Uworld Anatomy

What symptoms will be present due to damage of the radial nerve at the level of the deep branch/Posterior interosseous nerve?

*Weakness of extension of fingers and thumb *NO wrist drop will occur due to preservation of Extensor carpi radialis longus *NO sensation loss as the superficial radial nerve which provides cutaneous sensation is proximal to the injury. PIN has no cutaneous branches

The artery that gets ruptured leading to an epidural hematoma is a branch of which of the following? A) Facial B) Maxillary C) Middle cerebral D) Occipital

B) Maxillary Middle meningeal artery is a branch of the maxillary

A 66-year-old reports pain nn his left upper extremity and tingling and numbness in his 4th and 5th digits of his left hand. There is mild swlling of the left hand. The man reports pain and numbness that occurs when he is doing electric work with his arms overhead. X ray reveals the presence of a cervical rib. The artery liable to be compressed is? A) Axillary B) Radial C) Brachial D) Subclavian

D) Subclavian

In Klumpke's palsy, which nerve roots and muscles are affected?

C8-T1 Affects primarily the intrinsic muscles of the hand (notably the interossei, lumbricals, thenar and hypothenar muscles)

The recurrent laryngeal nerve innervates all of the intrinsic muscles of the larynx except?

Cricothyroid

A 29-year-old male is involved in a motorcycle accident and presents to the emergency room. On examination, his arm hangs limply and is internally rotated. His forearm is pronated. Which nerve roots have likely been injured? A C4-C5 B C7-C8 C C3-C4 D C6-C7 E C5-C6

EC5-C6

Emission vs Ejaculation

Emission *sympathetic nervous system *hypogastric nerve movement of ejaculate into prostatic urethra Ejaculation *somatic nervous system pudendal nerve movement of ejaculate through urethra and out of penis Erection: *P*elvic Nerve Emission: *H*ypogastric Nerve Ejaculation: *P*udendal Nerve "Point Hump and Pump"

A previously healthy 42-year-old carpenter comes to the physician because of a 6-month history of pain and numbness in his dominant hand that awakens him at night. He describes numbness in his long and index fingers after driving for extended periods of time. Examination shows minimal atrophy of the thenar muscles. There is normal sensation to light touch on the little finger and the palm of the right hand. Sensation to light touch is decreased at the tip of the thumb, index finger, and long finger. X-ray films of the right elbow and wrist show no abnormalities. Most likely site of nerve injury? A) Axillary nerve B) Cervical nerve root at the cervical foramen C) Long thoracic nerve D) Median nerve above the elbow E) Median nerve at the elbow F) Median nerve at the wrist G) Musculocutaneous nerve above the elbow H) Musculocutaneous nerve at the elbow I) Musculocutaneous nerve at the wrist J) Radial nerve above the elbow K) Radial nerve at the elbow L) Radial nerve at the wrist M) Suprascapular nerve N) Thoracodorsal nerve O) Ulnar nerve above the elbow P) Ulnar nerve at the elbow Q) Ulnar nerve at the wrist

F) Median nerve at the wrist *Pain that is worse at night + paresthesias in first 3 1/2 digits + atrophy of thenar + normal sensation over thenar area (palmar branch doesn't travel through carpal tunnel) + loss of sensation at distal 3 1/2 Dx: Carpal tunnel

What structure lies at the midinguinal point: midway point between the pubic symphysis and the ASIS ? What structures lie directly medial and lateral

Femoral artery Femoral nerve is medial Femoral vein is lateral VAN

What is the function of the flexor digitorum profundus?

Flexes digits 2,3,4,and 5 Median nerve supplies lateral aspect (digits 2/3) Ulnar nerve supplies medial aspect (digits 4/5)

The median nerve travels between which 2 muscles in the mid-forearm?

Flexor digitorum superficialis and flexor digitorum profundus

Which nerve is often injured by a fracture of the medial epicondyle of the distal humerus? What deficits result?

Fracture of the medial epicondyle of the distal humerus (cubital tunnel syndrome) causes damage to the *proximal ulnar nerve*

A 60-year-old mildly obese woman complains of a very bothersome burning pain on the anterolateral aspect of her right thigh from the groin almost as far distally as the knee. Examination shows reduction of sensation to touch and pinprick in the affected area. There is no loss of muscle strength, and reflexes are normal. The most likely diagnosis is: A) ruptured intervertebral disk B) femoral hernia C) nutritional neuropathy D) compression of the lateral femoral cutaneous nerve E) disruption of the lumbosacral plexus

Obese woman + pain/decreased sensation on anterolateral thigh = Meralgia paresthetica Entrapment of lateral femoral cutaneous nerve under inguinal ligament

Anterior hip dislocation may mean injury to which lower extremity nerve, causing what motor deficiency?

Obturator Nerve Loss of adduction of thigh

Which ovarian ligament connects the ovaries to the lateral pelvic wall? Which ovarian ligament connects the ovaries to the lateral uterus?

Ovaries to lateral pelvic wall: Suspensory ligament Ovaries to lateral uterus: Ovarian ligament

What is the motor innervation of the ulnar nerve?

Palmar and dorsal interossei => Adduct and abduct fingers 3rd & 4th lumbrical=> Flex MCP and extend ICP and DIP Adductor pollicis => Adduction of thumb Hypothenar muscles Flexor carpi ulnaris - Flexes and adducts the hand at the wrist. Flexor digitorum profundus (medial half) - Flexes the fingers.

What is the sensory innervation of the ulnar nerve?

Palmar and dorsal medial 1/3 of hand and medial 1 1/2 fingers Via dorsal and palmar cutaneous branch

What are the most common symptoms of Carpal Tunnel Syndrome?

Palmar surface of the first 3 digits and radial half of the 4th digit

Lymph node drainage of Testes, ovaries, kidneys, uterus

Para-aortic

What is the sensory innervation of the radial nerve?

Posterior aspect of the arm and forearm Proximal portions of first 3 1/2 digits Lateral half of dorsal hand

Proximal vs Distal median nerve lesions

Proximal: (proximal to bifurcation of palmar branch) -ex: supracondylar fracture -sensory loss of palmar 3 1/2 digits and distal dorsal 3 1/2 digits -weakness of wrist flexion/abduction -weakness of thumb flexion/opposition -weakness of flexion of 2nd and 3rd digitis **Presents as Hand of benedict; 2nd and 3rd remain extended when trying to make a fist* Distal: -lacerations just distal to the bifurcation of palmar branch -*Sensation in midpalm and thenar is still intact*; loss of sensation of distal dorsal 3 1/2 -flexion of 2nd and 3rd digitis is intact but lack of extension due to loss of lumbricals becomes evident **Presents as clawing of 2nd and 3rd when trying to extend the fingers* Superficial lacerations of the palm *Lesion of recurrent branch -Loss of thenar muscles => Ape hand -*No cutaneous deficits*

Proximal vs Distal Ulnar Lesions

Proximal: All muscles affected Distal: Only intrinsic muscles affected Proximal Inability to flex and adduct hand Inability to flex the 4th and 5th fingers (lack of flexor digitorum profundus) *Can't make a fist* Looks like a ok sign with 4th and 5th fingers up Distal Inability to extend 4th and 5th fingers (lack of lumbricals) *Claw like hand* Both will result in inability to grip paper placed between fingers (due to loss of interossei)

What is the general proximal-to-distal organization of the brachial plexus?

Roots → Trunks → Divisions → Cords → Branches Mnemonic: Real Texans Drink Cold Beer

Lymph drainage of the scrotum? Lymph drainage of the testes?

Scrotum: Superficial inguinal Testes: Para-aortic (Recall that superficial inguinal drain nearly al cutaneous lymph from umbilicus to feet including external genitalia EXCEPT testis, glans penis, cutaneous portion of posterior calf

How can we distinguish proximal vs distal median nerve lesions?

Sensation in the midpalm and thenar eminence The palmar branch of the median nerve arises proximal to the wrist and does not go through the carpal tunnel with the rest of the median nerve, therefore Proximal: Sensation in midpalm and thenar is lost Distal: Sensation in midpalm and thenar is still intact

What are the boundaries of the femoral triangle?

Superior: Inguinal ligament Lateral: Sartorius muscle Inferior: Adductor longus muscle

When performing an oophorectomy, what is the name of the structure containing the ovarian vessels that must be ligated to minimize hemorrhage?

Suspensory ligament of the ovary (AKA Infundibulopelvic ligament)

What muscle protects the brachial plexus and the subclavian vessels from the sharp ends of a clavicle fracture. The innervation of this muscle is derived from which part of the brachial plexus?

The *subclavius muscle* protects the brachial plexus and the subclavian vessels from the sharped end of a clavicle when fractured. It is innervated by the *nerve to the subclavius*, which is a *branch from the superior trunk* of the brachial plexus.

What is the primary (and most powerful) supinator of the forearm?

The biceps brachii is the primary and most powerful supinator of the flexed forearm (musculocutaneous nerve) The supinator muscle supinates the forearm in the absence of resistance. (radial nerve)

Lymph node drainage of GI tract

Trachea, Esophagus: Mediastinal Stomach -> Upper duodenum: Celiac Lower duodenum -> Splenic flexure: Superior mesenteric Splenic Flexure -> Upper 1/2 rectum: Inferior mesenteric Lower 1/2 rectum -> Above pectinate line: Internal iliac Below pectinate line: Superficial Inguinal

Which nerve enters the hand via Guyon's Canal? Name some of the borders of this canal

Ulnar nerve Hook of hamate Pisiform Flexor retinaculum (transverse carpal ligament)

Which ovarian ligament contains the uterine vessels? Which ovarian ligament contains the ovarian vessels?

Uterine vessels: Cardinal ligament Ovarian vessels: Suspensory ligament

A 25 year old man comes to the physician after injuring his right elbow while trying to lift an 80-lb dumbell at the gym. When he attempted to lift the weight from the rack, he felt a popping sensation and pain his right elbow. He uses anabolic steroids. His pulse is 78/min, and BP is 150/95 mm Hg. Examination of the right upper extremity shows swelling of the antecubital fossa and ecchymoses from the antecubital fossa to the mid forearm on the anterior side. There is tenderness to palpation over the proximal aspect of the forearm. He is able to flex the elbow actively, but he is unable to flex the elbow or supinate the forearm against resistance. This patient has most likely injured a muscle-tendon unit that is supplied by which of the following nerves? a) Anterior interosseous b) Median c) Musculocutaneous d) Radial e) Ulnar

c) Musculocutaneous Loss of flexion and supination against resistance = damage to MCN which supplies biceps brachii

What is the action of the lumbricals?

flex MCP and extend ICP and DIP

http://sketchymedicine.com/tag/hand-exam/

http://sketchymedicine.com/tag/hand-exam/

http://www.usmleforum.com/files/forum/2011/1/624186.php

http://www.usmleforum.com/files/forum/2011/1/624186.php

https://sakai.ohsu.edu/access/lessonbuilder/item/19614/group/Student_Support/USMLE%20Review%20Resources/NBME%20Anatomy%20Review%20_1_.pdf

https://sakai.ohsu.edu/access/lessonbuilder/item/19614/group/Student_Support/USMLE%20Review%20Resources/NBME%20Anatomy%20Review%20_1_.pdf

Meralgia Paresthetica

**Entrapment of the lateral femoral cutaneous nerve* as it *travels under the inguinal ligament* *Most commonly in obese or pregnant women; or in those who wear tight clothing around the hip *Presents as reduced sensation on the anterolateral part of the thigh

What are 4 ways the radial nerve is commonly injured?

**Prolonged compression of the axilla* -(e.g., inappropriate/prolonged use of crutches) -Saturday night palsy" — passing out drunk with arms hanging over a chair, balcony, etc. **Fracture of the lateral epicondyle* of the distal humerus **Midshaft humeral fracture* -Radial nerve courses on the surface of the midshaft of the humerus *Radial Head Subluxation/Nursemaid elbow -pulling an extended arm upwards (pulling up of a child's extended arm)

Radial Head Subluxation

*AKA Nursemaid's elbow *Pulling an extended arm upwards (pulling up of a child's extended arm) *Causes the annular ligament to slide into the radiohumeral joint, where it becomes trapped **All movements are still permitted except supination; patient keeps the arm pronated*

Anatomical Snuff box

*Borders: APL,EPB (lateral border); EPL (medial) *Radial artery travels in between *Scaphoid fracture results in pain in snuff box *Scaphoid fracture can result in avascular necrosis due to loss of proximal blood supply

Carpal tunnel syndrome

*Compression of median nerve in the carpal tunnel between the flexor tendons and the flexor retinaculum *Pain and paresthesias over palmar 3 1/2 digits *Symptoms are worse at night **Sensation of proximal palm (thernal eminence) will still be intact as palmar branch of median nerve does not travel in the canal* *Long term complication = demyelination and atrophy of thenar muscles (results in Ape hand)

Which two muscles are innervated by the ulnar nerve in the forearm?

*Flexor carpi ulnaris* - Flexes and adducts the hand at the wrist. *Flexor digitorum profundus* (medial half) - Flexes the fingers.

What are 5 ways the ulnar nerve is commonly injured?

*Fracture of the medial epicondyle or distal humerus *Cubital tunnel syndrome -compression of ulnar nerve near medial epicondyle *Fracture of the hook of the hamate *Injury during delivery (Klumpke's palsy) *Ulnar tunnel syndrome (Guyon canal syndrome) -commonly seen in cyclists putting pressure on ulnar area

Arcuate Line

*Horizontal line about halfway between umbilicus and pubic symphysis *Site of entry of the inferior epigastric artery into the rectus sheath *Rectus sheath constituents are different above vs below the arcuate line **Above the line, rectus abdominis is surrounded by anterior and posterior sheaths; below the line the muscle is covered only by the anterior sheath*

Ape Hand

*Loss of thumb flexion/opposition *Can result in thenar atrophy *Due to median nerve injury

Summar of Ulnar and Median lesions

*Proximal vs Distal Ulnar Lesions* Proximal: All muscles affected Distal: Only intrinsic muscles affected Proximal *Inability to flex and adduct hand *Inability to flex the 4th and 5th fingers when trying to make a fist *Looks like a OK sign with 2 fingers up Distal *Inability to extend 4th and 5th fingers (lack of lumbricals) *Claw like hand* *Both prox and dis will result in inability to grip paper placed between fingers (due to loss of interossei)* *Proximal vs Distal Median nerve lesions* Proximal: (proximal to bifurcation of palmar branch) *complete sensory loss of median distribution -weakness of wrist flexion/abduction *weakness of thumb flexion/opposition *weakness of flexion of 2nd and 3rd digitis **Presents as Hand of benedict; 2nd and 3rd remain extended when trying to make a fist* Distal: -lacerations just distal to the bifurcation of palmar branch -*Sensation in midpalm and thenar is still intact*; loss of sensation of distal dorsal 3 1/2 -flexion of 2nd and 3rd digitis is intact but lack of extension due to loss of lumbricals becomes evident **Presents as clawing of 2nd and 3rd when trying to extend the fingers* *Proximal ulnar and median nerve lesions result in the claw hands when trying to flex due to loss of flexion of fingers 2,3,4,5 by digitorum profundus Distal ulnar and median nerve lesions result in the OK sign and benedict sign when trying to extend fingers due to loss of extension of fingers 2,3,4,5 by lumbricals*

What is the rectus sheath and how is it different above and below the arcuate line?

*Rectus sheath encloses the rectus abdominus *Formed from the merging of the aponeurosis of transversus abdominis, external and internal oblique abdominal muscles *Superior to arcuate line, sheath has both anterior and posterior component *Inferior to arcuate line, sheath has only anterior Superior to Arcuate Anterior layer: External oblique, internal oblique *Posterior layer: internal oblique, transversus Inferior to Arcuate *Anterior layer: External oblique, internal oblique, transversus *No posterior layer: rectus abdominis muscle is in contact with the transversalis fascia

Linea Alba

*Shallow groove that runs vertically in the median plane from the xiphoid to the pubis *Separates the right and left rectus abdominis muscles

What are three ways the Median nerve is commonly injured

*Supracondylar fracture of the distal humerus or other fracture-dislocations around the elbow **Dislocation of the lunate anteriorly* into the carpal tunnel *Carpal tunnel syndrome

*Wrist adduction *Wrist flexion *Wrist extension *Sensation to hypothenar eminence *Sensation to thenar eminence *Passes posterior to medial epicondyle *Passes anterior to lateral epicondyle *Hook of hamate fracture *Dislocation of lunate *Supracondylar fracture *Midshaft humerus fracture *Passes through guyon's canal *Passes through supinator canal *Passes through carpal tunnel *Travels between flexor carpi ulnaris and flexor digitorum profundus *Travels between flexor digitorum superficialis and flexor digitorum profundus *Travels between brachialis and brachioradialis *Lumbricals 1&2 *Lumbricals 3&4 *All interossei *Medial forearm *Lateral forearm *Posterior forearm *Supination against resistance *Artery in the snuff box *Artery prone to damage by supracondylar fracture *Surgical neck of humerus fracture

*Wrist adduction: Ulnar *Wrist abduction: Median *Wrist flexion: Median > Ulnar *Wrist extension: Radial *Sensation to hypothenar eminence: Ulnar *Sensation to thenar eminence: Median *Passes posterior to medial epicondyle: Ulnar *Passes anterior to lateral epicondyle: Radial *Hook of hamate fracture: Ulnar *Dislocation of lunate: Median *Supracondylar fracture: Median *Midshaft humerus fracture: Radian *Passes through guyon's canal: Ulnar *Passes through supinator canal: Radial *Passes through carpal tunnel: Median *Travels between flexor carpi ulnaris and flexor digitorum profundus: Ulnar *Travels between flexor digitorum superficialis and flexor digitorum profundus: Median *Travels between brachialis and brachioradialis: Radian *Lumbricals 1&2: Median *Lumbricals 3&4: Ulnar *All interossei: Ulnar *Medial forearm: Medial cutaneous nerve from medial brachial plexus *Lateral forearm: Musculocutaneous *Posterior forearm: Radian *Supination against resistance: Musculocutaneous *Artery in the snuff box: Radial *Artery prone to damage by supracondylar fracture: Brachial *Surgical neck of humerus fracture: Axillary

What are the typical findings of radial nerve damage?

-Weakness of arm extension, decreased triceps reflex (if injury is proximal) -Weakness of extension of fingers and thumb -Wrist drop -Loss of senation over posterior arm, forearm, *dorsolateral hand*, dorsal thumb

A vascular surgeon is preparing to harvest the longest vein in the body to use as a conduit for peripheral arterial bypass procedure. Where will she find and harvest this vein? 1. Lateral aspect of the foot 2. Posterior to medial malleolus 3. Popliteal fossa 4. Medial side of the thigh 5. Femoral triangle

4. Medial side of the thigh *Great saphenous vein is the longest vein in the body and i *Drains medial aspect of the foot *Passes anteriorly to medial malleolus *Ascends up medial side of leg *Terminates at the femoral triangle where it joins the femoral vein

a 16 month old girl is brought to the physician because she has refused to move her right arm since her older brother grabbed her right hand 1 hour ago to stop her from running into the street. On examination,she is holding her right arm in pronation. Any motion of the right arm produces pain. There is no visible edema. Which of the following is the most likely explanation for these findings? 1 Dislocation of the shoulder 2 Fracture of distal radius and ulna 3 Salter harris type 1 fracture of humerus 4 Septic arthritis 5 Subluxation of the radial head

5 Subluxation of the radial head Older sibling pulling child back on to curb + Holds arm in pronation

A 15-year-old boy is brought to the physician because of right wrist pain that began when he landed on his hands after falling backward while skateboarding 4 hours ago. Examination of the right upper extremity shows no bone deformities of the wrist. There is point tenderness to palpation of the radial aspect of the wrist between the abductor pollicis longus and extensor pollicis brevis tendons. This patient is at increased risk for which of the following sequelae as a result of this injury? A) Avascular necrosis of the proximal aspect of the scaphoid bone B) Damage to the median nerve C) Damage to the ulnar nerve D) Rupture of the flexor carpi ulnaris tendon E) Spiral fracture of the ulna F) Subluxation of the distal aspect of the trapezium bone

A) Avascular necrosis of the proximal aspect of the scaphoid bone

A surgeon performs an exploratory laparotomy, producing a large incision in the patient's abdomen. Poor blood supply to which of the following is most likely to cause problems during the healing process? A. Adipose tissue B. Aponeuroses C. Loose connective tissue D. Muscle E. Skin

A. Adipose tissue Adipose tissue has a poor blood supply which may delay healing Surgeons worry about their obese patients more than their skinny ones, because a thick layer of relatively poorly vascularized subcutaneous fatty tissue is both mechanically unstable (it holds stitches poorly) and heals very slowly. These patients have a frequent rate of dehiscence (tearing open of the incisional site) with subsequent, difficult-to-control infection (access by antibiotics, leukocytes, and serum antibodies are all hampered by the poor blood supply).

Cremasteric reflex afferent and efferent

Afferent: Efferent:

Describe the reflex arc involving physical stimulation of the penis and erection

Afferent: sensory innervation by pudendal nerve carried to S2-S4 region Efferent: parasypathetic pelvic splanchic nerves which increase NO production, vasodilation, and erection

What is the motor innervation of the median nerve?

Anterior forearm muscles (Except Flexor carpi ulnaris and half of Flexor digitorum profundus (Ulnar nerve) Thenar eminence musculature —Thumb opposition/flexion (*Recurrent branch*) 1st & 2nd lumbrical=> Flex MCP and extend ICP

The anterior portion of the rectus sheath below the arcuate line is formed from the: A. aponeuroses of the external oblique and transversus abdominis muscle. B. aponeuroses of the external oblique, internal oblique and transversus abdominis muscle. C. aponeuroses of the external oblique, transfersalis fascia and internal oblique. D. transversalis fascia. E. none of the above.

B. aponeuroses of the external oblique, internal oblique and transversus abdominis muscle.

Why is the linea alba a common site of surgical incisions?

Because it *consists of only connective tissue, and doesn't contain important nerves or blood vessels*, a median incision through the linea alba is a common surgical approach

What is the motor innervation of the musculocutaneous nerve?

Biceps brachii, coracobrachialis, brachialis Flexion of elbow and shoulder Biceps brachii — Forearm supination

Which nerve innervates the big toe dermatome? little toe?

Big toe: L5 Little toe: S1

Which nerve roots contribute to the brachial plexus?

C5, C6, C7, C8, T1

On the advice of a lawyer, a 27-year-old casino employee visited her personal physician because she found she could no longer flex her thumb and was unable to deal cards. Examination revealed weakness at the interphalangeal joint of the thumb as well as difficulty in bending the tips of the index and middle fingers. She could make a fist but had some difficulty in pinching with the thumb and index finger. There was some forearm pain but no tingling or numbness. These symptoms indicate damage to which of the following nerves? A. Posterior interosseus branch of the radial nerve B. Palmar branch of the ulnar nerve C. Recurrent branch of the median nerve D. Anterior interosseus branch of the median nerve E. Digital branches of the ulnar nerve

D. Anterior interosseus branch of the median nerve Flexion of thumb + difficulty flexing digits 2/3 = median nerve Recurrent branch supplies thenar only

After piercing through one of the muscles that it innervates, the deep branch of the radial nerve changes its name. What muscle does it pierce and what nerve does it become?

Deep branch of radial nerve pierces *Supinator* and becomes the *Posterior interosseous nerve*

A 17-year-old boy is brought to the emergency department after being injured in a football game. He appears to have dislocated his elbow and is unable to abduct and adduct his fingers. Which of the following nerves is most likely injured? A) Axillary B) Median C) Musculocutaneous D) Radial E) Ulnar

E) Ulnar PAD DAB Palmar interossei adduct, dorsal interossei abduct fingers Both are innervated by u

A 47 year old man comes to the emergency department 2 hrs after the onset of severe neck pain that began while he was lifting a heavy tool at his construction job. The pain is exacerbated when he turns his neck or coughs and now radiates over his right shoulder and arm. He has a 3 year history of intermittent neck pain that is relieved by ibuprofen use. He is in severe distress. When asked to turn his head he turns it slowly to avoid pain. Muscle strength is 4/5 in the elbow flexor and wrist extensor muscles on the right. Deep tendon reflexes are decreased on the right biceps and brachioradialis muscles. Which of the following is the most likely cause of these findings? A) central cord lesion B) compression of the lower brachial plexus C) compression of the musculocutaneous nerve D) compression of the upper brachial plexus E) herniated disc C5-6

E) herniated disc C5-6 *Cervical herniated disc often presents with pain that radiates down shoulder and arm *Activities that increase pressure (coughing, sneezing) will exacerbate pain *May have neck pain that is exacerbated when turning

A 23 year old man comes to the physician because of difficulty maintaining an erection. He was involved in an automobile collision that damaged his thoracic spinal cord, affecting motor sensory functions of the lower trunk and extremities. He is only able to obtain an erection through physical contact with his penis by his wife, and the erection doesnot last a long time. The best explanation for this type of erection is an intact spinal reflex arc between the sacral parasympathetic nerves and which of the following? A)Genitofemoral B)Ilio-inguinal C)Lumbo sacral trunks D)Obturator nerves E)Pudendal nerves

E)Pudendal nerves

What is the motor innervation of the radial nerve?

Function: Extend the elbow, arm, wrist, fingers and supinate the arm. -Triceps/Anconeus: Extension of arm/elbow -All extensors of forearm + arm + occasional flexion of the arm via Brachioradialis (However the biceps muscle innervated by musculocutaneous nerve is the major supinator) The posterior interosseous branch of the radial nerve specifically provides innervation for the supinator and wrist/finger/thumb extensors.

https://www.youtube.com/watch?v=Vv78MFi-HRY

GO THROUGH DR EBRHEIM VIDEOS TO REVIEW

Compare the location of a Gartner's duct cyst vs Bartholin cyst

Gartner: Anterior lateral wall Bartholin: Posterior lateral wall

What is the position of the arm with an Erb's palsy? This due to deficits of which muscles?

Hanging by side (lack of abduction) Medially rotated (lack of lateral rotation) Extended and pronated (lack of flexion and supination) Due to deficits of Deltoid, supraspinatus, infraspinatus, Biceps => Unopposed action of Latissimus dorsi (extension, adduction, medial rotation)

What are 2 consequences of long thoracic nerve injury?

Inability to raise the arms above the horizontal (90°) Medial winging of the scapula (Damage to CN XI causes Lateral winging of scapula)

If the rectus abdominis muscle is incised laterally below the arcuate, which artery is at greatest risk of injury?

Inferior epigastric artery

What structure lies at the midpoint of the inguinal ligament

Inguinal ligament

What land mark can be used to assess the pudendal nerve during a pudendal nerve block?

Ischial spine

What is the sensory innervation of the musculocutaneous nerve?

Lateral Forearm

The radial nerve descends into the forearm anteriorly to which structure? Which two structures is it between at this point?

Lateral epicondyle Brachialis, Brachioradialis

What are the terminal branches of the brachial plexus?

MARMU -musculocutaneous -axillary -radial -median -ulnar

Supracondylar fracture of the distal humerus may injure what nerves? What vessel?

Median and Ulnar nerve (Ulnar more common?) Brachial artery

What is the sensory innervation of the median nerve?

Midpalm and thenar eminence (palmar cutaneous branch) Palmar aspect of the lateral 3 1/2 digits Distal part of the dorsal aspect of the lateral 3 1/2 digits (digital cutaneous branch)

Common Peroneal vs Tibial Nerve -Plantarflexion? -Dorsiflexion? -Eversion? -Inversion?

Mnemonic: PED TIP Peroneal: Eversion, Dorsiflexion Tibial: Inversion, Plantarflexion

What two nerves are at risk of being damaged due to anterior shoulder dislocation?

Musculocutaneous and Axillary *Most commonly it will result in axillary damage