Upper Limb

Median Nerve Anatomy Notes

Explain in detail about the Median Nerve under headings—origin, root value, course, branches, and innervation. Write a note on the injury to the nerve.
Answer:

• The median nerve is called the median because it runs in the median plane of the forearm.
• Median Nerve is called the eye of the hand because it gives sensory supply to the pulp of the thumb and index fingers.
• Median Nerve is also known as the laborers’ nerve.

Median Nerve Origin

• By the union of the medial and lateral cords of the brachial plexus.

Median Nerve Root Value

• C5, C6, C7, C8, T1.

Median Nerve Function

Median Nerve Course

1. In the axilla:
   • The median nerve goes down to enter in the arm from the lateral side of 3rd part of the axillary artery.
2. In the arm:
   • The median nerve lies lateral to the brachial artery.
   • But at the level of the middle of the arm, it crosses the brachial artery and runs medial to enter the cubital fossa.
3. In the cubital fossa:
   • It gives of muscular branches to flexor carpi radialis, flxor digitorum superfiialis and palmaris longus.
   • The median nerve leaves the cubital fossa between two heads of pronator teres and then deep to the fibrous arch of the flexor digitorum superficial.
4. In the forearm:
   • In the forearm, it is adhered to the deep surface of the flexor digitorum superficial and leaves the muscle along its lateral border.
   • It runs deep to the palmaris longus and gives of the palmar cutaneous branch before getting under the carpal tunnel.
5. In the palm:
   • After passing through the carpal tunnel, the median nerve divides into lateral and medial divisions.
   • Lateral division supplies 3 out of 4 thenar muscles, 1st and second lumbricals.
   • Medial division along with the remaining fingers of lateral division provides cutaneous supply to the lateral 3 and half digits and their nail beds including the skin of distal phalanges on their dorsal aspect.

Median Nerve Anatomy

Median Nerve Branches and Innervations

Mnemonic: Median Nerve: Hand Muscles Innervated

‘The LOAF muscles’:

• lumbrical 1 and 2
• Opponents pollicis
• Abductor pollicis brevis
• Flexor pollicis brevis
• Alternatively: LLOAF, with 2 L’s, to recall there is 2 lumbricals.
• To remember that these are the Median nerve muscles, think ‘Meat LOAF’.

Median Nerve Clinical Anatomy

• Injury to the median nerve can occur at various levels and the clinical features vary accordingly.

1. Injury At The Level Of The Elbow
   • Median Nerve can be due to:
     • Supracondylar fracture of humerus.
     • Entrapment of nerve between the two heads of pronator teres during its course.
     • Tight tourniquet usage during venipunctures.
   • The clinical features are:
     • Loss of pronation as pronator teres is paralyzed.
     • Weak wrist flexion due to paralysis of flexors supplied by the median nerve.
     • The wrist will be adducted due to weakening of the flexor carpi radialis and unopposed action of the flexor carpi ulnaris and medial half of flexor digitorum profundus.

• Benedicts Deformity:
  • Median nerve injury leads to no flexion at interphalangeal joints of the index and middle fingers due to paralysis of the flexor digit running the superficial and lateral half of the flexor digitorum profundus. It results in placing of hand in a position comparable to Benedict’s hand.

• Ape thumb deformity:
  • It is characterized by flttening of thenar eminence with lateral rotation and adduction of thumb due to paralysis of thenar muscles supplied by the median nerve

Median Nerve Injury

1. Injury At The Level Of The Forearm

2. Injury At The Carpal Tunnel:

• Median nerve can get compressed in the tightly packed carpal tunnel due to:
  • Myxedema
  • Tenosynovitis of flxor tendons
  • Dislocation of lunate bone following fracture
  • Retention of fluid in pregnancy
  • Osteoarthritis in the wrist joint
• Median Nerve is presented with:
  • Burning sensation over the area of sensory supply of median nerve in the hand (lateral 3½ digits) more during the night
  • Weakening of thenar muscles
  • Ape thumb deformity, if left untreated
  • Reduced conduction velocity in nerve conduction studies
  • Phalen’s test and Tinel’s test were positive.

Median Nerve Pathway

Mnemonic: Carpal Tunnel Syndrome Causes

MEDIAN TRAP

• Myxoedema
• Edema premenstrually
• Diabetes
• Idiopathic
• Acromegaly
• Neoplasm
• Trauma
• Rheumatoid arthritis
• Amyloidosis
• Pregnancy

Mnemonic fits nicely since the median nerve is trapped.

Ulnar Nerve Anatomy Notes PDF

Explain in detail about the ulnar nerve under headings— origin, root value, course, branches, and innervation. Write a note on the injury to the nerve.
Answer:

• The Ulnar Nerve runs along the ulnar side of the upper limb, hence the name.
• Ulnar Nerve is the nerve of fine movement and is called the musician’s nerve.

Ulnar Nerve Origin

• Medial cord of brachial plexus.

Ulnar Nerve Root Value

• C8 and T1 spinal segments mainly. C7 also contributes.

Upper Limb Anatomy – Ulnar Nerve Explained

Ulnar Nerve Course

1. In the axilla, Ulnar nerve lies medial to the third part of the brachial artery.
2. In the arm:
   • It enters the arm along the medial side of the brachial artery and runs up to the level of the mid-arm.
   • The ulnar nerve pierces the medial intermuscular septum to reach the back of the arm.
   • From there, the ulnar nerve descends to pass through the cubital tunnel formed by the medial epicondyle and the fibrous band extending from the medial epicondyle to the olecranon process.
   • The ulnar nerve has no branches in the axilla as well as in the arm.
3. In the forearm:
   • In the upper 1/3rd, the ulnar nerve passes between the two heads of flexor carpi ulnaris to reach underneath the muscle and runs vertically down.
   • In the lower 2/3rd, it becomes superficial and runs downwards along with the ulnar artery being on the lateral side.
   • Branches of the ulnar artery in the forearm are:
   • Proximal forearm Muscular branch:
     • Flexor carpi ulnaris
     • Medial half of flxor digitorum profundus
   • Mid forearm
     • Cutaneous branch: Palmar cutaneous branch
   • Distal forearm
     • Cutaneous branch: Dorsal cutaneous branch

Ulnar Nerve In the Hand

• The ulnar nerve enters the hand superficial to the carpal tunnel through the ulnar tunnel and divides into superficial and deep terminal branches.
• The superficial branch gives sensory supply to the palmar aspect of the medial ½ digits and motor supply to the palmaris brevis muscle.
• Deep branches give off
  • Articular branches to the wrist
  • Muscular branches to:
    • 2 medial lumbricals
    • 4 palmar interossei
    • 4 dorsal interossei
    • Flexor digiti minimi (hypothenar muscle)
    • Abductor digiti minimi (hypothenar muscle)
    • Opponents digiti minimi (hypothenar muscle)
    • Adductor pollicis (thenar muscle)

Ulnar Nerve Branches and Supply

Ulnar Nerve Clinical Anatomy: Injury to the ulnar nerve can occur in the elbow or wrist.

1. Injury To The Ulnar Nerve At The Elbow
   • Common causes are:
     • Compression of the nerve in between the two heads of flexor carpi ulnaris
     • Fracture and dislocation of medial epicondyle
     • Valgus deformity of the elbow
     • Thickening of the fibrous roof of the cubital tunnel (cubital tunnel syndrome).

Ulnar Nerve Injury and Claw Hand – Essay

• • • Claw hand deformity affecting ring and little fingers where the metacarpophalangeal joints are extended while the interphalangeal joints are fixed (it’s not a complete claw hand, complete claw hand is seen when both the ulnar nerve and medial nerve are injured simultaneously, resulting in the hyperextended wrist and metacarpophalangeal joints and fixed interphalangeal joints).
    • Flattening of the hypothenar eminence due to atrophy.
    • Adduction and abduction of figers are affcted.
    • Thmp can not be adducted.
    • Loss of sensation over the palmar and dorsal surface of the medial 1/3rd of the hand and medial 1-and-a-half
    • fingers
    • Foments sign will be positive when the integrity of the palmar interossei is tested.
    • The ulnar nerve can also get injured in the wrist. Here, the clawing is more pronounced known as the ulnar paradox.

Ulnar Nerve MCQs with Answers

Radial Nerve Anatomy Notes PDF

Explain in detail about the Radial Nerve under headings—origin, root value, course, branches, and innervation. Write a note on the injury to the nerve.
Answer:

• Radial Nerve is the largest nerve of the brachial plexus.
• In general, the Radial Nerve is the nerve of the dorsum of the arm, forearm, and hand.

Radial Nerve Root Value

• C5–C8, T1 spinal segments.

Radial Nerve Origin

• Radial Nerve is the continuation of the posterior cord of the brachial plexus.

Radial Nerve Course and Branches

Radial Nerve Course

• From the posterior cord, the radial nerve descends downwards to enter the axilla.
• In the axilla radial nerve has three branches:
• The posterior cutaneous nerve of the arm
• Nerve to the long head of triceps
• Nerve to medial head of triceps
• From the axilla, the radial nerve enters the posterior compartment of the arm through the intermuscular space between the medial and long head of triceps.
• The radial nerve reaches the spiral groove of the humerus and gives 5 branches:
  1. The lower lateral cutaneous nerve of arm
  2. The posterior cutaneous nerve of arm
  3. Nerve to the lateral head of triceps
  4. Nerve to medial head of triceps
  5. Nerve to anconeus.
• At the lower end of the spiral groove, the radial nerve pierces the lateral intermuscular septum to reach in between the brachialis and brachioradialis.
• Radial Nerve descends further down to run between the brachialis and extensor carpi radialis longus and enters the cubital fossa.
• In the anterior compartment of the arm, above the level of the lateral epicondyle, it gives of 3 branches:
  1. Brachialis
  2. Nerve to brachioradialis
  3. Nerve to extensor carpi radialis longus
• Radial Nerve then divides into superficial and deep branches at the level of the lateral condyle of the humerus in the cubital fossa.
• The deep branch or posterior interosseous nerve supplies 2 muscles:
  1. Extensor carpi radialis brevis
  2. Supinator
• The deep branch further descends to enter the posterior compartment and supplies:
  • All extensors of the forearm
  • Distal radioulnar, wrist, and carpal joints.
• The superficial branch passes down to the hand over the tendons of the anatomical snuff box to terminate as a cutaneous branch.

Radial Nerve Injuries – Essay and MCQs

Radial Nerve Branches And Innervation

Mnemonic: Radial Nerve: Muscles Innervated

• ‘Try A Big Chocolate Chip Sundae, Double Dip Cherries And Peanuts Preferably Included’:
• In order of their innervation, proximal to distal:
  • Triceps
  • Anconeus
  • Brachioradialis
    • Extenstion Carpi radialis longus
    • Extension Carpi radialis brevis
  • Supinator
    • Extension Digitorum
    • Extension Digiti minimi
    • Extension Carpi ulnaris
  • Abductor poll. longus
    • Extension Poll. brevis
    • Extension Poll. longus
    • Extension Indicis
• For the neighboring words that start with the same letter (for example, chocolate and chip), notice that the longer word is in the mnemonic.
• Corresponds to the longer of the two muscle names (example: extensor carpi radialis longus and ext. carpi radialis brevis).

Upper Limb Nerves – Radial Nerve Explained

Radial Nerve Clinical Anatomy

• Radial nerves can get injured at various sites.

1. Injury to the radial nerve in the axilla can occur due to pressure from the upper end of crutch called as crutch palsy.
2. Injury to radial nerve in the radial or spiral groove can occur due to:
   • Midshaft fracture of the humerus
   • The pressure was applied on the radial nerve against the humerus by a drunker who is asleep with the medial aspect of his arm resting over the chair (Saturday night palsy).
     • In such situations, the presentation will be:
       • Loss of extension of the wrist and fingers (wrist drop).
       • Loss of supination when the arm is extended.
       • Sensory loss is restricted only to a small area over the dorsum of the hand between the first and second metacarpals.
3. Injury to the radial nerve at the elbow
   • It is called radial tunnel syndrome.

Radial Nerve Viva Questions for MBBS Students

Musculocutaneous Nerve Anatomy Notes PDF

Explain in detail about the Musculocutaneous Nerve under headings—origin, root value, course, branches, and innervation. Make a note on the injury to the nerve.
Answer:

Upper Limb Nerves – Musculocutaneous Nerve Essay

Musculocutaneous Nerve is the nerve of the front of the arm.

Musculocutaneous Nerve Origin

• Lateral cord of the brachial plexus in the axilla.

Musculocutaneous Nerve Root Value

• C5, C6, and C7 spinal segments.

Musculocutaneous Nerve Injury and Symptoms

Musculocutaneous Nerve Course

• From the lateral cord of the brachial plexus, it runs downwards and laterally pierces the coracobrachialis by supplying it.
• From there, it further descends downwards between the biceps brachii and brachialis muscles by innervating them.
• It reaches the lateral aspect of the biceps tendon to pierce the deep fascia just above the elbow joint.
• From there, it continues down as the lateral cutaneous nerve of the forearm.

Musculocutaneous Nerve Branches and Innervation

• Muscular branches supplying
  • Biceps brachii
  • Coracobrachialis
  • Brachialis
• Cutaneous branch (lateral cutaneous nerve of the forearm)
  • Supplies skin over the front and lateral aspect of the forearm.
• Articular branch
  • To the elbow joint

Musculocutaneous Nerve Viva Questions and Answers

Musculocutaneous Nerve Clinical Anatomy

• Injury to the musculocutaneous nerve, though rare, can cause loss of
  • Flexion of the elbow
  • Biceps tendon reflex
  • Loss of sensation over the lateral aspect of the forearm.

• Axillary Region Anatomy
• Bones of the Upper Limb
• Brachialis Anatomy
• Fascia Of The Back
• Muscles of the Anterior Forearm Anatomy

• Muscles of the Pectoral Region
• Nerves Of Upper Limb
• Scapula Anatomy
• Wrist And Hand Anatomy

Upper Limb Introduction

• The forelimbs and hind limbs are developed basically for weight bearing and locomotion in the quadriceps.
• In human beings, evolution brought erect posture and forelimbs are now used for prehension and more skilled works and hind limbs for weight bearing and locomotion, hence called upper limbs and lower limbs respectively.

Read And Learn More: Upper Limb

• Due to this variation in functions, upper limbs are more mobile at the cost of stability and strength whereas lower limbs are more stable, bulkier, and stronger at the cost of mobility.
• However, on the basis of basic anatomy, the upper limb and lower limb can be compared since they share homologous parts.

Upper Limb Question  And Answers

Question 1. What are the homologous parts shared by upper limb and lower limb?
Answer:

Question 2. What are the parts of upper limb?
Answer:

• Upper limb is divided into:
  • Shoulder region
  • Upper arm (brachium)
  • Fore arm (antebrachium)
  • Hand (manus)

Muscles Of The Pectoral Region – Full Notes Pectoral Region Introduction

• The pectoral region lies on the front of the chest.
• It consists of structures that connect the upper limb to the anterolateral chest wall.

Pectoral Region Question And Answers

Question 1. Briefly mention the superficial fascia of the pectoral region.
Answer:

Superficial Fascia

• It lies under the skin of the pectoral region and is continuous with surrounding superficial fascia. Its contents are:
  • Moderate amount of fat
  • Cutaneous nerves derived from the cervical plexus and intercostal nerves
  • Cutaneous arterial branches from internal thoracic and posterior intercostal arteries
  • Platysma muscle
  • Breast/mammary gland.

Read And Learn More: Upper Limb

Question 2. Write a short note on platysma muscle.
Answer:

Platysma Muscle:

Pectoral Muscles Anatomy Short Essay

Question 3. Explain in detail about the breast under the headings—situation and structure, blood supply, nerve supply, and lymphatic drainage.
Answer:

• The breast is a modified sweat gland.
• It is present in both sexes but rudimentary in males whereas well-developed in females after puberty.
• It is an important accessory organ of the female reproductive system and provides nutrition to the newborn in the form of milk.

Situation, Relations, And Extent

• It is situated in the superficial fascia of the pectoral region except for the tail which pierces the deep fascia of the axilla through the ‘foramen of Langer’ and is called the ‘tail of Spence’
• Breast extends:
  • Vertically: From 2nd to 6th rib
  • Horizontally: Lateral border of sternum to midaxillary line.
  • Superficial Relations: Skin and Superficial Fascia
  • Deep Relations:
    • Retromammary space: Loose areolar tissue separating the breast from the deep pectoral fascia, hence the breast is freely movable over the pectoralis major
    • Pectoral fascia
    • 3 muscles over which the base of the gland rests
      • Pectoralis major
      • Serratus anterior
      • External oblique (a part)
    • Structures deeper to them
      • Clavipectoral fascia
      • Pectoralis major

Pectoral Region Muscles Viva Questions and Answers

Structure Of the Breast

1. The Structure consists of:
   • Skin
   • Areola
   • Parenchyma
   • Stroma
2. Structure Of Breast Skin
   • It covers the gland and presents the nipple and areola.
   • The nipple is the conical projection situated usually at the
     center of the breast corresponding to the 4th intercostal space.
   • It is pierced by 15–20 lactiferous ducts.
   • It is rich in sensory nerve endings and very sensitive to touch.
3. Structure of the Breast Areola
   • It is the circular area of pigmented skin surrounding the base of the nipple.
   • It is rich in sebaceous glands, especially in the outer margin, which produces oily secretion, preventing nipple and areola from drying and crusting.
   • In pregnancy, the areola becomes darker and enlarged.
   • Montgomery’s tubercles are the enlarged sebaceous glands around the nipple in pregnancy.
4. Structure of Breast Parenchyma
   • It is the glandular part of the mammary gland which secretes milk.
   • It consists of 15–20 lobes arranged in a radial fashion around the nipple and opens into it through lactiferous ducts.
   • Each lobe consists of lobules which are filled with clusters of acini-secreting milk.
   • Lactiferous sinuses are dilated part of the lactiferous duct that helps to secrete milk.
5. Structure of Breast Stroma
   • It is the supporting framework of the mammary gland.
   • It is made up of fibrofatty tissue.
   • The fibrofatty tissue is modified to form suspensory ligaments of cooper and suspends breast tissue to the skin and pectoral fascia.

Upper Limb Muscles – Pectoral Region Guide

Breast Blood Supply The breast is highly vascular. It is supplied by:

1. Branches of lateral thoracic artery;
2. Branches of internal thoracic artery;
3. Branches of acromiothoracic and superior thoracic arteries
4. Branches of 2nd, 3rd and 4th posterior intercostal arteries

• Arterial Supply
  • Internal thoracic artery through its perforating branches
  • Axillary artery through:
    • Lateral thoracic
    • Superior thoracic
    • Acromiothoracic arteries
  • Posterior intercostal arteries through lateral branches.
• Venous Drainage
  • Axillary vein
  • Internal thoracic vein
  • Posterior intercostal vein.
• Nerve Supply
  • Cutaneous supply by 4th, 5th, and 6th intercostal nerves.
• Lymphatic Drainage
  • Lymphatic drainage of the breast is of great importance as they are the common channels through which metastasis of the breast cancer cells occurs to the opposite breast and other organs.
  • The lymph nodes draining the breast are:

1. Axillary Lymph Node:

• They drain about 75% of the lymph from the breast.
• Among them, lymphatics end mainly in the anterior/pectoral group.
• Lymph from the anterior and posterior groups passes to central and lateral groups and through them to the apical group.
• Eventually, lymph reaches the supraclavicular lymph nodes.

2. Internal Mammary Nodes are arranged along the internal thoracic vessels.

• They drain about 20% of the lymph from the breast.
• They drain from both the inner and outer half of the breast.

3. Supraclavicular Nodes.

4. Cephalic/deltopectoral Lymph Nodes.

5. Posterior Intercostal Nodes.

6. Subdiaphragmatic Lymph Nodes.

7. Subperitoneal Lymph Plexus.

• Lymphatic Vessels draining the breast are:
  • Superficial lymphatics drain the skin over the breast except for the nipple and areola to the surrounding lymph nodes (axillary, internal mammary, posterior intercostal nodes) radially.
  • It is important to note that superficial lymphatics of the breast on one side communicate with those of the opposite side. So unilateral breast malignancies become bilateral through metastasis.
  • Deep lymphatics drain the parenchyma of the breast along with the nipple and areola.
  • The subareolar plexus of sappy is a plexus of lymphatics present deep in the areola. They drain into anterior axillary lymph nodes.
  • Lymphatics from the deeper part of the breast drain directly into the apical group of axillary lymph nodes or to the internal mammary lymph nodes.
  • Few lymph vessels from the inner part of the breast communicate with the subdiaphragmatic and subperitoneal lymphatic plexus.

Clinical Anatomy

• Knowledge of lymphatic drainage of the breast is very important as lymphadenopathy is an early and important sign for staging, treatment, and prognosis of breast cancer.
• Though lymphatics cancer cells can communicate with the opposite breast and other organs in the body.
• Self-examination of the breast stands as the simplest, yet important, way to find malignancy in the early stage itself. On examination note:
  • Symmetry of breast and nipple
  • Change in the color of skin
  • Retraction of nipple
  • Discharge from nipple
  • Any palpable lump
• Cancer cells from the breast can shed of to the peritoneal cavity and move to the ovary causing ovarian tumors known as Krukenberg’s tumor.
• Tubercle of Montgomery stands as an important medico-legal evidence of pregnancy.
• The suspensory ligament of Cooper degenerates with aging and the breast becomes pendulous as age advances.
• Gynecomastia is the development of breasts in males due to hormonal imbalance and other reasons.

Pectoralis Major and Minor – Short Answer Type Questions

Question 4. Write briefly about clavipectoral fascia. What are the structures passing through it?
Answer:

Clavipectoral Fascia is a fibrous sheet situated deep in the clavicular part of the pectoralis major muscle.

Clavipectoral Fascia Extend

• Vertically: From the clavicle above to the axillary fascia below.
• Medially: Attached to the first rib and costoclavicular ligament and blend with the external intercostal membrane of the upper two intercostal spaces.
• Laterally: Attached to the coracoids process and blends with coracoclavicular ligament.
• The clavipectoral fascia is split into two laminae in the upper part to enclose the subclavius muscle.
• The anterior lamina is attached to the clavicle while the posterior lamina is continuous with the investing layer of deep cervical fascia.
• It is split into two laminae in the lower part to enclose the pectoralis minor muscle.
• After enclosing the muscle, it extends downwards as the suspensory ligament of axilla which helps to pull up the dome of axillary fascia.

Structures Piercing the Clavipectoral Fascia

• Lateral pectoral nerve
• Cephalic vein
• Thracoacromial vessels
• Lymphatics from the breast and pectoral region to the apical group of axillary lymph nodes.

Question 5. Enumerate pectoral muscles.
Answer:

Enumerate Pectoral Muscles They are:

• Pectoralis major
• Pectoralis minor
• Known as the key muscle of the axilla as it divides the axillary artery into:
  • Subclavius
  • Serratus anterior (not strictly a muscle of the pectoral region).

Question 6. Write a short note on the pectoralis major muscle.
Answer:

Pectoralis Major

Pectoralis Major Origin

• Small clavicular head: Medial half of anterior aspect of the clavicle
• Large sternocostal head:
  • The lateral half of the anterior surface of the sternum up to the 6th rib
  • The medial end of 2nd to 6th costal cartilages
  • The aponeurosis of the external oblique muscle of the abdomen

Pectoralis Major Insertion

• Inserted into lateral lip of intertubercular sulcus by a U shaped bilaminar tendon
• Anterior lamina of tendon is formed by clavicular fiers
• Posterior lamina formed by sternocostal fiers
• Two laminas are continuous inferiorly
• Lower sternocostal and abdominal fibers are twisted in a way such that the lowest fibers are inserted highest

Pectoralis Major Nerve Supply

• Lateral pectoral nerve
• Medial pectoral nerve

Pectoralis Major Actions

• Clavicular Head: Flexes arm
• Sternocostal Head: Adducts and medially rotates the arm.

Question 7. Write about the origin, insertion, nerve supply, and actions of the remaining pectoral muscles.
Answer:

Question 8. Write a note on the serratus anterior muscle.
Answer:

Serratus Anterior Origin

• 8 digitations from the upper 8 ribs
• Fascia covering intervening intercostal muscles

Serratus Anterior Insertion: Costal surface of the scapula along its medial border

Serratus Anterior Nerve Supply: Nerve to serratus anterior (from the root of C5, C6, and C7)

Serratus Anterior Actions

• Pulls scapula forwards around the chest wall (along with pectoralis major)
• Keep the medial border of the scapula in firm contact with the chest wall
• Rotates scapula laterally and upwards during overhead abduction of arm

Mnemonic

• Serratus anterior: Innervation
• SALT: Serratus Anterior = Long Thoracic

Mnemonic Clinical Anatomy

• Injury to the long thoracic nerve (nerve of bell) can occur in:
  • Stab wounds
  • During the removal of a breast tumor
  • Sudden pressure on the shoulder from above
  • Carrying a heavy load on the shoulder
• It results in paralysis of the serratus anterior and results in winging of the scapula

Pectoral Region Multiple-Choice Questions

Question 1. On climbing a tree, which of these two muscles at together?

1. Teres major and teres minor
2. Latissimus dorsi and teres major
3. Pectoralis major and latissimus dorsi
4. Teres major and pectoralis major

Answer: 3. Pectoralis major and latissimus dorsi

Question 2. Ligaments of cooper are modifications of:

1. Axillary fascia
2. Pectoral fascia
3. The fatty tissue of the breast
4. The fibrous stroma of breast

Answer: 4. Fibrous stroma of breast

Question 3. Which among these does not pierce clavipectoral fascia?

1. Lateral pectoral nerve
2. Cephalic vein
3. Thracoacromial vessels
4. Subclavian artery

Answer: 4. Subclavian artery

Question 4. Which among these are not an early warning sign of breast cancer?

1. Change in the color of skin
2. Gliding mass under the skin of the breast
3. Retraction of nipple
4. Discharge from nipple

Answer: 2. Gliding mass under the skin of the breast

Question 5. Which among these is not a pure pectoral muscle?

1. Pectoralis major
2. Pectoralis minor
3. Serratus anterior
4. Subclavius

Answer: 3. Serratus anterior

Axilla Question And Answers

Question 1. What is an axilla and what are its boundaries and contents?
Answer:

• The axilla or armpit is a four side pyramidal space located between the upper part of the arm and the chest wall.
• It has an apex, base, anterior, posterior, medial, and lateral walls.

Axilla Apex:

• Axilla is directed upwards and medially towards the root of the neck.
• Axilla is truncated, not pointed.
• The axillary artery and brachial plexus enter the axilla through the apex and the passage is called the cervicoaxillary canal.

Read And Learn More: Upper Limb

Axilla Base:

• Axilla is directed downwards.
• The axillais formed by skin, superficial fascia, and axillary fascia.

Axilla Anterior wall:

• Axilla is formed by:
  • Pectoralis major in front
  • Clavipectoral fascia enclosing pectoralis minor and subclavius deep to pectoralis major muscle

Axilla Posterior Wall:

• Axilla is formed by:
  • Subscapularis above
  • Latissimus dorsi and teres major below

Axilla Medial wall:

• Axilla is formed by:
  • 1st to 4th ribs and their intercostal muscles
  • The upper part of serratus anterior muscle

Axilla Lateral wall:

• Axilla is very narrow
• Axilla is formed by:
  • The upper part of the shaft of the humerus
  • Short head of biceps brachia and coracobrachialis

Axilla Contents

• Axillary artery and its branches
• Axillary vein and its tributaries
• Part of brachial plexus below clavicle
• Five groups of axillary lymph nodes and associated lymphatics
• Long thoracic and intercostobrachial nerves
• Axillary fat and areolar tissue

Axilla Multiple Choice Question

Question 1. Which of the following forms the anterior fold of the axilla?

1. Pectoralis major
2. Pectoralis major and pectoralis minor
3. Pectoral muscles and subclavius
4. Clavipectoral fascia

Answer: 1. Pectoralis major

Back Of The Body Question And Answers

Question 1. Briefly mention the skin and fascia of the back.
Answer:

• As the man lies on his back, the skin is thick and strong in the back and is tied to the underlying fascia.
• The superficial fascia of the back is also thick and strong.

Fascia of the Back

• Cutaneous nerves
• Fat
• Cutaneous arteries and veins
  • The deep fascia is dense in texture.

Read And Learn More: Upper Limb

Question 2. Enumerate and write about the origin, insertion, nerve supply, and actions of the muscles connecting the upper limb with the vertebral column.
Answer:

• The upper limb is connected to the back of the trunk by several muscles
• These muscles are called posterior axioappendicular muscles.
• They are:
  • Trapezius
  • Latissimus dorsi
  • Levator scapulae
  • Rhomboideus minor
  • rhomboideus major

Upper Limb With The Vertebral Column Clinical Anatomy

• Paralysis of the trapezius muscle causes drooping of the shoulder which should be differentiated from a collapsed lung as both can be mistaken for each other.
• A small triangular area of auscultation is present in the back near the inferior angle of the scapula.
• It is bounded by:
  • Superior horizontal border of latissimus dorsi
  • The inferior border of the trapezius
  • The floor is formed by the 6th and 7th intercostal spaces, the seventh rib, and the rhomboideus major
• This area is not covered by big muscles. So the underlying upper part of the lower lobe can be auscultated through this area.
• Due to the peculiar feature of latissimus muscle, it can be conditioned and used as an autotransplant to repair a surgically removed portion of the heart.

Thoracolumbar Fascia

Back Of The Body Multiple Choice Questions

Question 1. Which of the following can extend, adduct, and medially rotate the arm?

1. Teres minor
2. Subscapularis
3. Latissimus dorsi
4. Deltoid

Answer: 3. Latissimus dorsi

Question 2. All of the listed actions are of the trapezius except:

1. Elevation of the scapula
2. Retraction of the scapula
3. Depress the scapula
4. None of them

Answer: 4. None of them

Question 3. All of the listed actions are of the latissimus dorsi except:

1. Adduction
2. Extension and medial rotation of the arm
3. Helps to climb
4. None among them

Answer: 4. None among them

Question 4. Paralysis of which muscle causes the drooping of the shoulder?

1. rhomboideus major
2. Rhomboideus minor
3. Trapezius
4. Serratus anterior

Answer: 3. Trapezius

Question 5. Which muscle can be used as an autotransplant?

1. Rhomboideus minor
2. Trapezius
3. Serratus anterior
4. Latissimus dorsi

Answer: 4. Latissimus dorsi

The scapular region consists of the muscles, intermuscular spaces, nerves, vessels, and anastomosis around the scapula.

Scapular Region Question And Answers

Question 1. Enumerate the muscles around the scapula.
Answer:

• Scapulae originate from the scapula and are inserted into the humerus, hence called scapulohumeral muscles.
• Scapulae are also called intrinsic shoulder muscles.
• The scapula acts on the glenohumeral joint.
• Scapulae are:
  • Deltoid
  • Supraspinatus
  • Infraspinatus
  • Teres major
  • Teres minor
  • Subscapularis.

Read And Learn More: Upper Limb

Question 2. Write a note on the deltoid muscle.
Answer:

Deltoid Muscle

• The Deltoid Muscle is a thick, powerful, and curved triangular muscle covering the shoulder joint contributing to its rounded contour.
• The Deltoid Muscle resembles the inverted Greek letter delta, hence the name
• Structurally, it is divided into 3 parts:
  • Clavicular part (unipennate)
  • Acromion part (multipennate)
  • Spinous part (unipennate)

Scapula Anatomy Notes PDF

Deltoid Muscle Origin

• Clavicular Part (Unipennate): Anterior part of lateral 1/3rd of clavicle
• Acromion Part (Multipennate): Lateral border of acromion
• Spinous part (Unipennate): Lower lip spine of the scapula

Deltoid Muscle Insertion

• Deltoid tuberosity of the humerus
• Nerve Supply
• Accessory nerve

Deltoid Muscle Actions

• Anterior Fibers: Flexion and medial rotation
• Middle Fibers: Abduction of the arm
• Posterior Fibers: Extension and medial rotation of the arm

Deltoid Muscle Clinical Anatomy

• Intramuscular injections are given commonly in the lower half of the muscle to avoid injury to the axillary nerve which winds around the neck of the humerus under the muscle.
• In the shoulder region, injury to the supraspinatus tendon is common, and the patient feels difficulty in the initiation of abduction of the shoulder joint.
• The tendon of the supraspinatus may undergo degeneration and subsequent calcification as advances and results to rupture of the tendon.

Question 3. Write about the origin, insertion, nerve supply, and actions of the muscles around the scapula.
Answer:

Question 4. What is the rotator cuff or musculocutaneous cuff of the shoulder joint? Write about its formation and functions.
Answer:

• It is a fibrous sheath formed by the flattened tendons of four scapulohumeral muscles.
• They are:
  • Supraspinatus fusing superiorly
  • Infraspinatus fusing posteriorly
  • There is minor fusion posteriorly
  • Subscapularis fusing anteriorly
• It is blended with the capsule of the shoulder joint.

Scapula Bones – Medical Students’ Guide

Rotator Cuff Or Musculocutaneous Cuff Functions

• It gives strength to the shoulder joint.
• It grasps and holds the relatively larger head of the humerus
• against smaller and shallower glenoid cavities.

Rotator Cuff Or Musculocutaneous Cuff Clinical Anatomy

• The cuff is deficient inferiorly, through which inferior dislocation of the humerus from the joint can take place more easily.

Mnemonic: Rotator cuff muscles

• The SITS muscles:
  • Clockwise from top:
• Supraspinatus
• Infraspinatus
• Teres minor
• Subscapularis
• A pro baseball pitcher has injured his rotator cuff muscles.
• As a result, he SITS out for the rest of the game and then gets sent to the minor leagues.

Scapula Bone Viva Questions and Answers

Question 5. Write a short note on the subacromial bursa.
Answer:

• Suba cromial Bursa is the largest bursa of the body.
• The Subacromial Bursa is situated below the coracoacromial arch and the deltoid muscle.
• Under the bursa, there are:
  • Tendon of supraspinatus
  • Greater trochanter of the humerus.

Subacromial Bursa Functions

• Subacromial Bursa protects the supraspinatus tendons against friction with the acromion process.
• Subacromial Bursa facilitates the movements of the greater tubercle of the humerus under the acromion during overhead abduction.

Subacromial bursa Clinical Anatomy

• Subacromial bursitis commonly appears after inflammation of the supraspinatus tendon. It causes pain when pressure is applied just below the acromion.

Question 6. List the intermuscular spaces with their boundaries and contents.
Answer:

• Quadrangular Spaces are two triangular and one quadrangular spaces formed by the muscles in the scapular region.
• Quadrangular Spaces are seen clearly from behind after reflecting the posterior part of the deltoid.
• They are:

Quadrangular Space Boundaries:

• Superior:
  • Teres minor posteriorly
  • Subscapularis anteriorly
  • The capsule of the shoulder joint between the above two muscles
• Inferior: Teres major
• Medial: Long head of triceps
• Lateral: Surgical neck of the humerus.

Structures Passing Through Quadrangular Space:

• Axillary nerve
• Posterior circumflex humeral artery and vein.

Upper Triangular Space Boundaries

• Superior: Teres minor
• Lateral: Long head of triceps
• Inferior: Teres major

Structures Passing Through Upper Triangular Space:

• Circumflx scapular artery.

Lower Triangular Space Boundaries:

• Medial: Long head of triceps
• Lateral: Shaft of the humerus
• Superior: Teres major.

Scapula Structure and Features Essay

Structures PassingThrough Lower Triangular Space:

• Radial nerve
• Profunda brachii artery and vein.

Scapular Region

Question 1. The following part of the scapula forms the lateral most palpable landmark on the shoulder:

1. Superior angle
2. Glenoid cavity
3. Coracoid process
4. Acromion

Answer: 4. Acromion

Question 2. Subacromial bursa separates coracoacromial arch from the tendon of:

1. Subscapularis
2. Teres minor
3. Supraspinatus
4. Infraspinatus

Answer: 3. Supraspinatus

Question 3. Which of the following has actions similar to that of teres minor?

1. Supraspinatus
2. Infraspinatus
3. Subscapularis
4. Teres major

Answer: 2. Infraspinatus

Upper Limb Anatomy – Scapula Explained

Question 4. Which muscle does NOT substantially contribute to the stability of the shoulder joint?

1. Subscapularis
2. Supraspinatus
3. Infraspinatus
4. Teres minor

Answer: 1. Subscapularis

Question 5. Which is NOT a boundary of the quadrangular space?

1. Teres major
2. Teres minor
3. The long head of the triceps
4. Latissimus dorsi

Answer: 4. Latissimus dorsi