Anatomy
U world
Supplement to First Aid
MSS
Upper Extremity
Rotator cuff injury
Rotator cuff: (SITS)
Supraspinatus,
Infraspinatus,
Teres Minor and
Subscapularis
Most commonly injured: Supraspinatus
tendon
Presentation: Pain on Abduction of arm
Impingement Test: Supraspinatus
Jobes Test or Empty can test
GH joint is the most common dislocated joint in body
Anterior
dislocations are
more common
than posterior
Cause: due to forceful external rotation and abduction of arm
Nerve: Axillary n. injury
Result: Deltoid paralysis (flattening) and lateral arm sensation loss
Radial Head
Subluxation
Most common elbow injury in kids (age 1-4)
Injury: Due to sharp pull on hand while forearm is pronated and
elbow extended
Annular ligament tears
After age 5, the annular ligament thickens and becomes stronger, less
likely to tear
Child presents (similar position of injury) with arm held close to
body with forearm pronated and elbow extended
Scaphoid Fracture
Outstretched arm fall. Present w/
Anatomical snuff box tenderness
Risk: Avascular Necrosis (radial a.)
Winged Scapula- Long Thoracic n.
Serratus anterior muscle paralysis
Pt asked to press against a wall and Winged scapula deformity
occurs
Unable to abduct the arm higher than horizontal position or >90
First 90 abduction due to Deltoid and Supraspinatus muscle
Long Thoracic n. injury
Penetrating trauma (knife fight)
Iatrogenic (Radical Mastectomy- axillary node dissection)
Long Thoracic n. (Serratus Anterior m.)
0- 90 Abduction
Supraspinatus (10-15)
Deltoid (>30)
Long head of biceps
Winged scapula
90-180 Abduction
Serratus
Anterior
Radial n. Injury
Wrist Drop
- Mid-shaft humerus
fractures
- Crutch palsy
- Supplies extensors
muscles (posterior) and
sensory to posterior
arm
- Wrist drop b/c cant
extend
Posterior Arm
From
Axillary n.
Radial n.
Radial n. course
Ulnar n.
Passes by Medial epicondyle in
arm (most common injury site)
and the guoyons canal over
Hook of hamate (another site of
injury)
Guoyons canal
Nerve passing by
hook of hamate
Ulnar n. injury Claw-Hand deformity
Courses w/
brachial a.
between biceps
brachii and
brachialis m.
Median
n.
C6-T1
Antecubital
fossa
Median n. supply to muscles in hand
See loss of
Thenar
eminence w/
median n.
damage
ape hand
deformity
Median n. injury Injury
Suicide attempts
Carpal tunnel syndrome
Tx: release flexor retinaculum
Denervation atrophy
Loss of thenar eminence so ape
hand deformity
Benedict/Bishop/pope hand when
asked to make fist
Loss of sensation
Palmar surface
1st three and fingers
Procedures and Nerve Injuries
Radical Mastectomy Long thoracic n.
Thyroidectomy- Recurrent Laryngeal n.
Recurrent laryngeal during ligation Inferior thyroid a.
External branch of superior laryngeal nerve during ligation of superior thyroid a.
Delivery of child- (Shoulder Dystocia)
Musculocutaneous and Suprascapular n.
Head and shoulder violently stretched apart
Erb-Duchenne palsy (Waiters Tip)
Shoulder adducted, arm pronated, elbow extended
MSS
Lower Extremity
Common Peroneal (Fibular) n.
(FOOT DROP)
Prone to injury b/c
superficial location
especially lateral blow
to leg or during leg
cast
Common peroneal
superficial peroneal
and deep peroneal n.
Deep peroneal
innervates anterior
compartment which
dorsiflexes foot
Superficial peroneal
innervates lateral
compartment
(everts foot)
Sensory Innervation: Peroneal n.
Posterior
Leg
Sciatic n. branches to Tibial n. and Common Peroneal n. in popliteal
fossa (posterior leg)
Superficial peroneal n. provides sensation to dorsum of foot
Deep peroneal n. provides sensation to skin b/w 1st and 2nd toe
Shows
branching
of sciatic n
to Tibial
and
Common
Peroneal n.
Tibial n
Posterior
thigh
(plantarflex
and invert).
Sensory to
sole of foot
Femoral n. injury
Can be due to big retroperitoneal hematoma, trauma, stretch injury,
etc
Innervates quadriceps muscles so:
Presentation: difficulty w/ climbing stairs and knee buckling
Sensory loss:
Anterior and medial thigh
Medial leg (saphneous n.)
Saphneous nerve is the largest purely sensory branch of femoral n.
Patellar reflex diminished
Superior Gluteal n. Injury
Gluteus medius and minimus muscles weaken
Result: Waddling gait
Cause: Supero-medial buttock injections
Positive Trendelenburgs sign
Injury is:
C/L side of dropped hip/pelvis
I/L side of standing leg
Pic: We see Right sided n. injury
Superior Gluteal n. injury
Superolateral
quadrantsafest place
for buttock
injections
Superomedial
injection can injure
superior gluteal n.
The other three
quadrants can cause
injury to sciatic
nerve
Femoral Head
supply
Medial femoral circumflex a. provides the
majority of the blood to femoral head and
neck
Courses posteriorly
Injury to this vessel can cause avascular necrosis
of femoral head.
Lateral femoral circumflex a.
Courses anteriorly
A source of blood supply of femoral head and
neck
Obtruator artery
Injury more important/crucial in kids
ACL- origin: Lateral Femoral condyle
PCL- origin: Medial Femoral condyle
ACL tear- Anterior Drawer Test
Knee flexed
90 and
place
anterior
traction the
tibia
Note: Lachmans
test for ACL tear
is MORE sensitive
PCL tear- Posterior Drawer test
Knee flexed
90 and
place
posterior
traction the
tibia
PCL tear
Terrible Unhappy Triad
Lateral collateral
ligament is stronger
than medial
Lateral blow to the
knee
ACL tear
Tibial (Medial)
collateral
ligament
Medial
Meniscus tear
Prepatellar bursitis AKA
housemaids knee:
Due to repeated kneeling of
knee
Now common in: roofers,
plumbers and carpet layers
Symptoms: knee pain,
swelling, redness, unable to
flex knee,
Signs: Erythema and
Crepitance with edema
Anserine bursitis
Overuse in athletes
Chronic trauma in OBESE pts
Pain at medial aspect of
knee
Psoas Muscle
Located Paravertebral B/L
Common Deformities
Presentation
Nerve Injured
Wrist Drop
Radial n
Claw Hand
Ulnar n.
Winging of Scapula
Long Thoracic n
Ape hand
Median n
Foot Drop
Common Peroneal n.
Head and neck
Brief
Jugular Foramen (Vernet)
Syndrome
Jugular foramen (CN IX, X, XI)
- Loss of taste from posterior
1/3 of tongue (CN IX)
- Reduced parotid gland secretion
(CN IX)
- Loss of gag reflex (CN IX, X)
- Dysphagia (CN IX, X)
- Dysphonia/hoarseness (CN X)
- Soft palate drop with deviation of
uvula C/L to site of lesion (CN
X)
- Sternocleidomastoid and
trapezius muscLe paresis (CN
XI)
Foramen Spinosum- Middle meningeal
artery & vein
Pancoast Tumors
Apical lung tumors or Pancoast
tumors locally invade and cause
variety of symptoms
Horner Syndrome
Ptosis
Miosis
Anhydrosis
SVC syndrome
Arm weakness due to brachial
nerve plexus compression.
Hoarseness secondary to recurrent
laryngeal nerve compression
Piriform recess
Foreign bodies (fish, chicken
bones) can get stuck here
Attempts to remove foreign
body or a sharp fish bone
itself can damage the thin
membrane that overlies the
piriform recess
Internal laryngeal nerve
which is a branch of the
superficial laryngeal nerve
which is a branch of the
Vagus nerve (CN X) can get
damaged
Internal laryngeal carries only
autonomic and sensory fibers
unlike recurrent or external
laryngeal nerves which carry
motor to vocal cords
It mediates the afferent
(sensory) limb of cough reflex
ABOVE the vocal cords
Conclusion:
FB usually lodge in piriform recess
and pose a risk of damaging
Internal Laryngeal nerve and
losing the cough reflex
Chest
Right Atrium- majority of the R border of heart on P-A chest films
Right Ventricle- Anterior wall of heart (best seen with lateral films)
SVC & IVC superior & inferior borders of cardiac silhouette
Thoracentesis should
be preformed b/w the
visceral pleura and
parietal pleura and on
the Upper border of rib
to avoid damaging
intercostal n, a, v (which
course at the lower border of ribs)
Note:
Light
purpleLung
Midclavicular
line
Midaxillary
Paravertebral
Visceral
(Lung) Pleura
6th rib
8th rib
10th rib
Parietal
Pleura
8th rib
10th rib
12th rib
Aspiration Pneumonia
Upper lobe: Posterior segment
Lower lobe: Superior segment
GI
Cardiovascular Dysphagia
(rare but due to LA enlargement from mitral stenosis and LV hypertrophy)
Chest CT
Trachea- Radiolucent structure (identify this first)
Esophagus- located behind trachea and anterior to vertebral bodies
(GERD)
Two big blobs- aorta (ascending and descending)
Trachea
Azygous v.
Esophagus
Abdominal CT
A- 2nd part of
duodenum (lies by
the head of
pancreas)
B- Pancreas
C- IVC (lies to the R
side of vertebral
column)
D- Aorta (lies to the L
side of vertebral
column)
E- jejunum loops
Pancreas Head by the 2nd part of duodenum, L2 vertebrae.
Body overlies L Kidney, aorta, IVC and SMA, L1-L2
Tail lies in splenorenal ligament
Blood supply of GI tract
Foregut: all structures from mouth to 2nd part of duodenum
Celiac trunk (except mouth, pharynx and proximal esophagus)
Liver, gallbladder and pancreas are foregut derivative structures (endoderm)
Note: Spleen is NOT a foregut derivative structure (mesoderm) but gets
its blood supply from splenic a. ( celiac a. which supplies foregut)
Midgut: 3rd part of duodenum proximal 2/3 of transverse colon
SMA
Hindgut: distal 1/3 transverse colon rectum
IMA
Foregut: all structures from
mouth to 2nd part of duodenum
Celiac trunk (except mouth,
pharynx and proximal esophagus)
Midgut: 3rd part of duodenum
proximal 2/3 of transverse
colon
SMA
Hindgut: distal 1/3 transverse
colon rectum
IMA
Note: spleen is NOT a
foregut structure
Venous drainage Hepatic Portal v. (NOT IVC)
Gastric ( hepatic portal v.)
SMA ( hepatic portal v.)
IMA ( splenic v. hepatic portal v.)
GI Ulcers
Most Gastric ulcers occur at the lesser curvature (LC) of the stomach and
tend to hemorrhage
Proximal LC: Left gastric (Celiac trunk)
Distal LC: Right gastric ( Proper hepatic a.)
Duodenal ulcers are more common than gastric ulcers. Found in the
bulb.
Anterior bulb: Perforate
Posterior bulb: Hemorrhage through gastroduodenal a. ( common
hepatic a. )
Most gastric ulcers lesser curvature hemorrhage L. gastric a. ( from
celiac trunk)
Duodenum
1st part
- NOT
Retroperitoneal
2nd part
(Celiac a.)
3rd part (SMA)
Duodenum
1st part:
Horizontal; emerges from pylorus of stomach
ONLY part NOT Retroperitoneal
2nd part:
Vertical; lies close to head of pancreas
Has ampulla of Vater (where CBD and pancreatic duct merge and secrete)
3rd part:
Horizontal; courses over ab. Aorta & IVC
closely assoc w/ uncinate process of pancreas & SMA (tumor invasion)
Uncinate process of Pancreas
- Part of head
- Close assoc w. SMA and SMV
CBD + Main
pancreatic duct
Drain into
ampulla of
Vater (2nd part
duodenum)
SMA and
plexus
courses over 3rd
part of
duodenum
SMA Syndrome
- When the angle
b/w SMA and
aorta decreases
less than 20
(norm 45) it can
compress the
transverse
portion of
duodenum (3rd
part) causing S&S
of SBO.
- Usually occurs
secondary to
rapid weight loss
(lose mesenteric
fat pad) or spinal,
scoliosis surgery
Lesser Omentum
-
Double layer of peritoneum
Liver lesser curvature of
stomach and beginning of
duodenum
Consists of hepaogastric
ligament and
hepatoduodenal ligament
Hepatic a. , CBD, portal vein,
lymphatic . (hepatoduodenal)
R & L gastric a. and gastric
veins lie by (hepatogastric)
During gastric band surgery,
we go through the lesser
omentum in order to encircle
the cardiac part of stomach or
upper stomach
Proper Hepatic a.
CBD
portal vein
Hepatoduodenal ligament
of lesser omentum
R &L Gastric a. and
gastric v.
Gallstone Ileus
Occurs in pts with long-standing Cholelithiasis (middle- elderly age
women)
Large (>2.5 cm) stone lodges through cholecyst-enteric fistula and
enters duodenum
Caliber of duodenum and jejunum is big so stone passes through
Stone gets stuck at the ileocecal valve. Causes air from intestine to travel
to biliary tree and gallbladder
S&S: SBO (N/V/distention)
Dx: Ab imaging Shows air in Gallbladder and biliary tree
(Pneumobilia)
Tx: Surgical removal of stone. Dont usually operate on fistula
Cholecystenteric
Fistula Gallstone ileus
- Very important to realize
that gallstone in the
duodenum doesnt enter
through the biliary tree
or ampulla of vater
- It enters through a fistula
that forms between the
weak gallbladder wall
and the duodenum.
- Fistula allows air to enter
gallbladder and biliary
tree (pneumobilia)
Pneumobilia in Gallstone Ileus
Retroperitoneal Organs
Vessels
Abdominal aorta
IVC and branches
Solid organs
Pancreas (except tail) [hint: tail moves]
Kidneys
Adrenal Glands
Hollow organs
2nd and 3rd part of duodenum (part of 4th
part)
Ascending and descending colon
Rectum
Ureters
Bladders
MSS
Vertebral Column and pelvic muscles
SADPUCKER
Suprarenal glands (adrenal
glands)
Aorta and Inferior Vena Cava
Duodenum second, third,
and fourth segments
Pancreas head, neck, and
body
Ureters
Colon ascending,
descending
Kidneys
Esophagus
Rectum
Retroperitoneal hematoma
Due to blunt or penetrating abdominal trauma
50% of pts w/ blunt trauma
Usually after MVA (seat belts, steering wheels) get pancreatic injury
Pancreatic injury can present with mild sx or asymptomatic hence imp.
to check for hematomas by CT especially in stable pts w/ blunt
abdominal trauma
[Side note: FAST scan is done in trauma bay to evaluate for Hemoperitoneum or
pericardial effusion after MVA, looks for blood by liver, spleen, heart and pelvis. FASTFocused assessment Sonography of Trauma]
Retroperitoneal
hematoma can
compress and injure
femoral nerve causing
anterior thigh paresis
Pancreatic hemorrhage signs
Late findings
Grey- Turner sign: Flank
hemorrhage
Cullen sign: Peri-umbilical
Cirrhosis
and
portal
HTN
Liver cirrhosis fibrosis of vessels portal HTN
Leads to splenomegaly, paraumbilical veins engorgement, hemorrhoids and
esophageal varices due to the 4 portocaval anastomoses site.
The portal vein is found in the R hepatic lobe and is located anterior to IVC (CT
identification)
GU
Hernias
-
Both inguinal (direct and
indirect hernias) lie above the
inguinal ligament.
Indirect inguinal hernias are
more common than direct
hernias especially in males
Direct are medial to epigastric
vessels and found in
Hesselbachs triangle
Indirect are found in deep
inguinal ring/ internal inguinal
ring and lateral to epigastric
vessels.
- Deep inguinal ring is an
opening in transversalis
fascia
Femoral hernia
More common in females
Found below inguinal ligament
Prone to incarceration b/c femoral canal is small thus causes
bowel obstruction (N/V/ Ab. Pain distention)
Incarceration Strangulation within a few hours; ischemic
necrosis results (fever)
Emergent surgery
Horseshoe Kidney
- Most times fused at the
inferior pole, sometimes
superior pole
- Inferior mesenteric a.
prevents it from ascending.
- Prone to infections, renal
stones and hydronephrosis but
nml functioning kidney
- Associated with chromosomal
aneuploidy syndromes
(Trisomy 13, 18, 21) and
Turners syndrome (XO)
Ureter
- At risk for injury during pelvis
surgeries
- The gonadal arteries and veins
cross OVER the ureter in the
middle
- Once the ureter crosses over the
common iliac, it is now known
to be in true pelvis
- In the pelvis, it crosses over
common iliac a. and is found
anterolateral to the internal
iliac artery
Water under the
bridge
- Ureter (water) lies
under the Uterine
vessels (bridge)
- Do not confuse with
ovarian vessels
which travel lateral
to ureter when
crossing over the
common iliac a in
the pelvic brim.
Ureter at DANGER:
Hysterectomy:
Ureter lies
underneath
uterine a.
Ovarectomy
Ureter and
ovarian
vessels cross
pelvic inlet so
both at risk
11/12TH Rib Fracture- Kidney injury
Transplanted kidney
- Iliac fossa
- Attach donor renal a
recipient ext/internal iliac
a.
- Transplant ureter or attach to
old ureters (recipients ureter)
Lymph node drainage
Para-aortic nodes: Testes b/c follows embryological origin
(retroperitoneal)
Also blood supply to testes is from aorta
Superficial Inguinal- All cutaneous drainage below umbilicus,
including external genitalia (scrotum and labia) and anus up to
pectinate line
Deep inguinal- glans penis and clitoris drain directly. Afferent
from superficial inguinal nodes
External iliac- drain superficial and deep inguinal nodes
Patent
Process
Vaginalis
(Communicating
hydrocele )
Varicocele
Left testes more
common
b/c Left testicular v.
drains Renal v.
IVC
L renal vein travels
b/w aorta and SMA
so can be
compressed easily
especially if SMA
engorges
Anterior urethra- Damaged during saddle injuries (fence or falling off bike
injuries) urine leaks beneath deep fascia of Buck
Posterior urethra- Membranous portion is the weakest part and is prone to
injury during pelvic fractures (MVA). Urine leak into retropubic space
Urethral injury S&S: full bladder sensation, inability to void, high riding boggy
prostate, blood at urethral meatus
Foley is C/I
Pudendal nerve
block
Nerve runs behind
ischial spine and
sacrospinous ligament
Intravaginal pudendal block
in OB (palpate ischial spine)
Done when its too late for
epidural anesthesia
