lower pole of the scapula with another
hand.
Latissimus dorsi (thoracodorsal nerve – C6,7,8)
While the arm is supported in a flexed position, ask the patient to push
down (while the examiner palpates for musle contraction).

12. Examination of plexus cont..
Deltoids (axillary nerve – C5,6)
Extend, abduct and flex the shoulder to test the posterior, middle and anterior parts
respectively (unless the muscle is clearly wasted).
Demonstrate specific signs (if isolated nerve palsy suspected):
Swallow-tail sign
The patient is asked to extend the shoulder while bending the trunk
forward. A result of 20˚ or greater of extension lag relative to the normal
side indicates a positive sign.
Abduction internal rotation
Actively and maximally abduct the shoulder in internal rotation with the
elbow flexed. Abduction lag relative to the normal side indicates a
positive sign.
Standing from the front
Pectoralis major (lateral and medial pectoral nerves)
Clavicular head (C5,6)
Atrophy would imply lateral cord injury.
Ask the patient to touch their contralateral shoulder (and the examiner
palpates for evidence of contraction).
Sternocostal head (C7,8,T1)
Atrophy would imply medial cord injury.
Ask the patient to push against the hip (and the examiner palpates the axillary
fold).

13. Examination of plexus cont..
Rotator cuffs
Supraspinatus (suprascapular nerve - C5,6)
Test shoulder abduction in the scapular plane with the thumb pointing
downwards.
Infraspinatus (suprascapular nerve - C5,6)
Test external rotation with the shoulder in adduction and the elbow flexed.
Teres minor (axillary nerve – C5,6)
Test external rotation with the shoulder in abduction and the elbow flexed.
Subscapularis (upper and lower subscapular nerves – C5,6,7)
Belly-press sign. Ask the patient to bring the elbows forward while
pressing the belly. A flexed wrist relative to the normal side indicates a
positive sign.
Elbow flexion (C5,6)
Elbow extension (C7,8)
Forearm supination (C6)
Forearm pronation (C7,8)
Wrist flexion/extension (C6,7)
MCPJ flexion/extension (C7,8)
Grip (C8)
Fingers abduction (T1)

14. Examination of plexus cont..
Sensory testing
Establish normal sensation in an uninjured area (such as forehead or sternum).
First, assess the dermatomes (C5-lateral elbow; C6-thumb tip; C7-middle finger tip;
C8-little finger tip; T1-medial elbow) and then if necessary such as in infraclavicular
BPI, examine according to the terminal branch distribution.
Check for Tinel's signs (and take note of the dermatomal distribution).
Palpate for the radial pulse and check the reflexes.

15. Differential Diagnosis of plexus
C4 radiculopathy: scapular winging.
C5 radiculopathy: deltoid, biceps weakness.
C6 radiculopathy: brachialis, wrist extension
weakness; numbness to thumb, index finger.
C7 radiculopathy: triceps, wrist flexion
weakness; numbness to middle finger.
C8 radiculopathy: weakness in fine motor
function of hand; numbness to ring, small
fingers

16. Conclusion
Plexus is a branching network of vessels or nerves such as
veins, capillaries or lymphatic vessels. The nerves are
typically axons outside the central nervous system. There
are several plexuses in the body, including. Just to name
few, spinal plexus, Celiac plexus (solar plexus) - serves
internal organs
Auerbach's plexus (myenteric plexus) - serves the
gastrointestinal tract
Meissner's plexus (submucosal plexus) - serves the
gastrointestinal tract
Pharyngeal plexus of vagus nerve - serves the palate and
pharynx and Cardiac plexus - which serves the heart. They
play a vital role in the human body making it a unique one
in terms of functionality.

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